Abstract
Background/Objectives: This study investigated postural stability in male inmates of a semi-open correctional facility, with a specific focus on comparing individuals with and without a history of substance dependence. The aim was to identify how addiction-related neurophysiological changes impact postural control under varying sensory and biomechanical demands. Methods: A total of 47 adult male prisoners (mean age: 24.3 years) participated in this study. Nineteen inmates had a documented history of alcohol or drug dependence (addicted group), while twenty-eight had no such history (non-addicted group). All participants were physically able and free of neurological disorders. Postural control was assessed using a stabilometric platform and wireless IMU across six 30 s standing tasks of varying difficulty (bipedal/unipedal stance and eyes open/closed). Linear (center of pressure path and ellipse area) and nonlinear (sample entropy, fractal dimension, and the Lyapunov exponent) sway metrics were analyzed, along with trunk kinematics from IMU data. This study received institutional ethical approval; trial registration was not required. Results: The addicted group showed greater instability, especially in the eyes-closed and single-leg tasks, with increased sway and irregularity in the anterior-posterior direction. IMU data indicated altered trunk motion, suggesting impaired neuromuscular control. In contrast, non-addicted individuals demonstrated more efficient, targeted postural strategies, while addicted participants relied on broader, less selective movements, possibly reflecting compensatory or neuroadaptive changes from substance use. Conclusions: Substance dependence is associated with compromised postural stability in incarcerated men. Balance assessments may be valuable for detecting functional impairments and guiding rehabilitation within prison healthcare systems.