Aron Murphy

• University of New England

We evaluated the reliability of an over-ground running three-minute all-out test (3MT) and compared this to traditional multiple-visit testing to determine the critical speed (CS) and distance >CS (D´). Using a novel energetics model during the 3MT, critical power (CP) and work >CP (W´) were also evaluated for reliability and compared to the multip...

An amendment to this paper has been published and can be accessed via the original article.

Cummins, C, Charlton, G, Naughton, M, Jones, B, Minahan, C, and Murphy, A. The validity of automated tackle detection in women's rugby league. J Strength Cond Res XX(X): 000-000, 2020-This study assessed the validity of microtechnology devices to automatically detect and differentiate tackles in elite women's rugby league match-play. Elite female p...

Background: Collisions (i.e. tackles, ball carries, and collisions) in the rugby league have the potential to increase injury risk, delay recovery, and influence individual and team performance. Understanding the collision demands of the rugby league may enable practitioners to optimise player health, recovery, and performance. Objective: The ai...

Purpose We compared a new locomotor-specific model to track the expenditure and reconstitution of work done above critical power (W´) and balance of W´ (W´BAL) by modelling flat over-ground power during exhaustive intermittent running. Method Nine male participants completed a ramp test, 3-min all-out test and the 30–15 intermittent fitness test (...

Objective: This study aimed to: (a) identify the association between external-workloads and injury-risk in the subsequent week; and (b) understand the effectiveness of workload variables in establishing injury-risk. Design: Retrospective cohort study. Methods: Workload and injury data (soft-tissue) were collected from forty-eight professional male...

Quantifying the training and competition loads of players in contact team sports can be performed in a variety of ways, including kinematic, perceptual, heart rate or biochemical monitoring methods. Whilst these approaches provide data relevant for team sports practitioners and athletes, their application to a contact team sport setting can sometim...

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)...

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 determ...

Background: Stiffness is commonly assessed in relation to injury and athletic performance. The purpose of this research was to compare the validity and reliability of 3 in vivo methods of stiffness assessment using 1 cohort of participants. Methods: To determine inter-day reliability, 15 female netballers were assessed for stiffness twice within...

This study investigated relationships between 10 m sprint acceleration, step kinematics (step length and frequency, contact and flight time), and leg muscle performance (power, stiffness, strength). Twenty-eight field sport athletes completed 10 m sprints that were timed and filmed. Velocity and step kinematics were measured for the 0-5, 5-10, and...

This study aimed to predict 500 m time-trial (TT) and 2,000 m pursuit speed of adolescent cyclists (age range = 13-15 years) using mechanical parameters derived from a Critical Power (CP) test and anthropometric variables. Ten well-trained, competitive cyclists were assessed for body composition, body mass, stature and Frontal Surface Area (FSA), a...

This study, firstly, established the betweenmatch variability of soccer-match performance among under-14 players and, secondly, investigated the relationship between match performance variability and both maturity and chronological age. Participants were recruited from two under-14 youth squads in England. The between-match variation of each player...

Whilst there are a range of studies examining the differences in match demands between levels of competition, there is an absence of the analysis these differences between teams within the same level of competition. The study used notational analysis to identify performance indicators that differentiated between sub-elite futsal teams from Brazil,...

Abstract We compared the effects of (1) accurate and (2) surreptitiously augmented performance feedback on power output and physiological responses to a 4000 m time-trial in the heat. Nine cyclists completed a baseline (BaseL) 4000 m time-trial in ambient temperatures of 30°C, followed by two further 4000 m time-trials at the same temperature, rand...

Aim: This study aimed to quantify the activity profiles of futsal players during a tournament, and detect changes in performance towards the final matches, focusing on changes in high-intensity activity. Methods: One team competing in the Australian National Futsal Championships was assessed over six matches across three days. Ball possession, a...

Purpose: To investigate the validity and reliability of accelerometry of the SPI-ProX II dual data logger (GPSports, Canberra, Australia). Methods: Controlled laboratory assessments determined the accuracy and reproducibility of raw accelerometer data. Intra- and interdevice reliability assessed the ability of the SPI-ProX II accelerometers to r...

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 i...

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 d...

The mechanisms for speed performance improvement from sprint (ST) and plyometrics (PT) training, especially relating to stance kinetics, require investigation in field sport athletes. This study determined the effects of ST and PT on 10-meter (m) sprint time (0-5, 5-10, 0-10 m intervals), step kinematics (step length and frequency, contact and flig...

This study aimed to identify characteristics of match performance and physical ability that discriminate between elite and sub-elite under-14 soccer players. Players were assessed for closed performance and movement, physiological responses and technical actions during matches. Elite players covered more total m·min-1 (115.7 ± 6.6 cf. 105.4 ± 7.7 m...

