Andrew Harrison

• PhD
• Professor Emeritus at University of Limerick

This chapter gives a snapshot of sub-fields of FDA that are well-suited to analysing modern biomechanical data. Functional mixed-effects models allow the complex grouping and dependence structures (e.g., induced by multiple subjects being measured for repeated trials/sessions) that arise in large biomechanical datasets to be modelled appropriately....

The aim of this chapter is to bring together the concepts and applications reviewed and described in Chaps. 2–4 by means of a practical case study on the large-scale, publicly-available GaitRec biomechanics dataset. The focus of this chapter is on practical implementation, so equations and mathematical notation are kept to a minimum, and the R pack...

This chapter gives an overview of functional regression techniques used to model biomechanical data. Regression with a functional response and scalar covariates, i.e., function-on-scalar regression, is the most commonly used technique in the biomechanical literature. We provide a detailed description of function-on-scalar regression, along with a p...

Exploring variation is often the goal when researchers apply the tools of functional data analysis to biomechanical data. This chapter describes functional summary statistics, such as the mean and covariance functions, as a first step for this purpose. Then, visualisation tools for functional data analysis, which are useful for understanding variab...

This chapter describes how to transform observed biomechanical data into smooth functions using B-spline or Fourier basis function expansions, using least-squares or penalised least-squares estimation approaches. It also discusses the characteristics of certain types of biomechanical data that might make other (e.g., wavelet or FPCA) basis function...

This editorial article advocates the study of esports through the lens of biomechanics.

Brady, CJ, Harrison, AJ, Flanagan, EP, Haff, GG, and Comyns, TM. The relationship between the isometric squat and stretch shortening cycle function and sprint acceleration performance in hurling players. J Strength Cond Res XX(X): 000–000, 2024—The primary aim was to examine the relationship between sprint acceleration performance and the performan...

The purpose of this study was to analyse the differences in joint kinematic patterns among runners with different spatiotemporal characteristics in the running cycle. Lower extremity kinematic data and spatiotemporal stride parameters were collected for ninety-two recreational runners during a treadmill run at a self-selected comfortable speed. A K...

Introduction: Comparison of the neuromuscular performance of different athlete types may give insight into the in vivo variability of these measures and their underpinning mechanisms. The study aims to compare the neuromuscular function of the plantar flexors of sprinters and physically active individuals to assess any differences in explosive forc...

Maximal sprinting in humans requires the contribution of various muscle–tendon units (MTUs) and joints to maximize performance. The plantar flexor MTU and ankle joint are of particular importance due to their role in applying force to the ground. This narrative review examines the contribution of the ankle joint and plantar flexor MTUs across the p...

Introduction Comparison of the neuromuscular performance of different athlete types may give insight into the in vivo variability of these measures and their underpinning mechanisms. The study aims to compare the neuromuscular function of the plantar flexors of sprinters and physically active individuals to assess any differences in explosive force...

PURPOSE: As a result of COVID-19 and the associated lockdowns in Ireland limited rugby training and matches occurred during the 2020/21 nine-month season (September to May). In October 2020 collective training and rugby matches were suspended for the season. This study aimed to assess the potential impact of this lack of training and playing on mat...

PURPOSE: Injury surveillance data in school rugby has focused on match injuries with limited data reported on the characteristics of injury during training. To fully appreciate the injury profile of this cohort, research on injuries within training is needed. To effectively develop and implement optimal injury reduction protocols, the true profile...

Establishing the limits of sprint start response time (SSRT) requires the mapping of the muscular sequence of activation and mechanical response delays and was the aim of the current study. Sprint start performance of 15 sprinters was examined with kinematic, EMG, and block force data collected. A general muscle activation sequence was identified,...

The reliability of mechanical measures can be impacted by the protocol used, including factors such as joint angle and the sex of participants. This study aimed to determine the inter-day reliability of plantar flexor mechanical measures across ankle joint angles and contraction types and consider potential sex-specific effects. 14 physically-activ...

