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1.
J Biomech ; : 109669, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-32019678

RESUMO

Prospective knee abduction moments measured during the drop vertical jump task identify those at increased risk for anterior cruciate ligament injury. The purpose of this study was to determine which muscle forces and frontal plane biomechanical features contribute to large knee abduction moments. Thirteen young female athletes performed three drop vertical jump trials. Subject-specific musculoskeletal models and electromyography-informed simulations were developed to calculate the frontal plane biomechanics and lower limb muscle forces. The relationships between knee abduction moment and frontal plane biomechanics were examined. Knee abduction moment was positively correlated to vertical (R = 0.522, P < 0.001) and lateral ground reaction forces (R = 0.395, P = 0.016), hip adduction angle (R = 0.358, P < 0.023) and lateral pelvic tilt (R = 0.311, P = 0.061). A multiple regression showed that knee abduction moment was predicted by reduced gluteus medius force and increased vertical and lateral ground reaction forces (P < 0.001, R2 = 0.640). Hip adduction is indicative of lateral pelvic shift during landing. The coupled hip adduction and lateral pelvic tilt were associated to the increased vertical and lateral ground reaction forces, propagating into higher knee abduction moments. These biomechanical features are associated with ACL injury and may be limited in a landing with increased activation of the gluteus medius. Targeted neuromuscular training to control the frontal pelvic and hip motion may help to avoid injurious ground reaction forces and consequent knee abduction moment and ACL injury risk.

2.
J Strength Cond Res ; 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32028463

RESUMO

Devine, NF, Hegedus, EJ, Nguyen, A-D, Ford, KR, and Taylor, JB. External match load in women's collegiate lacrosse. J Strength Cond Res XX(X): 000-000, 2020-Quantifying external loads during athletic activities, particularly game-level competition, can provide objective data for the management of athlete performance, late-stage rehabilitation, and return-to-play decisions after lower extremity injury; yet, no studies have quantified these data in collegiate women's lacrosse athletes. The purpose of this study was to report external load values for collegiate women's lacrosse players and identify positional differences in activity demands during game competition. Load data were collected on 18 collegiate women's lacrosse players using a wearable global positioning system unit during a 19-game season. Descriptive statistics of distance, speed, and frequency (sprints, high-intensity sprints, high-intensity accelerations, high-intensity decelerations) measures were computed. Linear mixed models were used to identify differences between positions and phases of the season (α = 0.05). On average, players travelled 4,733 ± 2,294 m per game (range, 1,259-7,811 m), of which 656 ± 446 m (range 60-1,633 m) occurred at high-intensity speeds and reached a maximum speed of 24.1 ± 2.6 km·h (range, 19.2-27.7 km·h). In each game, subjects averaged 124 ± 68 sprints, 6.1 ± 4.1 high-intensity sprints, 51 ± 34 high-intensity accelerations, and 38 ± 25 high-intensity decelerations. Positional differences were identified for total (p = 0.04) and relative (p = 0.01) distance travelled at high-intensity speeds, and frequency of sprints (p = 0.01) and high-intensity decelerations (p = 0.03). During game competition, collegiate women's lacrosse demands significant external load, much of which occurs at high intensities. These data provide sport- and position-specific values for reference during late-stage rehabilitation and return-to-play testing, allowing clinicians to quantitatively progress load tolerance throughout rehabilitation and guide safe return to play.