The assessment of musculo-articular stiffness (MAS) with the free-oscillation technique is a popular method with a variety of applications. This study examined the sources of variability (load applied and frequency of oscillation) when MAS is assessed. Over two testing occasions, 14 healthy men (27.7±5.2 yr, 1.82±0.04 m, 79.5±8.4 kg) were measured...

Field sport athletes must generate high velocities over short distances (10 meters [m] or less). The interaction between step kinematics (step length, step frequency, contact time, flight time) determines sprint velocity. This study determined the step kinematics that predicted 10-m sprint performance (0-5, 5-10, 0-10 m intervals) through stepwise...

The interaction between step kinematics and stance kinetics determines sprint velocity. However, the influence stance kinetics has upon effective acceleration in field sport athletes requires clarification. 25 men (age = 22.4 ± 3.2 years; mass = 82.8 ± 7.2 kilograms; height = 1.81 ± 0.07 m) completed 12 10-meter (m) sprints, 6 sprints each for kine...

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 employed to measure Kleg in the left and right legs of 25 professional AFL players (24.9 ± 4.3 years, 86.8 ± 8.1 k...

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 distan...

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...

Session ratings of perceived exertion (session RPE) are commonly used to assess global training intensity for team sports. However, there is little research quantifying the intensity of field-based training protocols for speed development. The study's aim was to determine the session RPE of popular training protocols (free sprint [FST], resisted sp...

Leg stiffness is a modifiable mechanical property that may be related to soft tissue injury risk. The purpose of this study was to examine mean leg stiffness and bilateral differences in leg stiffness across an entire professional Australian Football League (AFL) season, and determine whether this parameter was related to the incidence of lower bod...

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, with 69 player files collected. Additionally, match events relative to playing time and distance...

A variety of resistance training interventions are used to improve field sport acceleration (e.g., free sprinting, weights, plyometrics, resisted sprinting). The effects these protocols have on acceleration performance and components of sprint technique have not been clearly defined in the literature. This study assessed 4 common protocols (free sp...

Speed and acceleration are essential for field sport athletes. However, the mechanical factors important for field sport acceleration have not been established in the scientific literature. The purpose of this study was to determine the biomechanical and performance factors that differentiate sprint acceleration ability in field sport athletes. Twe...

Futsal is the Fédération de Internationale Football Association's officially recognized five-a-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...

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 patt...

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...

The aim of this study was to determine differences in bat swing kinematics in baseball hitters of varying ability. Kinematic data for the upper and lower body were collected from 20 trained male baseball players (22.3 ± 5.3 yr, 1.82 ± 0.07 m, 83.5 ± 10.9 kg), using three-dimensional computerized motion-analysis techniques. Participants were ranked...

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 professional Australian Rules footballers during the 2006 season. Higher hamstring stiffness and leg stiffness ar...

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 manipul...

The purpose of this study was to elucidate the effect of normal fluctuating [non-monophasic oral contraceptive pill (MOCP) users] and low, consistent (MOCP users) endogenous plasma estrogen levels on the strain behavior of the Achilles tendon in vivo. Twenty women (age 28.0 +/- 4.2 yr, height 1.67 +/- 0.07 m, mass 61.6 +/- 6.8 kg) who had been usin...

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)....

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. Thirty participants (mean age=73.7 years, SD=4.6) were randomly assigned to a vibration exercise training (VIB) group or an exercise without vibrati...

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 t...

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 ran...

Acceleration is a significant feature of game-deciding situations in the various codes of football. However little is known about the acceleration characteristics of football players, the effects of acceleration training, or the effectiveness of different training modalities. This study examined the effects of resisted sprint (RS) training (weighte...

The high risk of anterior cruciate ligament (ACL) injuries in female athletes may be related to hormonal fluctuations resulting in an increased laxity of ligaments and muscles. This study examined changes in lower limb musculotendinous stiffness (MTS) and knee laxity over the course of the menstrual cycle and investigated the interaction of warm-up...

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 exami...

The purpose of this study was to examine the influence of overreaching on muscle strength, power, endurance and selected biochemical responses in rugby league players. Seven semi-professional rugby league players (V̇O 2max = 56.1 ± 1.7 mL·kg-1·min -1; age = 25.7 ± 2.6 yr; BMI = 27.6 ± 2.0) completed 6 weeks of progressive overload training with lim...

Two popular methods of assessing lower body musculotendinous stiffness include the hopping and oscillation tests. The disparity and paucity of reliability data prompted this investigation into leg musculotendinous stiffness (Kleg) and ankle musculotendinous stiffness (Kank) measures. Kleg and Kank were assessed on three separate occasions in 20 fem...