PURPOSE: In many team sports the use of synthetic artificial pitch playing surfaces is common, especially when the playing season spans winter. In amateur community Rugby Union in Ireland there is a mix of both artificial and natural grass surfaces used for training and matches and a need to examine whether there may be injury trends unique to eith...

The response time (RT) in the sprint start in athletics is determined automatically from sensors on the blocks but the final decision on whether an athlete is disqualified is determined by visual inspection of the sensor data. This study explored the level of uncertainty of the visual detection of athletes' RT in the sprint start. Fifteen sprinters...

Objective: The aim of this systematic review was to identify prospectively measured ankle sprain risk factors in field-based team contact sports. Methods: Eight databases including SPORTDiscus, CINAHL Complete, MEDLINE (EBSCO), Education Source, Web of Science, Scopus, Embase and Pubmed were searched using specific Boolean terms. A modified-CASP...

Background Rugby participation rates are rising, particularly in the female game where a 60% increase in player numbers was observed from 2013 to 2017. Despite the recent growth, the female amateur game is lacking comprehensive long-term injury surveillance. Objective To compare injuries in male and female amateur Rugby Union. Design Prospective...

Tendon stiffness (KT) is a widely examined musculoskeletal measure due to its reported links with muscle-tendon unit performance and as a potential injury risk factor. This study examined the influence of ankle joint angle (θANK) on KT and the inter-day reliability of KT across θANK. KT was measured during maximal voluntary plantarflexion contracti...

This study examined differences in explosive muscular torque production of the plantar flexors of participants with differing training backgrounds. Explosive performance of a group of elite sprinters (n = 14) and physically active individuals (n = 14) were examined during explosive and maximal isometric contractions across different muscle-tendon u...

Background The shoulder has been reported as a frequent location of injury in adult professional and amateur rugby, with match injury incidence rates ranging from 1.8 to 3 per 1000 player-hours (h). An increased understanding of the incidence and mechanism of shoulder injuries in school rugby players is vital to establish effective injury preventiv...

Accurate identification of surface electromyography (EMG) muscle onset is vital when examining short temporal parameters such as electromechanical delay. The visual method is considered the 'gold-standard' in onset detection. Automatic detection methods are commonly employed to increase objectivity and reduce analysis time, but it is unclear if the...

Background: Rugby union is a physically demanding sport that carries an inherent risk of injury. Despite being a popular and widely played team sport, little is known about injuries occurring across the male and female amateur game. Purpose: To establish and compare injury incidence, nature, and severity in male and female Irish amateur rugby un...

The purpose of this study was to assess and compare the effects of plyometric training and combined training programs on vertical jump kinematics and kinetics of female basketball players. Thirty-six female basketball players were included in the study and further divided into three groups: plyometric training, n = 11; combined training n =13; and...

The sprint start in athletics is strictly controlled to ensure the fairness of competition. World athletics (WA)-certified start information systems (SIS) record athletes’ response times in competition to ensure that no athletes gain an unfair advantage by responding in < 100 ms after the start signal. This critical review examines the legitimacy o...

ForewordComprehensive injury surveillance systems in amateur Rugby Union are needed to enhance player welfare and this innovative project to date has involved the research, design and implementation of an online injury recording platform. Collection has now been completed of a third season’s data and this 2019/20 season report documents our collabo...

ForewordComprehensive injury surveillance systems in underage Rugby Union are needed to enhance player welfare and this innovative project to date has involved the research, design and implementation of an online injury recording platform. Collection has now been completed of the season’s data and this second schools’ 2019/20 season report document...

Principal components analysis (PCA) of waveforms and functional PCA (fPCA) are statistical approaches used to explore patterns of variability in biomechanical curve data, with fPCA being an accepted statistical method grounded within the functional data analysis (FDA) statistical framework. This technical note demonstrates that PCA of waveforms is...

Background: Irish school children have demonstrated poor proficiency in fundamental movement skills (FMS) and consistent with international literature, females and overweight children tend to be less skilled than males and non-overweight children. Interventions that are suitable for children of all abilities and which provide long-term improvements...

