Associate Professor Mark Watsford is the Deputy Head of School (Research) in the School of Sport, Exercise and Rehabilitation at UTS. He has extensive experience with the physiological and biomechanical assessment of athletes, and has several research interests in the area of applied sports science.
Mark’s primary research focus is the examination of muscle properties as they relate to soft-tissue injuries and performance in athletes, however, he has published in the areas of nutrition, biomechanics and exercise physiology. He has a long-standing research collaboration with the conditioning department at the Sydney Swans Football Club, performing research to optimise performance in Australian rules football. He has also worked with athletes from a variety of other sports including netball, rugby league, soccer, futsal and swimming.
Mark has published more than 70 peer-reviewed journal articles in the sports science discipline and regularly presents at conferences. He teaches and co-ordinates subjects in the areas of nutrition, clinical exercise physiology, exercise rehabilitation and sports medicine.
In 2016 Mark received a citation for Outstanding Contributions to Student Learning at the Australian Awards for University Teaching, indicating his sustained commitment to undergraduate and postgraduate students.
Can supervise: YES
- Neuromechanical properties of muscle as they relate to injury and athletic performance
- Performance analysis and player development in Australian football
- Factors contributing to injury risk in sport
Sheehan, WB, Tribolet, R, Watsford, ML, Novak, AR, Rennie, MJ & Fransen, J 2020, 'Using cooperative networks to analyse behaviour in professional Australian Football.', Journal of Science and Medicine in Sport.View/Download from: Publisher's site
OBJECTIVES:Reducing the dimensionality of commonly reported complex network characteristics obtained from Australian Football League (AFL) games to facilitate their practical use and interpretability. DESIGN:Retrospective longitudinal design where individual players' interactions, determined through the distribution and receipt of kicks and handballs, during official AFL games were collected over three seasons. METHODS:A principal component analysis was used to reduce the number of characteristics related to the cooperative network analysis. RESULTS:The principal component analysis derived two individual-based principal components pertaining to in- and out-degree importance and three team-based principal components related to connectedness and in- and out-degree centralisation. CONCLUSIONS:This study is the first to provide a simplified, novel method for analysing complex network structures in an Australian Football context with both the team- and individual-derived metrics revealing useful information for coaches and practitioners. This may consequently guide opposition analysis, training implementation, player performance ratings and player selection.
Kalkhoven, JT, Watsford, ML & Impellizzeri, FM 2020, 'A conceptual model and detailed framework for stress-related, strain-related, and overuse athletic injury.', Journal of science and medicine in sport, vol. 23, no. 8, pp. 726-734.View/Download from: Publisher's site
A multitude of athletic injuries occur when the various tissues that make up the human body experience stresses and strains that exceed their material strength. The precise amount of stress and strain that any given tissue can withstand is determined by the mechanical properties and resultant strength of that particular tissue. These mechanical properties are directly determined by an individual's physiology and acute regulation of these properties. A number of theoretical frameworks for athletic injury occurrence have been proposed, however, a detailed conceptual framework for injury aetiology that considers the interplay between the physiological and mechanical factors and outlines the causal pathways to tissue damage and injury is needed. This will guide injury research towards a more thorough investigation of causal mechanisms and understanding of risk factors. Further, it is important to take into account the considerable differences in loading patterns which can result in varying injury outcomes such as acute stress-related, strain-related, or overuse injury. Within this article a simplified conceptual model of athletic injury is proposed along with a detailed, evidence-informed, conceptual framework for athletic injury aetiology that focuses on stress-related, strain-related, and overuse injury.
Sheehan, WB, Bower, RG, and Watsford, ML. Physical determinants of golf swing performance: A review. J Strength Cond Res XX(X): 000-000, 2019-Traditionally, golf practice has primarily focused on the mental, technical, and skill aspects as the primary means to improve performance. Only recently has a greater emphasis been placed on the physical components with balance, muscular strength, power, and specific muscle-tendon properties demonstrating positive associations with club head speed and carry distance. Accordingly, this review will explore the influence of these physical components on measures of golf swing performance. Superior balance may allow players to effectively deal with the need to shift weight during the swing as well as different stance positions, whereas superior lower-body muscular strength, power, and stiffness may allow more mechanical work to be performed on the club during the swing per unit of time, consequently increasing club head speed. Alternatively, flexibility may also contribute to enhanced force production with a greater range of motion, particularly when generating the "X-factor," allowing for a longer backswing and more time to produce higher angular velocities and forces. Furthermore, training intervention studies focusing on the aforementioned components have demonstrated enhancements in swing performance. Targeting multiple muscle groups, including those implicated via electromyography activation, and utilizing multiple modalities have proven effective at increasing club head speed. However, such multifaceted programs have made it difficult to determine the mechanisms that specifically contribute to performance gains. Despite these limitations, strength, power, and musculotendinous stiffness, particularly in the lower body, seem to be stronger determinants of club head speed and carry distance than flexibility. Furthermore, acute improvements can be induced using resistance-orientated warm-ups.
Millett, EL, Moresi, MP, Watsford, ML, Taylor, PG & Greene, DA 2020, 'Variations in lower body stiffness during sports-specific tasks in well-trained female athletes.', Sports biomechanics, pp. 1-16.View/Download from: Publisher's site
The present study aimed to assess the differences in leg stiffness and the associated performance variables between athletes from various training backgrounds during tasks relevant to athletic training. Forty-seven female participants (20 nationally identified netballers, 13 high-level endurance athletes and 14 age-matched controls) completed a sprint, anticipated sidestep change of direction and unilateral repetitive hopping task to assess leg stiffness and the relationship of stiffness between the different tasks. Leg stiffness and performance variables were evaluated with a 10-camera motion analysis system and force plate, and leg stiffness was derived through the McMahon and Cheng methodology (1990). Significant differences were evident in leg stiffness, and the contributing performance variables between groups across all assessed tasks (p < 0.001-0.017). Furthermore, results indicated the control group displayed no leg stiffness relationship between the evaluated tasks, while the stiffness relationship between tasks within athletic populations reflected training-specific demands of athletes. The results of this study indicated that the athletic training background of individuals may contribute to inherent leg stiffness differences between groups. Furthermore, the stiffness relationship observed between tasks suggests practitioners should take care in the selection of task used to monitor leg stiffness from a performance or injury risk perspective.
Novak, AR, Bennett, KJM, Pluss, MA, Fransen, J, Watsford, ML & Dascombe, BJ 2019, 'Power profiles of competitive and non-competitive mountain bikers.', Journal of Strength and Conditioning Research, vol. 33, no. 2, pp. 538-543.View/Download from: Publisher's site
The performance of Olympic distance cross-country mountain bikers (XCO-MTB) is affected by constraints such as erosion of track surfaces and mass start congestion which can affect race results. Standardised laboratory assessments quantify inter-seasonal and intra-seasonal cycling potential through the assessment of multiple physiological capacities. Therefore, this study examined whether the power profile assessment could discriminate between competitive XCO-MTB and non-competitive mountain bikers (NC-MTB). Secondly, it aimed to report normative power profile data for competitive XCO-MTB cyclists. Twenty-nine male participants were recruited across groups of XCO-MTB (n=14) and NC-MTB (n=15) mountain bikers. Each cyclist completed a power profile assessment that consisted of increasing duration maximal efforts (6, 15, 30, 60, 240 and 600 s) that were interspersed by longer rest periods (174, 225, 330, 480 and 600 s) between efforts. Normative power outputs were established for XCO-MTB cyclists ranging between 13.8 ± 1.5 W·kg (5 s effort) to 4.1 ± 0.6 W·kg (600 s effort). No differences in absolute peak power or cadence were identified between groups across any effort length (p>0.05). However, the XCO-MTB cyclists produced greater mean power outputs relative to body mass than the NC-MTB during the 60 s (6.9 ± 0.8 vs 6.4 ± 0.6 W·kg; p=0.002), 240 s (4.7 ± 0.7 vs 3.8 ± 0.4 W·kg; p<0.001) and 600 s (4.1 ± 0.6 vs 3.4 ± 0.3 W·kg; p<0.001) efforts. The power profile assessment is a useful discriminative assessment tool for XCO-MTB and highlights the importance of aerobic power for XCO-MTB performance.
Tribolet, R, Watsford, ML, Coutts, AJ, Smith, C & Fransen, J 2019, 'From entry to elite: The relative age effect in the Australian football talent pathway.', Journal of Science and Medicine in Sport, vol. 22, no. 6, pp. 741-745.View/Download from: Publisher's site
OBJECTIVES:This study aimed to assess the first instance and prevalence of the Relative Age Effect (RAE) in the male Australian Football (AF) talent development pathway through to the Australian Football League (AFL). DESIGN:Retrospective cross-sectional analysis. METHODS:Birthdate distribution was accessed from an U10-U12 AF academy trial (n=514), U13-U19 AF academy players (n=408), AFL state, national and international combines (n=2989), AFL Rising Star nominees (n=50) and the top ten AFL Brownlow vote recipients (n=50) between 2013-2017. RESULTS:Chi-squared analysis showed significant overrepresentation to early born players in the selection year for both quartile and half-year compared to the previously known distribution at different stages of the talent pathway. Odds ratio demonstrated bias to players born in quartiles one and two of the selection year compared to players born in quartile four in every cohort examined. CONCLUSIONS:RAEs appear between ages 10-12 in the male AF development pathway and continue to senior professional competition. RAEs are amplified as the competition for positions increases and at points where selection cut-offs occur. Interestingly, players receiving votes for the AFL's best and fairest award were 12.6 times more likely to be born in the first half of the year. This may suggest a latent effect, which has long term benefits for relatively older players. Nonetheless, the RAE affects career progression in a male AF talent pathway.
