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ABSTRACT Hamstring injury prevention puts emphasis on optimizing the muscle's strength-length relationship. To assure appropriate muscle length, flexibility training is imperative. As neurodynamics play an important role herein, the goal of this study was to explore the intervention effect of home-based neurodynamic slider program on hamstring flexibility. Fifty physically active male subjects were randomly assigned to either performing a neurodynamic sliding technique (3 × 20 reps) or a static stretching protocol (3 × 30″) on a daily basis for a 6-week period. Hamstring flexibility was assessed by means of the Straight Leg Raise at baseline, immediately after the intervention and after 4 weeks follow up. There was no between group baseline difference in hamstring flexibility. The repeated measure ANOVA showed a significant interaction effect for group × time ( p  < 0.001). Independent sample t -test showed a significantly higher increase in flexibility gain in the neurodynamic group immediately after the intervention ( p  < 0.001), as well as at 4 weeks retention analysis ( p  = 0.001) compared to the static stretch group. In conclusion, neurodynamic sliders might be more efficient than regular static stretching in affecting hamstring flexibility in the long run.

Context: Although taping has been proven effective in reducing ankle sprain events in individuals with chronic ankle instability, insight into the precise working mechanism remains limited., Objectives: To evaluate whether the use of taping changes ankle joint kinematics during a sagittal and frontal plane landing task in subjects with chronic ankle instability., Design: Repeated measure design., Setting: Laboratory setting., Participants: A total of 28 participants with chronic ankle instability performed a forward and side jump landing task in a nontaped and taped condition. The taping procedure consisted of a double "figure of 6" and a medial heel lock., Main Outcome Measures: 3D ankle joint kinematics was registered. Statistical parametric mapping was used to assess taping effect on mean ankle joint angles and angular velocity over the landing phase., Results: For both the forward and side jump, a less plantar flexed and a less inverted position of the ankle joint were found in the preparatory phase till around touchdown (TD) in the taped condition (P < .05). In addition, for both jump landing protocols, a decreased dorsiflexion angular velocity was found after TD (P < .05). During the side jump protocol, a brief period of increased inversion angular velocity was registered after TD (P < .05)., Conclusions: Taping is capable of altering ankle joint kinematics prior to TD, placing the ankle joint in a less vulnerable position at TD.

Introduction: This study aimed to simplify and optimize the distinction between nonfunctional overreaching (NFO) and overtraining syndrome (OTS) by developing a multivariate approach (discriminant analysis [DA]) including hormonal and psychological changes measured during the Training Optimization (TOP) test., Methods: Sensitivity of previously defined cutoff values for hypothalamic-pituitary-adrenal axis hormonal changes were recalculated on a larger database (n = 100). Discriminant analysis including hormonal and psychological variables measured during the TOP test was used to discriminate between NFO and OTS and predict the diagnosis of new cases., Results: Adrenocorticotrophic hormone (ACTH) and prolactin (PRL) responses to the second exercise test were most sensitive to NFO and OTS. Cutoff values for ACTH and PRL response to the second test (NFO > cutoff value (200%) > OTS), showed a sensitivity of 67% for ACTH and 93% for PRL in case of OTS and 74% for both ACTH and PRL in case of NFO. A DA including hormonal and psychological changes measured during the TOP test, resulted in the accurate diagnosis of NFO and OTS with 98% sensitivity. The ACTH and PRL responses to the first and second exercise tests and feeling of fatigue were the most discriminating variables., Conclusions: The ACTH and PRL responses during the TOP test are the most sensitive markers to discriminate between NFO and OTS. Discriminant analysis including hormonal and psychological responses during the TOP test, can be used to optimize the diagnosis of NFO and OTS.

Rationale: Type 1 diabetes (T1D), a chronic autoimmune disease, can result in cognitive dysfunction and is associated with vascular dysfunction. Cocoa flavanols (CFs) can stimulate nitric oxide-dependent vasodilation, resulting in enhanced hemodynamic responses and better cognitive function., Objectives: To investigate whether acute CF supplementation can improve cognitive function and hemodynamic responses in T1D., Methods: In this randomized, double-blinded, cross-over pilot study, 11 patients with T1D and their healthy matched controls consumed CF (900 mg CF) and placebo (15 mg CF) 2 h before a flanker test. fMRI was used to measure blood oxygen level-dependent (BOLD) response during the cognitive test. Repeated measure ANOVAs were used to test the effects of CF and T1D on BOLD response and cognitive performance., Results: CF improved reaction time on the flanker test and increased the BOLD response in the supramarginal gyrus parietal lobe and inferior frontal gyrus, compared to placebo, in both groups. In patients with T1D, cognitive performance was not deteriorated while the BOLD response was smaller in T1D compared to healthy controls in the subgyral temporal lobe and the cerebellum., Conclusions: Acute CF intake improved reaction time on the flanker test and increased the BOLD response in the activated brain areas in patients with T1D and their matched controls.

