ECSS Paris 2023: OP-MH12
INTRODUCTION: High prevalence rates of shoulder overuse injuries have been documented among overhead youth athletes, suggesting a pressing need for injury prevention efforts. In recent years, there has been increasing discussion regarding the importance of context-specific injury prevention programs, which takes into consideration the implementation context during the development phase, such as end-users’ characteristics and equipment available. This vital consideration would improve uptake and compliance following implementation of the program into the real-world. However seemingly no injury prevention program has been developed specifically for the prevention of shoulder overuse injuries among overhead youth athletes in the Asian context. Owing to the popularity of volleyball in Singapore and the biomechanical similarities in the overhead motion across different overhead sports, this study employed the sport of volleyball as a representative of overhead sports in Singapore. The aim of this study was to develop the Singapore Youth Shoulder Overuse Injury Prevention Program (YoSO-IPP) specifically for competitive overhead youth athletes in Singapore. METHODS: Employing a Delphi technique, a panel comprising of content and context experts was convened to provide feedback on YoSO-IPP, which consists of (1) an exercise program for the overhead youth athletes, (2) an education program regarding overuse injuries for coaches of overhead youth athletes, and (3) an education program regarding overuse injuries for overhead youth athletes. Consensus was set at 75% agreement. A group of youth volleyball athletes were recruited as potential end-uses to specifically assess the feasibility of the exercise program using a feasibility assessment questionnaire. RESULTS: Eighteen experts comprising of nine content (e.g., sports medicine physicians, a paediatrician, university professor in sports science and medicine, and sports physiotherapists) and nine context experts (e.g., youth volleyball coaches and volleyball teacher-coaches) completed two Delphi rounds with 100% response rate. Consensus was achieved for the exercise program and both education programs. Twelve youth athletes completed the feasibility assessment questionnaire and found the exercises to be feasible in terms of usefulness, practical use, instructions, duration, and ease of execution. CONCLUSION: Developed specifically for competitive overhead youth athletes in Singapore, YoSO-IPP reached consensus among experts via a Delphi technique. It was also deemed feasible by end-users (i.e., youth athletes) in a feasibility assessment. Comprising of (1) an exercise program for the overhead youth athletes, (2) an education program regarding overuse injuries for coaches of overhead youth athletes, and (3) an education program regarding overuse injuries for overhead youth athletes, the context-specific YoSO-IPP can be considered as robust, comprehensive, and in a state of readiness for implementation in practice.
Read CV Rachel LauECSS Paris 2023: OP-MH12
INTRODUCTION: Understanding the relationship between asymmetry and injury risk may be relevant for clinicians and researchers as runners at risk could be identified by measuring differences in biomechanical variables from both legs. Then, preventive measures could be introduced to reduce asymmetry, including running technique interventions, when a link to previous injury is deemed clinically plausible. Also, understanding the main determinants explaining the inter-subject variability of asymmetry may help identify runners at risk provided asymmetry indeed relates to injury risk. Therefore, the objectives of this study were to describe the magnitude of asymmetry in spatiotemporal and kinetic variables in 800+ recreational runners, identify the determinants of asymmetry, investigate if asymmetry increases running-related injury risk, and compare spatiotemporal and kinetic variables at baseline between the involved and uninvolved limb in runners having sustained an injury during follow-up. METHODS: Healthy recreational runners were tested on an instrumented treadmill at their preferred running speed at baseline and then followed up for 6 months. Spatiotemporal and kinetic variables were derived for each lower limb from ground reaction force recordings. The symmetry index was computed for each variable. Correlations and multiple regression analyses were performed to identify potential determinants of asymmetry. Cox regression analyses were used to investigate the association between asymmetry and injury risk. Analyses of variance for repeated measures were used to compare the involved and uninvolved limb in runners having sustained an injury during follow-up. RESULTS: The analysis includes 836 participants (38,6% females, mean age (SD): 40.3(10.0) years, and body mass index: 24.0(2.9) kg.m-2). 107 participants reported at least one running-related injury. Leg length and fat mass were the most common determinants of asymmetry, but all correlation coefficients were negligible (0.01 to 0.13) and explained variance was very low (multivariable adjusted R2 <0.01 to 0.03). Greater asymmetry for flight time and peak breaking force was associated with lower injury risk (Hazard Ratio [95%CI]: 0.80 [0.64; 0.99] and 0.96 [0.93; 0.98], respectively). No between-limb differences were observed in runners having sustained an injury. CONCLUSION: This study demonstrated that asymmetry in spatiotemporal and kinetic variables was not associated with higher injury risk in recreational runners. Therefore, the search for bilateral asymmetry in the lower limbs in healthy runners as an approach for primary prevention is not supported by scientific evidence. The study also illustrated the high intra-individual (across variables) and inter-individual variability of asymmetry in biomechanics. Consequently, applying a threshold to determine “acceptable” or “normal” asymmetry levels appears very challenging. Finally, the determinants identified only marginally explained the variability in asymmetry.
Read CV Laurent MalisouxECSS Paris 2023: OP-MH12
INTRODUCTION: Different angles of hip flexion during hip adductor contraction can have a significant effect on strength and electromyographic activity (EMGA) (1). However, this has so far only been verified in isometric conditions. Therefore, the aim of this study was to investigate hip joint torque and EMGA of the adductor longus during eccentric exercises for hip adductors while maintaining three different angles of hip flexion (0°, 45°, or 90°). METHODS: Sixteen recreationally active participants (mean age: 27 ± 5 years) preformed bilateral eccentric contractions of the hip adductors at slow speed (13°/sec) using a custom-made isokinetic dynamometer, at 0°, 45°, and 90° of hip flexion. EMGA was recorded from the adductor longus muscle using the Trigno Delsys Wireless System (Delsys Inc., Massachusetts, USA). RESULTS: Peak joint torque was significantly lower during the variation with 90° hip flexion compared to both 0° and 45° variations (p < 0.001) while there were no significant differences between the 0° and 45° variations. Adductor longus EMGA did not significantly differ between variations. CONCLUSION: This study demonstrates that hip flexion angle significantly affects hip joint torque during eccentric hip adduction exercises, with lower torque observed at 90° compared to 0° or 45°. However, adductor longus EMGA remained consistent across all three different hip flexion angles. These findings may contribute to the optimisation of hip adductor strength training, which is one of the most effective measures in the prevention and rehabilitation of hip adductor injuries (the most common type of groin injury in various sports). 1. Delahunt E, Kennelly C, McEntee BL, Coughlan GF, Green BS. The thigh adductor squeeze test: 45° of hip flexion as the optimal test position for eliciting adductor muscle activity and maximum pressure values. Man Ther. 2011;16(5):476–80.
Read CV Jan MarušičECSS Paris 2023: OP-MH12