3.
Gait Posture ; 77: 105-111, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32028076

RESUMO

BACKGROUND: Although unimpaired gait is typically assumed to be symmetrical, side-to-side differences in discrete instances of time have been reported in adult and youth runners. These previous results fail to account for the entirety of the motion. RESEARCH QUESTION: Are waveform pattern similarities strong in youth long-distance runners and are the waveform pattern similarities influenced by sex and maturation? METHODS: A cohort of injury-free children and adolescents (n = 103) who participated in long-distance running activities were recruited for the study. Three-dimensional kinematics were collected as participants ran on a treadmill at a self-selected speed. Lower extremity side-to-side waveform symmetries were assessed using the Linear Fit Model. Unpaired t-tests and one-way ANOVA with post-hoc analysis were calculated to determine if sex and/or maturation influenced waveform symmetries. RESULTS: As a whole, waveform similarities were found to be strongest in the sagittal plane and weaker, but still of appropriate strength, in the coronal and transverse planes. Hip rotation and knee varus/valgus measures were found to have the weakest waveform similarities. High waveform similarity variability was measured within the cohort, particularly in the coronal and transverse planes. Waveform similarities were not found to be influenced by either sex or maturation. SIGNIFICANCE: While the group as a whole demonstrated strong waveform similarities, some level of asymmetry in a population of uninjured, long-distance youth runners is normal as none of the measures demonstrated perfect symmetry. Prospective study is warranted to identify thresholds of waveform similarity and to determine if these findings can be used to predict running performance and injury risk.

4.
Sports Med ; 50(2): 331-342, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31643019

RESUMO

BACKGROUND: Temporal spatial parameters during running are measurable outside of clinical and laboratory environments using wearable technology. Data from wearable technology may be useful for injury prevention, however the association of temporal spatial parameters with overuse injury in runners remains unclear. OBJECTIVE: To identify the association between overuse injury and temporal spatial parameters during running. DATA SOURCES: Electronic databases were searched using keywords related to temporal spatial parameters, running, and overuse injury, and authors' personal article collections through hand search. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Articles included in this systematic review contained original data, and analytically compared at least one temporal spatial parameter (e.g. cadence) between uninjured and retrospectively or prospectively injured groups of runners. Articles were excluded from this review if they did not meet these criteria or measured temporal spatial parameters via survey. STUDY APPRAISAL AND SYNTHESIS METHOD: The internal validity of each article was assessed using the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Meta-analyses were conducted for temporal spatial parameters if data existed from at least three separate cohorts of the same prospective or retrospective design. Data were pooled and analyzed using an inverse variance fixed-effect model. RESULTS: Thirteen articles which tested a total of 24 temporal spatial parameters during running were included in the review. Meta-analyses were conducted on four temporal spatial parameters using data from eleven retrospective studies. Healthy runners and those with a history of overuse injury had a similar average stride time (mean difference: 0.00 s, 95% CI - 0.01 to 0.01 s), contact time (mean difference: 0.00 s, 95% CI 0.00 to 0.01 s), cadence (mean difference: 0.3 steps per minute (spm), 95% CI - 1.8 to 2.5 spm), and stride length (mean difference 0.00 m, 95% CI - 0.05 to 0.05 m) during running. LIMITATIONS: Data pooled for meta-analyses were limited to retrospective design studies. Studies included in the systematic review had low methodological consistency. CONCLUSION: Based on pooled results from multiple studies, stride time, contact time, cadence, and stride length averages are not distinguishable between runners either with or without a history of overuse injury. More prospective studies are required to determine the association of temporal spatial parameters with overuse injury development in runners. SYSTEMATIC REVIEW REGISTRATION REGISTRY AND NUMBER: CRD42018112290.

5.
Ecol Lett ; 23(1): 140-148, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31663682

RESUMO

Ecologists expect species and biomes to shift poleward and upward with climate change, but non-climatic factors complicate these predictions. In mountains, forests are expected to expand upward along climate gradients into subalpine/alpine meadows, while meadows expand upward onto bare ground. However, soils also vary across elevation, with bare soil above the meadows potentially poorer for plant establishment. Poor soil might constrain expansion at meadows' upper edges, while rich meadow soil might facilitate contraction at lower edges by promoting tree establishment. We assessed climate and soil effects on establishment by transplanting soil and seedlings of meadow and tree species across climate gradients on Mount Rainier. There were considerable interspecific differences, but some generalisations emerged. Survival often declined with earlier snow disappearance, with somewhat smaller declines in meadow soil. Size often increased with earlier snow disappearance, with larger increases in meadow soil. Thus, soil patterns may complicate range shifts.


