Thomas Dos'Santos

Manchester Metropolitan University | MMU · Department of Exercise and Sport Science

Side-step cutting is an action associated with non-contact anterior cruciate ligament (ACL) injury with a plethora of negative economical, health, and psychological implications. Although ACL injury risk factors are multifactorial, biomechanical and neuromuscular deficits which contribute to “high-risk” and aberrant movement patterns are linked to...

Background Most cutting biomechanical studies investigate performance and knee joint load determinants independently. This is surprising because cutting is an important action linked to performance and non-contact anterior cruciate ligament (ACL) injuries. The aim of this study was to investigate the relationship between cutting biomechanics and cu...

Dos'Santos, T, Thomas, C, Comfort, P, and Jones, PA. Biomechanical effects of a 6-week change of direction speed and technique modification intervention: implications for change of direction side step performance. J Strength Cond Res XX(X): 000-000, 2020-The aim of this study was to evaluate the biomechanical effects of change of direction (COD) sp...

The investigation of inter-limb asymmetries has increased in recent years, with practitioners and researchers typically exploring the impact of inter-limb asymmetry on athletic performance, screening inter-limb asymmetry in relation to injury risk, and monitoring of inter-limb asymmetry during injury rehabilitation. A contentious issue regarding th...

Changes of direction (CODs) are key manoeuvres linked to decisive moments in sport and are also key actions associated with lower limb injuries. During sport athletes perform a diverse range of CODs, from various approach velocities and angles, thus the ability to change direction safely and quickly is of great interest. To our knowledge, a compreh...

Hamstring strain injuries are one of the most common injuries in sprint-based sports with the mechanism of injury considered the result of an interaction between applied mechanical strain and the capacity of the muscle to tolerate strain. To date, injury prevention and rehabilitation strategies have frequently focused on enhancing the capacity of t...

This study developed a cutting technique modification training program and investigated its effects on cutting performance and movement quality in adolescent American football players. For six weeks, an intervention group (IG) of 11 players participated in 25 min cutting technique modification training sessions integrated into team training twice a...

We aimed to understand whether ankle dorsiflexion range of motion (ROM) and dynamic knee valgus (DKV) kinematic inter-limb asymmetries would be associated with the Lateral Step-Down Test (LSD) in basketball players with chronic ankle instability (CAI), patellofemoral pain (PFP) and healthy controls (HC). An observational cross-sectional study with...

Background: The cutting movement assessment score (CMAS) provides a qualitative assessment of the side-step cutting (S-SC) technique. Previous research has been undertaken primarily by biomechanists experienced with S-SC evaluations. Little is known about the agreement between various sports science and medicine practitioners to ascertain whether t...

The aims of this study were to establish whether directional dominance is displayed during change of direction (COD) tasks across various angles, to determine the angle-variation data for the asymmetry magnitude and direction, and to analyse the relationships in COD performance (completion time and COD deficit) across tasks. Twenty-four young (U-16...

The objective of the study was to evaluate the effectiveness of the Safe Landing (SL), a 6-week technique-modification (TM) programme, on cutting and jump-landing movement quality in football players. In a non-randomized design, 32 male semi-professional football players from two Spanish clubs participated in the study: one served as the control gr...

The aim of this study was to quantify and tactically contextualise (i.e., phase of play and tactical outcome [TO]) sprints (≥7.0 m/s) of an English Premier League (EPL) soccer team during match-play. Videos of 901 sprints (10 matches) were evaluated using the Football Sprint Tactical-Context Classification System. Sprints occurred within a variety...

Background Eumenorrheic women experience cyclic variations in sex hormones attributed to the menstrual cycle (MC) which can impact anterior cruciate ligament (ACL) properties, knee laxity, and neuromuscular function. This systematic review aimed to examine the effects of the MC on ACL neuromuscular and biomechanical injury risk surrogates during dy...

Introduction Sprint running mechanics are thought to be a risk factor for Hamstring Strain Injuries (HSI). However, there is limited evidence to support this association, which may be explained by the lack of in-field assessment methods to evaluate sprint running mechanics.This study aimed to investigate whether a new qualitative screening tool, th...

Introduction Qualitative movement screening tools have been developed across several activities, aiming to identify mechanical patterns associated with potential injury risk. Although sprint running mechanics are thought to influence hamstring strain injuries (HSI), there are currently no field-based screening tools available allowing quick assessm...

Over the years, soccer has become more physically demanding; the number and frequency of high-intensity actions have increased, and these activities are decisive in determining the match outcome. Importantly, the reductionist approach commonly used to analyze high-intensity actions does not contemplate a more contextualized perspective on soccer pe...