Objectives: To investigate the association of maturity status with injury incidence in Middle-Eastern youth athletes., Design: Prospective cohort study., Setting: Four consecutive seasons (2010-2014), Aspire Academy, Qatar., Participants: Male athletes (age range: 11-18 years) representing four disciplines enrolled and grouped into two categories: individual sports and racquet sports., Outcome Measures: Injury data collected over four seasons. Athletes' anthropometric characteristics assessed to calculate age at peak height velocity. Predicted mature heights (PMHs) collected and categorised into four quartiles. Athletes had wrist and hand radiographs for assessment of skeletal age (SA). Early and late maturers with an SA of >1 year older or younger than their chronological age (CA)., Results: For the sample (n=67) across all groups, 43 (64%) athletes had one or more injuries: total of 212 injuries, 4.9 injuries per athlete across study. Survival analysis of maturity status using SA found early maturing athletes had two-fold greater injury risk compared with late maturers (HR 2.04, 95% CI 1.15 to 3.61, p=0.015). PMH associated with injury risk (HR 1.05, 95% CI 1.01 to 1.08, p=0.006).Athletes in fourth quartile (≥184 cm) had up to two-fold injury risk (HR 2.41, 95% CI 1.42 to 4.08, p=0.001). Racquet and individual sports involved similar injury risk (HR 1.14, 95% CI 0.86 to 1.52, p=0.37)., Conclusion: SA early maturity and PMH gradient were significant predictors of injury in youths., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To prospectively identify hip strength associated risk factors contributing to the development of lower extremity (LE) injury., Design: Data were prospectively collected on healthy female physical education students., Setting: This study was conducted in the institution of the University of Ghent., Participants: Eighty-nine female physical education students aged 19.53 ± 1.07 years., Assessment of Risk Factors: Testing included isokinetic hip strength measurements of abductors, adductors, internal rotators, and external rotators (ERs)., Main Outcome Measures: Follow-up of the participants was assessed using a weekly online questionnaire and a 3-month retrospective control questionnaire. Lower extremity injury was diagnosed by an experienced medical doctor. Cox regression was used to identify the potential risk factors for the development of an LE injury., Results: Thirty-four participants were diagnosed with an LE injury during follow-up. This study identified that decreased average power (AP) (P = 0.031) on concentric ER strength was found to be a significant risk factor for LE injury. No other hip strength parameters were found to be significant contributors to the development of LE injury., Conclusions: Decreased AP of the hip ER muscles was identified as a significant predictor for LE injury, whereas no hip abduction weakness or peak torque parameters were found to be predictive. Because controlling LE extremity movements is an important function of the hip muscles, they might be more challenged in a dynamic measure such as AP than in a point measure such as peak torque. Concentric AP of hip ER muscles can therefore be seen as an interesting factor to include in LE injury screening protocols.

Objective: To prospectively identify proximal risk factors contributing to the development of exertional medial tibial pain (EMTP)., Methods: Data were prospectively collected on healthy female students in physical education, who were freshmen in 2010-2011 and 2011-2012. 95 female students, aged 18.15 ± 0.84, were tested at the beginning of their first academic year. Testing included isokinetic hip strength measurements of the abductors, adductors, internal rotators and external rotators. The follow-up of the individulas was assessed using a weekly online questionnaire and a 3-monthly retrospective control questionnaire. EMTP was diagnosed by an experienced MD (Doctor of Medicine). Cox regression analysis was used to identify the potential risk factors for the development of EMTP., Results: 21 individuals were diagnosed with EMTP during follow-up. The results of this study identified that decreased hip abductor concentric strength is a predictive parameter for the development of EMTP in females. More specifically, total work (p=0.010) and average power (p=0.045) for concentric abduction strength were found to be significant predictors for this lower leg overuse injury., Conclusions: Hip abductor weakness is a significant predictor for EMTP in women. Preventive screening methods for EMTP should therefore include this proximal contributing factor., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Purpose: This study aimed to prospectively analyze the role of factors on the contralateral side of the kinetic chain in the development of exertional medial tibial pain (EMTP)., Methods: Eighty-one female physical education students were tested at the beginning of their first academic year. Within the testing protocol, contralateral isokinetic hip muscle strength and full-body kinematic parameters during a single-leg drop jump were evaluated. Online questionnaires were administered weekly, and personal interviews were conducted every 3 months to assess injury follow-up. EMTP was diagnosed by an experienced medical doctor. Cox regression analysis was used to identify the potential risk factors for the development of EMTP., Results: After exclusion of subjects with diagnosed bilateral EMTP, 11 subjects were included in the EMTP group. Fifty-three subjects did not develop any lower extremity overuse injury and were included in the control group. The leg not at risk within subjects who developed EMTP was compared with an uninjured leg of those in the control group. Increased transverse plane motion for the contralateral lower leg segment during landing phase was found to be a significant predictor (P = 0.012) for EMTP. Analysis of the isokinetic data did not reveal altered hip muscle strength parameters for the leg not at risk within the EMTP group., Conclusions: Impaired dynamic joint stability or accessory movements were found in the transverse plane of the contralateral lower leg segment of EMTP subjects. This contralateral instability might have contributed to altered movement patterns within the kinetic chain function of EMTP subjects. No contralateral hip muscle strength parameters were found to predict EMTP in this study.

