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1.
J Appl Biomech ; : 1-9, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38866380

RESUMO

Assessment of player's postural control following a lower limb injury is of interest to sports medicine practitioners due to its fundamental role in daily tasks and sporting activities. The aim was to longitudinally monitor professional rugby union players' postural control during each phase of the rehabilitation program (acute, middle, and late) following a lower limb injury. Seven male rugby union players (height 1.80 [0.02] m; mass 100.3 [11.4] kg; age 24 [4] y) sustained a time loss, noncontact lower limb injury. Static postural control was assessed via sway path (in meters), and dynamic postural control was assessed via vertical postural stability index. Group differences (P < .05) were reported across the acute, middle, and late phase. Smaller magnitudes of sway path were observed for eyes-open sway path, and for the middle and late phase smaller magnitudes of vertical postural stability index (P < .05) at the end session compared with first session. Whereas larger magnitudes of vertical postural stability index were found between baseline and the last session (P < .05). Large interindividual and intraindividual variation was apparent across the 3 phases of rehabilitation. Postural control improvements were identified during rehabilitation. However, postural control did not return to baseline, with altered kinetics throughout each rehabilitation phase.

2.
J Sports Sci ; 42(7): 589-598, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38743402

RESUMO

The aim was to examine the effect of focus of attention cues on foot angle for retraining movement purposes. Twenty (females: 8) rearfoot-striking recreational runners (mass: 72.5 ± 11.8 kg; height: 1.73 ± 0.09 m; age: 32.9 ± 11.3 years) were randomly assigned to an internal focus (IF) (n = 10) or external focus (EF) (n = 10) verbal cue group. Participants performed 5 × 6 minute blocks of treadmill running (control run, 3 × cued running, retention run) at a self-selected running velocity (9.4 ± 1.1 km∙h-1) during a single laboratory visit. Touchdown foot angle, mechanical efficiency, internal and external work were calculated and, centre of mass (COM) and foot movement smoothness was quantified. Linear-mixed effect models showed an interaction for foot angle (p < 0.001, ηp2 = 0.35) and mechanical efficiency (p < 0.001, ηp2 = 0.40) when comparing the control to the cued running. Only the IF group reduced foot angle and mechanical efficiency during cued running, but not during the retention run. The IF group produced less external work during the 1st cued run than the control run. COM and foot smoothness were unaffected by cueing. Only an IF produced desired technique changes but at the cost of reduced mechanical efficiency. Movement smoothness was unaffected by cue provision. Changes to foot angle can be achieved within 6 minutes of gait retraining.


Assuntos
Atenção , Sinais (Psicologia) , , Marcha , Corrida , Humanos , Corrida/fisiologia , Masculino , Adulto , Feminino , Fenômenos Biomecânicos , Marcha/fisiologia , Pé/fisiologia , Atenção/fisiologia , Adulto Jovem , Movimento/fisiologia
3.
Sports Med ; 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609697

RESUMO

OBJECTIVES: The aim of this study was to compare the incidence, severity, and burden of injury in starting and replacement players from professional men's teams of five rugby unions. METHODS: Match injuries of greater than 24 h time-loss (including data on the severity, match quarter, event, body region) and player minutes of match exposure data were collated for all starting and replacement players in the men's English Premiership, Welsh Pro14 (both 2016/17-2018/19 seasons), and Australian, New Zealand, and South African Super Rugby (all 2016-2018 seasons) teams. Injury incidences and mean injury burden (incidence × days missed) were calculated, and rate ratios (RRs) (95% confidence intervals [CIs]) were used to compare injury incidence and burden between starting (reference group) and replacement players. RESULTS: Overall injury incidence was not different between starters and replacements for all injuries (RR = 0.98, 95% CI 0.88-1.10), nor for concussions (RR = 0.85; 95% CI 0.66-1.11). Mean injury burden was higher for replacement players (RR = 1.31, 95% CI 1.17-1.46). Replacement injury incidence was lower than the starters in the third (RR = 0.68, 95% CI 0.51-0.92) and fourth (RR = 0.78, 95% CI 0.67-0.92) match quarters. Injury incidence was not different between starters and replacements for any match event or body region, but compared with starters, replacements' injury burden was higher in lower limbs (RR = 1.24, 95% CI 1.05-1.46) and in the tackled player (RR = 1.30, 95% CI 1.01-1.66). CONCLUSION: This study demonstrated a lower injury incidence in replacement players compared with starters in the second half of matches, with a higher injury burden for replacement players due to higher mean injury severity.