The aim of this study was to quantify and contextualize sprinting actions (≥ 7.0 m/s) of English Premier League (EPL) soccer match-play with respect to the movement skills and patterns employed. Video footage (3.2.6, Premier League DVMS, ChyronHego) and raw video-based locomotor coordinates of 901 sprint efforts from 10 matches of an EPL soccer tea...

The authors wish to make the following corrections to this paper [...]

This study aimed to compare the significant turning demands of English Premier League soccer match play relative to playing position using LiDAR technology. Turning data were collected from an English Premier League soccer team (2020-2021 season; 18 fixtures) using a Sportlight® LiDAR tracking system. Turns were tracked during match play, sub-categ...

Objectives To investigate the relationship between the Landing Error Scoring System (LESS) and Cutting Movement Assessment Score (CMAS) to evaluate movement quality, their intra- (INTRAob) and inter-observer (INTERob) reliability, and the comparison between the two drop vertical jump (DVJ) landings (1st and 2nd). Design Cross-sectional. Participa...

Rapid horizontal accelerations and decelerations are crucial events enabling the changes of velocity and direction integral to sports involving random intermittent multi-directional movements. However, relative to horizontal acceleration, there have been considerably fewer scientific investigations into the biomechanical and neuromuscular demands o...

Agility is a complex skill that is influenced by several physical, technical and cognitive factors. In this position stand, we discuss agility as it relates to invasion sports such as the many football codes. An important concept when conceptualising agility is understanding how it is applied on the field or court. Agility is particularly important...

Attacking agility actions, such as side steps, shuffle steps, crossover cutting, split steps, spins, decelerations, and sharp turns, are important maneuvers in invasion team sports, often linked with decisive match winning moments. Generally, the aims of these actions are to (a) evade and create separation from an opponent, (b) generate high exit v...

The purpose of this study was to compare countermovement jump force–time measures between strength-matched male and female soccer players. Males (n = 11) and females (n = 11) were strength-matched via isometric mid-thigh pull testing, whereby peak force values were normalised to body mass. Subjects performed three maximal-effort countermovement jum...

An important element of developing agility with athletes is to evaluate technique in performing actions associated with match play. For practitioners it is important to understand what the key elements of ideal movement technique are to enhance performance. The aim of this article is to revisit an approach to creating a technical framework to help...

Anterior cruciate ligament (ACL) is one of the most concerning injuries for football players. The aim of this review is to investigate the effects of exercise-based interventions targeting at reducing ACL injury rate or mitigating risk factors of ACL injury in adult football players. Following PRISMA guidelines, a systematic search was conducted in...

High-intensity horizontal decelerations occur frequently in team sports and are typically performed to facilitate a reduction in momentum preceding a change of direction manoeuvre or following a sprinting action. The mechanical underpinnings of horizontal deceleration are unique compared to other high-intensity locomotive patterns (e.g., accelerati...

The aim of this was study to examine the inter-task relationships and compare change of direction (COD) biomechanics between different angles (45°, 90°, and 180°). Twenty-seven men performed three COD tasks, whereby lower-limb and trunk kinematics and kinetics were assessed via 3D motion and ground reaction force (GRF) analysis. Key mechanical diff...

Multidirectional speed (MDS) can be defined as the competency and capacity to accelerate, decelerate, change direction, and maintain speed in multiple directions and movements, within the context of sport-specific scenarios."The components of MDS are linear speed, change of direction speed, curvilinear speed, contextual speed, and agility. A MDS de...

The aim of this study was to explore differences in 10 m, 20 m and 40 m sprint times (STs) and initial acceleration kinematic and spatiotemporal step mechanics between Rugby Union (RU) forwards and backs. Nineteen elite male academy RU players (12 forwards; 7 backs; age: 18.0 ± 0.5 years, height: 1.83 ± 0.07 m, mass: 90.3 ± 10.0 kg) were recruited...

This review provides a definition for multidirectional speed (MDS) and evaluates its technical and mechanical underpinnings. This review explores each component of MDS while considering unique aspects of youth physiology and epidemiology. With a theoretical understanding of MDS, practitioners will be more informed on the planning and periodization...

Dos'Santos, T, Thomas, C, Comfort, P, and Jones, PA. Biomechanical effects of a 6-week change-of-direction technique modification intervention on anterior cruciate ligament injury risk. J Strength Cond Res XX(X): 000-000, 2021-The aim of this study was to evaluate the biomechanical effects of a 6-week change-of-direction (COD) technique modificatio...

