Ryan Timmins

• Doctor of Philosophy
• Senior Lecturer at Australian Catholic University

Purpose: This study aimed (i) to determine the reliability of two-dimensional ultrasonography for the assessment of biceps femoris long head (BFlh) architectural characteristics and (ii) to determine whether limbs with a history of strain injury in the BFlh display different architecture and eccentric strength compared to uninjured limbs. Methods...

Background/aim: To investigate the role of eccentric knee flexor strength, between-limb imbalance and biceps femoris long head (BFlh) fascicle length on the risk of future hamstring strain injury (HSI). Methods: Elite soccer players (n=152) from eight different teams participated. Eccentric knee flexor strength during the Nordic hamstring exerci...

Background: The architectural characteristics of muscle (fascicle length, pennation angle muscle thickness) respond to varying forms of stimuli (eg, training, immobilisation and injury). Architectural changes following injury are thought to occur in response to the restricted range of motion experienced during rehabilitation and the associated neu...

Background Quadriceps dysfunction is ubiquitous after anterior cruciate ligament (ACL) reconstruction (ACLR). Addressing quadriceps dysfunction is crucial to improve function, reduce the reinjury risk, and maintain long-term knee health. While deficits specific to the quadriceps are well documented, less is known about the effect of an ACL injury o...

Cowley, N, Nicholson, V, Timmins, R, Munteanu, G, Wood, T, García-Ramos, A, Owen, C, and Weakley, J. The effects of percentage-based, rating of perceived exertion, repetitions in reserve, and velocity-based training on performance and fatigue responses. J Strength Cond Res - This study assessed the effects of percentage-based training (% 1RM), rati...

OBJECTIVE: To determine the Fragility Index of hamstring injury risk factors, defined as the minimum number of participants who would need to change classification to make a hamstring injury risk factor statistically nonsignificant. DESIGN: Retrospective secondary data analysis. METHODS: Studies that investigated one or more risk factors for hamstr...

Background Including the Nordic hamstring exercise (NHE) as part of a training program reduces hamstring strain injury (HSI) risk. The lack of NHE implementation may be due to fear of muscle soreness caused by this eccentric stimulus, which has led to interest in isometric interventions. Despite interest in isometric hamstring exercises, there has...

Background Hamstring strain injuries (HSIs) occur frequently in Australian Football. Objective To determine which factors were most predictive of HSIs during different stages of competition. Design Prospective cohort Setting Professional Australian Football Participants Male professional Australian Footballers (n=311) Assessment of Risk Factor...

The aponeurosis is a large fibrous connective tissue structure within and surrounding skeletal muscle and is a critical component of the muscle-tendon unit (MTU). Due to the lack of consensus on terminology and heterogeneous nature of the aponeurosis between MTU’s, there are several questions that remain unanswered. For example, the aponeurosis is...

Background The etiology of hamstring strain injury (HSI) in American football is multi-factorial and understanding these risk factors is paramount to developing predictive models and guiding prevention and rehabilitation strategies. Many player-games are lost due to the lack of a clear understanding of risk factors and the absence of effective meth...

Objectives. Document changes in fascicle length during rehabilitation from hamstring injury of the injured and uninjured legs and secondarily to describe any association between these changes and reinjury rate. Design. Multicentre case series. Methods. Fifty-two prospectively included hamstring injured athletes had their biceps femoris long head fa...

Purpose To investigate the differences in maximal (isometric and concentric peak torque) and explosive (rate of torque development (RTD)) hamstring and quadriceps strength symmetry between males and females during early- and late-phase rehabilitation after anterior cruciate ligament reconstruction (ACLR) using hamstring tendon (HT) autografts and t...

Purpose: To investigate hamstring architectural, strength and morphological adaptations following an eccentric or isometric hip extension exercise intervention. Methods: Twenty-four recreationally active males performed either an eccentric (n=12) or isometric hip extension (n=12) exercise intervention, twice per week for six weeks, followed by a...