There is an opportunity for sports medicine to progress research ideation using synthetic datasets, maintaining research momentum when data collection is not feasible. These processes maximise the potential for application of open science practice, while retaining the commitment to privacy and ethics. Synthetic data could lead to more sustainable u...

This study aimed at comparing a prototype of a new Start Information System (SIS) with a World Athletics (WA) certified SIS which was used in competition. Twenty sprinters performed sprints under simulated race conditions. Response time (RT) was recorded by the WA certified SIS and the new SIS prototype based on a custom force plate and a new event...

Electromechanical delay (EMD) is an important determinant of explosive neuromuscular performance. Factors such as muscle contraction type and initial muscle-tendon unit (MTU) length influence this delay period. The aim of this study is to compare differences in EMD from plantar flexors across different contraction modes and MTU lengths. EMD of phys...

The hurdle jump is a commonly prescribed plyometric exercise for sprint athletes. The purpose of this study was to assess the lower body kinematic differences between maximal velocity sprinting and hurdle jumps performed over a range hurdle heights. Six competitive male sprinters performed maximum effort sprints over 50 m and hurdle jumps over 0.60...

Editorial - free online access at https://doi.org/10.1080/14763141.2020.1782555

This study compares sprint start response times (RT) derived from load cells in the blocks with a RT from rail mounted accelerometer using methods similar to World Athletics (WA) approved start information systems (SIS). Seven national and international sprinters completed sprint trials that replicated race competition start procedures. Load cells...

Despite the importance of balance in Acrobatic Gymnastic Pyramid performance, there is limited biomechanical analysis of balance during this activity. The aims of this study were to analyse the effect of pyramid difficulty on the centre of pressure (COP) excursion and its inter-trial variability, and determine which parameters had strongest relatio...

Swimming performance requires a whole body coordinated movement to elicit high propulsive forces with the majority of forces produced from the upper body musculature. The current academic literature highlights a range of dry-land resistance exercises that show moderate to strong correlations to swimming performance; however, association does not im...

Objectives To ascertain the extent of injury surveillance and prevention practices currently in operation and the availability of medical personnel across Rugby playing schools in the Republic of Ireland. Design Cross-sectional survey design. Setting Rugby playing schools across Ireland. Participants The Rugby games master, head Rugby coach or t...

Research examining the reliability of stiffness measures during hopping has shown strong consistency in leg-spring stiffness (kleg), but high variability in joint stiffness (kjoint) measures. Sled-based systems (SBS) reduce movement degrees-of-freedom and are used to examine stretch-shortening cycle (SSC) function under controlled conditions. The a...

Motor simulation (MS) interventions incorporating motor imagery (MI), and more recently action observation (AO), are readily accepted as effective interventions to enhance motor skill performance. Existing models in the MS literature fail to consider the entire spectrum of MS interventions, focusing on MI or AO alone. This paper examines the theore...

Context: Dynamic movement-based screens, such as the Landing Error Scoring System (LESS), are becoming more widely used in research and practical settings. Currently, 3 studies have examined the reliability of the LESS. These studies have reported good interrater and intrarater reliability. However, all 3 studies involved raters, who were founders...

In the sprint start, a defined sequence of distinct response delays occurs before the athlete produces a movement response. Excitation of lower limb muscles occurs prior to force production against the blocks, culminating in a movement response. The time delay between muscle excitation and movement, electromechanical delay (EMD), is considered to i...

Purpose This study aimed to determine the accuracy of a 4 split time modelling method to generate velocity-time and velocity-distance variables in elite male 100-m sprinters and subsequently to assess the roles of key sprint parameters with respect to 100-m sprint performance. Additionally, this study aimed to assess the differences between faster...

The Irish Rugby Injury Surveillance (IRIS) project involves research stemming from ongoing sports performance, injury prevention and psychological preparation work by University of Limerick academics across a range of sports, as well as our specific expertise in Rugby Union. It has effectively brought together academics with expert practitioner exp...