Assuntos
Plântula , Solo , Mudança Climática , Florestas , Neve , Árvores
6.
Med Sci Sports Exerc ; 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31809412

RESUMO

INTRODUCTION: Coordination of multiple degrees of freedom in the performance of dynamic and complex motor tasks presents a challenging neuromuscular control problem. Experiments have inferred that humans exhibit self-organized, preferred coordination patterns, which emerge due to actor and task constraints on performance. The purpose of this study was to determine if the set of effective coordination strategies that exist for a task centers on a small number of robust, invariant patterns of behavior. METHODS: Kinetic movement patterns computed from a cohort of 780 primarily female adolescent athletes performing a drop vertical jump task (DVJ) were analyzed in order to discover distinct groups into which individuals could be classified based on the similarity of movement coordination solutions. RESULTS: Clustering of reduced-dimension joint moment of force time series revealed three very distinct, precisely delineated movement profiles that persisted across trials, and which exhibited different functional performance outcomes, despite no other apparent group differences. The same analysis was also performed on a different task-a single-leg drop landing (SLD)-which also produced distinct movement profiles; however, the three DVJ profiles did not translate to this task as group assignment was inconsistent between these two tasks.The task demands of the DVJ and SLD-successful landing, reversal of downward momentum, and, in the case of the DVJ, vertical propulsion toward a maximally positioned target-constrain movement performance such that only a few successful outcomes emerge. Discovery of the observed strategies in the context of associated task constraints may help our understanding of how injury risk movement patterns emerge during specific tasks, as well as how the natural dynamics of the system may be exploited to improve these patterns.

8.
Int J Sports Phys Ther ; 14(3): 359-367, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31681495

RESUMO

Background: There is a growing incidence of foot injuries in basketball, which may be from the sport's repetitive, forceful multi-directional demands. Modifying midsole stiffness of the basketball shoe has been reported to alter ankle motion and plantar forces to reduce the risk of injury; however, the effects on anatomical, in-shoe foot (metatarsal), motion is not well understood. Purpose: The purpose of this study was to identify differences in foot and ankle biomechanics between basketball shoes with differing midsole stiffness values during single-leg jump landings. It was hypothesized that a stiffer midsole would elicit lower 1st metatarsophalangeal joint (MTPJ) dorsiflexion angles, higher ankle dorsiflexion angles, and higher plantar forces and relative loading in the distal foot. Study Design: Experimental cross-sectional study. Methods: Twenty high school and collegiate-aged basketball players performed a single-leg side drop jump and a single-leg cross drop jump in a pair of standard basketball shoes and a pair of shoes modified with a fiberglass plate to increase midsole stiffness. Three-dimensional motion analysis and flexible insoles quantified foot and ankle kinematics and plantar force distribution, respectively. Separate 2 (footwear) × 2 (task) repeated measures ANOVA models were used to analyze differences in 1) ankle kinematics, 2) 1st metatarsophalangeal kinematics, 3) maximal regional plantar forces, and 4) relative load. Results: The stiffer shoe elicited decreased peak ankle plantarflexion (mean difference = 5.8 °, p = 0.01) and eversion (mean difference = 6.6 °, p = 0.03) and increased peak ankle dorsiflexion angles (mean difference = 5.0 °, p = 0.008) but no differences were observed in 1st MTPJ motion (p > 0.05). The stiffer shoe also resulted in lower peak plantar forces (mean difference = 24.2N, p = 0.004) and relative load (mean difference = 1.9%, p = 0.001) under the lesser toes. Conclusions: Altering the midsole stiffness in basketball shoes did not reduce motion at the MTPJ, indicating that added stiffness may reduce shoe motion, but does not reduce in-shoe anatomical motion. Instead, a stiffer midsole elicits other changes, including additional ankle joint motion and a reduction in plantar forces under the lesser toes. Collectively, this indicates that clinicians need to account for unintended compensations that can occur throughout the kinetic chain when altering a shoe property to alleviate a musculoskeletal injury. Level of Evidence: 2b.

