Alasdair R Dempsey

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• Doctor of Philosophy
• Professor (Associate) at Murdoch University

Context: As blood flow restriction gains popularity across different populations (eg, young and older adults) and settings (eg, clinical and sports rehabilitation), the accuracy of blood flow restricted percentage becomes crucial. We aimed to compare manually measured arterial occlusion pressure (AOP) among young adults to understand whether lower...

INTRODUCTION & AIMS Team-sport players’ repeated-sprint ability improves following repeated-sprint training with systemic hypoxia (reduced fraction of inspired oxygen) through enhanced metabolic demands compared to sea-level training. Localised hypoxia (i.e., blood flow restriction; BFR) presents a limb-specific alternative strategy, though central...

INTRODUCTION & AIMS The Landing Error Scoring System (LESS) is used for screening noncontact anterior cruciate ligament (ACL) injury risk. The LESS is deemed a valid and reliable indicator of landing biomechanics that predict noncontact ACL injuries. We have sought to validate a Single-Leg Landing Error Scoring System (SLESS) against the establishe...

This study examined the impact of continuous blood flow restriction (BFR) during repeated‐sprint exercise (RSE) on acute performance, peripheral, systemic physiological, and perceptual responses. In a randomized crossover design, 26 adult male semi‐professional and amateur team‐sport players completed two RSE sessions (3 sets of 5 × 5‐s sprints wit...

This study investigated the impact of blood flow restriction (BFR) during treadmill walking on gait kinematics. Twenty-one participants completed one familiarisation and four experimental sessions, including two walking speeds (moderate [5.0 ± 0.3km·h-1] and fast [6.4 ± 0.4km·h-1]) and two occlusion conditions (BFR [60% of arterial occlusion pressu...

Background Sports-related concussion (SRC) assessment tools are primarily based on subjective assessments of somatic, cognitive, and psychosocial/emotional symptoms. SRC symptoms remain underreported, and objective measures of SRC impairments would be valuable to assist diagnosis. Measurable impairments to vestibular and oculomotor processing have...

PurposeTo investigate whether performing resistance exercise in hypoxia augments physiological and perceptual responses, and if altering work-rate by performing repetitions to failure compared to sub-maximally increases the magnitude of these responses.Methods Twenty male university students (minimum of 2 year resistance training experience) comple...

Objectives Undesirable bowling kinematics can increase the risk of low back injury. This study investigated if an exercise-based injury prevention program (IPP) could modify bowling kinematics in community-level adolescent pace bowlers. Design: Cluster-randomised controlled trial. Methods Pace bowlers from eight cricket organisations were cluster-...

Objectives: To investigate if an exercise-based injury prevention program (IPP) can modify risk factors for injury in community-level adolescent cricket pace bowlers. Design: Cluster-randomised controlled trial. Methods: Eight cricket organisations (training two times per week and no previous involvement in a structured IPP) participated in th...

The purpose of this study was to investigate the reliability and validity of predicting 1-repetition maximum (1RM) in trained individuals using a load-velocity relationship. Twenty strength-trained men (age: 24.3±2.9 years, height: 180.1±5.9 cm, body mass: 84.2±10.5 kg) were recruited and visited the laboratory on three occasions. The load-velocity...

Objectives: Sport-related concussion (SRC) can result in impaired oculomotor function. Oculomotor performance, measured utilizing the King-Devick/Eye Tracking test (K-D/ET), is reported to be able to identify sub-optimal brain function. The objectives of the study were to determine the diagnostic accuracy of the K-D/ET in identifying SRC occurring...

Objective The main purpose of this study was to investigate the effect of a decrease in the A-frame angle of incline on the vertical and cranio-caudal ground reaction forces observed in a homogeneous cohort of agility dogs during entrance and contact with the A-frame. Materials and Methods A crossover study design was applied to eight large breed d...

This experiment investigated the contribution of visual and additive motor experience to improvement of visual anticipation. Club cricket batters were randomized into (a) a visual-perceptual group that received temporal occlusion training ( n = 13), (b) a visuomotor group that received temporal occlusion training coupled with motor pattern practice...

Purpose: Investigate the construct validity of prognostic factors purported to predict clinical success with stabilization exercise for low back pain by exploring their associations with lumbar multifidus composition. Methods: Patients with low back pain were recruited from a hospital imaging department. The presence of fivepredictors (age <40 year...

The purpose of this study was to investigate using load-velocity relationships to quantify fluctuations in maximal strength (1-repetition maximum; 1RM) which occur as a result of training-induced fatigue. The nineteen well-trained males (age: 24.3±2.9 years, height: 180.1±5.9 cm, body mass: 84.2±10.5 kg, squat 1RM: 151.1 ± 25.7 kg) who were recruit...

Adolescent cricket pace bowlers are prone to non-contact shoulder, low back and lower-limb injuries. Exercise-based injury prevention programmes (IPPs) are effective for reducing non-contact injuries in athletes; however, a specific programme for adolescent pace bowlers has not been published. This paper therefore seeks to provide a rationale for t...