Objectives: This study aimed to investigate the number of days following hamstring strain injury (HSI) taken to introduce high-intensity eccentric loading (HIEL) into rehabilitation based on exercise-specific progression criteria, and whether pain resolution during isometric knee flexion strength testing occurred before or after this milestone. D...

This study examined the inter-session reliability of force output from a novel isometric strength assessment protocol (the Kicker); and its suitability to monitor soccer player's combined hip flexion and knee extension force capacity over 72-h post-competitive matches. Reliability (Part-A) testing was completed over three sessions on 20 individuals...

Objective: To determine the impacts of anterior cruciate ligament reconstruction (ACLR) and recent (< 12 months) hamstring strain injury (HSI) on 1) future HSI risk ; and 2) eccentric knee flexor strength and between-limb imbalance during the Nordic hamstring exercise (NHE). A secondary goal was to examine whether eccentric knee flexor strength was...

Purpose: To determine if a pre-season field-based test battery was prospectively associated with non-contact ACL injury in elite female footballers. Methods: In total, 322 elite senior and junior female Australian Rules Football and soccer players had their isometric hip adductor and abductor strength, eccentric knee flexor strength, countermove...

Purpose: To examine the dose-response of the Nordic hamstring exercise (NHE) on biceps femoris long head (BFlh) architecture and eccentric knee flexor strength. Design: Randomized interventional trial. Methods: Forty recreationally active males completed a 6-week NHE training program consisting of either intermittent low volumes (group 1; n =...

Background Lower limb muscle strain injury is highly prevalent in running-based sports and is considered a risk factor for recurrent injury. It is possible that differences in muscle activity and activation in previously strain-injured limbs may contribute to the elevated risk of reinjury. Objectives To systematically review available literature i...

Anterior cruciate ligament (ACL) injury and reconstructive surgery is known to cause long term negative impacts on quadriceps muscle size. With the known link between reduced muscle size and the health and functioning of the knee joint, it is important rehabilitation programs aim to restore quadriceps mass as safely and quickly as possible. However...

Introduction: Whether short-term, single-mode exercise training can improve physical fitness prior to a period of reduced physical activity (e.g. post-surgery recovery) is not well characterized in clinical populations nor middle-age adults. We investigated skeletal muscle adaptive responses following endurance exercise training (ENT), high-intens...

Objective To compare lower limb strength and countermovement jump (CMJ) kinetics between elite female footballers with and without a history of anterior cruciate ligament reconstruction (ACLR), hamstring strain, or hip/groin injury. Design Cross-sectional. Setting Field-based. Participants 369 elite female Australian football, soccer and rugby l...

Background Hamstring strain injuries are the most common injuries in team sports. Biceps femoris long head architecture is associated with the risk of hamstring injury in soccer. To assess the overall predictive ability of architectural variables, risk factors need to be applied to and validated across different cohorts. Purpose To assess the gene...

Objective: To review the quality of reporting and identify the content of exercise interventions prescribed for hamstring strain injury (HSI) rehabilitation in the scientific literature since 2010. Design: Scoping review. Literature search: We searched the bibliometric databases Web of Science, CINAHL, SPORTDiscus, Scopus, Cochrane Library, ME...

Purpose: To determine if eccentric knee flexor strength and biceps femoris long head (BFlh) fascicle length were associated with prospective HSI in professional Australian Football players, and if more frequent assessments of these variables altered the association with injury risk. Methods: Across two competitive seasons, 311 Australian Footbal...

Background Interventions utilising the Nordic hamstring exercise (NHE) have resulted in reductions in the incidence of hamstring strain injury (HSI). Subsequently, quantifying eccentric knee flexor strength during performance of the NHE to identify an association with the occurrence of future HSI has become increasingly common; however, the data to...