Sporri, D, Pine, MJ, Cameron, ML, Spurrs, RW, Sheehan, WB, Bower, RG & Watsford, ML 2019, 'Relationship between vertical stiffness and soft-tissue injuries in professional Australian football.', Journal of Sports Sciences, vol. 37, no. 21, pp. 2425-2432.View/Download from: Publisher's site
Soft-tissue injuries are common in Australian football. Recently, literature has identified non-modifiable and modifiable risk factors, including vertical stiffness (Kvert). However, limitations regarding measurement frequency and duration exist; thus, further information is required about the role of Kvert as a modifiable risk factor for injury. This study examined the seasonal variation in Kvert and its relationship to soft-tissue injuries in professional Australian football. The mean Kvert and bilateral asymmetry were assessed and compared between injured and non-injured players. For the seasonal analysis, 56 players were tested across two seasons with no variation in bilateral asymmetry evident (p= 0.33). While there were generally no changes in Kvert, the value from the end of the second pre-season revealed 5% lower values than the mean of two seasons (p= 0.02). Considering the injury analysis, 21 lower-body soft-tissue injuries were recorded from 18 participants. No differences were recorded for mean Kvert between the injured and non-injured groups (p= 0.16-0.76). When assessing Kvert asymmetry, the injured group displayed a 4.5% higher value than the non-injured group at the end of the pre-season test (p= 0.03) but not at other time-points (p= 0.16-0.99). Higher Kvert bilateral asymmetry measures after the pre-season appear to be related to lower-body soft-tissue injury in professional Australian footballers. Medical and conditioning staff should consider this measure when trying to mitigate the onset of injury or identify at-risk players.
Kelly, SJ, Watsford, ML, Rennie, MJ, Spurrs, RW, Austin, D & Pine, MJ 2019, 'Match-play movement and metabolic power demands of elite youth, sub-elite and elite senior Australian footballers.', PloS one, vol. 14, no. 2.View/Download from: Publisher's site
AIMS:Currently minimal research has quantified physical requirement differences in match-play between youth and senior Australian football players. The aim of the current research was to describe and compare the movement profiles and energy cost of youth, sub-elite and elite senior Australian football match-play. METHODS:Fifty-seven Australian footballers playing in an elite senior 20, sub-elite senior 16 and elite youth competition 21 participated in this study. Distance, speed based indices and metabolic power measures recording via Global Positioning System (GPS) devices were compared across three competition tiers. Kicks and handballs were collected via a commercial statistics provider (Champion Data) and compared across the competition tiers. RESULTS:Youth players recorded less field time (elite: ES = 1.37/sub-elite: ES = 1.68), total distance (elite: ES = 1.64 /sub-elite: ES = 1.55) and high speed running (elite: ES = 0.90/sub-elite: ES = 0.26) compared to the elite and sub-elite players. The average energy cost of elite (ES = 2.19) and sub-elite (ES = 1.58) match-play was significantly higher that youth match-play. CONCLUSIONS:A progressive increase regarding physical demands was evident across AF competition tiers. The findings suggest that sub-elite match-play can provide a viable pathway for youth players to develop physical capacity and technical skills before transitioning to elite senior match-play.
Sheehan, WB, Watsford, ML & Pickering Rodriguez, EC 2019, 'Examination of the neuromechanical factors contributing to golf swing performance.', Journal of Sports Sciences, vol. 37, no. 4, pp. 458-466.View/Download from: Publisher's site
This study investigated the relationship between a range of neuromechanical variables in the lower- and upper-body, and golf performance. Participants were assessed for individual muscle stiffness, vertical stiffness (Kvert), flexibility, power and maximal isometric strength. Furthermore, golf performance was determined by handicap and club head speed. Pearson's correlations quantified the relationships between neuromechanical variables and performance measures. Participants were also separated into relatively high club head speed (HC) and low club head speed (LC) groups and compared for physical characteristics. Club head speed showed positive relationships with Kvert and power and a negative relationship with hip mobility. The HC group exhibited superior Kvert and power, while strength and flexibility measures were not related to performance. Higher levels of lower-body stiffness, rate of force development and power output appear to be beneficial for generating superior club head speed. A stiffer system may reduce the time needed to remove the "slack" from the series elastic component therefore, reducing electromechanical delay and enhancing rate of force development. The large positive association with rate of force development suggests that increasing this component, along with power production may be superior focal components for training in golfers due to the short duration of the downswing.
Peek, K, Gatherer, D, Bennett, KJM, Fransen, J & Watsford, M 2018, 'Muscle strength characteristics of the hamstrings and quadriceps in players from a high-level youth football (soccer) Academy.', Research in sports medicine (Print), vol. 26, no. 3, pp. 276-288.View/Download from: Publisher's site
The objective of this study was to investigate knee muscle strength characteristics in players from a high-level youth football Academy. In total, 110 players (aged 8-15 years) underwent muscle strength assessments carried out by a research physiotherapist using a computer-linked hand-held dynamometer. Results indicated that isometric hamstrings and quadriceps strength increased with age, whereas the isometric hamstring to quadriceps (H/Q) ratio decreased with age. A number of youth football players (n = 20; 18%; 95% CI: 11-27%) demonstrated isometric H/Q ratios of less than 0.60, as well as muscle strength asymmetries between limbs for the hamstrings (n = 40, 36%; 95% CI: 27-46%) and quadriceps (n = 51, 46%; 95% CI 37-56%), potentially increasing injury risk. This study provides new evidence that the isometric H/Q ratio reduces with advancing age during adolescence which may have important implications for junior athlete development and long-term injury prevention in football.
Tribolet, R, Bennett, KJM, Watsford, ML & Fransen, J 2018, 'A multidimensional approach to talent identification and selection in high-level youth Australian Football players.', Journal of sports sciences, vol. 36, no. 22, pp. 2537-2543.View/Download from: Publisher's site
There is limited research in talent identification in youth Australian Football (AF), especially the factors that underpin selection into higher-level development programs. Therefore, this study explored age-related differences in high-level youth AF players and investigated characteristics influencing selection into a high-level development program. Anthropometry (stature, sitting height, body mass), maturity (estimated age at peak height velocity), motor competence (Körperkoordinationstest für Kinder), fitness (change of direction speed, lower body power and upper body muscular endurance) and coach skill ratings (kicking, marking and handballing) of 277 state academy players (U13-U15) were assessed. MANOVAs identified significant age-related differences for anthropometry, fitness, and coach skill ratings. Furthermore, 90.9 and 90.0% of U15 selected and deselected players were classified correctly. Selected players were more mature, taller, heavier, more explosive, faster at changing directions, and had superior kick technique and marking results. These results demonstrate considerable age-group performance outcome differences, highlighting that high-level academies should aim to select or deselect after 15 years of age. Additionally, it appears earlier maturing players are favoured for selection into a high-level academy. While practitioners must consider the confounding effect of maturation, early maturing players may be favoured for their ability to withstand increasing demands in higher-level youth AF.
Inman, LAG, Rennie, MJ, Watsford, ML, Gibbs, NJ, Green, J & Spurrs, RW 2018, 'Reference values for the creatine kinase response to professional Australian football match-play.', Journal of Science and Medicine in Sport, vol. 21, no. 8, pp. 852-857.View/Download from: Publisher's site
Due to the importance of monitoring markers of muscle damage in high-level sport from a medical and athlete recovery perspective, this study aimed to determine the upper limits of normal (ULN) for post-match plasma creatine kinase (CK) in professional Australian footballers. Raw CK values were considered, along with intra-individual deviations from the season-mean.Case series.CK was collected between 36-48h following professional Australian football match-play. A total of 1565 samples from 62 players were assessed over three consecutive seasons. The ULN were determined for raw scores and as a percentage of each player's season-mean response.The ULN for raw CK, as determined by the 97.5th, 95th and 90th percentiles were 1715 (90%CI: 1605-1890), 1380 (90%CI: 1325-1475) and 1110 (90%CI: 1050-1170) UL-1 respectively. The ULN intra-individual response (97.5th percentile) was defined as a player's score being greater than 94% (90%CI: 84-102%) above their season-mean.Professional Australian football elicits a profound effect on the CK response. The values provide a reference tool for athletes competing at this level of competition. The novel method of representing the CK response as a percentage difference from an individuals' season-mean enables a superior comparative ability between CK responses and reduces the high CK responder bias that occurs when using raw scores alone. The data will assist medical and conditioning staff in excluding medical emergencies and also aid in individualising the prescription of training loads and recovery to optimise athlete performance and minimise further muscle damage.
