Dynamics of Center of Pressure Trajectory in Gait: Unilateral Transfemoral Amputees Versus Non-Disabled Individuals

The primary goal of rehabilitation for individuals with lower limb amputation, particularly those with unilateral transfemoral amputation (uTFA), is to restore their ability to walk independently. Effective control of the center of pressure (COP) during gait is vital for maintaining balance and stability, yet it poses a significant challenge for individuals with uTFA. This study aims to study the COP during gait in individuals with uTFA and elucidate their unique compensatory strategies. This study involved 12 uTFA participants and age-matched non-disabled controls, with gait and COP trajectory data collected using an instrumented treadmill. Gait and COP parameters between the control limb (CL), prosthetic limb (PL), and intact limb (IL) were compared. Notably, the mediolateral displacement of COP in PL exhibited significant lateral displacement compared to the CL from 30% to 60% of the stance. In 20% to 45% of the stance, the COP forward speed of PL was significantly higher than that of the IL. Furthermore, during the initial 20% of the stance, the vertical ground reaction force of PL was significantly lower than that of IL. Additionally, individuals with uTFA exhibited a distinct gait pattern with altered duration of loading response, single limb support, pre-swing and swing phases, and step time. These findings indicate the adaptability of individuals with uTFA in weight transfer, balance control, and pressure distribution on gait stability. In conclusion, this study provides valuable insights into the unique gait dynamics and balance strategies of uTFA patients, highlighting the importance of optimizing prosthetic design, alignment procedures, and rehabilitation programs to enhance gait patterns and reduce the risk of injuries due to compensatory movements.