The present investigation examined the physiological parameters that contribute to 3-km running performance. Following 2 familiarization sessions, 16 experienced male triathletes (Vo(2)max = 55.7 +/- 4.9 ml.kg(-1).min(-1), age = 31.3 +/- 11.7 years) performed a 3-km time trial (3kmTT) and were assessed for selected physiological and anthropometrica...

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 assessment of the heart. The experimental group (N = 9) ingested 20g x day(-1) of Cr for seven days...

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 (50–59 years) or group B (60–69 years). Males (n = 14) and females (n = 22) were examined separately. Physical capacity was determined usin...

The high risk of anterior cruciate ligament (ACL) injuries in female athletes may be related to hormonal fluctuations resulting in an increased laxity of ligaments and muscles. This study examined changes in lower limb musculotendinous stiffness (MTS) and knee laxity over the course of the menstrual cycle and investigated the interaction of warm-up...

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 exercise participation. This research examined the role of habitual exercise in respiratory-musc...

Background: Sarcopenia affects respiratory system function, potentially decreasing thoracic cavity pressure development and exercise performance. Research question: To investigate the role of walking training on reductions in respiratory muscle strength which are conceivably due to aging. Type of study: Randomised control study. Methods: Twenty-six...

The purpose of the present study was to examine the influence of direct supervision on muscular strength, power, and running speed during 12 weeks of resistance training in young rugby league players. Two matched groups of young (16.7 +/- 1.1 years [mean +/- SD]), talented rugby league players completed the same periodized resistance-training progr...

The purpose of this investigation was to evaluate changes in myosin heavy chain (MyHC) and titin isoforms after using various loads during explosive jump squat training. Twenty-four male athletic subjects were recruited for this study. Two experimental groups performed 8-weeks of jump squats using either 30% (n = 9) or 80% (n = 9) of their previous...

Acceleration performance is important for field sport athletes that require a high level of repeat sprint ability. Although acceleration is widely trained for, there is little evidence outlining which kinematic factors delineate between good and poor acceleration. The aim of this study was to investigate the kinematic differences between individual...

Weighted sled towing is a common resisted sprint training technique even though relatively little is known about the effects that such practice has on sprint kinematics. The purpose of this study was to explore the effects of sled towing on acceleration sprint kinematics in field-sport athletes. Twenty men completed a series of sprints without resi...

Objectives. To determine the inter-day reliability and concurrent validity of a test of unilateral triceps-surae stiffness.Design. Cross-sectional study.Setting. Human Performance Laboratory, University of Technology, Sydney.Participants. Twenty healthy males with no history of injury to the lower body musculature.Main outcome measures. Stiffness m...

The purpose of this investigation was to evaluate changes in myosin heavy chain (MyHC) and titin isoforms after using various loads during explosive jump squat training. Twenty-four male athletic subjects were recruited for this study. Two experimental groups performed 8-weeks of jump squats using either 30% (n = 9) or 80% (n = 9) of their previous...

Weighted sled towing is a common resisted sprint training technique even though relatively little is known about the effects that such practice has on sprint kinematics. The purpose of this study was to explore the effects of sled towing on acceleration sprint kinematics in field-sport athletes. Twenty men completed a series of sprints without resi...

Maximally accumulated oxygen deficit (MAOD) has been argued to be currently the best non-invasive method for estimating anaerobic capacity (Medbø et al., 1988, Ramsbottom et al., 1997). An easy to administer field test that could accurately predict MAOD, would be of great use to many field sport athletes and coaches. Fifteen male rugby union player...

Poor mobility has been associated with age-related deterioration in muscle strength. While previous work has examined the effects of improved strength on level walking, we have quantified the effects of a resistance-training program on obstructed gait tasks using biomechanical-dependent measures. Forty-five community-dwelling participants aged 62 y...

Previous research has reported that plyometric training improves running economy (RE) and ultimately distance-running performance, although the exact mechanism by which this occurs remains unclear. This study examined whether changes in running performance resulting from plyometric training were related to alterations in lower leg musculotendinous...

Anecdotal reports suggesting that creatine (Cr) supplementation may cause side effects, such as an increased incidence of muscle strains or tears, require scientific examination. In this study, it was hypothesized that the rapid fluid retention and "dry matter growth" evident after Cr supplementation may cause an increase in musculotendinous stiffn...

This study examined the effects of improved strength on an obstacle course (OC) simulating gait tasks commonly encountered by community -living older adults. Forty-five adults (mean age 68.2 ± 1.5 years) were randomly assigned to a control (10 women, 5 men) or an experimental group (EXP; 19 women, 10 men) and trained 3 days/week for 12 weeks. Using...

