Spinal cord injury (SCI) causes major challenges to mobility and daily life activities and maintaining balance becomes a crucial issue. Individuals with SCI often need to adopt new strategies to manage balance with minimal discomfort. Sports and physical activities have become one of the most popular rehabilitation methods for people with SCI. The assessment of balance improvement currently relies on subjective evaluation scales, and this study aims to quantitively assess the efficacy of sports on the balance strategies of people with SCI. Twenty-two SCI people remained seated still for 30 s, with their eyes open and closed, and we recorded trunk kinematics with an optoelectronic system before and after a three-months sports program. We also computed trunk total sway length, mean velocity, and sway density curve. Statistical analyses were performed to compare SCI people before and after the rehabilitation program and to investigate any correlations between the trunk balance parameters and the clinical scales. The results demonstrate improvements in static balance, with significant reductions in sway length and mean velocity. In conclusion, our findings confirm the potential of sports to enhance balance in SCI individuals and suggest that integrating structured sports programs into rehabilitation can improve stability and postural control.

Aquatic physical activity plays a vital role in sports training and rehabilitation, yet precise motion analysis in water remains challenging due to the limitations of traditional motion capture systems. This study validates the use of experimental wearable inertial measurement units, TinyTag, combined with OpenSense software to estimate joint angles on land and underwater. The method was assessed through a two-phase approach: First, TinyTag-OpenSense joint angle estimates were validated against the gold standard motion analysis system in a controlled laboratory setting; second, the framework was applied to analyze lower-limb joint range of motion during four hydrotherapy exercises in 15 healthy adults on land and in water. The results demonstrated good agreement with the reference system for squat and knee-to-chest exercises, with a root mean square error below 5 ° and a Spearman correlation coefficient greater than 0.85. The underwater assessment revealed an increase of at least 10% (p¡0.005) in range of motion for all exercises except squats and frontal leg swing, highlighting the supportive effects of water. This study presents a validated open source methodology for underwater motion tracking, offering a solution for clinical and research applications in aquatic rehabilitation and sports science.