10.
J Biomech ; 95: 109293, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31455500

RESUMO

Knee kinetic asymmetries are present during jump-landings in athletes returning to sport following anterior cruciate ligament (ACL) reconstruction, and are associated with an increased risk for sustaining a second ACL injury. The loadsol® is a wireless load sensing insole that can be used in non-laboratory settings. The purpose of this study was to determine if the loadsol® could be used to predict knee extension moment and power symmetry during a bilateral stop jump task in healthy recreational athletes. Forty-two uninjured recreational athletes completed seven bilateral stop jumps. During each landing, the loadsol® (100 Hz) measured plantar load while 3D ground reaction forces (1920 Hz) and lower extremity kinematics (240 Hz) were collected simultaneously. Peak impact force, loading rate, and impulse were quantified using the loadsol® and peak knee extension moment, average knee extension moment, and total knee work was quantified using the laboratory instrumentation. Limb symmetry indices were quantified for each outcome measure. Multivariate backwards regressions were used to determine if loadsol® symmetry could predict knee kinetic symmetry. Intraclass correlation coefficients (ICCs) and Bland-Altman plots were used to determine the agreement and error between predicted and actual knee kinetic symmetry. Loadsol® impulse and peak impact force symmetry significantly predicted kinetic knee symmetry and explained 42-61% of its variance. There was good agreement (ICCs = 0.742-0.862) between predicted and actual knee kinetic symmetry, and the error in the predicted outcomes range from ±18 to ±43. These results support using the loadsol® to screen for kinetic symmetries during landing in athletes following ACL reconstruction.

12.
Front Pediatr ; 7: 268, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31316956

RESUMO

Sport specialization is a growing trend in youth athletes and may contribute to increased injury risk. The neuromuscular deficits that often manifest during maturation in young, female athletes may be exacerbated in athletes who specialize in a single sport. The purpose of this study was to investigate if sport specialization is associated with increased lower extremity biomechanical deficits pre- to post-puberty in adolescent female athletes. Seventy-nine sport-specialized female adolescent (Mean ± SD age = 13.4 ± 1.8 years) basketball, soccer, and volleyball athletes were identified and matched with seventy-nine multi-sport (soccer, basketball, and volleyball) female athletes from a database of 1,116 female adolescent basketball, soccer, and volleyball athletes who were enrolled in one of two large prospective, longitudinal studies. The athletes were assessed over two visits (Mean ± SD time = 724.5 ± 388.7 days) in which they were classified as pre-pubertal and post-pubertal, respectively. Separate 2 × 2 analyses of covariance were used to compare sport-specialized and multi-sport groups and dominant/non-dominant limbs with respect to pubertal changes in peak knee sagittal, frontal, and transverse plane joint angular measures and moments of force recorded while performing a drop vertical jump task. The sport-specialized group were found to exhibit significantly larger post-pubertal increases in peak knee abduction angle (p = 0.005) and knee abduction moment (p = 0.006), as well as a smaller increase in peak knee extensor moment (p = 0.032) during landing when compared to the multi-sport group. These biomechanical changes are indicative of potentially compromised neuromuscular control that may increase injury risk pre- to post-puberty in sport-specialized female athletes. Consideration of maturation status may be an important factor in assessing the injury risk profiles of adolescent athletes who specialize in sport.