The Irish Rugby Injury Surveillance (IRIS) project involves research stemming from ongoing sports performance, injury prevention and psychological preparation work by University of Limerick academics across a range of sports, as well as our specific expertise in Rugby Union. It has effectively brought together academics with expert practitioner exp...

Objectives: To investigate factors associated with injury in amateur male and female rugby union players. Design: A prospective cohort study. Setting: Amateur rugby clubs in Ireland. Participants: Male (n = 113) and female (n = 24) amateur rugby union players from 5 of the top 58 amateur clubs in Ireland. Main outcome measures: Pre-season...

Everard, E, Lyons, M, and Harrison, AJ. An examination of the relationship between the functional movement screen, landing error scoring system and 3D kinematic data during a drop jump task. J Strength Cond Res XX(X): 000-000, 2019-Tests such as the Functional Movement Screen (FMS) and Landing Error Scoring System (LESS) have become an established...

The studies aim was to assess the specificity of dry-land resistance training exercises (RT) to front crawl swimming (FC) using electromyography (EMG) waveform analysis. Fourteen male international and national level swimmers were recruited. EMG data were collected during FC and bench press (BP) and pull up (PU) exercises. 3 x 35 m FC bouts and 3 x...

PURPOSE Specificity is an integral component in understanding the mechanism of transfer of dry-land resistance training exercises (RT) to front crawl swimming (FC). The specificity of intra and inter muscular coordination is deemed to be important, with neuromuscular adaptations at the forefront namely motor unit recruitment, synchronisation and co...

There is an inherent risk of injury in Rugby, due to the physical demands and exposure to collisions. While injuries in the professional Rugby game are widely reported, little is known about the amateur game. Investigating relationships between physical and wellness screening measures may identify injury causal factors and aid the development of ta...

PURPOSE: Despite recent growth in game popularity worldwide, Women’s Rugby Union is currently lacking rigorous, comprehensive injury surveillance programs (World Rugby). This long-term study aimed to monitor injury trends, that may emerge, which will aid future implementation of evidence-based injury prevention strategies to minimize injury risk an...

Background: Rugby union is a physically demanding, full-contact team sport that has grown in popularity. In order to reduce injury risk a full understanding of the incidence and nature of injuries is required. Injury surveillance systems are lacking in the amateur rugby game worldwide. The use of consistent injury definitions and methods of data c...

Rugby Union is one of the most played and watched team sports worldwide. Despite high injury incidence rates widely reported in the literature, no long-term injury surveillance system monitoring of the incidence of injury in both male and female amateur Rugby currently exists. Unlike the professional code, amateur cohorts often have limited resourc...

The purpose of this study was to examine the effect of speed on coordination and its variability in running gait using vector coding analysis. Lower extremity kinematic data were collected for thirteen recreational runners while running at three different speeds in random order: preferred speed, 15% faster and 15% lower than preferred speed. A dyna...

Background: Rugby Union is one of the world’s most popular team sports and school Rugby in particular, has increased in popularity and professionalism in recent times. Due to the physical nature of the sport, evaluating injury risk in school players is paramount to player welfare and safety. Although comprehensive injury surveillance practices have...

Purpose This investigation examined the relationships between the isometric mid-thigh pull (IMTP), isometric squat (ISqT) and sprint acceleration performance in track & field sprinters, and to determine whether there are differences between males and females. Methods Fifteen male and ten female sprinters performed 3 maximal effort IMTPs, ISqTs and...

Furlong, L-AM, Harrison, AJ, and Jensen, RL. Measures of strength and jump performance can predict 30-m sprint time in Rugby Union players. J Strength Cond Res 35(9): 2579-2583, 2021-Performance and fitness monitoring in Rugby Union often include jumping, sprinting, and strength tests, but repeatability of and relationships between these measures a...

This study examined the kinetic and temporal differences between countermovement jumps (CMJs) and eccentrically loaded CMJs. A survey of 109 coaches and athlete showed that 87% of respondents regularly used jumps with added mass within training. Sixteen male and thirteen female track and field athletes from sprinting, hurdling and jumping events pe...

