Comparative Analysis of Thermoplastic and Resin-Laminated PTBSC Sockets on Quadriceps Muscle Profile in a Transtibial Amputee: A Case Study

Background: Socket design and material significantly affect comfort, function, and muscle engagement in transtibial prosthetic users. This case study compares the influence of thermoplastic and resin-laminated PTBSC (Patellar Tendon Bearing Supracondylar) sockets on the quadriceps muscle profile of a transtibial amputee using surface electromyography (sEMG). Methods: A 32-year-old male with a right-sided transtibial amputation was fitted with two prosthetic sockets—first with a thermoplastic PTBSC socket and then with a resin-laminated PTBSC socket. Each was worn for three months. EMG activity of the rectus femoris muscle was recorded during controlled knee extension using a surface EMG system. The average of three trials was calculated for each condition. Results: Mean quadriceps muscle activity for the thermoplastic socket was 0.5467 ± 0.08910, and for the resin-laminated socket, 0.5853 ± 0.08717. No statistically significant difference in muscle activity was observed. However, the patient subjectively reported better comfort, reduced weight, and ease of use with the resin-laminated socket. Conclusion: Both socket types provided comparable biomechanical support as reflected in muscle activity. The resin-laminated socket, while not superior in EMG performance, was preferred by the user due to better subjective comfort and usability. These findings suggest that socket material selection should consider both functional and user-centered factors to optimize prosthetic outcomes. Further research with larger samples is warranted. Keywords: Transtibial Amputation, PTBSC Socket, Thermoplastic Socket, Resin-Laminated Socket, Surface Electromyography (sEMG), Quadriceps Muscle Activity, Prosthetic Socket Design, Patient Satisfaction, Rehabilitation Engineering.