A correction to this paper has been published: https://doi.org/10.1007/s40279-021-01485-y

Background Anterior cruciate ligament (ACL) injury is known to have a number of deleterious effects on lower limb muscle function. Alterations in muscle size are one such effect that have implications towards reductions in strength and functioning of the lower limbs. However, a comprehensive analysis of alterations in muscle size has yet to be unde...

This study examined the spatial patterns of hamstring and gluteal muscle activation during high-speed overground running in limbs with and without aprior hamstring strain injury. Ten active males with arecent (<18 month) unilateral biceps femoris long head (BFLH) strain injury underwent functional magnetic resonance imaging before and immediately a...

The aim of this study was to determine the architectural, eccentric strength and sprinting adaptations following a hip‐dominant flywheel (FLY) or Nordic hamstring exercise (NHE) intervention in Australian footballers. Twenty‐seven male athletes were randomised to FLY (n=13) or NHE (n=14) training across a 39‐week period (inclusive of pre‐season and...

Background Emerging research has suggested a plausible relationship may exist between lower limb coordination and musculoskeletal injury. A small number of studies have investigated the link between coordination and anterior cruciate injury during sidestep cutting. While prior work has shown unanticipated sidestep cutting to exhibit a more ‘at risk...

Objectives To investigate the architectural and strength adaptations of the hamstrings following 6-weeks of inertial flywheel resistance training. Design Randomised, stratified training intervention Methods Twenty healthy males undertook 6-weeks of a conventional (n = 10) or eccentrically-biased (n = 10) flywheel leg-curl training intervention as...

This chapter will provide the anatomical foundation for the content to come in later portions of this book. It will begin with an overview of the proximal insertion sites of the muscles that comprise the hamstring group. The proximal tendons and musculotendinous junctions (MTJs) of semimembranosus, semitendinosus and the long and short heads of bic...

Objective: The primary aim was to compare time from acute hamstring strain injury (HSI) to return-to-play (RTP) clearance following a standardized rehabilitation protocol performed within either pain-free or pain-threshold limits. Secondary aims were to compare isometric knee flexor strength, biceps femoris long head (BFLH) fascicle length, fear o...

Objectives: Investigate the determinants of hamstring fascicle length in professional rugby league players. Design: Retrospective cohort study METHODS: Thirty-three elite male athletes underwent testing in the pre-season and in-season periods. Fascicle length measurements of the biceps femoris long head, 3D kinematics and elapsed time-periods at...

Introduction: This study aimed to 1) identify the impact of external load variables on changes in wellness and 2) identify the impact of age, training/playing history, strength levels and pre-season loads on changes in wellness in elite Australian footballers. Methods: Data were collected from one team (45 athletes) during the 2017 season. Self-...

Purpose: Harvest of the semitendinosus (ST) tendon for anterior cruciate ligament reconstruction (ACLR) causes persistent hypotrophy of this muscle even after a return to sport, although it is unclear if hamstring activation patterns are altered during eccentric exercise. It was hypothesised that in comparison with contralateral control limbs, limb...

Study design: Prospective cohort. Background: Hip and groin injuries are a significant cause of time lost from training and competition in elite soccer. Objectives: To explore the association between pre-season assessments of 1) isometric hip adductor and abductor strength using a novel field-test; and 2) the Copenhagen Hip and Groin Outcome S...

Injuries are a common occurrence in team sports and can have significant financial, physical and psychological consequences for athletes and their sporting organizations. As such, an abundance of research has attempted to identify factors associated with the risk of injury, which is important when developing injury prevention and risk mitigation st...

Objectives: To investigate whether five-weeks of concentric (CON) or eccentric (ECC) hamstring strength training have different effects on recovery from sprint running, eccentric strength and architecture of the biceps femoris long head (BFLH). Design: Cohort study. Methods: Thirty males (age, 22.8±4.1y; height, 180.1±6.4cm; weight, 85.2±14.6k...

Study design: Randomized controlled trial. Background: Conventional guidelines recommend hamstring strain injury (HSI) rehabilitation should only be performed and progressed in complete absence of pain, despite lack of comparison to alternative approaches. Objectives: The primary aim of this study was to compare the number of days from acute H...