4.
Sports Med ; 54(5): 1269-1316, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38446400

RESUMO

BACKGROUND: Running biomechanics is considered an important determinant of running economy (RE). However, studies examining associations between running biomechanics and RE report inconsistent findings. OBJECTIVE: The aim of this systematic review was to determine associations between running biomechanics and RE and explore potential causes of inconsistency. METHODS: Three databases were searched and monitored up to April 2023. Observational studies were included if they (i) examined associations between running biomechanics and RE, or (ii) compared running biomechanics between groups differing in RE, or (iii) compared RE between groups differing in running biomechanics during level, constant-speed, and submaximal running in healthy humans (18-65 years). Risk of bias was assessed using a modified tool for observational studies and considered in the results interpretation using GRADE. Meta-analyses were performed when two or more studies reported on the same outcome. Meta-regressions were used to explore heterogeneity with speed, coefficient of variation of height, mass, and age as continuous outcomes, and standardization of running shoes, oxygen versus energetic cost, and correction for resting oxygen or energy cost as categorical outcomes. RESULTS: Fifty-one studies (n = 1115 participants) were included. Most spatiotemporal outcomes showed trivial and non-significant associations with RE: contact time r = - 0.02 (95% confidence interval [CI] - 0.15 to 0.12); flight time r = 0.11 (- 0.09 to 0.32); stride time r = 0.01 (- 0.8 to 0.50); duty factor r = - 0.06 (- 0.18 to 0.06); stride length r = 0.12 (- 0.15 to 0.38), and swing time r = 0.12 (- 0.13 to 0.36). A higher cadence showed a small significant association with a lower oxygen/energy cost (r = - 0.20 [- 0.35 to - 0.05]). A smaller vertical displacement and higher vertical and leg stiffness showed significant moderate associations with lower oxygen/energy cost (r = 0.35, - 0.31, - 0.28, respectively). Ankle, knee, and hip angles at initial contact, midstance or toe-off as well as their range of motion, peak vertical ground reaction force, mechanical work variables, and electromyographic activation were not significantly associated with RE, although potentially relevant trends were observed for some outcomes. CONCLUSIONS: Running biomechanics can explain 4-12% of the between-individual variation in RE when considered in isolation, with this magnitude potentially increasing when combining different variables. Implications for athletes, coaches, wearable technology, and researchers are discussed in the review. PROTOCOL REGISTRATION: https://doi.org/10.17605/OSF.IO/293 ND (OpenScience Framework).


Assuntos
Estudos Observacionais como Assunto , Corrida , Humanos , Corrida/fisiologia , Fenômenos Biomecânicos , Metabolismo Energético , Consumo de Oxigênio
6.
J Biomech ; 164: 111984, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38330884

RESUMO

Running studies, particularly those examining footwear effects, commonly use warm-up or familiarization periods prior to testing. There is no consensus for how long these familiarization periods should be to ensure stable running kinematics prior to experimental testing in novel footwear. The aim of this study was to assess the time to stability of kinematic variables during treadmill running in novel compared to habitual neutral cushion footwear in distance runners. A cross-sectional analysis of 15 distance runners (seven women, eight men) during 10-minute treadmill running bouts in minimal, neutral cushion, and maximal cushioned footwear was conducted while lower extremity kinematics were recorded for 10 s at the end of each minute. Test-retest intra-class correlation coefficients (ICC, 3, k) were used to detect time to stability in cadence, vertical oscillation, peak dorsiflexion angle, peak eversion angle, and peak knee flexion angle. All kinematic variables were stabilized within two to three minutes (ICC < 0.90) and the type of novel footwear did not influence time to stability. These findings indicate that a two to three minute, ∼310-540 steps, depending on running cadence, familiarization period, regardless of footwear novelty, is sufficient for stabilization of these kinematic variables during treadmill running.


