OBJECTIVE: To evaluate strength profile of the upper and lower limbs among adolescent elite Malaysian badminton players.
DESIGN: Cross-sectional study.
SETTING: Laboratory.
PARTICIPANTS: Forty-eight asymptomatic athletes (24 males and 24 females) were grouped into early and late adolescence (13-14 y old and 15-17 y old, respectively).
MAIN OUTCOME MEASURE(S): Strength (absolute and normalized) of the external/internal rotators of the shoulder and flexor/extensor of the knee and strength derivatives, conventional strength ratio (CSR), dynamic control ratio (DCR), and bilateral deficits were measured.
RESULTS: Males showed greater strength in all strength indices (P < .05). The older group had greater strength compared to younger for most of the upper and lower limb indices (P < .05); these effects diminished when using normalized data. For females, there was no age group effect in the shoulder and knee strength. All players displayed lower shoulder and knee normative values for CSR and DCR. Dominant and non-dominant knee strength were comparable between sex and age groups.
CONCLUSIONS: For males, growth and maturation had a greater contribution to strength gained compared to training, whereas for females, growth, maturation, and training did not improve strength. The normalized data indicated that training did not improve all indices measured apart from external rotator strength in females. All players also displayed lower normative values of CSR and DCR. These results suggest that training in elite adolescent Malaysian badminton players lacks consideration of strength gain and injury risk factors.
METHODS: In experiment 1 (n = 10), we tested the direction of force exerted in an isometric aiming task before and after 40 repetitions of 2-s maximal-force ballistic contractions toward a single directional target. In experiment 2 (n = 12), each participant completed three training conditions in a counterbalanced crossover design. In two conditions, both the aiming task and the training were conducted in the same (neutral) forearm posture. In one of these conditions, the training involved weak forces to determine whether the level of neural drive during training influences the degree of bias. In the third condition, high-force training contractions were performed in a 90° pronated forearm posture, whereas the low-force aiming task was performed in a neutral forearm posture. This dissociated the extrinsic training direction from the pulling direction of the trained muscles during the aiming task.
RESULTS: In experiment 1, we found that aiming direction was biased toward the training direction across a large area of the work space (approximately ±135°; tested for 16 targets spaced 22.5° apart), whereas in experiment 2, we found systematic bias in aiming toward the training direction defined in extrinsic space, but only immediately after high-force contractions.
CONCLUSION: Our findings suggest that bias effects of training involving strong neural drive generalize broadly to untrained movement directions and are expressed according to extrinsic rather than muscle-based coordinates.
OBJECTIVES: To investigate exercise preferences, levels, influencing factors among a diverse Parkinson's disease (PD) population, to understand exercise adoption patterns and plan informed interventions.
METHODS: A cross-sectional survey collected data through online platforms and paper-based methods. The Exercise Index (ExI) calculated exercise level based on frequency and duration.
RESULTS: Of 2976 PwP, 40.6% exercised regularly, 38.3% occasionally, and 21.2% did not exercise. The overall mean ExI was 18.99 ± 12.37. Factors associated with high exercise levels included exercising in groups (ExI 24-26), weightlifting (ExI 27 (highest)), using muscle-building equipment (ExI 25-26), and exercising at home following an app (ExI 26). A positive trend between ExI and varied exercise groups, locations, types, and equipment was observed. No expected benefit from exercise achieved the lowest ExI (8). Having at least two exercise-promoting factors, a bachelor's degree or higher, receiving exercise advice at initial visits, and aged ≤40 years at PD onset were strong predictors of exercise (adjust OR = 7.814; 6.981; 4.170; 3.565). Falls and "other" most troublesome PD symptoms were negative predictors (aOR = 0.359; 0.466). Barriers to exercise did not predict the odds of exercise.
CONCLUSIONS: The study shows that PwP's exercise behavior is influenced by their exercise belief, age at PD onset, doctor's advice at initial visits, education level, symptoms, and exercise-promoting factors. High exercise levels were associated with certain types of exercises and exercising in groups.