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This study aimed to clarify the kinematic, kinetic characteristics associated with lateral ankle sprain.A 16-month prospective cohort study.Laboratory.A total of 179 college athletes.Joint kinematics, moment during single-leg landing tasks, and ankle laxity were measured. The attendance of each participating team, injury mechanism, existence of body contact, presence of orthosis, with or without medical diagnosis, and periods of absence were recorded.Twenty-nine participants incurred lateral ankle sprain during non-contact motion. The Cox regression analysis revealed that greater knee varus peak angle (hazard ratio: 1.16 [95% confidence interval: 1.10-1.22], p 0.001) and greater pelvic internal rotation peak angle toward the support leg were associated with lateral ankle sprain (hazard ratio: 1.08 [95% confidence interval: 1.02-1.15], p = 0.009). The cut-off values for each predictive factor were -0.17° (area under the curve = 0.89, p 0.001) and 6.63° (area under the curve = 0.74, p 0.001), respectively.A greater knee varus peak angle and pelvic internal rotation peak angle after single-leg landing are predictive factors for lateral ankle sprain.

Introduction Maintaining flexibility, often defined as range of motion (ROM), is important. Recently, self-massage using a foam roller (FR) has been used in clinical and/or sports settings to effectively and immediately improve ROM. Many studies have found significant increases in ROM following the FR intervention; however, the mechanism of the effect is unclear. We aimed to clarify this mechanism regarding the ROM effects following the FR intervention by evaluating local tissue and autonomic nervous system responses. Method The study employed a crossover design that included a comparison between non-intervention (CON trial: left leg) and intervention (FR trial: right leg) groups. Fourteen volunteers participated. Nine outcomes (passive maximum ankle ROM [ROM with a specified and non-specified passive strength], tissue hardness, skin temperature, water contents, circumference, blood flow velocity, pressure pain threshold, autonomic nervous system, and heart rate) were investigated before (PRE) and 0 min (POST0), 20 min (POST20), 40 min (POST40), and 60 min (POST60) post intervention. Results Skin temperature, impedance, and circumference changed significantly following the intervention, and increased ROM with non-specified strength was observed. Discussion Although we found that the FR intervention influenced skin temperature, impedance, circumference, and ROM, adaptability to the intervention may differ depending on an individual's characteristics. Females and/or individuals with a high body water content could obtain greater positive ROM effects than males and/or individuals with a low body water content. Conclusion These findings suggest that the FR intervention may be an effective method to improve ROM, with alterations of skin temperature, impedance, and circumference.

Objective To assess the discriminability as well as the reliability, and internal consistency of the Identification of Functional Ankle Instability questionnaire translated into Japanese (IdFAI-J). Design Cross-sectional study. Setting Collegiate athletic training/sports medicine clinic. Participants Twenty bilingual and sixty-five collegiate athletes including participants with and without functional instability (FI). Main outcome measures The sensitivity, specificity, test retest reliability, and internal consistency of IdFAI-J. Results The optimal cutoff score between the FI and non-FI participants was >10, with an area under the curve of 0.92. We calculated high sensitivity (0.94) and specificity (0.77) at the cutoff point. For the test-retest reliability, the intraclass correlation coefficient value of the IdFAI-J was 0.96; the standard error of measurement and minimal detectable change value was 1.69 and 3.60, respectively. Cronbach's α was 0.87; there was no improvement when a particular item was deleted from the scale. Conclusions The IdFAI-J has excellent discriminability, test-retest reliability, and internal consistency. Hence, the IdFAI-J significantly contribute to clinical practice and future research related to ankle instability in Japan.

Background The Kerlan-Jobe Orthopaedic Clinic (KJOC) score has been used to describe various parameters of throwing shoulder and elbow function for the return to play after a long period of rehabilitation, such as after ulnar collateral ligament reconstruction. No study has yet to identify how scapular dyskinesis (SD) in baseball players affects the KJOC score. This study investigated the relationship of the KJOC score to SD evaluated in collegiate baseball players with and without upper extremity injury. Materials and methods The study participants were 30 male collegiate baseball players (13 pitchers) belonging to the National Collegiate Athletic Association D-I conference. Participants were assessed with the KJOC instrument in the beginning (PRE) and end (POST) of the season. The SD test was conducted (PRE) in shoulder flexion to identify SD Results The mean value of KJOC score was significantly less in POST than that of PRE for the pitchers with SD (89.3 and 60.5, respectively; P = .001), whereas no difference was found in the KJOC score between PRE and POST for the pitchers without SD. For the position players, no difference in the mean value of KJOC score was found between PRE and POST, regardless of SD. Conclusion The results of this study provide evidence that collegiate baseball pitchers with mild SD may have lower KJOC scores, particularly setup or relief pitchers.

Background: Anterior cruciate ligament (ACL) injury is one of the most devastating injuries in sports. Althoughmany studies have demonstrated successful prevention program in research settings, the rate of ACL injury remains high. One of the reasons might be a low participants adherence to injury prevention training programs. More effective and efficient strategy is needed to reduce the rate of ACL injury. This study implemented a simplified skill training program that was specific to basketball in order to encourage the athletes and coaches to perform the program with a high adherence. This study also attempted to train younger athletes than those who were usually targeted, as learning proper movement skills could be better achieved in younger population. Purpose:To evaluate the effects of skill training on lowerextremity kinematics and muscle function in female pubertal athletes. Methods: Nine female basketball players (age 12.6± 0.5 years) participated in the study. A 12-week skill training program was implemented. The focus of the program was to ensure proper landing techniques. The skills required in basketball, such as jumping, stopping, and pivoting, were practiced with the instruction to use proper body mechanics. Isokinetic strength of the hip and knee joints, and lower-extremity kinematics and preparatory muscle activities during drop vertical jumps were evaluated before and after the training period. The data were compared between the preand post-test by using a paired t-test or a Wilcoxon signed-rank test. Results: The knee abduction angle at 40ms after ground contact, when ACL injuries typically occur, was significantly decreased after the training period (−1.9± 5.8 vs. −4.5± 3.8◦, p= 0.04). The preparatory muscle activities of the rectus femoris, vastus medialis, and gluteus maximus were significantly decreased (rectus femoris: 38.0± 25.2 vs. 21.5± 7.7%MVIC, p= 0.04; vastusmedialis: 37.6± 22.8 vs. 23.0± 13.1%MVIC, p= 0.01; gluteus maximus: 13.8± 9.2 vs. 5.4± 1.8%MVIC, p= 0.02) and the isokinetic strength of knee flexion was significantly increased after the training period (0.83± 0.18 vs. 0.94± 0.10Nm/kg, p= 0.04). These changes in the muscle function might suggest an improved proficiency in the performance of the landing task. Conclusion(s): A 12-week training program that focused on proper landing skills might be effective in reducing the knee abduction angle at 40ms after ground contact. The training program also changed the preparatory muscle activity and isokinetic strength. These results suggested that the skill training program might have improved not only the landing skills but also the neuromuscular function in female pubertal athletes. Implications: Simplified skill training might be sufficient for young athletes to modify the landing technique and muscle function. The implementation of the skill training should be encouraged in pubertal girls to reduce the risk of developing ACL injury.