Assuntos
Corrida , Sapatos , Masculino , Humanos , Feminino , Fenômenos Biomecânicos , Estudos Transversais , Extremidade Inferior
7.
Phys Ther Sport ; 65: 130-136, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38181563

RESUMO

OBJECTIVES: Investigate 1) if collecting and analysing wristwatch inertial measurement unit (IMU) and global positioning system (GPS) data using a commercially-available training platform was feasible in recreational runners and 2) which variables were associated with subsequent injury. DESIGN: Prospective longitudinal cohort. PARTICIPANTS: Healthy recreational runners. MAIN OUTCOME MEASURES: We set a priori feasibility thresholds for recruitment (maximum six-months), acceptance (minimum 80%), adherence (minimum 70%), and data collection (minimum 80%). Participants completed three patient-reported outcome measures (PROMS) detailing their psychological health, sleep quality, and intrinsic motivation to run. We extracted baseline anthropometric, biomechanical, metabolic, and training load data from their IMU/GPS wristwatch for analysis. Participants completed a weekly injury status surveillance questionnaire over the next 12-weeks. Feasibility outcomes were analysed descriptively and injured versus non-injured group differences with 95% confidence intervals were calculated for PROM/IMU/GPS data. RESULTS: 149 participants consented; 86 participants completed (55 men, 31 women); 21 developed an injury (0.46 injuries/1000km). Feasibility outcomes were satisfied (recruitment = 47 days; acceptance = 133/149 [89%]; adherence = 93/133 [70%]; data collection = 86/93 [92%]). Acute load by calculated effort was associated with subsequent injury (mean difference -562.14, 95% CI -1019.42, -21.53). CONCLUSION: Collecting and analysing wristwatch IMU/GPS data using a commercially-available training platform was feasible in recreational runners.


Assuntos
Relesões , Corrida , Dispositivos Eletrônicos Vestíveis , Masculino , Humanos , Feminino , Estudos Prospectivos , Estudos de Viabilidade , Corrida/lesões
8.
Br J Sports Med ; 58(4): 183-195, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38191239

RESUMO

Returning to running postpartum presents challenges such as musculoskeletal pain and pelvic floor dysfunction for some females, but there is little guidance on developing and progressing postpartum training programmes. This study aims to establish expert consensus recommendations on designing and modifying a postpartum return-to-running training programme, highlight costs and access to qualified professionals as potential barriers and discuss clinical, research and sports policy implications.A three-round Delphi survey of clinical and exercise professionals working with postpartum runners was conducted. Round I consisted of open-ended questions related to designing the training plan, modifications based on biopsychosocial factors, key muscle groups to train and referral and payment sources. Rounds II and III involved Likert-scale voting to identify consensus (≥75% agreement).118 participants completed Round I, 107 completed Round II (response rate 90.6%) and 95 completed Round III (response rate 80.5%). Consensus was reached in 42/47 (89%) statements, including recommendations for a period of relative rest, gradual increases in duration and intensity, starting with a walk-run protocol and incorporating strength training. Training should be modified based on musculoskeletal or pelvic symptoms, sleep, mental health, lactation or energy availability concerns. Cost and access to experienced postpartum running professionals were identified as potential barriers for runners to receive care.Consensus recommendations for a postpartum return-to-running programme include an individualised exercise prescription, gradual increases in physical activity, walk-run protocols and targeted muscle strengthening. Further research and improved access to clinical and exercise professionals are needed to inform and facilitate best practices.