Kalkhoven, JT & Watsford, ML 2018, 'The relationship between mechanical stiffness and athletic performance markers in sub-elite footballers.', Journal of Sports Sciences, vol. 36, no. 9, pp. 1022-1029.View/Download from: Publisher's site
This study investigated the relationship between several measures of lower-body stiffness and physical performance variables in 22 sub-elite male football players (mean ± SD; 21.9 ± 1.5 yr; 1.79 ± 0.06 m; 72.2 ± 7.2 kg). The participants were assessed for individual muscle stiffness of the Rectus Femoris (RF), Biceps Femoris (BF) and Medial Gastrocnemius (MG) muscles and vertical stiffness (Kvert) was also assessed assessed running acceleration, maximal sprint speed, agility, vertical jumping and muscular strength. Pearson's correlations quantified the relationships and participants were also separated into relatively stiff (SG) and compliant groups (CG) for each variable. When ranked by Kvert the SG exhibited superior performance during sprinting, agility, jumping and strength (p ≤ 0.05) and when ranked by RF stiffness, SG exhibited superior sprint, agility and drop jump performance (p ≤ 0.05), while MG and BF stiffness were not related to performance. Higher stiffness appears to be beneficial to athletic performance for football players and therefore it may be beneficial for practitioners working with athletes that are required to perform dynamic activities to consider the contribution of stiffness to athletic performance.
Rennie, MJ, Watsford, ML, Spurrs, RW, Kelly, SJ & Pine, MJ 2018, 'Phases of match-play in professional Australian Football: Descriptive analysis and reliability assessment.', Journal of Science and Medicine in Sport, vol. 21, no. 6, pp. 635-639.View/Download from: Publisher's site
To examine the frequency and time spent in the phases of Australian Football (AF) match-play and to assess the intra-assessor reliability of coding these phases of match-play.Observational, intra-reliability assessment.Video footage of 10 random quarters of AF match-play were coded by a single researcher. Phases of offence, defence, contested play, umpire stoppage, set shot and goal reset were coded using a set of operational definitions. Descriptive statistics were provided for all phases of match-play. Following a 6-month washout period, intra-coder reliability was assessed using typical error of measurement (TEM) and intra-class correlation coefficients (ICC).A quarter of AF match-play involved 128±20 different phases of match-play. The highest proportion of match-play involved contested play (25%), followed by offence (18%), defence (18%) and umpire stoppages (18%). The mean duration of offence, defence, contested play, umpire stoppage, set shot and goal reset were 14, 14, 10, 11, 28 and 47s, respectively. No differences were found between the two coding assessments (p>0.05). ICCs for coding the phases of play demonstrated very high reliability (r=0.902-0.992). TEM of the total time spent in each phase of play represented moderate to good reliability (TEM=1.8-9.3%). Coding of offence, defence and contested play tended to display slightly poorer TEMs than umpire stoppages, set shots and goal resets (TEM=8.1 vs 4.5%).Researchers can reliably code the phases of AF match-play which may permit the analysis of specific elements of competition.
Sporri, D, Ditroilo, M, Pickering Rodriguez, EC, Johnston, RJ, Sheehan, WB & Watsford, ML 2018, 'The effect of water-based plyometric training on vertical stiffness and athletic performance.', PloS one, vol. 13, no. 12, pp. e0208439-e0208439.View/Download from: Publisher's site
Since higher vertical stiffness is related to superior athletic performance, training has traditionally been aimed at augmenting this variable to enhance neuromuscular output. However, research has linked elevated stiffness with increased injury risk, therefore, this study examined the effect of a novel training intervention on vertical stiffness and athletic performance. Vertical stiffness, jump performance and athletic performance were assessed in two randomly allocated groups, prior to, and following, an eight-week period. One group was exposed to a training intervention involving aqua-based plyometrics (n = 11) over the 8 weeks while the other acted as a control group (n = 9). The training intervention involved hopping, jumping and bounding in water at a depth of 1.2m whilst control participants performed their normal training. There were no significant changes in vertical stiffness in either group. Countermovement jump height and peak power significantly increased within the aqua plyometric group (p < 0.05). Athletic performance markers improved in the aqua plyometric group as measured using an agility and a 5-bound test exhibiting superior values at the post-test (p < 0.05). The results suggest that an aqua plyometric training program can enhance athletic performance without elevating stiffness. The increase in athletic performance is likely due to a reduction in ground reaction forces created by the buoyancy of the water, causing a shorter amortization phase and a more rapid application of concentric force. The findings from this study can inform exercise professionals and medical staff regarding the ability to enhance neuromuscular performance without elevating vertical stiffness. This has implications for improving athletic performance while concurrently minimising injury risk.
Pickering Rodriguez, EC, Watsford, ML, Bower, RG & Murphy, AJ 2017, 'The relationship between lower body stiffness and injury incidence in female netballers.', Sports Biomechanics, vol. 16, no. 3, pp. 361-373.View/Download from: Publisher's site
The aim of this study was to provide contemporary information on injury rates in an elite and sub-elite netball population and to explore the relationship between lower body stiffness and lower body injuries. One elite and two sub-elite teams of female netballers (n = 29) performed the vertical hop test to assess active lower body stiffness (Kvert) and myometry to assess quasi-static stiffness. Lower body injuries were monitored via self-reporting and liaison with physiotherapists. Twelve lower body non-contact injuries were sustained by 10 players, equating to 11.29 lower body injuries per 1,000 exposure hours. The most commonly injured sites were the calf (33%) and ankle (25%). No significant differences between Kvert of injured and non-injured players were reported, however, injured elite players recorded significantly higher season mean quasi-static stiffness in the soleus (p = 0.037) and Achilles (p = 0.004) than non-injured elite players. Elite and sub-elite netball players recorded a higher injury incidence than previous reports of injuries in recreational netballers. Within the constraints of the study, relatively high stiffness of the soleus and Achilles appears to be related to lower body non-contact injury incidence in female netballers, particularly at the elite level. These results provide a basis for development of injury prevention strategies.
Gibbs, N & Watsford, M 2017, 'Concussion Incidence and Recurrence in Professional Australian Football Match-Play: A 14-Year Analysis.', Journal of Sports Medicine, vol. 2017, pp. 1-7.View/Download from: Publisher's site
Concussion incidence rates in professional Australian football may be underreported due to the injury classification definition. A myriad of factors contribute to concussion risk; however, there is limited long-term surveillance in Australian football. This study analysed concussion in one Australian football team over an extended period.Match-play concussion injuries in one team (n = 116 participants) were diagnosed and treated by the team physician over 14 years. Analysis of factors related to concussion including matches played, time of day and season, and return to play provided an insight into occurrence and recurrence rates.140 concussions were recorded (17.6 per 1000 player match hours). A strong relationship was evident between matches played and concussion incidence (r = 0.70) and match conditions did not negatively affect the concussion rate. Whether an athlete returned to play in the same match or suffered a loss-of-consciousness concussion (p = 0.84), their ensuing rate of concussion was not affected.Concussion in professional Australian football was related to the number of matches played. Further, neither previous incidence nor loss of consciousness affected future concussion risk. This study provides ecologically valid evidence of the concussion incidence rate in professional Australian football and has implications for the management of athletes sustaining concussion injuries.
Kelly, SJ, Watsford, ML, Austin, DJ, Spurrs, RW, Pine, MJ & Rennie, MJ 2017, 'Differences in Physical Capacity Between Junior and Senior Australian Footballers.', Journal of Strength and Conditioning Research, vol. 31, no. 11, pp. 3059-3066.View/Download from: Publisher's site
Kelly, SJ, Watsford, ML, Austin, DJ, Spurrs, RW, Pine, MJ, and Rennie, MJ. Differences in physical capacity between junior and senior Australian footballers. J Strength Cond Res 31(11): 3059-3066, 2017-The purpose of this study was to profile and compare anthropometric and physical capacities within elite junior and senior Australian football (AF) players of various chronological ages and stages of athletic development. Seventy-nine players, including junior and senior AF players from one professional club, were profiled using 11 assessments. Junior players were divided into 2 groups based on chronological age (under 16 and 18 years) and senior players according to years since drafted to a professional AF team (1-2 years, 3-7 years, and 8+ years). Parametric data were assessed using a 1-way analysis of variance (ANOVA), whereas nonparametric data were assessed using a Kruskal-Wallis ANOVA. The magnitude difference between players was measured using the Hopkins' effect size (ES). Significant differences were evident between under-16 players and all senior player groups for anthropometric (p = 0.001-0.019/ES = 1.25-2.13), absolute strength (p = 0.001-0.01/ES = 1.82-4.46), and relative strength (p = 0.001-0.027/ES = 0.84-3.55). The under-18 players displayed significantly lower absolute strength (p = 0.001-0.012/ES = 1.82-3.79) and relative strength (p = 0.001-0.027/ES = 0.85-4.00) compared with the 3-7 and 8+ players. Significant differences were evident between the under-16 players and senior player groups for explosive jumping and throwing tests (p = 0.001-0.017/ES = 1.03-2.99). Minimal differences were evident between all player groups for running assessments; however, the under-16 players were significantly slower compared with the 8+ players for the 3-km time trial (p < 0.02/ES = 1.31), whereas both junior player groups covered significantly less distance during the Yo-Yo IR2 (p < 0.02/ES = 1.19 and 1.60). Results of this study display a significant deficit in...