Abstract: This study aimed to examine the effects of change of direction (COD) speed and technique modification training on 180� turning performance (completion time, ground contact time [GCT], and exit velocity), kinetics, and kinematics. A non-randomised 6 week intervention study was administered. Thirteen male multidirectional sport athletes for...

Objective: In soccer, vertical jump means jumping toward a ball. Since no vertical jump test includes the ball as a reference element, the effect that the ball would have in a vertical jump test is unknown. The aim of this study was to examine the biomechanical differences between run-up vertical jump measurements without (Run-up Vertical Jump) and...

In this study, we aimed to analyze the magnitude and direction of interlimb asymmetries in ankle dorsiflexion range of motion (ROM), power (using iso-inertial devices), and a neuromuscular skill (change of direction). Secondarily, we aimed to determine the relationship between interlimb asymmetry scores for each test and also between these scores a...

Thomas, C, Dos'Santos, T, Warmenhoven, J, and Jones, PA. Between-limb differences during 180° turns in female soccer players: application of statistical parametric mapping. J Strength Cond Res 36(11): 3136-3142, 2022-This study was exploratory in nature and investigated the ability of statistical parametric mapping (SPM) to assess between-limb diff...

Practitioners usually include change of direction (COD) and linear speed measurements in the testing batteries of soccer players; however, despite being a commonly occurring action, curve sprint (CS) ability is rarely assessed in soccer. The aims of this study were to analyze the association between linear sprint, CS, and COD speed performances, an...

The aim of the study was to compare ground reaction force (GRF) characteristics between the antepenultimate foot contact (APFC), penultimate foot contact (PFC), and final foot contact (FFC), and to examine the relationships between APFC, PFC, and FFC GRF characteristics with 505 change of direction (COD) speed performance. Twenty university male so...

The purpose of this study was to identify whether ten repetitions and three trials were necessary to achieve stability in peak reactive strength index (RSI) during the 10/5 repeated jumps test (RJT). Twenty-five males, from multiple sports, performed three trials of the RJT on an in-ground force plate, with 90 seconds' rest between trials. Intracla...

Background Cutting actions are associated with non-contact ACL injuries in multidirectional sports due to the propensity to generate large multiplanar knee joint loads (KJLs) that have the capacity to increase ACL loading and strain. Numerous studies have investigated the biomechanical determinants of KJLs in cutting tasks. The aim of this systemat...

Change of direction manoeuvres is important in soccer and associated with non-contact anterior cruciate ligament injury, yet it is not known how the mechanics differentiate between males and females during 180° turns. Twenty-eight soccer players (14 males and 14 females) performed 180° turns with ground reaction forces collected over penultimate an...

Background In youth, the development of change of direction (COD) and sprint performance is a key component for successfully competing in soccer across age. During a COD, the presence of directional asymmetries may be detrimental due to the unpredictable nature of the sport. Therefore, the aims of the study were to investigate asymmetries in COD ab...

The countermovement jump (CMJ) is considered an important test in rugby league, and the force platform is the recommended tool for assessing CMJ performance in this cohort. Because of inconsistent methods applied across previous studies, there is currently a lack of understanding of what constitutes a “good” CMJ performance, with respect to the typ...

Purpose: The reactive strength index (RSI) provides a value that indicates how efficiently an athlete can utilize the stretch shortening cycle. This study aimed to compare RSI values between the 10/5 repeated jumps test (RJT) and drop jumps (DJs) from 30 cm (DJ30) and 40 (DJ40). Methods: Thirty males (age = 23.97 ± 5.94, height (m) = 1.80 ± 0.08 an...

The countermovement jump (CMJ) test and multiple-repetition rebound jump (RJ) test (usually, 3-5 RJs) are routinely conducted with athletes to evaluate their neuromuscular function (NMF) and stretch-shortening cycle (SSC) ability, respectively. Jump height (JH), reactive strength index (RSI) and RSI modified (RSImod) are regularly reported for thes...

Thomas, C, Dos'Santos, T, Comfort, P, and Jones, PA. Effect of asymmetry on biomechanical characteristics during 180° change of direction. J Strength Cond Res XX(X): 000-000, 2020-The aim of this study was to explore the effect of asymmetry on biomechanical characteristics during two 180° change of direction (CoD) tasks (505 and modified 505 [505mo...

Comfort, P, Jones, PA, Thomas, C, Dos'Santos, T, McMahon, JJ, and Suchomel, TJ. Changes in early and maximal isometric force production in response to moderate- and high-load strength and power training. J Strength Cond Res XX(X): 000-000, 2020-The aims of this study were to determine the changes in early (50-, 100-, 150-, 200-, 250 ms) and maximal...

