Articles
International Journal Of Technology (20869614)15(4)pp. 1173-1182
Knee and anterior cruciate ligament (ACL) are among the most injured parts of the body during sports activities. Therefore, this study aimed to evaluate knee torque and mechanical stress on ACL under various conditions of stop-jump landing, as well as identify risk factors for injury, and propose improved strategies. The stop-jump landing was modeled using anthropometric and kinematic data. Knee torque was calculated with the inverse dynamic method, and ACL stress was determined using a Finite Element Model (FEM). Different landing strategies were simulated, including variations in knee flexion at initial foot contact, as well as knee and hip angular displacement. The results showed based on mechanical stress analysis, females (6.30 MPa) had a higher probability of ACL injury compared to males (4.51 MPa). Increasing knee flexion at initial contact caused decreased knee torque and approximately a 7% reduction in ACL stress. Furthermore, increasing knee and hip angular displacement led to a decrease in knee torque, with a reduction in ACL stress by 44% and 11% respectively. To reduce the risk of ACL injury, it is recommended to increase knee flexion at initial contact as well as promote knee and hip angular displacement during landing. © (2024), (Faculty of Engineering). All rights reserved.
Objectives The ability to safely walk up and down the stairs is an essential factor in older adults’ independence and quality of life. This study aims to investigate the effect of combined exercises on stair negotiation performance of older men. Methods & Materials In this randomized controlled clinical trial, 30 older men with at least 60 years of age living in Isfahan, Iran, in 2021 were selected who had functional independence, mental health, the ability to perform daily activities without using an assistive device, and without a history of falling. They assigned randomly to two parallel groups of intervention and control groups. Participants in the intervention group completed 12 weeks of combined exercise. The center of pressure (COP) parameters were measured by a force plate, and the time of stair ascending and descending was recorded by the Qualisys motion analysis system. The stair negotiation performance was evaluated by the timed up and down stairs (TUDS) test and the stair self-efficacy (SSE) scale. Data were analyzed by mixed ANOVA in SPSS software, version 24. The significance level was set at 0.05. Results The combined exercise program was effective in reducing the COP parameters during stairs ascending and descending (P<0.05). Stance time and time of ascending and descending decreased after the exercise (P≤0.034). The results of TUDS test (P≤0.002) and SSE scale (P≤0.048) showed improved performance in the intervention group compared to the control group. Conclusion The combined exercise program, by focusing on the factors such range of motion, strength, power, and balance, is effective in improving the stair negotiation performance of older men. Due to the prevalence of stair use in daily activities and its potential risk for older adults, this combined exercise program is recommended for older men. © (2023), (Negah Institute for Scientific Communication). All Rights Reserved.