Prior injury is a commonly identified risk factor for subsequent injury. However, a binary approach to classifying prior injury (i.e., yes/no) is commonly implemented and may constrain scientific findings, as it is possible that variations in the amount of time lost due to an injury will impact subsequent injury risk to differing degrees. According...

Purpose Harvest of the semitendinosus (ST) tendon for anterior cruciate ligament reconstruction (ACLR) causes persistent hypotrophy of this muscle even after a return to sport, although it is unclear if hamstring activation patterns are altered during eccentric exercise. It was hypothesised that in comparison with contralateral control limbs, limbs...

Background Hip and groin injuries are a significant cause of time lost from training and competition in elite football. Purpose To explore the association between hip/groin injury in professional footballers and pre-season assessment of 1) hip adductor and abductor strength, and 2) the Copenhagen Hip and Groin Outcome Score (HAGOS). Study Design...

Objectives To investigate knee flexor strength and biceps femoris long head (BFlh) architectural adaptations following two different Nordic hamstring exercise (NHE) interventions and one razor hamstring curl (RHC) intervention. Methods Thirty recreationally‐active males performed a total of 128 reps of NHEbodyweight (n=10), NHEweighted (n=10) or R...

Purpose: To investigate strength and structural adaptations after 12 weeks of resistance, endurance cycling, and concurrent training. Methods: Thirty-two healthy males undertook 12 weeks of resistance-only (RT; n = 10), endurance-only (END; n = 10), or concurrent resistance and endurance training (CONC; n = 12). Biceps femoris long head (BFlh) a...

Background We implemented a high-protein diet (2 g·kg⁻¹·d⁻¹) throughout 12 weeks of concurrent exercise training to determine whether interferences to adaptation in muscle hypertrophy, strength and power could be attenuated compared to resistance training alone. Methods Thirty-two recreationally active males (age: 25 ± 5 years, body mass index: 24...

Zusammenfassung Hamstring-Verletzungen werfen viele Sportler aus der Bahn. Neuere Untersuchungen haben ergeben, dass dafür neben kaum zu beeinflussenden Faktoren eine ungenügende exzentrische Kraft der Knieflexoren sowie verkürzte Faszikel des Caput longum des M. biceps femoris das Risiko für das Auftreten solcher Verletzungen erhöhen. Mit einem ge...

Objectives This study aimed to determine if diffusion tensor MR imaging (DTI) methodology inbuilt within manufacturer software can reliably measure biceps femoris long head (BFlh) fascicle length (FL) and to investigate agreement between ultrasound (US) measures and inbuilt DTI measures of BFlh FL. Methods Both legs of 20 males were examined (40 l...

Introduction: Hamstring strain injuries are endemic across a range of running-based sports. Themost commonly injured of these muscles is the biceps femoris long head (BFlh), which accounts for approximately 84% of all occurrences. Recent evidence shows that elite soccer players with short BFlh fascicles (<10.56 cm) were 4.1 times more likely to suf...

Objective Attenuated muscle strength, hypertrophy and power adaptations with combined resistance and endurance (‘concurrent’) training may result from blunted cell signalling. Protein intake potentiates anabolic signalling pathways to facilitate adaptation. We hypothesized that 12 wk concurrent training with a high protein diet would elicit similar...

Purpose To determine the time course of architectural adaptations in the biceps femoris long head (BFLH) following high or low volume eccentric training. Methods Twenty recreationally active males completed a two week standardised period of eccentric Nordic hamstring exercise (NHE) training, followed by four weeks of high (n=10) or low volume (n=1...

Strength training is a valuable component of hamstring strain injury prevention programmes; however, in recent years a significant body of work has emerged to suggest that the acute responses and chronic adaptations to training with different exercises are heterogeneous. Unfortunately, these research findings do not appear to have uniformly influen...