Anwar, T, Al-Jumaily, A & Watsford, M 2017, 'Estimation of Torque Based on EMG Using ANFIS', 2016 IEEE INTERNATIONAL SYMPOSIUM ON ROBOTICS AND INTELLIGENT SENSORS (IRIS 2016), vol. 105, pp. 197-202.View/Download from: Publisher's site
Chan, V, Duffield, R & Watsford, M 2016, 'The effects of compression garments on performance of prolonged manual-labour exercise and recovery.', Applied Physiology, Nutrition and Metabolism, vol. 41, no. 2, pp. 125-132.View/Download from: Publisher's site
This study investigated the effects of wearing compression garments during and 24 h following a 4-h exercise protocol simulating manual-labour tasks. Ten physically trained male participants, familiar with labouring activities, undertook 4 h of work tasks characteristic of industrial workplaces. Participants completed 2 testing sessions, separated by at least 1 week. In the experimental condition, participants wore a full-length compression top and compression shorts during the exercise protocol and overnight recovery, with normal work clothes worn in the control condition. Testing for serum creatine kinase and C-reactive protein, handgrip strength, knee flexion and extension torque, muscle stiffness, perceived muscle soreness and fatigue as well as heart rate and rating of perceived exertion (RPE) responses to 4-min cycling were performed before, following, and 24 h after exercise. Creatine kinase, muscle soreness, and rating of perceived fatigue increased following the exercise protocol (p < 0.05) as did RPE to a standardised cycling warm-up bout. Conversely, no postexercise changes were observed in C-reactive protein, handgrip strength, peak knee flexion torque, or stiffness measures (p > 0.05). Knee extension torque was significantly higher in the control condition at 24 h postexercise (3.1% ± 5.4% change; compression: 2.2% ± 11.1% change), although no other variables were different between conditions at any time. However, compression demonstrated a moderate-large effect (d > 0.60) to reduce perceived muscle soreness, fatigue, and RPE from standardised warm-up at 24 h postexercise. The current findings suggest that compression may assist in perceptual recovery from manual-labour exercise with implications for the ability to perform subsequent work bouts.
Johnston, RJ, Watsford, ML, Austin, D, Pine, MJ & Spurrs, RW 2016, 'Movement profiles, match events and performance in Australian football.', Journal of Strength and Conditioning Research, vol. 30, no. 8, pp. 2129-2137.View/Download from: Publisher's site
This study examined the relationship between movement demands, match events and match performance in professional Australian football. This data was collected from 19 players using Global Positioning System units during two Australian Football League seasons. A range of movement demands and instantaneous power measures were collected. The players were divided into high calibre (HC, ≥17/20) and low calibre (LC, ≤8/20) groups based on their coach's rating score. A Mann-Whitney U-test, independent samples t-test and effect sizes were used to determine whether any differences existed between the two groups. The HC group had a significantly higher match duration (7.2%), higher total distance (9.6%) and covered more distance and spent more time high-speed running per minute (12.7% and 11.9%). Whilst not significant the effect sizes revealed that the HC group tended to have a higher mean metabolic power output (2.6%) and spent more time at the high power zone (7.9%). For the match event data the HC group had significantly more involvements with the football. The results demonstrated the higher physical demands placed on the HC group. The findings suggest that analysing instantaneous power measures can provide valuable information about the physical demands placed on team- sport athletes to coaches and conditioning staff.
Millett, EL, Moresi, MP, Watsford, ML, Taylor, PG & Greene, DA 2016, 'Lower Body Stiffness Modulation Strategies In Well Trained Female Athletes.', Journal of Strength and Conditioning Research, vol. 30, no. 10, pp. 2845-2856.View/Download from: Publisher's site
Lower extremity stiffness quantifies the relationship between the amount of leg compression and the external load to which the limb are subjected. This study aimed to assess differences in leg and joint stiffness and the subsequent kinematic and kinetic control mechanisms between athletes from various training backgrounds. Forty-seven female participants (20 nationally identified netballers, 13 high level endurance athletes and 14 age and gender matched controls) completed a maximal unilateral countermovement jump, drop jump and horizontal jump to assess stiffness. Leg stiffness, joint stiffness and associated mechanical parameters were assessed with a 10 camera motion analysis system and force plate. No significant differences were evident for leg stiffness measures between athletic groups for any of the tasks (p=0.321-0.849). However, differences in joint stiffness and its contribution to leg stiffness, jump performance outcome measures and stiffness control mechanisms were evident between all groups. Practitioners should consider the appropriateness of the task utilised in leg stiffness screening. Inclusion of mechanistic and/or more sports specific tasks may be more appropriate for athletic groups.
Whitty, AG, Murphy, AJ, Coutts, AJ & Watsford, ML 2016, 'The effect of low- vs high-cadence interval training on the freely chosen cadence and performance in endurance-trained cyclists', Applied Physiology, Nutrition, and Metabolism, vol. 41, no. 6, pp. 666-673.View/Download from: Publisher's site
The aim of this study was to determine the effects of high- and low-cadence interval training on the freely chosen
cadence (FCC) and performance in endurance-trained cyclists. Sixteen male endurance-trained cyclists completed a series of
submaximal rides at 60% maximal power (Wmax) at cadences of 50, 70, 90, and 110 r·min−1, and their FCC to determine their
preferred cadence, gross efficiency (GE), rating of perceived exertion, and crank torque profile. Performance was measured via
a 15-min time trial, which was preloaded with a cycle at 60% Wmax. Following the testing, the participants were randomly
assigned to a high-cadence (HC) (20% above FCC) or a low-cadence (LC) (20% below FCC) group for 18 interval-based training
sessions over 6 weeks. The HC group increased their FCC from 92 to 101 r·min−1 after the intervention (p = 0.01), whereas the LC
group remained unchanged (93 r·min−1). GE increased from 22.7% to 23.6% in the HC group at 90 r·min−1 (p = 0.05), from 20.0% to
20.9% at 110 r·min−1 (p = 0.05), and from 22.8% to 23.2% at their FCC. Both groups significantly increased their total distance and
average power output following training, with the LC group recording a superior performance measure. There were minimal
changes to the crank torque profile in both groups following training. This study demonstrated that the FCC can be altered with
HC interval training and that the determinants of the optimal cycling cadence are multifactorial and not completely understood.
Furthermore, LC interval training may significantly improve time-trial results of short duration as a result of an increase in
strength development or possible neuromuscular adaptations.
Dogramaci, S, Watsford, ML & Murphy, A 2015, 'Activity profile differences between sub-elite futsal teams', International Journal of Exercise Science, vol. 8, no. 2, pp. 112-123.
Dogramaci, S, Watsford, ML & Murphy, A 2015, 'Changes in futsal activity profiles in a multiday tournament', The Journal of Sports Medicine and Physical Fitness, vol. 55, no. 7-8, pp. 722-729.
Johnston, RJ, Watsford, ML, Austin, DJ, Pine, MJ & Spurrs, RW 2015, 'An Examination of the Relationship Between Movement Demands and Rating of Perceived Exertion in Australian Footballers', Journal of Strength and Conditioning Research, vol. 29, no. 7, pp. 2026-2033.View/Download from: Publisher's site
Johnston, RJ, Watsford, ML, Austin, DJ, Pine, MJ & Spurrs, RW 2015, 'Movement Demands and Metabolic Power Comparisons Between Elite and Subelite Australian Footballers', Journal of Strength and Conditioning Research, vol. 29, no. 10, pp. 2738-2744.View/Download from: Publisher's site
Johnston, RJ, Watsford, ML, Pine, MJ, Spurrs, RW & Austin, D 2015, 'Player acceleration and deceleration profiles in professional Australian football', Journal Of Sports Medicine And Physical Fitness, vol. 55, no. 9, pp. 931-939.
This study aimed to determine the validity and reliability of global positioning system (GPS) units for measuring a standardized set of acceleration and deceleration zones and whether these standardized zones were capable of identifying differences between playing positions in professional Australian football. Eight well trained male participants were recruited to wear two 5 Hz or 10 Hz GPS units whilst completing a team sport simulation circuit to measure acceleration and deceleration movements. For the second part of this article 30 professional players were monitored between 1-29 times using 5 Hz and 10 Hz GPS units for the collection of acceleration and deceleration movements during the 2011 and 2012 Australian Football League seasons. Players were separated into four distinct positional groups -- nomadic players, fixed defenders, fixed forwards and ruckman. The GPS units analysed had good to poor levels of error for measuring the distance covered (<19.7%), time spent (<17.2%) and number of efforts performed (<48.0%) at low, moderate and high acceleration and deceleration zones. The results demonstrated that nomadic players and fixed defenders perform more acceleration and deceleration efforts during a match than fixed forwards and ruckman. These studies established that these GPS units can be used for analysing the distance covered and time spent at the acceleration and deceleration zones used. Further, these standardized zones were proven to be capable of distinguishing between player positions, with nomadic players and fixed defenders required to complete more high acceleration and deceleration efforts during a match.
Kelly, SJ, Murphy, AJ, Watsford, ML, Austin, D & Rennie, MJ 2015, 'Reliability and validity of sports accelerometers during static and dynamic testing.', International Journal of Sports Physiology and Performance, vol. 10, no. 1, pp. 106-111.View/Download from: Publisher's site
Abstract PURPOSE: The aim of this study was to investigate the validity and reliability of accelerometry within the SPI-ProX II dual data logger (GPSports, Canberra, Australia).