This study describes the results of a survey of resistance training practices of sprint coaches. This study investigated why sprint coaches prescribe resistance training to their athletes, what exercises they select, and what factors are involved with their selection. Forty-one of 73 (56%) sprint coaches with mean ± SD coaching experience of 8.4 ±...

Rugby-related injuries are widely reported in professional teams, however little is currently known about the amateur game, and even less so in women’s Rugby. Despite its growing popularity in Ireland, no long-term prospective injury surveillance system currently exists in Irish amateur Rugby. Aim To establish the incidence, nature and severity of...

This study examined fundamental movement skill (FMS) proficiency among male (N = 216) and female (N = 198) Irish primary school pupils from Year 2 to Year 7 (9.0 ± 1.7 years). Following anthropometric measurements, participants were video-recorded performing 15 FMS and scored using the TGMD-3, Victorian Fundamental Movement skills Manual and the Ge...

Objectives: To describe the development, implementation and evaluation of a comprehensive injury surveillance system. Design: The four phases; i) A survey of 58 medical professionals working in amateur rugby. ii) The design of a web-based injury surveillance system (IRISweb). iii) Recruitment of 21 of the top 58 amateur clubs to use IRISweb....

Simulation studies show that jump performance can be improved by increasing the depth of countermovement. The purpose of this study was to determine how modifications to the depth of countermovement lead to changes in jump height and the biomechanical parameters related to center of mass displacement and force application. Twenty-nine competitive m...

Results of a pilot investigation highlighting the differences in FMS proficiency between males and females and between overweight and non-overweight Irish schoolchildren

This study examined the delay in sprint start performance related to electromechanical delay (EMD) in the triceps surae muscle and aimed to determine whether sprinters may gain an advantage in sprint start response time (SSRT). SSRT's of nineteen sprinters were measured using an International Association of Athletics Federations approved SSRT detec...

This study aimed to provide a method comparison of a rail mounted accelerometer for detection of block response-times (RT) with an International Association of Athletic Federation (IAAF) approved automatic start control system (IAAF RT). Twenty national and international sprinters completed sprint trials under simulated race conditions. An accelero...

The Irish Rugby Injury Surveillance (IRIS) project involves research stemming from ongoing sports performance, injury prevention and psychological preparation work by University of Limerick academics across a range of sports, as well as our specific expertise in Rugby Union. It has effectively brought together academics with expert practitioner exp...

The purpose of this study was to determine the effects of training on the force-, velocity-, and displacement-time curves using principal component analysis (PCA) to examine the pre to post intervention changes. Thirty-four trained women basketball players were randomly divided into training and control groups. The training intervention consisted o...

Purpose: The primary aim was to assess the relationships between reactive strength measures and associated kinematic and kinetic performance variables achieved during drop jumps. A secondary aim was to highlight issues with the use of reactive strength measures as performance indicators. Methods: Twenty eight national and international level spr...

Purpose: The aims of this study were to examine the prescription of dry-land resistance training (RT) modalities and exercises among elite swimming S&C coaches and explore coach’s rationale and justification for prescribing dry-land RT modalities and dry-land exercises. Methods: Coaches completed an online questionnaire consisting of seven sections...

Healy, R, Smyth, C, Kenny, IC, and Harrison, AJ. Influence of reactive and maximum strength indicators on sprint performance. J Strength Cond Res XX(X): 000-000, 2018-The primary aim of this study was to assess the relationship between reactive and maximal strength measures with 40 m sprint performance and mechanical properties. Fourteen male and 1...

Objectives: To ascertain current injury surveillance and player education practices in Irish amateur rugby union. Design: Cross-sectional survey. Setting: Amateur rugby clubs in Ireland. Participants: Medical professionals and rugby coaches of the top 58 amateur rugby clubs in Ireland. Main outcome measures: The survey investigated the cur...

