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To evaluate the adaptive movement and motor control patterns of a group with a 6-month history of first-time lateral ankle sprain (LAS) injury during a drop vertical jump (DVJ) task. Fifty-one participants with a 6-month history of first-time acute LAS injury and twenty controls performed a DVJ task. 3D kinematic and sagittal plane kinetic profiles were plotted for the lower extremity joints of both limbs for the drop jump (phase 1) and drop landing (phase 2) phases of the DVJ. Inter-limb symmetry and the rate of impact modulation (RIM) relative to bodyweight (BW) during both phases of the DVJ were also determined. LAS participants displayed bilateral increases in knee flexion and an increase in ankle inversion during phases 1 and 2, respectively. They also displayed reduced ankle plantar flexion on their injured limb during both phases of the DVJ (p < 0.05); increased inter-limb asymmetry of RIM was noted for both phases of the DVJ, while the moment-of-force profile exhibited bilaterally greater hip extensor dominance during phase 1. Participants with a 6-month history of first-time LAS display some movement patterns consistent with those observed in chronic ankle instability populations during similar tasks., (© 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

Background: Youth rugby players represent 45.2% (N = 69,472) of the Irish rugby union playing population. The risk and consequences of concussion injury are of particular concern in these young athletes, but limited epidemiological data exists. This study investigated annual and lifetime prevalence of concussion in an Irish schoolboy rugby union cohort., Methods: An anonymous cross-sectional survey of youth rugby players was conducted. Diagnosed concussion was defined as an incident where diagnosis was confirmed by a health professional or coach. Demographics, prevalence, and attitudes to concussion were collated. Data were analyzed with descriptive statistics, chi-square test, t-tests, Mann-Whitney tests, and logistic regression., Results: Overall, 304 youth (aged 12-18 years) responded. Lifetime prevalence of diagnosed concussion was 19.4%, with annual (2010) prevalence 6.6%. Approximately 25.4% of players with diagnosed concussions returned to play without medical advice. Internal motivation (11.8%) was the predominant factor in feeling pressure to play while concussed. A desire for further concussion education was expressed by 89.5% of participants., Conclusions: Reform is required to prevent and manage concussion injuries among youth players in the rugby union, including mandatory education specific to concussion and implementation of return-to-play protocols. These findings have relevance for governing bodies, coaches, clinicians, schools, parents, and rugby union players., (© 2014, American School Health Association.)

The aim of this study was to determine if anterior cruciate ligament reconstructed (ACL-R) female athletes exhibit altered lower limb kinematic profiles during jump landing when compared to a non-injured age, sex, and activity matched control group. Fourteen ACL-R and 14 non-injured control subjects performed 3 vertical drop jump (DVJ) trials. Lower limb kinematics were recorded at 200 Hz. Peak and time-averaged angular displacements were quantified and utilized for between-group analysis. The ACL-R group displayed altered hip joint frontal and transverse plane kinematic alterations, and knee joint frontal and sagittal plane kinematic alterations. Specifically the ACL-R group displayed an increased adducted (p < 0.05) and internally rotated (p < 0.05) hip joint position, both peak and time-averaged, following landing. The ACL-R group also displayed a decreased adducted (p < 0.05) and flexed (p < 0.05) position of the knee joint following landing. The observed aberrant lower limb kinematics could pre-dispose ACL-R athletes to potential future knee joint injuries. Further studies are required to determine in a prospective manner whether such deficits increase the incidence of recurrent ACL injury, and whether specific sensorimotor protocols following ACL reconstruction can minimize these kinematic deficits., (Copyright © 2011 Orthopaedic Research Society.)

The purpose of this study was to identify differences in 3D kinematics, kinetics, and ankle joint muscle activity in subjects with functional instability (FI) of the ankle joint during a drop jump. Twenty-four subjects with the subjective complaint of FI of the ankle joint and 24 noninjured control subjects performed 10 single leg drop jumps onto a force-plate. Timing and magnitude of kinetic data, timing of kinematic data, and integrated EMG (IEMG) activity of the rectus femoris, peroneus longus, tibialis anterior, and soleus muscles during two 200-ms time periods either side of initial contact (IC) with the ground were analyzed and compared between groups. Subjects with FI demonstrated a significant decrease in pre-IC peroneus longus IEMG activity, which was accompanied by a change in frontal plane movement at the ankle joint during the same time period. Following IC, FI subjects were less efficient than control group subjects in reaching the closed packed position of the ankle joint. Significant differences were seen between the groups' time-averaged and peak vertical and sagittal components of ground reaction force. The altered pre-IC peroneus longus IEMG and increased inversion of the ankle joint observed in FI subjects could help to explain why subjects with FI may suffer from inversion injury to their ankle joint when subjected to an unanticipated ground contact. The kinematic and kinetic differences observed in subjects with FI may lead to repeated injury and damage to the supporting structures of the ankle joint., (Copyright (c) 2006 Orthopaedic Research Society.)