Assuntos
Exercício Físico , Corrida , Feminino , Humanos , Técnica Delphi , Exercício Físico/fisiologia , Terapia por Exercício , Período Pós-Parto
9.
Br J Sports Med ; 58(6): 299-312, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38148108

RESUMO

Female athletes have identified a lack of guidance as a barrier to successfully returning to running postpartum, and existing guidelines are vague. Our aim was to define the current practice of determining postpartum run-readiness through a consensus survey of international clinicians and exercise professionals in postpartum exercise to assist clinicians and inform sport policy changes.A three-round Delphi approach was used to gain international consensus from clinicians and exercise professionals on run-readiness postpartum. Professionals who work with postpartum runners participated in an online survey to answer open-ended questions about the following postpartum return-to-running topics: definitions (runner and postpartum), key biopsychosocial milestones that runners need to meet, recommended screening, timeline to initiate running, support items, education topics and factors that contribute to advising against running. Consensus was defined as ≥75% participant agreement.One hundred and eighteen professionals participated in round I, 107 participated in round II (response rate 90.6%) and 95 participated in round III (response rate 80.5%). Responses indicated that, following a minimum 3-week period of rest and recovery, an individualised timeline and gradual return to running progression can be considered. Screening for medical and psychological concerns, current physical capacity, and prior training history is recommended prior to a return to running.This study proposes recommendations for the initial guidance on return-to-running postpartum, framed in the context of current research and consensus from professionals. Future research is needed to strengthen and validate specific recommendations and develop guidelines for best practice when returning-to-running after childbirth.


Assuntos
Parto Obstétrico , Corrida , Humanos , Feminino , Gravidez , Técnica Delphi , Exercício Físico , Período Pós-Parto
10.
J Athl Train ; 2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37681667

RESUMO

CONTEXT: General and local muscular fatigue is postulated to negatively alter lower limb biomechanics; however, few prospective studies have examined the effect of fatigue on tuck jump performance. The tuck jump assessment (TJA) is a criteria-based visual screening tool designed to identify neuromuscular deficits associated with ACL injury. Utilization of kinetics during the TJA following an intense sport-specific fatigue protocol may identify fatigue induced neuromuscular deficits associated with ACL injury risk. OBJECTIVE: To examine the effects of a sport-specific fatigue protocol on visually evidenced (2D) technical performance of repeated tuck jumps and lower limb kinetic stabilisation. DESIGN: Cross-sectional Study. SETTING: Laboratory. PATIENTS OF OTHER PARTICIPANTS: Twelve recreational female athletes (age 20.8 ± 2.6 yrs; height 170.0 ± 0.04 m; body mass 67.5 ± 7.4 kg). INTERVENTION(S): Sport-specific fatigue protocol. MAIN OUTCOME MEASURE(S): Paired t-tests and effect sizes were used to evaluate differences and magnitude of differences in TJA scoring criterion, kinetics, and kinetic stabilisation pre-to post-fatigue. RESULTS: A moderate increase (p < 0.01; g = 0.45) was observed for relative leg stiffness (kleg) post-fatigue. Ground contact time, flight time, jump height, net impulse, and centre of mass displacement (p ≤ 0.02) decreased with small to moderate effect sizes (g = 0.41-0.74). No differences were observed for TJA composite scores, peak VGRF, and stabilisation indices of kinetic variables (p > 0.05) following the fatigue protocol. CONCLUSIONS: Kinetic analysis of repeated 26 tuck jumps following a fatigue protocol identified an altered jumping strategy, that was not identifiable via visual 2D assessment. However, based on kinetic measures, fatigue induces a stiffer jumping strategy and practitioners should consider assessing load attenuation strategies that may not be visually evident when evaluating ACL injury risk factors in athletes who are fatigued.

12.
Br J Sports Med ; 57(18): 1164-1174, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37349084

RESUMO

The IOC made recommendations for recording and reporting epidemiological data on injuries and illness in sports in 2020, but with little, if any, focus on female athletes. Therefore, the aims of this supplement to the IOC consensus statement are to (i) propose a taxonomy for categorisation of female athlete health problems across the lifespan; (ii) make recommendations for data capture to inform consistent recording and reporting of symptoms, injuries, illnesses and other health outcomes in sports injury epidemiology and (iii) make recommendations for specifications when applying the Strengthening the Reporting of Observational Studies in Epidemiology-Sport Injury and Illness Surveillance (STROBE-SIIS) to female athlete health data.In May 2021, five researchers and clinicians with expertise in sports medicine, epidemiology and female athlete health convened to form a consensus working group, which identified key themes. Twenty additional experts were invited and an iterative process involving all authors was then used to extend the IOC consensus statement, to include issues which affect female athletes.Ten domains of female health for categorising health problems according to biological, life stage or environmental factors that affect females in sport were identified: menstrual and gynaecological health; preconception and assisted reproduction; pregnancy; postpartum; menopause; breast health; pelvic floor health; breast feeding, parenting and caregiving; mental health and sport environments.This paper extends the IOC consensus statement to include 10 domains of female health, which may affect female athletes across the lifespan, from adolescence through young adulthood, to mid-age and older age. Our recommendations for data capture relating to female athlete population characteristics, and injuries, illnesses and other health consequences, will improve the quality of epidemiological studies, to inform better injury and illness prevention strategies.