13.
Ann Biomed Eng ; 47(12): 2416-2430, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31290036

RESUMO

The anterior cruciate ligament is the primary structural restraint to tibial anterior shear force. The anterior force occurring at the knee during landing contributes to anterior cruciate ligament injury risk, but it cannot be directly measured experimentally. The objective of this study was to develop electromyography-informed musculoskeletal simulations of the drop vertical jump motor task and assess the contribution of knee muscle forces to tibial anterior shear force. In this cross-sectional study, musculoskeletal simulations were used to estimate the muscle forces of thirteen female athletes performing a drop vertical jump using an electromyography-informed method. Muscle activation and knee loads that resulted from these simulations were compared to the results obtained with the more common approach of minimization of muscle effort (optimization-based method). Quadriceps-hamstrings and quadriceps-gastrocnemius co-contractions were progressively increased and their contribution to anterior shear force was quantified. The electromyography-informed method produced co-contraction indexes more consistent with electromyography data than the optimization-based method. The muscles that presented the largest contribution to peak anterior shear force were the gastrocnemii, likely from their wrapping around the posterior aspect of the tibia. The quadriceps-hamstring co-contraction provided a protective effect on the ACL and reduced peak anterior shear force by 292 N with a co-contraction index increase of 25% from baseline (31%), whereas a quadriceps-gastrocnemius co-contraction index of 61% increased peak anterior shear force by 797 N compared to baseline (42%). An increase in gastrocnemius contraction, which might be required to protect the ankle from the impact with the ground, produced a large quadriceps-gastrocnemius co-activation, increasing peak anterior shear force. A better understanding of each muscle's contribution to anterior shear force and, consequently, anterior cruciate ligament tension may inform subject-specific injury prevention programs and rehabilitation protocols.

14.
Sports (Basel) ; 7(2)2019 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-30781535

RESUMO

The aim of this study was to determine whether the speed, agility, aerobic and anaerobic capacities of football players varied by playing positions. Elite youth football players (n = 123, age = 15.7 ± 0.5 years) who played in six different positions, as goalkeepers (GK), full backs (FB), central defenders (CD), wide midfielders (WM), central midfielders (CM), and attackers (AT), were assessed. Multivariate analysis of variances was used to compare the following variables: Linear running sprint for 5 m (S5) and 10 m (S10), flying sprint for 20 m (F20), agility 505 test with turn on the dominant (A505D) and non-dominant leg (A505N), agility K-test, Yo-Yo intermittent recovery (YYIR1) test and repeat sprint ability (RSA) test. The results showed significant influence of playing positions on linear-running sprint performance (F1,123 = 6.19, p < 0.01, ηp² = 0.23). Midfielders reached significantly higher performance levels (CM = 2.44 ± 0.08 s, WM = 2.47 ± 0.13 s) in the A505N test compared to GK (2.61 ± 0.23 s). Outfield players had significantly higher performance in both YYIR1 and RSA tests compared to GK (p < 0.01). The results of this study may provide insightful strategies for coaches and clinical practitioners for developing position-specific conditioning programs.

16.
Artigo em Inglês | MEDLINE | ID: mdl-30259145

RESUMO

PURPOSE: To investigate the differences in demographic, anthropometric, biomechanical, and/or performance variables between those that do (responders) and do not (non-responders) exhibit reductions in knee abduction moments after an anterior cruciate ligament injury prevention program (ACL-IPP). METHODS: Forty-three adolescent female athletes completed biomechanical (3D motion analysis of a drop vertical jump) and performance testing before and after randomization into a 6-week ACL-IPP. Participants were classified into responders and non-responders based on their level of reduction of knee abduction moment from pre- to post-test. RESULTS: Compared to non-responders, responders exhibited increased hip adduction excursion at baseline (p = 0.02) and trended towards attending more training sessions (p = 0.07) and participating in soccer and not basketball (p = 0.07). Responders also showed greater improvements in hip flexion angles (p = 0.02) and moments (p < 0.001), and knee abduction angles (p < 0.001) and excursions (p = 0.001). There were no significant differences in age or experience with prior injury prevention programs (n.s.). CONCLUSIONS: After an ACL-IPP, athletes that exhibit the greatest reduction in knee abduction moments exhibit greater hip adduction excursion at baseline and show corresponding improvements in hip flexion and knee abduction kinematics and hip flexion moments. These results can help clinicians prospectively identify individuals that may not respond to an ACL-IPP and target individualized training for those at risk of injury. LEVEL OF EVIDENCE: I. CLINICAL TRIAL REGISTRATION NUMBER: Clinicaltrials.gov NCT02530333.