This study examined the effects of improved strength on an obstacle course (OC) simulating gait tasks commonly encountered by community-living older adults. Forty-five adults (mean age 68.2 +/- 1.5 years) were randomly assigned to a control (10 women, 5 men) or an experimental group (EXP; 19 women, 10 men) and trained 3 days/week for 12 weeks. Usin...

To determine the relationship between lower body strength of community-dwelling older adults and the time to negotiate obstructed gait tasks. A correlational study. The Biomechanics Laboratory, Deakin University, Australia. Twenty-nine women and 16 men aged 62 to 88 were recruited using advertisements placed in local newspapers. The participants we...

This study investigated whether there was a worsening of the neuromuscular capacity of older adults after the seventh decade of life. Fifteen healthy community-dwelling old (< 70 years of age) and 15 older adults (> or = 70 years of age) were assessed for maximal isometric strength (MVC) and force production characteristics, a one-repetition maximu...

The purpose of this investigation was to determine whether modifying an isokinetic test to be more specific to dynamic performance improved the relationship between the test and performance, as compared to a relatively non-specific test. In addition, the ability of the specific and non-specific isokinetic tests to monitor training induced changes i...

This study examined the comparative effects of functional isometric (FI) and heavy weight (HW) training on the development of strength and power together with specific hormonal adaptations in experienced athletes. Thirty three subjects were randomly divided into 3 groups: Fl weight training, HW, and Control. Both the FI and HW completed an 8-week t...

We examined the ability of isokinetic and isoinertial tests of muscular function to track training-induced changes in performance. Subjects completed the following tests before and after training: (1) two isoinertial tests using concentric and eccentric actions; (2) isokinetic knee extension at two velocities; and (3) a one-repetition maximum squat...

Although explosive power in lower-body movements has been extensively studied, there is a paucity of research examining such movements in the upper body. This study aimed to investigate the influence of load and the stretch shortening cycle (SSC) on the kinematics, kinetics, and muscle activation that occurs during maximal effort throws. A total of...

This study aimed to assess whether the benefits associated with stretch shorten cycle (SSC) movements required the movement frequency to be in resonance with the natural frequency of the elastic structures. Seventeen untrained participants performed SSC and concentric bench press throws. Further, quasi-static muscular actions were also performed in...

This investigation compared the relationship of isokinetic and isoinertial tests of muscular function to dynamic upper body performances. The electromiyographic activity of each of the tests of muscular function, as recorded by surface electrodes, were examined to determine whether neural differences underlie the ability of the test to relate to pe...

The study was performed in an effort to gain greater insights into the adaptations invoked by plyometric and weight training. Forty-one previously trained males were randomly allocated in either a control, plyometric, or weight-training group. The experimental groups trained for 8 weeks, performing either heavy lifts or dynamic plyometric exercises...

Isometric assessment of muscular function is a popular form of testing which has been used in exercise science for over 40 years. It typically involves a maximal voluntary contraction performed at a specified joint angle against an unyielding resistance which is in series with a strain gauge, cable tensiometer, force platform or similar device whos...

The aim of this study was to investigate the validity and reliability of an in vivo test of lower body musculotendinous stiffness. Male subjects (n = 23) with at least 12 months of weight training experience performed a series of quasi-static muscular actions in a supine leg press position during which a brief perturbation was applied. The resultin...

The aim of this study was to determine if pre-training strength and power tests could provide data that effectively discriminated between subjects whose cycling performance improved considerably from training, from those who did not. Twenty active healthy male subjects performed 10 weeks of plyometric or weight training. Prior to and at the complet...

There is a paucity of research into the importance of performing strength training exercises in postures specific to the movements they are attempting to facilitate. In addressing this question, 27 previously trained subjects were randomly allocated into heavy weight training and control groups. The weight training group performed 4-6 sets of 6-10...

The purpose of this research was to perform isometric tests at two joint angles and examine their relationship to dynamic performance. In addition, electromyograph data were collected from the triceps brachii and pectoralis major muscles to compare underlying neural characteristics between the isometric tests and dynamic movement. A group of 24 hea...

The aim of this study was to investigate the kinematics, kinetics, and neural activation of the traditional bench press movement performed explosively and the explosive bench throw in which the barbell was projected from the hands. Seventeen male subjects completed three trials with a bar weight of 45% of the subject's previously determined 1RM. Pe...

The aim of this study was to investigate the kinematics, kinetics, and neural activation of the traditional bench press movement performed explosively and the explosive bench throw in which the barbell was projected from the hands. Seventeen male subjects completed three trials with a bar weight of 45% of the subject's previously determined lRM. Pe...

The purpose of this study was to quantify the rate of force development (RFD) and maximum force in isometric, concentric, and stretch-shorten cycle contraction modes and to determine their relationships to sprint running performance. Fifteen athletic subjects performed a series of isometric, concentric, and stretch-shorten cycle RFD tests in an upr...