Using Stubby Prosthesis After Bilateral Transfemoral Amputation: A Biomechanical Case Study

Background: After bilateral transfemoral amputation, people may experience limitations in everyday life due to limited mobility and prosthesis problems. Materials and method: The case study covered a 54-year-old man after bilateral traumatic amputation of his lower limbs. Transfemoral amputations were performed using the Caldwell method; disproportion in the length of stumps was 5 mm. The motion task was recorded using the SMART-E optoelectronic system (BTS Bioengineering, Milan, Italy) according to the standard Davis protocol (the Newington model). Biomechanical evaluation included the measurement of angle-time relationships, characterizing the range of motion (ROM) in lower limb joints and Ground Reaction Force (GRF). The analyzed tasks are walking with self selected speed, fast gait and walking in stubby prostheses. Results: Step width was the most similar to the gait of healthy persons walking with stubby prostheses (0.17 +/- 0.01 m for healthy people, 29% higher for stubbies, 35% for prosthetic gait with self-selected gait speed and 41% for fast gait speed). Step width was the smallest when walking with stubbies. Conclusions: The reduction of body height allows to reduce the risk of fall. Higher metabolic cost of gait in people after amputation result from a greater need to maintain balance and posture, and to perform walking movement.