Pruyn, EC, Watsford, ML & Murphy, AJ 2015, 'Differences in lower body stiffness between levels of netball competition', Journal of Strength and Conditioning Research, vol. 29, no. 5, pp. 1197-1202.View/Download from: Publisher's site
There are many notable differences in physical and skill attributes between competition levels, especially in team sports. Stiffness is an important mechanical factor to measure when considering athletic performance and injury incidence. Active vertical stiffness (Kvert) during hopping and passive stiffness during lying and standing were measured during the preseason period for 46 female netballers (24.0 ± 3.7 years, 72.2 ± 7.6 kg, 175.2 ± 6.7 cm). Participants were classified as elite, sub-elite, representative or recreational based on their current level of competition. A 1-way analysis of variance revealed that elite players possessed significantly higher Kvert than recreational players (p = 0.018). Large effect sizes (ES) suggested that elite players also possessed higher Kvert than sub-elite (d = 1.11) and representative (d = 1.11) players. A number of large and moderate ES were also present when comparing the passive stiffness of elite players to their lower-ranked counterparts. The results of this study suggest that elite players possess higher levels of active stiffness when compared with their lower-ranked counterparts. The differences in stiffness levels may contribute to a player's ability to physically perform at an elite level and also provide one explanation into elevated rates of injury at higher levels of competition
Woods, MA, Watsford, ML, Cavanagh, BP & Pruyn, EC 2015, 'Factors affecting jump performance in professional Australian rules footballers.', The Journal of Sports Medicine and Physical Fitness, vol. 55, no. 10, pp. 1114-1121.
This study examined factors contributing to jump performance in professional Australian Rules Football (ARF) players.Thirty-two ARF players performed a countermovement jump (CMJ) and were divided into groups based on jump performance: high calibre (HC) or low calibre (LC). During CMJ assessment, force, rate of force development, movement velocity and power were measured. Physical measures included mass, height, age, lower body strength, eccentric utilization ratio and leg stiffness (Kleg). HC and LC groups were compared to determine the variables contributing to jump performance and correlation and regression analyses also aided in identifying such variables. CMJ height was higher in the HC group (P<0.001).The HC group demonstrated a higher CMJ velocity (9.8%, P=0.004) and CMJ power (14.4%, P=0.042) when compared to the LC group. Further, the HC group demonstrated 7.5% higher Kleg than the LC group (P=0.019). Spearman's rho correlations demonstrated moderate-large relationships between jump height and strength, velocity and power, while the regression analysis revealed velocity was the sole predictive variable of jump performance. Jumping performance clearly differs within a group of professional ARF athletes.Movement velocity appears to be an important factor contributing to jump performance; however, lower body power and Kleg are also important for jump performance.
Johnston, RJ, Watsford, ML, Kelly, SJ, Pine, MJ & Spurrs, RW 2014, 'The Validity and reliability of 10 Hz and 15 Hz GPS units for assessing athlete movement demands', Journal of Strength and Conditioning Research, vol. 28, no. 6, pp. 1649-1655.View/Download from: Publisher's site
Johnston, RJ, Watsford, ML, Pine, MJ & Spurrs, RW 2014, 'Standardisation of Acceleration Zones in Professional Field Sport Athletes', International Journal of Sports Science and Coaching, vol. 9, no. 5, pp. 1161-1168.View/Download from: Publisher's site
Pruyn, EC, Watsford, ML & Murphy, AJ 2014, 'The relationship between lower-body stiffness and dynamic performance', Applied Physiology, Nutrition, and Metabolism, vol. 39, no. 10, pp. 1144-1150.View/Download from: Publisher's site
Abstract: Greater levels of lower-body stiffness have been associated with improved outcomes for a number of physical performance variables involving rapid stretch-shorten cycles. The aim of this study was to investigate the relationship between several measures of lower-body stiffness and physical performance variables typically evident during team sports in female athletes.
Musculo-articular stiffness (MAS) measured with the free oscillation technique is a comprehensive measurement of joint stiffness which includes the stiffness of the muscle-tendon unit, skin, ligaments and articular capsule, along with a number of other mechanical and neuromuscular factors .
Johnston, RJ, Watsford, ML, Pine, MJ, Spurrs, RW & Sporri, D 2013, 'Assessment of 5 Hz and 10 Hz GPS units for measuring athlete movement demands', International Journal of Performance Analysis in Sport, vol. 13, no. 1, pp. 262-274.View/Download from: Publisher's site
This study aimed to assess the validity and inter-unit reliability of 5 Hz and 10 Hz global positioning system (GPS) units and determine the differences between these units as measures of team sport athlete movement demands.
Pruyn, EC, Watsford, ML, Murphy, AJ, Pine, MJ, Spurrs, RW, Cameron, M & Johnston, RJ 2013, 'Seasonal Variation of Leg Stiffness in Professional Australian Rules Footballers', Journal of Strength and Conditioning Research, vol. 27, no. 7, pp. 1775-1779.View/Download from: Publisher's site
Leg stiffness (Kleg) is an important component to consider in both performance and injury in the Australian Football League (AFL). Kleg has not yet been examined longitudinally throughout an entire AFL season. A unilateral hop test was used to measure Kleg in the left and right legs of 25 professional AFL players (24.9 ± 4.3 years, 86.8 ± 8.1 kg, 187.0 ± 7.3 cm). Kleg was assessed at least once per month for each participant. Furthermore, the session rate of perceived exertion method was used to quantify the average weekly training loads experienced by the participants. One-way analysis of variance revealed no significant difference between the average monthly bilateral Kleg scores; however, average weekly training loads varied between 1,400 and 2,000 AU, depending on the training period. Thirteen participants were randomly selected to perform hop tests on 2 consecutive weeks. Reliability tests revealed these measurements to have a typical error of the measurement of 4.15% and an intraclass correlation of 0.8, proving the methods to be reliable. Although training intensity appears to vary, Kleg does not fluctuate significantly across an entire AFL season, suggesting that weekly training loads between 1,400 and 2,000 AU may be prescribed without the risk of fluctuating stiffness levels.
Johnston, RL, Watsford, ML, Pine, MJ, Spurrs, RW, Murphy, AJ & Pruyn, EC 2012, 'Movement Demands And Match Performance In Professional Australian Football', International Journal of Sports Medicine, vol. 33, no. 2, pp. 89-93.View/Download from: Publisher's site
This study examined the relationship between coaches' perception of match performance and movement demands in Australian Football. Movement demands were collected from 21 professional players over 12 matches during one Australian Football League season,
Johnston, RL, Watsford, ML, Pine, MJ, Spurrs, RW, Murphy, AJ & Pruyn, EC 2012, 'The Validity And Reliability Of 5-Hz Global Positioning System Units To Measure Team Sport Movement Demands', Journal of Strength and Conditioning Research, vol. 26, no. 3, pp. 758-765.View/Download from: Publisher's site
The validity and reliability of 5-Hz global positioning system units to measure team sport movement demands. J Strength Cond Res 26(3): 758-765, 2012-The purpose of this research was to investigate the validity and the reliability of 5-Hz MinimaxX global positioning system (GPS) units measuring athlete movement demands. A team sport simulation circuit (files collected from each unit = 12) and flying 50-m sprints (files collected from each unit = 34) were undertaken, during which the total distance covered; peak speed; player load; the distance covered; time spent and number of efforts performed walking, jogging, running, highspeed running, and sprinting were examined. Movement demands were also separately categorized into low-intensity activity, high-intensity running, and very high-intensity running. The results revealed that GPS was a valid and reliable measure of total distance covered (p > 0.05, percentage typical error of measurement [% TEM] <5%) and peak speed (p > 0.05, % TEM 5-10%). Further, GPS was found to be a reliable measure of player load (% TEM 4.9%) and the distance covered, time spent, and number of efforts performed at certain velocity zones (% TEM <5% to >10%). The level of GPS error was found to increase along with the velocity of exercise. The findings demonstrated that GPS is capable of measuring movement demands performed at velocities <20 km.h(-1), whereas more caution is to be exercised when analyzing movement demands collected by using GPS velocities >20 km.h(-1).
Pruyn, EC, Watsford, ML, Pine, MJ, Spurrs, RW, Murphy, AJ, Cameron, ML & Johnston, R 2012, 'Relationship between stiffness and lower body soft-tissue injury in professional Australian Rules footballers', Journal of Sports Sciences, vol. 30, no. 1, pp. 71-78.View/Download from: Publisher's site
Inkster, BJ, Murphy, AJ, Bower, R & Watsford, ML 2011, 'Differences in the Kinematics of the Baseball Swing between Hitters of Varying Skill', Medicine and Science in Sports and Exercise, vol. 43, no. 6, pp. 1050-1054.View/Download from: Publisher's site
Differences in the Kinematics of the Baseball Swing between Hitters of Varying Skill. Med. Sci. Sports Exerc., Vol. 43, No. 6, pp. 10501054, 2011. Purpose: The aim of this study was to determine differences in bat swing kinematics in baseball hitters of varying ability. Methods: Kinematic data for the upper and lower body were collected from 20 trained male baseball players (22.3 T 5.3 yr, 1.82 T 0.07 m, 83.5 T 10.9 kg), using three-dimensional computerized motion-analysis techniques. Participants were ranked before testing based on a novel coachs rating scale and seasonal batting average. They were subsequently separated into a relatively high-caliber group of hitters (n = 10) and a relatively low-caliber group of hitters (n = 10) for comparison. Importantly, the two groups were significantly different in terms of coachs rating (P G 0.01) and batting average (P G 0.05). Results: The results showed a significant difference in maximum bat swing velocity (P G 0.05) with high-caliber hitters having a higher velocity (36.8 mIsj1) in comparison with relatively low-caliber hitters (33.8 mIsj1). Lead elbow maximum angular velocity was significantly higher (35.9%) among relatively high-caliber hitters (P G 0.05). Angular velocity of the hip segment approached significance between the groups (P = 0.056). High-caliber hitters also had a right knee angle of 106- at ball contact, which was significantly (P G 0.05) higher than that of relatively low-caliber hitters (100-).