Background: Enhancing the accuracy of a risk factor screening test is an important element of sports injury prevention., Purpose: To determine the effect of muscle fatigue on a screening tool for those at risk of exertional medial tibial pain (EMTP)., Study Design: Cohort study (prognosis); Level of evidence, 2., Methods: Sixty-nine female students in a physical education program with a mean age of 19.24 ± 0.86 years were tested at the beginning of their first academic year and followed for 1 to 2 years. Participants completed an online questionnaire every week and a retrospective control questionnaire every 3 months, which were used to assess injury follow-up. A diagnosis of EMTP was made by an experienced medical doctor. A Cox regression analysis was used to identify the potential risk factors by comparing prefatigue and postfatigue data between uninjured participants and those with EMTP. Both the leg that developed EMTP and the contralateral leg were compared with legs of a matched control group., Results: During injury follow-up, 21 female participants were diagnosed with EMTP. Results of the comparison between uninjured versus EMTP participants, respectively, are as follows: For the leg at risk in the nonfatigued state, only increased range of motion in the transverse plane (ROMT) of the hip during landing could be identified as a risk factor (8.44° ± 2.94° vs. 11.69° ± 3.41°; P = .002). In the fatigued state, increased ROMT of the hip and pelvis during landing (hip: 8.04° ± 2.34° vs. 9.36° ± 3.22°; P = .038; pelvis: 6.99° ± 2.20° vs. 8.58° ± 3.13°; P = .040) and increased ROMT of the thorax during pushoff (8.83° ± 2.74° vs. 10.69° ± 3.20°; P = .036) could be identified. For the leg not at risk for EMTP, increased ROMT of the knee during landing (10.96° ± 3.12° vs. 14.07° ± 4.88°; P = .023) and decreased ROMT of the pelvis during pushoff (8.16° ± 3.48° vs. 6.47° ± 2.47°; P = .034) were identified in the nonfatigued state but were not significant in the fatigued state., Conclusion: Adding a muscle fatigue protocol to the single-legged drop jump as a screening test for EMTP risk factors may enhance the possibility of identifying the leg at risk in a predisposed athlete and might determine the proximal risk factors for that leg at risk more thoroughly.

Objective: To prospectively determine risk factors contributing to the development of exertional medial tibial pain (EMTP)., Methods: Data were prospectively collected on healthy female students in physical education, who were freshmen in 2010-2011 and 2011-2012. Eighty-six female students aged 19.38±0.85 years, were tested at the beginning of their first academic year. Kinematic parameters in the frontal and transverse plane were measured during a single-leg drop jump (SLDJ). For further analysis, the SLDJ task was divided in two phases: touchdown until maximal knee flexion (MKF) and then MKF until take-off, representing landing and push-off phase, respectively. The injury follow-up of the students was assessed using a weekly online questionnaire and a 3-monthly retrospective control questionnaire. EMTP was diagnosed by an experienced medical doctor. Cox regression analysis was used to identify the potential risk factors for the development of EMTP., Results: During injury follow-up (1-2 years), 22 participants were diagnosed with EMTP. The results of this study identified that increased range of motion (ROM) in the transverse plane of hip and thorax during landing (p=0.010 and 0.026, respectively) and during push off (p=0.019 and 0.045, respectively) are predictive parameters for the development of EMTP in women., Conclusions: Increased ROM values of hip and thorax in the transverse plane, which can be interpreted as impaired ability to maintain dynamic joint stability resulting in increased accessory movements, are significant contributors to the development of EMTP in women.