Purpose: Three of the most commonly identified hamstring strain injury (HSI) risk factors are age, previous HSI and low levels of eccentric hamstring strength. However, no study has investigated the ability of these risk factors to predict the incidence of HSI in elite Australian footballers. Accordingly, the purpose of this prospective cohort stu...

Study Design Reliability and case-control injury study. Background Knee flexor strength is a key variable when dealing with hamstring strain injury (HSI), and methodologies of objective measurement of strength are often limited to single exercises. Objectives To establish test-retest reliability of a novel apparatus to measure knee flexor strengt...

Kettlebell exercises have become an increasingly popular form of resistance training and component of lower body rehabilitative training programs; despite a lack of scientific literature illustrating internal mechanisms and effectiveness of these approaches. Participants (n=14) performed three different styles of kettlebell swings (hip hinge, squat...

Background: Rehabilitation progression and return-to-play (RTP) decision making following hamstring strain injury (HSI) can be challenging for clinicians, owing to the competing demands of reducing both convalescence and the risk of re-injury. Despite an increased focus on the RTP process following HSI, little attention has been paid to rehabilita...

Purpose: To assess in-season alterations of biceps femoris long head (BFlh) fascicle length in elite Australian footballers with and without a history of HSI. Methods: Thirty elite Australian football players were recruited. Twelve had a history of unilateral HSI. Eighteen had no HSI history. All had their BFlh architecture assessed at approxima...

Muscle injuries are not all the same. All clinicians have experienced treating injuries that just won’t heal quickly, even though they seem like they should. We feel increasingly anxious as pressure from the patient and team management mounts. One factor that may delay healing of a ‘muscle strain’ is involvement of intramuscular tendon in the injur...

Background Hamstring strain injuries (HSIs) are the most common cause of time loss from training and competition in elite football. Anterior cruciate ligament (ACL) ruptures are also prevalent and typically require surgery from hamstring grafts, which often results in chronic deficits in eccentric knee flexor strength, a known risk factor for HSI....

Background There has been significant interest in exploring the patterns of muscle activity in hamstring exercises, however, there is no research examining the architectural and morphological adaptations of these muscles to different exercise interventions. Objective To evaluate changes in biceps femoris long head (BFLH) fascicle length and hamstr...

Background Hamstring strain injuries (HSI) are the predominant injury in the elite Australian Football League (AFL). Athletes who possess short biceps femoris long head (BFlh) fascicle lengths have an increased risk of future HSI than those who have longer fascicles. Fascicle length can be altered following interventions, however it is unknown what...

First I looked to see if two-dimensional ultrasound could show us anything new in the battle against hamstring strain injuries (HSI), mainly in those with a history of injury, but also seeing if biceps femoris long head (BFlh) architecture alters future injury risk. I then implemented a resistance training programme to see if we can change these ch...

Background To investigate the association between running exposure and the risk of hamstring strain injury (HSI) in elite Australian footballers. Methods Elite Australian footballers (n=220) from 5 different teams participated. Global positioning system (GPS) data were provided for every athlete for each training session and match for the entire 2...

Background: The architectural and morphological adaptations of the hamstrings in response to training with different exercises have not been explored. Purpose: To evaluate changes in biceps femoris long head (BFLH) fascicle length and hamstring muscle size following 10-weeks of Nordic hamstring exercise (NHE) or hip extension (HE) training. Met...

Objective To systematically review the evidence base related to hamstring strength and flexibility in previously injured hamstrings. Design Systematic review and meta-analysis. Data sources A systematic literature search was conducted of PubMed, CINAHL, SPORTDiscus, Cochrane Library, Web of Science and EMBASE from inception to August 2015. Inclusio...

Background The architectural and morphological adaptations of the hamstrings in response to training with different exercises have not been explored. Purpose To evaluate changes in biceps femoris long head (BFLH) fascicle length and hamstring muscle size following 10-weeks of Nordic hamstring exercise (NHE) or hip extension (HE) training. Methods 3...