Ditroilo, M, Watsford, ML & DeVito, G 2011, 'Validity and inter-day reliability of a free-oscillation test to measure knee extensor and knee flexor musculo-articular stiffness', Journal of Electromyography & Kinesiology, vol. 21, no. 3, pp. 492-498.View/Download from: Publisher's site
The purpose of this study was to assess the validity and inter-day reliability of musculo-articular stiffness (MAS) in the knee-extensor (KE) and knee-flexor (KF) muscle groups, measured with a free-oscillation technique. Fourteen participants were measured, on two occasions, for KE and KF maximal isometric voluntary contraction, rate of torque development (RTD) and electromechanical delay (EMD), along with MAS using multiple sub-maximal loads relative to the individuals maximal voluntary contraction (MAS%MVC). Furthermore, 18 participants were tested for MAS using one fixed assessment load for each muscle group (MASFL) during a separate series of tests on three occasions. MAS%MVC was significantly increased as load increased both in KE and in KF (p < 0.01) fitting a curvilinear relationship as depicted in similar studies. Validity was demonstrated relating MAS%MVC to RTD (r = 0.510.71, p < 0.05) and to EMD (r = 0.56 to 0.67, p < 0.05). While MAS%MVC reliability (ICC = 0.620.89; CV = 8.113.1%) was questionable to acceptable, MASFL exhibited good to excellent reliability (ICC = 0.810.94; CV = 3.7 6.5%). No significant systematic bias was detected for any of the variables considered. The assessment of KE and KF MAS using the free-oscillation technique appears to be valid and reliable, with the use of MASFL yielding higher reliability than the use of MASMVC.
Ditroilo, M, Watsford, ML, Fernandez-pena, E, D'amen, G, Lucertini, F & De Vito, G 2011, 'Effects Of Fatigue On Muscle Stiffness And Intermittent Sprinting During Cycling', Medicine and Science in Sports and Exercise, vol. 43, no. 5, pp. 837-845.View/Download from: Publisher's site
Effects of Fatigue on Muscle Stiffness and Intermittent Sprinting during Cycling. Med. Sci. Sports Exerc., Vol. 43, No. 5, pp. 837-845, 2011. Purpose: It was recently
Ditroilo, M, Watsford, ML, Murphy, AJ & DeVito, G 2011, 'Assessing Musculo-Articular Stiffness Using Free Oscillations: Theory, Measurement and Analysis', Sports Medicine, vol. 41, no. 12, pp. 1019-1032.View/Download from: Publisher's site
Stiffness, the relationship between applied load and elastic deformation, is an important neuromechanical component related to muscular performance and injury risk. The free-oscillation technique is a popular method for stiffness assessment. There has been wide application of this technique assessing a variety of musculature, including the triceps surae, knee flexors, knee extensors and pectorals. The methodology involves the modelling of the system as a linear damped mass-spring system. The use of such a model has certain advantages and limitations that will be discussed within this review. Perhaps the major advantage of such a model is the specificity of the measure, whereby it is possible for the assessment conditions to simulate the type of loading witnessed during functional tasks and sporting situations. High levels of reliability and construct validity have typically been reported using such procedures. Despite these assurances of accuracy, a number of issues have also been identified. The literature reveals some concerns surrounding the use of a linear model for stiffness assessment. Further, procedural issues surrounding the administration of the perturbation, attention focus of the participant during the perturbation, signal collection, data processing and analysis, presentation of stiffness as a linear or torsional value, assessment load (single vs multiple vs maximal) and the stiffness-load relationship have been identified, and are all fundamentally related to the quality of the calculated output data. Finally, several important considerations for practitioners have been recommended to ensure the quality and consistency of stiffness data collection, processing and interpretation.
Dogramaci, S, Watsford, ML & Murphy, AJ 2011, 'The Reliability And Validity Of Subjective Notational Analysis In Comparison To Global Positioning System Tracking To Assess Athlete Movement Patterns', Journal of Strength and Conditioning Research, vol. 25, no. 3, pp. 852-859.View/Download from: Publisher's site
Subjective notational analysis can be used to track players and analyse movement patterns during match-play of team sports such as futsal. The purpose of this study was to establish the validity and reliability of the Event Recorder for subjective notational analysis. A course was ·designed, replicating ten minutes of futsal match-play movement patterns, where ten participants undertook the course. The course allowed a comparison of data derived from subjective notational analysis, to the known distances of the course, and to GPS data. The study analysed six locomotor activity categories, focusing on total distance covered, total duration of activities and total frequency of activities. The values between the known measurements and the Event Recorder were similar, whereas the majority of significant differences were found between the Event Recorder and GPS values. The reliability of subjective notational analysis was established with all ten participants being analysed on two occasions, as well as analysing five random futsal players twice during match-play. Subjective notational analysis is a valid and reliable method of tracking player movements, and may be a preferred and more effective method than GPS, particularly for indoor sports such as futsal, and field sports where short distances and changes in direction are observed.
Dogramaci, S, Watsford, ML & Murphy, AJ 2011, 'Time-motion analysis of international and national level futsal', Journal of Strength and Conditioning Research, vol. 25, no. 3, pp. 646-651.View/Download from: Publisher's site
Futsal is the Fe´de´ ration de Internationale Football Associations officially recognized fivea- side indoor soccer, which although increasing in popularity worldwide, lacks the Australian or other English language research necessary to enable the growth of the sport. The purpose of this study was to establish a comprehensive overview of the demands of futsal by a time-motion analysis on 8 Australian National Team players and 10 State League Team players over 4 futsal matches. The study analyzed 6 locomotor activity categories, focusing on total distance covered, total duration of activities, total frequency of activities, effort distance, and effort duration. The national team covered a 42% greater overall distance than the state league team. In terms of relative data normalized for match duration, only the standing duration value was significantly different between the teams. Furthermore, futsal players of elite and subelite level in Australia perform a change in activity every 89 seconds on the court, and the national team athletes attained a higher, yet nonsignificant, average match-play velocity. This may be because of the national futsal athletes participating in an extended game duration, potentially suggesting that higher levels of competition facilitate a higher intensity of match play and greater physiological demands on individual players. Apart from the differences in timing structure and overall metabolic work, there was no real difference between the levels of competition within the Australian futsal analysis, although at higher levels of competition, there may be a need for more recovery because of the elevated intensity of the match. When comparing the data with other countries, however, Australian futsal players produce less distance and duration than Spanish futsal players.
Watsford, ML, Ditroilo, M, Fernandez-pena, E, D'amen, G & Lucertini, F 2010, 'Muscle stiffness and rate of torque development during sprint cycling', Medicine and Science in Sports and Exercise, vol. 42, no. 7, pp. 1324-1332.View/Download from: Publisher's site
Muscle Stiffness and Rate of Torque Development during Sprint Cycling. Med. Sci. Sports Exerc., Vol. 42, No. 7, pp. 1324-1332, 2010. Purpose: Crank torque (CT) application and rat
Watsford, ML, Murphy, AJ, McLachlan, KA, Bryant, A, Cameron, M, Crossley, KM & Makdissi, M 2010, 'A prospective study of the relationship between lower body stiffness and hamstring injury in professional Australian Rules footballers', American Journal of Sports Medicine, vol. 38, no. 10, pp. 2058-2064.View/Download from: Publisher's site
Background: Hamstring strains remain one of the most prevalent injuries in Australian Rules football. The authors prospectively examined the relationship between musculotendinous stiffness of the hamstring and leg stiffness with hamstring injury in profe
Rees, SS, Murphy, AJ & Watsford, ML 2009, 'Effects of whole body vibration on postural steadiness in an older population', Journal of Science and Medicine in Sport, vol. 12, no. 4, pp. 440-444.View/Download from: Publisher's site
The aim of this study was to investigate the effects of vibration exercise on postural steadiness performance in a healthy, older population. Forty-three healthy, older participants (23 men and 20 women, aged 73.5 +/- 4.5 yr) were randomly assigned to either a vibration group (VIB), an exercise without vibration group (EX) or a control group (CONT). The VIB and EX groups undertook static and dynamic bodyweight exercises three times per week for eight weeks. Static balance was assessed using a one-legged postural steadiness (OLPS) test. This test was performed prior to and immediately after the training period. OLPS improved significantly for the VIB intervention after eight weeks training (p < 0.05) compared to the EX and CONT groups. The improvements in OLPS were significantly affected by the baseline values, with the largest changes evident for VIB participants with a poorer initial score (p<0.01). Vibration exercise can contribute to improved static one-legged balance in a healthy, older population. As improvements in OLPS were related to baseline values, vibration exercise as an intervention would appear to serve the most benefit for those that exhibit diminished postural control.
Whitty, AG, Murphy, AJ, Coutts, AJ & Watsford, ML 2009, 'Factors associated with the selection of the freely chosen cadence in non-cyclists', European Journal Of Applied Physiology, vol. 106, no. 5, pp. 705-712.View/Download from: Publisher's site
The purpose of this study was to examine both the freely chosen cadence (FCC) and the physical variables associated with cadence selection in non-cyclists. Eighteen participants pedalled at 40, 50, and 60% of their maximal power output (determined by a maximal oxygen uptake test, W (max)), whilst cadence (50, 65, 80, 95, 110 rpm, and FCC) was manipulated. Gross efficiency, was used to analyse the most economical cadence whilst central and peripheral ratings of perceived exertion (RPE) were used to measure the most comfortable cadence and the cadence whereby muscle strain was minimised. Peak (T (peak)), mean crank torque (T (mean)) and the crank torque profile were analysed at 150 and 200 W at cadences of 50, 65, 80, 95, and 110 rpm in order to determine the mechanical load. FCC was found to be approximately 80 rpm at all workloads and was significantly higher than the most economical cadence (50 rpm). At 60% W (max), RPE peripheral was minimised at 80 rpm which coincided with the FCC. Both T (peak) and T (mean) decreased as cadence increased and, conversely, increased as power output increased. An analysis of the crank torque profile showed that the crank angle at both the top (DPtop) and the bottom (DPbot) dead point of the crank cycle at 80 rpm occurred later in the cycling revolution when compared to 50 rpm. The findings suggested that the FCC in non-cyclists was more closely related to variables that minimise muscle strain and mechanical load than those associated with minimising metabolic economy.