Assuntos
Traumatismos em Atletas , Medicina Esportiva , Esportes , Adolescente , Adulto , Feminino , Humanos , Adulto Jovem , Atletas , Traumatismos em Atletas/prevenção & controle , Projetos de Pesquisa , Medicina Esportiva/métodos
13.
Sports Biomech ; : 1-23, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37313654

RESUMO

Changes in surface hardness are likely to alter an athlete's movement strategy. Anterior cruciate ligament (ACL) injury risk assessments that are performed on a different surface to that used for training and competition may, therefore, not represent an athlete's on-field movement strategies. The aim of this study was to examine the influence of surface hardness on multidirectional field sport athletes' movement strategies in movements that are commonly used in ACL injury risk assessments (bilateral and unilateral drop jumps, and a cutting manoeuvre). Ground reaction forcesand three-dimensional lower limb kinematics were recorded from 19 healthy, male, multidirectional field sport athletes performing bilateral and unilateral drop jumps, and a 90° cutting task on Mondo track (harder surface) and artificial turf (softer surface). Continuous (statistical parametric mapping) and discrete analyses revealed alterations in vertical and horizontal braking forces and knee and hip moments between surfaces of different hardness in all three movements (p ≤ 0.05, d > 0.5). Injury risk assessments performed on a harder surface (e.g. Mondo track) can misrepresent an athlete's risk of ACL injury compared to the same movements performed on a softer more cushioned surface that is typically used for training and/or matches (e.g. artificial turf).

14.
Artigo em Inglês | MEDLINE | ID: mdl-37107757

RESUMO

Rugby Union (rugby) is a full-contact team sport characterised by frequent collision events. Over one third (2.7 million) of global rugby participants are women and girls. Yet, most rugby research, laws, and regulations are derived from the men's game with limited transferability to the women's game. This includes research focused on injury and concussion management. Greater insights are urgently required to enable appropriate adaptations and support for all rugby participants. Therefore, this paper presents the protocol for a project that sought to gather insights into the understanding, experiences, and attitudes of players and coaches in women's rugby regarding key issues of concussion, injury, and training for injury prevention, as well as the implications of the menstrual cycle for training and performance. From August 2020 to November 2020, online, open, cross-sectional surveys for players and coaches were distributed globally through rugby governing bodies and women's rugby social media platforms using snowball sampling. Survey responses were recorded anonymously via a GDPR-compliant online survey platform, JISC (jisc.ac.uk, Bristol, England). Participant eligibility included being ≥18 years and either actively playing or coaching women's rugby 15s and/or sevens, or having done so in the past decade, at any level, in any country. To enhance the number and accuracy of responses, the survey was professionally translated into eight additional languages. A total of 1596 participants from 62 countries (27 ± 6 years; 7.5 ± 5.1 years of playing experience) and 296 participants from 37 countries (mean age = 36.64, SD = 9.09, mean experience = 6.53 years, SD = 3.31) completed the players' and coaches' surveys, respectively. Understanding women's participation in and experiences of rugby is important to enable lifelong engagement and enjoyment of the sport and health during and following participation.


