Self-Adaptive Transtibial Prosthesis: Automatic Detection and Compensation of Leg Length Discrepancy

Background: Despite the development of manual and passive mechanisms for adjusting prosthesis length, their efficiency remains limited, and users continue to face challenges related to leg length discrepancy (LLD). This dysfunction is an unresolved issue in prosthetics, and the lack of a prosthesis capable of automatically correcting LLD highlights a critical gap in the field. Methods: This study introduces a transtibial self-adaptive prosthesis capable of autonomously compensating for LLD. The prosthesis’s performance was evaluated using the ARAMIS 3D Digital Image Correlation (DIC) system, which monitored the displacement of markers strategically placed on a test mannequin in a strategic manner. Simulated LLDs were generated by inserting standardized plates beneath the mannequin’s intact limb. Results: The proposed prosthesis demonstrated efficient compensation of simulated LLD, with a mean relative error of 8.8% for a 1 mm simulation and 7.2% for a 10 mm simulation. The DIC system highlighted the rapidity and precision of the prosthesis mechanism in adjusting its length to eliminate LLD. Conclusions: The proposed transtibial self-adaptive prosthesis represents a significant advancement in the automatic correction of LLD, enhancing gait symmetry and user stability. The results suggest substantial potential for clinical applications, with promising implications for users of unilateral prostheses.