Rees, SS, Murphy, AJ & Watsford, ML 2008, 'Effects of whole-body vibration exercise on lower-extremity muscle strength and power in an older population: A randomized clinical trial', Physical Therapy, vol. 88, no. 4, pp. 462-470.View/Download from: Publisher's site
Background and Purpose Vibration training is a relatively new exercise intervention. This study investigated the effects of vibration exercise on strength (force-producing capacity) and power in older adults who are healthy. Participants and Methods Thirty participants (mean age=73.7 years, SD=4.6) were randomly assigned to a vibration exercise training (VIB) group or an exercise without vibration training (EX) group. The interventions consisted of 3 sessions per week for 8 weeks. Outcome measures included isokinetic flexor and extensor strength and power of the hip, knee, and ankle. Results The VIB group significantly improved ankle plantar flexor strength and power compared with the EX group. However, there were no significant differences between the VIB and EX groups for knee flexor or extensor strength. Discussion and Conclusion Vibration training contributed to an increase in plantar flexor strength and power. However, the strength gains for the knee and hip flexors and extensors for the VIB group and the EX group were comparable. Future vibration protocols should explore different body positions to target muscles higher up on the leg.
Watsford, ML & Murphy, AJ 2008, 'The effects of respiratory-muscle training on exercise in older women', Journal of Aging and Physical Activity, vol. 16, no. 3, pp. 245-260.View/Download from: Publisher's site
This research examined the effects of respiratory-muscle (RM) training on RM function and exercise performance in older women. Twenty-six women (60-69 yr of age) were assessed for spirometry, RM strength (maximal inspiratory and expiratory pressure), inspiratory-muscle endurance, and walking performance to a perceived exertion rating of "hard." They were randomly allocated to a threshold RM training group (RMT) or a nonexercising control group (CON) for 8 wk. After training, the 22% (inspiratory) and 30% (expiratory) improvements in RM strength in the RMT group were significantly higher than in the CON group (P < .05). The RMT group also displayed several significant performance improvements, including improved within-group treadmill performance time (12%) and reductions in submaximal heart rate (5%), percentage of maximum voluntary ventilation (16%), and perceived exertion for breathing (8%). RM training appears to improve RM function in older women. Furthermore, these improvements appear to be related to improved submaximal exercise performance.
Rees, SS, Murphy, AJ & Watsford, ML 2007, 'Effects of vibration exercise on muscle performance and mobility in an older population', Journal of Aging and Physical Activity, vol. 15, no. 4, pp. 367-381.
This study was designed to investigate the effects of vibration on muscle performance and mobility in a healthy, untrained, older population. Forty-three participants (23 men, 20 women, 66-85 y old) performed tests of sit-to-stand (STS), 5- and 10-m fast walk, timed up-and-go test, stair mobility, and strength. Participants were randomly assigned to a vibration group, an exercise-withoutvibration group, or a control group. Training consisted of 3 sessions/wk for 2 mo. After training, the vibration and exercise groups showed improved STS (12.4%, 10.2%), 5-m fast walk (3.0%, 3.7%), and knee-extension strength (8.1%, 7.2%) compared with the control (p < 0.05). Even though vibration training improved lower limb strength, it did not appear to have a facilitatory effect on functional-performance tasks compared with the exercise-without-vibration group. Comparable mobility and performance changes between the experimental groups suggest that improvements are linked with greater knee-extension strength and largely attributed to the unloaded squats performed by both exercise groups. Brain Res. 2007 Nov 7; : 18048005
Rees, SS, Murphy, AJ, Watsford, ML, McLachlan, KA & Coutts, AJ 2007, 'Effects of Proprioceptive Neuromuscular Facilitation Stretching on Stiffness and Force-Producing Characteristics of the Ankle in Active Women', Journal Of Strength and Conditioning Research, vol. 21, no. 2, pp. 572-577.
Effects of proprioceptive neuromuscular facilitation stretching on stiffness and force-producing characteristics of the ankle in active women. J. Strength Cond. Res. 21(2):572577. 2007.The purpose of this study was to examine the effect of proprioceptive neuromuscular facilitation (PNF) stretching on musculotendinous unit (MTU) stiffness of the ankle joint. Twenty active women were assessed for maximal ankle range of motion, maximal strength of planter flexors, rate of force development, and ankle MTU stiffness. Subjects were randomly allocated into an experimental (n 10) group or control group (n 10). The experimental group performed PNF stretching on the ankle joint 3 times per week for 4 weeks, with physiological testing performed before and after the training period. After training, the experimental group significantly increased ankle range of motion (7.8%), maximal isometric strength (26%), rate of force development (25%), and MTU stiffness (8.4%) (p 0.001). Four weeks of PNF stretching contributed to an increase in MTU stiffness, which occurred concurrently with gains to ankle joint range of motion. The results confirm that MTU stiffness and joint range of motion measurements appear to be separate entities. The increased MTU stiffness after the training period is explained by adaptations to maximal isometric muscle contractions, which were a component of PNF stretching. Because a stiffer MTU system is linked with an improved the ability to store and release elastic energy, PNF stretching would benefit certain athletic performance due to a reduced contraction time or greater mechanical efficiency. The results of this study suggest PNF stretching is a useful modality at increasing a joints range of motion and its strength.
Watsford, ML, Murphy, AJ & Pine, MJ 2007, 'The effects of ageing on respiratory muscle function and performance in older adults', Journal Of Science And Medicine In Sport, vol. 10, no. 1, pp. 36-44.View/Download from: Publisher's site
The reduced physiological capacity evident with ageing may affect the ability to perform many tasks, potentially affecting quality of life. Previous research has clearly demonstrated the reduced capacity of the respiratory system with ageing and described the effect that habitual physical activity has upon this decline. This research aimed to examine the influence of age on respiratory muscle (RM) function and the relationship between RM function and physical performance within the Australian population. Seventy-two healthy older adults (50-79 years) were divided into males (n=36) and females (n=36) and examined for pulmonary function, RM strength, inspiratory muscle endurance (IME) and 1.6 km walking performance. There were no significant age by gender effects for any variables; however, ageing was significantly related to reduced RM function and walking capacity within each gender. Furthermore, regression analysis showed that the RM strength could be predicted from age. Partial correlations controlling for age indicated that expiratory muscle strength was significantly related to walking performance in males (p=0.04), whilst IME contributed significantly to walking performance in all participants. These within-gender effects and relationships indicate that RM strength is an important physiological variable to maintain in the older population, as it may be related to functional ability.
Dogramaci, S & Watsford, ML 2006, 'A comparison of two different methods for time-motion analysis in team sports', International Journal of Performance Analysis in Sport, vol. 6, no. 1, pp. 73-83.
Time-motion analysis has been extensively used to provide an insight into the movement patterns of athletes in team sports. However, few studies have indicated whether analysis involved breaks in play, or all the activities within the standard clock-time. Therefore, the purpose of this study was to differentiate whether differences existing between clock-time and match-time time-motion analysis had an affect on the results. Data was collected from the Australian National Futsal Team. Analysis was initially conducted against the actual playing clock-time of 40 min, then on a match-time of 70 min including all actions and breaks in play, excluding half-time and time-out intervals. When comparing match-time to clock-time data, there was a 16% greater total overall distance covered, a 6.9% increase in the time spent in low-intensity activities, and a change in activity every 4.00 s vs. 3.28 s, respectively. There was little change in the high-intensity activities from clock-time to match-time comparison. As clock-time data may misrepresent the movement patterns of the game, it is important to establish a standard method of analysis, namely based on match-time data. This may have implications on similar sports based on clock-time such as water polo, basketball, ice hockey and handball
McLachlan, KA, Murphy, AJ, Watsford, ML & Rees, SS 2006, 'The interday reliability of leg and ankle musculotendinous stiffness measures', Journal of Applied Biomechanics, vol. 22, no. 4, pp. 296-304.
Murphy, AJ & Watsford, ML 2005, 'The effect of walking training on respiratory function and performance in older females', International SportMed Journal, vol. 6, no. 3, pp. 171-184.
Murphy, AJ, Watsford, ML, Coutts, AJ & Richards, D 2005, 'Effects of creatine supplementation on aerobic power and cardiovascular structure and function', Journal of Science and Medicine in Sport, vol. 8, no. 3, pp. 305-313.View/Download from: Publisher's site
This project aimed to determine 1) whether creatine (Cr) supplementation affects cardiovascular structure and function and 2) to examine its effect on aerobic power. Eighteen males undertook aerobic testing on a cycle ergometer and echocardiographic asse
Pine, MJ & Watsford, ML 2005, 'Specific respiratory muscle training for athletic performance', Sports Coach, vol. 27, no. 4, pp. 29-31.