Assuntos
Concussão Encefálica , Futebol Americano , Masculino , Humanos , Feminino , Adulto , Estudos Transversais , Rugby , Futebol Americano/lesões , Internet
15.
Curr Sports Med Rep ; 22(3): 82-90, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36866951

RESUMO

ABSTRACT: The female athlete is seen as a specialist population meaning female considerations, such as pelvic floor dysfunction, are not widely taught within sports medicine. Females have unique anatomical characteristics compared with males including a wider pelvic diameter and an additional orifice in the form of the vagina. Furthermore, symptoms of pelvic floor dysfunction are prevalent among female athletes and transitional periods in their lifespan. They also are a barrier to training and performance. Therefore, it is essential that sports medicine practitioners understand how to identify and manage pelvic floor dysfunction. This report aims to describe the anatomy and function of the pelvic floor, outline the types and rates of pelvic floor dysfunction, discuss evidence-based management, and raise awareness of perinatal bodily changes. Practical recommendations are made to aid sports organizations and sports medicine practitioners in supporting the female athlete and in using a proactive approach to manage the perinatal athlete.


Assuntos
Medicina Esportiva , Esportes , Masculino , Gravidez , Humanos , Feminino , Diafragma da Pelve , Atletas , Longevidade
16.
Sensors (Basel) ; 22(23)2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36502001

RESUMO

Given the high rates of both primary and secondary anterior cruciate ligament (ACL) injuries in multidirectional field sports, there is a need to develop easily accessible methods for practitioners to monitor ACL injury risk. Field-based methods to assess knee variables associated with ACL injury are of particular interest to practitioners for monitoring injury risk in applied sports settings. Knee variables or proxy measures derived from wearable inertial measurement units (IMUs) may thus provide a powerful tool for efficient injury risk management. Therefore, the aim of this study was to identify whether there were correlations between laboratory-derived knee variables (knee range of motion (RoM), change in knee moment, and knee stiffness) and metrics derived from IMUs (angular velocities and accelerations) placed on the tibia and thigh, across a range of movements performed in practitioner assessments used to monitor ACL injury risk. Ground reaction forces, three-dimensional kinematics, and triaxial IMU data were recorded from nineteen healthy male participants performing bilateral and unilateral drop jumps, and a 90° cutting task. Spearman's correlations were used to examine the correlations between knee variables and IMU-derived metrics. A significant strong positive correlation was observed between knee RoM and the area under the tibia angular velocity curve in all movements. Significant strong correlations were also observed in the unilateral drop jump between knee RoM, change in knee moment, and knee stiffness, and the area under the tibia acceleration curve (rs = 0.776, rs = -0.712, and rs = -0.765, respectively). A significant moderate correlation was observed between both knee RoM and knee stiffness, and the area under the thigh angular velocity curve (rs = 0.682 and rs = -0.641, respectively). The findings from this study suggest that it may be feasible to use IMU-derived angular velocities and acceleration measurements as proxy measures of knee variables in movements included in practitioner assessments used to monitor ACL injury risk.


Assuntos
Lesões do Ligamento Cruzado Anterior , Traumatismos do Joelho , Masculino , Humanos , Lesões do Ligamento Cruzado Anterior/diagnóstico , Articulação do Joelho , Joelho , Fenômenos Biomecânicos
17.
J Sport Rehabil ; 31(4): 524-528, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-34983023

RESUMO

CONTEXT: Kinetic profiles of athletes performing the tuck jump assessment (TJA) are unknown and may provide insight into the risk of anterior cruciate ligament injury. DESIGN: The purpose of this study was to (1) analyze vertical kinetics of the TJA and (2) determine the stabilization of the kinetics across successive jumping cycles. METHODS: Twenty-five healthy female athletes (age = 22.0 [4.6] y; height = 1.69 [0.07] m; body mass = 69.3 [10.3] kg) completed one trial of repeated tuck jumps on a force plate for 10 seconds. RESULTS: Vertical ground reaction force data were used to calculate the following variables across all jump cycles: time of jump cycle (0.65 [0.04] s), ground contact time (0.22 [0.03] s), flight time (0.43 [0.04] s), duty factor (0.34 [0.05]), jump height (0.23 [0.04] m), peak vertical force (5.52 [0.91] body weight [BW]), peak center of mass displacement (0.15 [0.02] m), vertical leg stiffness (27.09 [7.06] BW·m-1), vertical average loading rate (105.94 [28.43] BW·s-1), vertical instantaneous loading rate (140.90 [28.49] BW·s-1), and net impulse (0.43 [0.03] BW·s). A sequential averaging technique indicated a minimum of 11 jumps were required for stabilization of the kinetics. CONCLUSIONS: The TJA exposes athletes to high magnitudes of vertical force. Based on the high variability of performance during early repetitions and the potential to miscategorize high-risk landing in female athletes, practitioners should consider scoring the TJA after 11 successive cycles and using kinetic profiling to support landing assessments.