Background Rugby Union is one of the most played and watched collision sports worldwide, with high injury incidences widely reported in the literature. Participation rates in Rugby Union are rising with increasing popularity, particularly in Ireland with 224 amateur clubs and approximately 190,400 players currently registered. Internationally, the...

The use of isometric strength testing, particularly the isometric mid-thigh pull (IMTP) has increased dramatically over the last decade. The IMTP and isometric squat (ISqT) provide one aspect of performance monitoring with variables such as peak force and rate of force development being derived from the force–time curve. The reliability of some of...

Crowley, E, Harrison, AJ, and Lyons, M. Dry-land resistance training practices of elite swimming strength and conditioning coaches. J Strength Cond Res 32(9): 2592-2600, 2018-No research to date has investigated dry-land resistance (RT) training practices of elite swimming strength and conditioning coaches. This is the first comprehensive study exp...

No research to date has investigated the current practice of prescription of dry-land resistance training by elite swimming strength and conditioning (S&C) coaches. The aims of this study were to examine the prescription of dry-land resistance training modalities and exercises among elite swimming S&C coaches and explore coach’s rationale and justi...

Background: Rugby union is a physically demanding, full-contact team sport that has gained worldwide popularity. The incidence of injury in rugby union has been widely reported in the literature. While comprehensive injury surveillance and prevention programmes have been implemented within the professional game, there is a need for similar strateg...

The long term Irish Rugby Injury Surveillance (IRIS) project delivers an effective and efficient Rugby Union specific injury surveillance system. This monitoring system assesses the incidence and type of injury in terms of nature and severity, ultimately developing the first long-term surveillance and prevention programme within the Irish amateur g...

Objectives To examine whether the Functional Data Analysis (FDA), Statistical Parametric Mapping (SPM) and Statistical non-Parametric Mapping (SnPM) hypothesis testing techniques differ in their ability to draw inferences in the context of a single, simple experimental design. Design The sample data used is cross-sectional (two-sample gender compa...

The purpose of this study was to examine the differences in coordination variability in running gait between trained runners and non-runners using continuous relative phase (CRP) analysis. Lower extremity kinematic data were collected for 22 participants during the stance phase. The participants were assigned to either a runner or non-runner group...

BACKGROUND: Differences between male and female muscle-tendon units have been previously observed but it is unknown if a sex-related difference exists in the plantarflexor response to repeated stretch-shortening cycles, such as that which occurs during everyday activities of daily living such as walking and running. METHODS: An adapted force sledge...

Asymmetries of the rowing stroke cycle have been assessed with reference to kinematics and foot-force measures in laboratory testing environments. It remains unclear how asymmetries in propulsive kinetic measures are related to on-water rowing performance. A new approach for the evaluation of both global and local asymmetries across the entire move...

Purpose: This investigation examined the reliability and usefulness of the isometric mid-thigh pull (IMTP) and isometric squat (ISqT) performed at the same knee and hip angles. The scores produced in each test were compared to determine the magnitude of differences between tests. Methods: Twenty six male and female athletes (23.6±4.3 y; 1.75±0.0...

The proliferation of new biomechanical technology in laboratory and field settings facilitates the capture of data-sets consisting of complex time-series. An understanding of the appropriate statistical approaches for analysing and interpreting these data-sets is required and the functional data analysis (FDA) family of statistical techniques has e...

Sporting performance is often investigated through graphical observation of key technical variables that are representative of whole movements. The presence of differences between athletes in such variables has led to terms such as movement signatures being used. These signatures can be multivariate (multiple time-series observed concurrently), and...

Background The majority of propulsive forces in swimming are produced from the upper body, with strong correlations between upper body strength and sprint performance. There are significant gaps in the literature relating to the impact of resistance training on swimming performance, specifically the transfer to swimming performance. Objective The a...

The aim of this investigation was to determine the influences of force application related variables and center of mass displacement on jump height differences between squat jump (SJ) and countermovement jump (CMJ). Twenty six males performed three squat jumps and three countermovement jumps with a 90° knee flexion. The center of mass displacement...