Document Type : Original article
Authors
1
Department of Sports Biomechanics, Central Tehran Branch, Islamic Azad University, Tehran, Iran
2
Department of Ergonomics, Social Welfare and Rehabilitation Sciences University, Tehran, Iran
Abstract
Background and Aims: Aging introduces physiological changes such as decreased walking speed, influencing motor control. Middle-aged women (ages 45-64) undergo physical and hormonal shifts affecting motor performance. Obstacle crossing challenges the neuromuscular system by altering centers of pressure (COP) and mass (COM), impacting movement strategies and balance assessment. Analyzing COP and ground reaction force (GRF) variability helps identify gait issues, assess fall risk, and develop interventions, critical for improving quality of life and preventing injuries in this age group. Comparing normal walking and obstacle crossing unveils age-related motor changes, advancing gait stability research.
Materials and Methods: This study employed a quasi-experimental design with a causal-comparative impact assessment model, using a pre-test/post-test approach. It focused on healthy middle-aged women (ages 55-64) in Tehran, with a minimum sample size of 24 determined using Gpower software (power = 0.8, effect size = 0.25, significance level = 0.05). Participants were selected through convenience sampling, briefed on study procedures and objectives, and provided consent. Motion errors were minimized by wearing specialized clothing. Data collection utilized AMTI force plates and Motion Analysis cameras, with analysis performed using SPSS version 22.
Results: The study found no significant differences in age, height, weight, and body mass index among participants. Significant increases were observed in the mediolateral (COP-COMx) and anteroposterior (COP-COMy) shifts of the center of pressure to center of mass, as well as in ground reaction forces in the anteroposterior and vertical directions of the right foot during obstacle crossing.
Conclusion: Gait changes were observed as early as middle-age, and changes in COP-COM and GRF became more evident as task difficulty increased. The increased gait challenge placed more demands on the neuromuscular system, revealing age-related gait modifications that were not evident in the natural walking gait task.
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