Introduction: Sport-related concussion (SRC) can result in impaired oculomotor function. Oculomotor performance, measured utilizing the King-Devick/Eye Tracking test (K-D/ET), is reported to be able to identify sub-optimal brain function. The objectives of the study were; (1) to determine the diagnostic accuracy of the K-D/ET in identifying SRC occ...

The aims of this study were to investigate the frequency, magnitude , and distribution of head impacts sustained by youth AF players over a season of games and report subjective descriptions on the mechanism-of-injury and sign and symptoms experienced. A prospective observational cohort study with participants (n = 19) (age range 13-14 yr., mean ±...

This study measured and compared the frequency, magnitude, and distribution of head impacts sustained by junior and adult Australian football players, respectively, and between player positions over a season of games. Twelve junior and twelve adult players were tracked using a skin-mounted impact sensor. Head impact exposure, including frequency, m...

Objectives: Sport-related concussion (SRC) research has focused on impaired oculomotor function. The King-Devick (K-D) test measures oculomotor performance and is reported to identify suboptimal brain function. The use of the K-D test in Australian football (AF), a sport involving body contact and tackling, has not been documented. Therefore, the...

The King-Devick (KD) test is an easily administered test of oculomotor function and has been shown to be impaired following traumatic head injury. The KD test appears to be a reliable and valid tool in the assessment of Sports-Related Concussion.

Objective: This article aims to investigate the effect of a decrease in the A-frame angle of incline on the highest carpal extension angle in agility dogs. Methods: Kinematic gait analysis (two-dimensional) measuring carpal extension was performed on 40 dogs entering the A-frame at 3 angles of incline: 40° (standard), 35° and 30°. The highest ca...

Background: Adolescent cricket pace bowlers are prone to injury. Recognising the risk factors for non-contact injury in this population will aid future injury prevention strategies. Objective: To identify the risk factors for non-contact injury in adolescent cricket pace bowlers. Methods: We systematically searched PubMed, Cochrane Library, PE...

Background: Altered knee joint biomechanics is thought to play a role in the pathogenesis of knee osteoarthritis and has been reported in patients after arthroscopic partial meniscectomy (APM) while performing various activities. Longitudinally, understanding knee joint biomechanics during jogging may assist future studies to assess the implicatio...

PURPOSE: To investigate the effects of ingesting branched-chain amino acids (BCAA) prior to and during prolonged self-paced cycling on performance and neuromuscular fatigue. METHOD: Eighteen recreationally active and healthy men (mean±SD age: 24.7±4.8 years old; mass 67.1±6.1 kg; height: 171.7±4.9 cm) completed three sessions. During the first se...

Efficient training of neuromuscular power and the translation of this power to sport-specific tasks is a key objective in the preparation of athletes involved in team-based sports. The purpose of the current study was to compare changes in center of mass (COM) neuromuscular power and performance of sport-specific tasks following short-term (6-week)...

Introduction: Adolescent fast bowlers are prone to sustaining lumbar injuries. Numerous components have been identified as contributing factors; however, there is limited empirical evidence outlining how the muscles of the lumbopelvic region, which play a vital role in stabilising the spine, function during the bowling action and the influence of...

The purpose of this study was to assess maximal isokinetic leg extension force in response to glucose ingestion and to determine whether any performance changes occur in a time-dependent manner. Seventeen young (22.1+/-3.9 years), lean (%BF: 14.3+/-8.0; %BF Males: 9.7+/-4.2; %BF Females: 23.7+/-4.2) and recreationally active (>150min/week of physic...

Purpose To examine differences in cartilage morphology between young adults 2–3 years post-anterior cruciate ligament reconstruction (ACLR), with or without meniscal pathology, and control participants. Methods Knee MRI was performed on 130 participants aged 18–40 years (62 with isolated ACLR, 38 with combined ACLR and meniscal pathology, and 30 he...

Expertise studies into visual perceptual-motor skills have mainly focused their investigation upon group comparisons rather than individual comparisons. This study investigated the pick-up of visual information to time weight transfer and bat kinematics within an exemplar group of striking sport experts using an in situ temporal occlusion paradigm....

Background. The mirror neuron network provides a neural mechanism to prime the motor system through action observation in stroke survivors. Objective. To examine whether action observation training with immediate physical practice improves upper-limb function in chronic stroke. Methods. In a within-subject design, 14 chronic stroke survivors were a...

Purpose: Higher knee load and quadriceps weakness are potential factors involved in the pathogenesis of knee osteoarthritis after arthroscopic partial meniscectomy (APM). In people following APM, this study evaluated the association between external knee joint moments and quadriceps strength and 2-yr change in indices of cartilage integrity in the...

This pilot study integrated sport expertise and biomechanics methodologies within a baseball batting task. Purpose was to examine differences within a highly skilled group of baseball batters to use visual information to guide weight transfer and bat movements. One batter who played at Major League Baseball (MLB) level was compared to five batters...

