Articles
PLoS ONE (19326203)20(5 May)
Knee and ankle injuries are the most common injuries in handball players. Many of these injuries occur toward the end of the game when fatigue sets in. The underlying mechanisms of this phenomenon are not well understood. This study investigated the effect of a handball match-simulation protocol on the hamstring-to-quadriceps (H:Q) and evertor-to-invertor (E:I) peak torque ratios. Thirty professional male handball players from Iranian super league teams participated in this study. Isokinetic concentric peak torque of the hamstrings, quadriceps, ankle invertor, and ankle evertors were measured at angular velocities of 60, 120, and 180 deg/s before and after the simulated handball match-induced fatigue protocol using a Biodex Isokinetic Dynamometer. Peak torque ratio of H:Q and E:I were calculated and compared between pre- and post-fatigue conditions. Fatigue significantly reduced H:Q peak torque ratio at 60 (p=0.049), 120 (p=0.002) and 180 (p=0.014) deg/s, as well as E:I peak torque ratio at 60 (p=0.010), 120 (p=0.003) and 180 (p=0.003) deg/s. These changes could contribute to an increased risk of anterior cruciate ligament (ACL) tears and lateral ankle sprains. Given the greater reduction in the H:Q peak torque ratio in hamstring muscles, targeted strengthening and improving the endurance of these muscles is recommended for professional handball players to mitigate fatigue effects. © 2025 Dastjerdi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Journal Of Rehabilitation Sciences And Research (23456159)11(2)pp. 109-116
Background: The present study focuses on elucidating the effects of an eight-week combined turning exercise program on the physical performance of female students with Down syndrome (DS), a genetic disorder characterized by intellectual disability and often associated with weaker muscle strength. Individuals with DS typically exhibit reduced muscle strength due to a lower percentage of slow-twitch muscle fibers and a diminished overall number of muscle fibers. Methods: In this semi-experimental clinical trial, the authors used purposive sampling to enroll 26 female students diagnosed with DS. Participants were randomly divided into an experimental group (n=13; mean age: 12.15±1.62 years, mean height: 139.23±8.94 cm, mean weight: 42.62±13.44 kg, mean IQ: 63.02±5.54) and a control group (n=13; mean age: 12.23±1.53 years, mean height: 141.15±10.31 cm, mean weight: 45.46±15.94 kg, mean IQ: 63.05±5.49). The authors evaluated muscle strength using a hand-held digital dynamometer, push-up test, long jump, and sit-up before and after the eight-week training period. The experimental group underwent a combined turning training program lasting 45-60 minutes daily, thrice a week, for eight weeks. We analyzed the data using repeated measures analysis of variance (ANOVA) with a significance level set at P≤0.05. Results: The findings revealed a significant enhancement in physical performance among participants in the experimental group compared to those in the control group (P≤0.05). Specifically, the combined turning exercise program positively influenced upper body, middle body, and lower body muscle strength in female students diagnosed with DS. Conclusion: The results of this investigation imply that incorporating combined turning exercises could serve as an effective strategy for enhancing muscle strength among female students diagnosed with DS. Integrating these exercises into rehabilitation programs tailored for individuals with DS may improve their physical performance and enhance their overall quality of life. 2024 © The Authors. Published by JRSR. All rights reserved.