Assuntos
Lesões do Ligamento Cruzado Anterior , Adulto , Atletas , Fenômenos Biomecânicos , Feminino , Humanos , Cinética , Adulto Jovem
18.
J Strength Cond Res ; 36(9): 2573-2580, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33278273

RESUMO

ABSTRACT: Pedley, JS, Lloyd, RS, Read, PJ, Moore, IS, Myer, GD, and Oliver, JL. A novel method to categorize stretch-shortening cycle performance across maturity in youth soccer players. J Strength Cond Res 36(9): 2573-2580, 2022-This study used a novel method to categorize stretch-shortening cycle (SSC) function during a drop jump (DJ) using the force-time curve. This method was then used to determine the effect of maturity status upon SSC function and effect of SSC function on DJ performance. Prepeak, circa-peak, and postpeak height velocity male youth soccer players completed a preseason 30-cm DJ onto a force plate. Stretch-shortening cycle function was categorized as poor (impact peak and not spring-like), moderate (impact peak and spring-like), or good (no impact peak and spring-like). Interactions between SSC function and maturity status, and SSC function and kinetic variables were explored. Youth soccer players displaying good SSC function were older and more mature than those with poor SSC function; however, 9.9% of post peak height velocity still displayed poor SSC function. Players with good SSC function recorded significantly shorter ground contact times, reduced time between peak landing and takeoff force, reduced center of mass displacement, and significantly greater takeoff forces than players with moderate and poor SSC function (all p < 0.05). SSC function during a standardized DJ improves with maturation, but a portion of mature players still demonstrate poor SSC function. Good SSC function was associated with improved DJ outcome measures except jump height. Tailored training interventions based on SSC competency may be required to optimally enhance SSC function.


Assuntos
Desempenho Atlético , Futebol , Adolescente , Estatura , Teste de Esforço/métodos , Humanos , Masculino
19.
Scand J Med Sci Sports ; 32(3): 612-621, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34797936

RESUMO

There are currently a multitude of tests used to assess readiness to return to sport (RTS) following anterior cruciate ligament reconstruction (ACLR). The aim of this study was to establish the extent to which movement strategies transfer between three common assessment tasks to help improve design of athlete testing batteries following ACLR. A cohort of 127 male patients 8-10 months post-ACLR and 45 non-injured controls took part in the study. Three movement tasks were completed (unilateral and bilateral drop jump, and 90° pre-planned cut), while ground reaction forces and three-dimensional kinematics (250 Hz) were recorded. Compared to the bilateral drop jump and cut, the unilateral drop jump had a higher proportion of work done at the ankle (d = 0.29, p < 0.001 and d = -1.87, p < 0.001, respectively), and a lower proportion of work done at the knee during the braking phase of the task (d = 0.447, p < 0.001 and d = 1.56, p < 0.001, respectively). The ACLR group had higher peak hip moments than the non-injured controls, although the proportion of work done at the ankle, knee and hip joints were similar. Movement strategies were moderately and positively related at the ankle (rs  = 0.728, p < 0.001), knee (rs  = 0.638, p < 0.001) and hip (rs  = 0.593, p < 0.001) between the unilateral and bilateral drop jump, but there was no relationship at the ankle (rs  = 0.10, p = 0.104), knee (rs  = 0.106, p = 0.166) and hip (rs  = -0.019, p = 0.808) between the unilateral drop jump and the cut. Clinicians could therefore consider omitting one of the drop jumps from assessment batteries but should include both jumping and cutting tasks.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Lesões do Ligamento Cruzado Anterior/cirurgia , Fenômenos Biomecânicos , Humanos , Articulação do Joelho/cirurgia , Masculino , Movimento , Volta ao Esporte
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