Volume 11, Issue 4 (3-2026)                   J Sport Biomech 2026, 11(4): 424-437 | Back to browse issues page

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Omidi H, Sabzevari Rad R, Ghorbani M. Biomechanical Changes of the Knee During Jump-Landing Tasks: A Longitudinal Study of Military Cadets at Imam Ali (AS) University. J Sport Biomech 2026; 11 (4) :424-437
URL: http://biomechanics.iauh.ac.ir/article-1-412-en.html
Biomechanical Changes of the Knee During Jump-Landing Tasks: A Longitudinal Study of Military Cadets at Imam Ali (AS) University
Hamid Omidi *1 , Reza Sabzevari Rad1 , Moosareza Ghorbani2
1- Department of Physical Education and Sport Sciences, Faculty of Command and management, Imam Ali Military' University, Tehran, Iran.
2- Department of Sport Injuries and Corrective Exercise, Faculty of Physical Education and Sport Sciences, University of Guilan, Rasht, Iran.
Abstract:   (21 Views)
Objective This study aimed to examine changes in knee flexion and abduction angles among military cadets at Imam Ali (AS) University during a jump-landing task following a period of intensive military training. Given the high prevalence of anterior cruciate ligament (ACL) injuries in military personnel and the influence of movement patterns on such injuries, this research sought to identify biomechanical adaptations resulting from military training.
Methods In this quasi-experimental study, 30 male cadets (mean age: 19.71 ± 2.30 years; height: 182.66 ± 6.21 cm; weight: 71.83 ± 7.71 kg) were assessed in two phases: a pre-test at the beginning of their first academic year and a post-test at the end of the year. A standardized jump-landing protocol was used. Kinematic data were collected using two Canon cameras (120 Hz) positioned in the frontal and sagittal planes and analyzed with Kinovea software (version 2.0). Knee flexion and abduction angles were measured at two critical moments: initial ground contact (first frame of foot-surface contact) and peak flexion (frame showing maximum knee flexion). Data were analyzed using two-way repeated-measures ANOVA in SPSS version 25.
Results Significant biomechanical changes in landing mechanics were observed. In the dominant leg, knee flexion at peak landing decreased significantly from 96.26° to 87.27° (p = 0.028), while knee abduction increased from 12.32° to 17.44° (p = 0.007). These changes were less pronounced in the non-dominant leg (flexion: 93.50° to 89.48°; abduction: 13.95° to 15.48°). A significant time × leg interaction (F = 5.12, p = 0.028) indicated the development of asymmetrical movement patterns after training.
Conclusion Intensive military training induces potentially risky biomechanical adaptations, particularly reduced flexion and increased abduction in the dominant knee, which may elevate ACL injury risk. Incorporating proper landing techniques and neuromuscular training into military programs is recommended to mitigate these risks.
Keywords: Anterior cruciate ligament, Military training, Jump-landing, Biomechanics
     
Type of Study: Research | Subject: Special
Received: 2025/07/20 | Accepted: 2025/09/26 | Published: 2025/10/5
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