17.
Am J Sports Med ; 46(11): 2761-2771, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30091937

RESUMO

BACKGROUND: Female athletes are at an increased risk of developing patellofemoral pain (PFP) relative to male athletes. The unique effects of maturation may compound that risk. Hypothesis/Purpose: The purpose was to evaluate the neuromuscular control mechanisms that are adaptive to pubertal maturation and determine their relative contribution to PFP development. It was hypothesized that aberrant landing mechanics (reduced sagittal-plane and increased frontal- and transverse-plane kinematics and kinetics) would be associated with an increased risk for PFP. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: There were 506 high school female athletes who completed a detailed medical history, the Anterior Knee Pain Scale, and a knee examination for the diagnosis of PFP and attended follow-up appointments. Athletes performed a drop vertical jump task instrumented with force plates, and biomechanical measures generated from standard 3-dimensional biomechanical analyses were used to classify participants into high- or low-risk knee and hip landing profiles for the development of PFP. The biomechanical measures used in the knee landing profile included sagittal-plane knee range of motion, peak knee abduction angle, peak knee abduction moment, and peak-to-peak transverse-plane knee moment. The biomechanical measures used in the hip landing profile included sagittal-plane hip range of motion, peak hip extensor moment, peak abductor moment, and peak hip rotator moment. Testing was conducted at sport-specific preseason appointments over the course of 2 years, and changes in pubertal status, landing profile, and PFP development were documented. RESULTS: Female athletes with high-risk hip landing profiles experienced increased hip flexion and decreased abductor, rotator, and extensor moments. Participants with high-risk hip landing profiles who transitioned to postpubertal status at follow-up had higher odds (odds ratio, 2.1 [95% CI, 1.1-4.0]; P = .02) of moving to a low-risk hip landing profile compared with those who had not reached postpubertal status at follow-up. Participants with high-risk knee landing profiles experienced decreased knee flexion and increased knee abduction, external abductor, and external rotator moments. Pubertal maturation was not associated with a change in the high-risk knee landing profile at follow-up. CONCLUSION: The progression from prepubertal to postpubertal status may have a protective effect on high-risk hip mechanics but no similar adaptations in high-risk knee mechanics during maturation. These data indicate that before puberty, maladaptive hip mechanics may contribute to PFP, while aberrant knee mechanics associated with PFP are sustained throughout the maturational process in young female athletes.


Assuntos
Artralgia/diagnóstico , Articulação do Quadril/fisiologia , Articulação Patelofemoral/lesões , Articulação Patelofemoral/fisiologia , Exercício Pliométrico , Puberdade/fisiologia , Adolescente , Fatores Etários , Artralgia/etiologia , Fenômenos Biomecânicos , Estudos de Coortes , Feminino , Humanos , Movimento , Fatores de Risco , Rotação , Maturidade Sexual/fisiologia , Análise e Desempenho de Tarefas , Adulto Jovem
18.
Int J Sports Phys Ther ; 13(3): 441-452, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30038830

RESUMO

Background: Lower extremity overuse injuries, including bone stress injuries (BSI), are common in runners and may result in prolonged recovery and time off from running. Identifying risk factors for running-related overuse injuries may have a clinically relevant role in prevention of these injuries. Purpose: The purpose of this study was to compare an adolescent and young adult population of male runners known to have a history of BSI with an injury-free cohort and retrospectively assess for kinematic differences that may differentiate the two cohorts. Study Design: Controlled laboratory case control investigation. Level of Evidence: Level 3. Methods: 25 male high school and collegiate cross-country runners were enrolled. Ten self-reported a prior history of BSI consisting of lower extremity stress fracture or shin splints/medial tibial stress syndrome and were categorized as injured (INJ). Fifteen self-reported no prior history of lower extremity injury and were categorized as uninjured (UNINJ). All runners were pain-free at time of testing. Runners ran at a self-selected speed on a treadmill with retro-reflective markers attached to thorax, pelvis, and each lower extremity segment. Three-dimensional kinematic calculations were made during stance phase (initial treadmill heel contact to toe off) and averaged over 20 steps. One-way ANCOVA was used to compare kinematic differences at the hip and knee between the INJ and UNINJ cohort. Results: Runners in the INJ group demonstrated greater peak hip flexion during stance phase on both the right limb [INJ = 32.5°(±3.8°) vs. UNINJ = 26.9°(±4.6°); p<0.01] and the left limb [INJ = 31.2°(±4.8°) vs. UNINJ = 26.8°(±3.1°); p = 0.01] when compared to the UNINJ group. No significant difference in step length or step rate between the INJ and UNINJ cohorts was noted when normalized to height and weight (p = 0.39 and 0.39). Conclusions: The results of this study demonstrate increased peak stance phase hip flexion in a population of young adult male runners with a previous history of BSI. This association may represent an important preliminary finding in the development of a clinically relevant tool to identify risk of BSI. Due to the retrospective nature of this study, future prospective investigations are warranted to validate these findings to determine if these alterations are compensatory following an injury or predictive of a future injury.