Change of direction (COD) manoeuvres are associated with anterior cruciate ligament (ACL) injury risk due to the propensity to generate large multiplanar knee joint loads. Given the short- and long-term consequences of ACL injury, practitioners are interested in methods that reduce knee joint loads and subsequent ACL loading. An effective strategy...

Dos'Santos, T, McBurnie, A, Thomas, C, Comfort, P, and Jones, PA. Biomechanical determinants of the modified and traditional 505 change of direction speed test. J Strength Cond Res XX(X): 000-000, 2019-The aim of this study was to investigate the whole-body biomechanical determinants of 180° change of direction (COD) performance. Sixty-one male ath...

Jones, PA, Dos'Santos, T, McMahon, JJ, and Graham-Smith, P. Contribution of eccentric strength to cutting performance in female soccer players. J Strength Cond Res XX(X): 000-000, 2019-The aim of this study was to examine the contribution of eccentric strength to performance of a 70-90° cutting task (CUT) (time to complete: 5 m approach, 70-90° cut...

Purpose: To determine the reliability of early force production (50, 100, 150, 200, and 250 ms) relative to peak force (PF) during an isometric mid-thigh pull and to assess the relationships between these variables. Methods: Male collegiate athletes (N = 29; age 21.1 [2.9] y, height 1.71 [0.07] m, body mass 71.3 [13.6] kg) performed isometric mi...

The purpose of this study was to explore whether limb preference influences braking strategy and knee joint mechanics during a 180° pivot task in female soccer players (mean ± SD; age = 20.6 ± 0.6 years; height = 165 ± 7.0 cm; body mass = 56.6 ± 6.3 kg). Three-dimensional motion analyses of pivoting on the preferred and non-preferred kicking limbs...

Cutting manoeuvres are important actions associated with soccer performance and a key action associated with non-contact anterior cruciate ligament injury; thus, training interventions that can improve cutting performance and movement quality are of great interest. The aim of this study, therefore, was to determine the effects of a six-week change...

This review aims to provide an overview of the current load-velocity (L-V) approaches and their ability to estimate one-repetition maximum (1RM). The bench press exercise appears to be the most valid and reliable when applying this approach. The ability for L-V relationship to predict 1RM for lower-body lifts remains questionable. Individualized re...

McBurnie, AJ, Dos'Santos, T, Jones, PA. Biomechanical associates of performance and knee joint loads during a 70-90° cutting maneuver in subelite soccer players. J Strength Cond Res XX(X): 000-000, 2019-The aim of this study was to explore the "performance-injury risk" conflict during cutting, by examining whole-body joint kinematics and kinetics t...

Objective: To assess the validity of the cutting movement assessment score (CMAS) to estimate the magnitude of peak knee abduction moments (KAM) against three-dimensional (3D) motion analysis, while comparing whole-body kinetics and kinematics between subjects of low (bottom 33%) and high CMASs (top 33%). Design: Cross-sectional study. Setting:...

Objective: To critically evaluate the effect of limb dominance on change of direction (COD) biomechanics associated with increased ACL injury-risk. Methods: A systematic review of the literature was conducted using Medline and Sport DISCUS databases. Studies that compared COD biomechanics (lower-limb/whole-body kinetics/kinematics) between limbs...

The aim of the present study was to evaluate the reliability of a modified version of the pro-agility test (MPA), as a means of assessing both static and rolling change of direction deficit (CODD), using solely one change of direction (COD) speed test. Sixteen male youth cricketers (age: 16 ± 1.6 years, height: 172 ± 9.7 cm, body mass: 72.0 ± 7.6 k...

Abstract Cutting actions are important maneuvers in multidirectional sport and are also key actions associated with non-contact anterior cruciate ligament injury; however, it is important to note that three primary cutting techniques have been studied within the literature: the side-step, crossover cut, and split-step. These cutting techniques demo...

Purpose: Skeletal-muscle function can be evaluated using force-times curves generated via the isometric midthigh pull (IMTP). Various sampling frequencies (500-1000 Hz) have been used for IMTP assessments; however, no research has investigated the influence of sampling frequency on IMTP kinetics. Therefore, the purpose of this study was to investi...

The primary aim of this investigation was to determine the effects of a four-week period of in-season strength training on the dynamic strength index (DSI). Pre and post a four-week period of strength-based training, twenty-four collegiate athletes (age = 19.9 ± 1.3 years; height = 1.70 ± 0.11 m; weight 68.1 ± 11.8 kg) performed three isometric mid...