Background Knee osteoarthritis is common following arthroscopic partial meniscectomy and a higher external peak knee adduction moment is believed to be a contributor. The peak knee adduction moment has been shown to increase over 2 years (from 3-months post-arthroscopic partial meniscectomy surgery). The aim of this study was to evaluate mechanisms...

Background: Knee muscle weakness and a greater external knee adduction moment are suggested risk factors for medial tibiofemoral knee osteoarthritis. Knee muscle weakness and a greater knee adduction moment may be related to each other, are potentially modifiable, and have been observed after arthroscopic partial meniscectomy. Questions/purposes:...

To explore the bivariate and multivariate relationships between fatty degeneration of the lumbar multifidus muscle (LMM) and LMM function among patients with low back pain (LBP). Cross-sectional clinical study. Hospital diagnostic imaging department PARTICIPANTS: 70 patients with LBP referred for lumbar spine magnetic resonance imaging. Not applica...

Objectives Determine if balance and technique training (BTT) implemented adjunct to 1,001 male Australian football (AF) players’ training influenced the activation/strength of the muscles crossing the knee during pre-planned (PpSS) and unplanned (UnSS) sidestepping. Design Randomized Control Trial. Methods Each AF player participated in either 28...

Anterior cruciate ligament (ACL) injuries are costly. Sidestep technique training reduces knee moments that load the ACL. This study examined whether landing technique training alters knee moments. Nineteen team sport athletes completed the study. Motion analysis and ground reaction forces were recorded before and after 6-weeks of technique modific...

Players are the targeted end-users and beneficiaries of exercise-training programmes implemented during coach-led training sessions, and the success of programmes depends upon their active participation. Two variants of an exercise-training programme were incorporated into the regular training schedules of 40 community Australian Football teams, ov...

Purpose: Individuals after arthroscopic partial meniscectomy (APM) are at increased risk of developing knee osteoarthritis (OA). Knee muscle weakness and a higher external knee adduction moment (KAM) are potential risk factors for knee OA. This exploratory longitudinal study assessed these risk factors at baseline in an APM group (3 months after s...

Objectives: To compare physical activity levels, subject-reported function, and knee strength in 21 arthroscopic partial meniscectomy (APM) patients (age 45.7 (6.06) years, BMI 27.3 (5.96) female 60%) 3 months post-surgery with 21 healthy controls (age 43.6 (5.71) years, BMI 24.5(4.2) female 60%) matched at the cohort level for age, gender and BMI...

Purpose To examine the relationship between tibiofemoral and patellofemoral joint articular cartilage and subchondral bone in the medial and gait biomechanics following partial medial meniscectomy. Methods For this cross-sectional study, 122 patients aged 30–55 years, without evidence of knee osteoarthritis at arthroscopic partial medial meniscecto...

Anterior cruciate ligament (ACL) injury rates have increased by ∼50% over the last 10 years. These figures suggest that ACL focused research has not been effective in reducing injury rates among community level athletes. Training protocols designed to reduce ACL injury rates have been both effective (n = 3) and ineffective (n = 7). Although a ratio...

Determine if balance and technique training (BTT) implemented adjunct to normal Australian football (AF) training reduces external knee loading during sidestepping. Additionally, the authors determined if an athlete's knee joint kinematics and kinetics change over a season of AF. Eight amateur-level AF clubs (n=1,001 males) volunteered to participa...

Background: Athletes suffering an anterior cruciate ligament injury tend to exhibit similar body postures that in sidestep cutting are associated with increased knee moments. This relationship, however, has not been investigated in landing. Catching a ball in different overhead positions may affect landing postures and knee joint moments. This stu...

To examine articular cartilage and subchondral bone changes in tibiofemoral and patellofemoral joints following partial medial meniscectomy. For this cross-sectional study, 158 patients aged 30-55 years, without evidence of knee osteoarthritis at arthroscopic partial medial meniscectomy (APMM), and 38 controls were recruited. MRI was performed once...

The objective of this work is to evaluate differences in trabecular bone (TB) texture between subjects with and without tibiofemoral cartilage defects using a variance orientation transform (VOT) method. A case-control study was performed in subjects without radiographic knee osteoarthritis (OA) (K&L grade <2) matched on sex, BMI, age, knee compart...

Prophylactic taping is commonly used to prevent ankle injuries during sports. However, unnatural constraint of the ankle joint may increase the risk of injury to proximal joints such as the knee. The association between ankle taping and knee joint loading during open sporting tasks has not been quantified. This research aimed to measure changes in...

Common lower limb postures have been found when noncontact anterior cruciate ligament (ACL) injuries occur during sidestep cutting tasks. These same postures have been linked to knee loadings known to stress the ACL. Whole body technique modification would reduce knee loading. Controlled laboratory study. Experienced team sport athletes were recrui...

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To identify the effect of modifying sidestep cutting technique on knee loads and predict what impact such change would have on the risk of noncontact anterior cruciate ligament injury. A force platform and motion-analysis system were used to record ground-reaction forces and track the trajectories of markers on 15 healthy males performing sidestep...

No Yes

No Yes