19.
J Sports Sci ; 36(21): 2492-2501, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29671383

RESUMO

Anterior cruciate ligament (ACL) injury prevention programmes have not been as successful at reducing injury rates in women's basketball as in soccer. This randomised controlled trial (ClinicalTrials.gov #NCT02530333) compared biomechanical adaptations in basketball and soccer players during jump-landing activities after an ACL injury prevention programme. Eighty-seven athletes were cluster randomised into intervention (6-week programme) and control groups. Three-dimensional biomechanical analyses of drop vertical jump (DVJ), double- (SAG-DL) and single-leg (SAG-SL) sagittal, and double- (FRONT-DL) and single-leg (FRONT-SL) frontal plane jump landing tasks were tested before and after the intervention. Peak angles, excursions, and joint moments were analysed using two-way MANCOVAs of post-test scores while controlling for pre-test scores. During SAG-SL the basketball intervention group exhibited increased peak knee abduction angles (p = .004) and excursions (p = .003) compared to the basketball control group (p = .01) and soccer intervention group (p = .01). During FRONT-SL, the basketball intervention group exhibited greater knee flexion excursion after training than the control group (p = .01), but not the soccer intervention group (p = .11). Although women's soccer players exhibit greater improvements in knee abduction kinematics than basketball players, these athletes largely exhibit similar biomechanical adaptations to ACL injury prevention programmes.


Assuntos
Lesões do Ligamento Cruzado Anterior/prevenção & controle , Basquetebol/lesões , Joelho/fisiologia , Condicionamento Físico Humano/métodos , Exercício Pliométrico , Futebol/lesões , Adaptação Fisiológica , Adolescente , Basquetebol/fisiologia , Fenômenos Biomecânicos , Humanos , Futebol/fisiologia , Análise e Desempenho de Tarefas , Adulto Jovem
20.
Clin J Sport Med ; 2018 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-29620577

RESUMO

OBJECTIVE: To identify relationships between self-reported limb preferences and performance measures for determining limb dominance in adolescent female basketball players. DESIGN: Cross-sectional cohort study. PARTICIPANTS: Forty adolescent female basketball players. INDEPENDENT VARIABLES AND MAIN OUTCOME MEASURES: Participants provided self-reported preferred kicking and jumping limbs, then completed 3 trials of a single-limb countermovement hop (HOPVER) and unilateral triple hop for distance (HOPHOR) on each limb. Each test was used to independently define limb dominance by the limb that produced the largest maximum vertical height and horizontal distance, respectively. RESULTS: Chi-square tests for independence identified a significant relationship between self-reported preferred kicking and jumping legs (χ = 7.41, P = 0.006). However, no significant relationships were found when comparing self-reported preference to measures of performance during the HOPHOR (χ = 0.33, P = 0.57) or HOPVER (χ = 0.06, P = 0.80). In addition, the 2 performance measures did not consistently produce the same definition of limb dominance among individuals (χ = 1.52, P = 0.22). CONCLUSIONS: Self-selection of the dominant limb is unrelated to performance. Furthermore, limb dominance, as defined by vertical jump height, is unrelated to limb dominance defined by horizontal jump distance. The results of this study call into question the validity of consistently defining limb dominance by self-reported measures in adolescent female basketball players.

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