Pine, MJ, Murphy, AJ & Watsford, ML 2005, 'Role of respiratory system function in the age-related decline of human functional capacity', Australasian Journal on Ageing, vol. 24, no. 3, pp. 153-156.View/Download from: Publisher's site
Keywords: disuse;physical activity;quality of life Objective: To examine the age-related decline of physical and respiratory system function in older individuals. Methods: Using a cross-sectional research design, 36 healthy participants were assigned to group A (5059 years) or group B (6069 years). Males (n = 14) and females (n = 22) were examined separately. Physical capacity was determined using a combination of two walking tests. Measures of pulmonary function, respiratory muscle (RM) strength and inspiratory muscle endurance (IME) were used to assess respiratory system function. Results: Significant age-related declines in RM strength, IME and walking ability were apparent for females, but not males. An increase in age was associated with less efficient breathing mechanics during exercise. Conclusions: The more substantial age-related declines in RM and physical function for females may be related to greater age-related reductions in physical activity participation. As individuals are living for increasingly longer periods, the continuance of such declines may significantly impair quality of life. Methods of overcoming respiratory system decline and the role of such methods in maintaining the physical capacity of ageing individuals require investigation.
Watsford, ML, Murphy, AJ, Pine, MJ & Coutts, AJ 2005, 'The effect of habitual exercise on respiratory-muscle function in older adults', Journal of Aging and Physical Activity, vol. 13, no. 1, pp. 34-44.
Older adults' participation in habitual exercise might be affected by alterations to respiratory mechanics such as decreased respiratory-muscle strength. This reduction can cause a decrease in efficiency of the ventilatory pump, potentially compromising
Murphy, AJ, Watsford, ML, Coutts, AJ & Pine, MJ 2003, 'Reliability of a test of musculotendinous stiffness for the triceps-surae', Physical Therapy In Sport, vol. 4, no. 4, pp. 175-181.View/Download from: Publisher's site
Spurrs, RW, Murphy, AJ & Watsford, ML 2003, 'The effect of plyometric training on distance running performance', European Journal Of Applied Physiology, vol. 89, no. 1, pp. 1-7.View/Download from: Publisher's site
Watsford, ML, Murphy, AJ, Spinks, WL & Walshe, AD 2003, 'Creatine supplementation and its effect on musculotendinous stiffness and performance', The journal of Strength and Conditioning Research, vol. 17, no. 1, pp. 26-33.View/Download from: 2.0.CO;2">Publisher's site
Watsford, ML, Murphy, AJ, Spinks, WL & Walshe, AD 2003, 'Reatine supplementation and its effect on musculotendinous stiffness and performance', JOURNAL OF STRENGTH AND CONDITIONING RESEARCH, vol. 17, no. 1, pp. 26-33.
Abela, MR, Watsford, ML & Murphy, AJ 2009, 'Musculotendinous stiffness and prior injury in female soccer players', Journal of Science and Medicine in Sport, Sports Medicine Australia, Brisbane, Australia, pp. 17-17.
Watsford, ML, Murphy, AJ, McLachlan, KA, Bryant, AL, Cameron, M, Crossley, KM & Spurrs, RW 2009, 'The role of musculotendinous stiffness in hamstring injuries in professional footballers', Journal of Science and Medicine in Sport, Sports Medicine Australia, Brisbane, pp. 18-18.
Rees, SS, Murphy, AJ, Watsford, ML & Lockie, RG 2007, 'The effects of whole body vibration training on strength and functional mobility in older adults', 12th Annual congress of the European College of Sports Science, European College of Sports Science, Jyvaskyla, Finland, pp. 196-196.
Watsford, ML, Dogramaci, S & Murphy, AJ 2007, 'Physical Characteristics and Match Performance in Elite Australian Futsal (Indoor Soccer)', 2007 Australian Conference of Science and Medicine in Sport, Sports Medicine Australia, Adelaide, pp. 14-14.
Murphy, AJ, Watsford, ML, Bryant, AL, McLachlan, KA & Cameron, M 2006, 'The effects of previous lower limb injury on leg stiffness in AFL players', Australian Conference of Science & Medicine in Sport, Australian Conference of Science and Medicine in Sport, Sports Medicine Australia, Fiji, pp. 13-13.
Rees, SS, Murphy, AJ, Watsford, ML & Lockie, RG 2006, 'Effects of vibration exercise on postural steadiness in the older population', 2nd Australian Association of Exercise and Sports Science Congress, Australian Association of Exercise and Sports Science Congress, Australian Association of Exercise and Sports Science, Sydney, pp. 52-52.
Watsford, ML & Murphy, AJ 2006, 'Can older females benefit from respiratory muscle training?', 11th Annual Congress of the European College of Sports Science, 11th Annual Congress of the European College of Sports Science, European College of Sports Science, Lausanne, Switzerland, pp. 288-288.
Watsford, ML & Murphy, AJ 2006, 'Energy expenditure and time-motion analysis during recreational surfing', 2006 Australian Conference of Science & Medicine in Sport, Australian Conference of Science and Medicine in Sport, Sports Medicine Australia, Fiji, pp. 8-8.
Ku, SY, Murphy, AJ, Walsh, SP & Watsford, ML 2005, 'The effects of acupuncture on recovery in team sport athletes', The Hong Kong Student Conference of Exercise Science, Health and Rehabilitation, The Hong Kong Student Conference of Exercise Science, Health and Rehabilitation, University of Hong Kong, Hong Kong, pp. 14-14.
McLachlan, KA, Murphy, AJ & Watsford, ML 2005, 'The inter-day reliability of ankle musculotendinous stiffness measures', 2nd International Ankle Symposium, 2nd International Ankle Symposium, University of Delaware, Newark, Delaware, USA, pp. 43-43.
Pine, MJ, Murphy, AJ, Watsford, ML & Coutts, AJ 2005, 'Specific respiratory muscle training: the effects of various strategies upon repeat sprint performance', Promoting Innovation, Measuring Success - Program & Abstracts of the 2005 Australian Conference of Science and Medicine in Sport, Australian Conference of Science and Medicine in Sport, Sports Medicine Australia, Melbourne, Autralia, pp. 64-64.
Rees, SS, Murphy, AJ, Watsford, ML & McLachlan, KA 2005, 'The effect of proprioceptive neuromuscular facilitation stretching on stiffness of the ankle', Promoting Innovation, Measuring Success - Program & Abstracts of the 2005 Australian Conference of Science and Medicine in Sport, Australian Conference of Science and Medicine in Sport, Sports Medicine Australia, Melbourne, Australia, pp. 21-21.
Watsford, ML & Spurrs, RW 2005, 'The relationship between respiratory muscle strength and running performance in elite Australian Rules athletes', Promoting Innovation, Measuring Success - Program & Abstracts of the 2005 Australian Conference of Science and Medicine in Sport, Australian Conference of Science and Medicine in Sport, Sports Medicine Australia, Melbourne, Australia, pp. 122-122.
Watsford, ML, Murphy, AJ & Pine, MJ 2005, 'A comparison between the effects of respiratory muscle training and exercise training in older females', Promoting Innovation, Measuring Success - Program & Abstracts of the 2005 Australian Conference of Science and Medicine in Sport, Australian Conference of Science and Medicine in Sport, Sports Medicine Australia, Melbourne, Australia, pp. 118-118.
McLachlan, KA, Murphy, AJ & Watsford, ML 2004, 'The inter-day reliability of ankle musculotendinous stiffness measures', Ankle Instability: Etiology, Biomechanics, Rehabilitation Surgical Management, 2nd International Ankle Symposium, -, Newark, USA, pp. 43-43.
Pine, MJ, Murphy, AJ, Watsford, ML & Coutts, AJ 2004, 'Specific respiratory muscle training: the effects of various training strategies upon repeat sprint performance.', 9th Annual Congress: European College of Sport Science - Book of Abstracts., 9th Annual Congress of the European College of Sport Science, -, Clermont-Ferrand, France, pp. 269-269.
Coutts, AJ, Reaburn, P, Murphy, AJ, Watsford, ML & Spurrs, RW 2003, 'Changes in physiological characteristics of semi-professional rugby league players in relation to training load: a case study', 2003 Australian Conference of Science and Medicine in Sport, Sports Medicine Australia, Canberra, pp. 37-37.
Watsford, ML, Murphy, AJ, Pine, MJ & Coutts, AJ 2003, 'The effect of specific respiratory muscle training on older females', Sports Medicine Australia Conference 2003, Sports Medicine Australia, Canberra.
Pine, MJ, Murphy, AJ & Watsford, ML 2002, 'The role of respiratory system function in the age related decline of human functional capacity', 2002 Australian Conference of Science and Medicine in Sport, 2002 Australian Conference of Science and Medicine in Sport, Sports Medicine Australia, Melbourne.
Spurrs, RW, Murphy, AJ & Watsford, ML 2002, 'Plyometric training-improves distance running performance: a case study', 2002 Australian Conference of Science & Medicine in Sport, 2002 Australian Conference of Science & Medicine in Sport, Sports Medicine Australia, Melbourne, pp. 41-41.
Watsford, ML, Murphy, AJ & Pine, MJ 2002, 'Physical activity and the age-related decline of respiratory system function', 2002 Australian Conference of Science and Medicine in Sport, 2002 Australian Conference of Science and Medicine in Sport, Sports Medicine Australia, Melbourne, pp. 22-22.
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