Development of Flexion Lock Function of Trans-femoral- Prosthetic Knee during Stair Ascending

Abstract

We previously developed a passive knee joint mechanism that enabled level walk and stair ascent with a transfemoral prosthesis, and stability of transfemoral prosthesis has been established in level walk mechanism. However, stability of transfemoral prosthesis has not been established in stair ascent. Unintended knee flexion should be avoided not to fall during both level walking and stair ascending. Therefore, in the present study, we developed a passive knee joint mechanism that prevents knee flexion during stair ascending. In the assessment experiment, the flexion lock function appropriately worked as designed, and the original functions that enable stair ascent were preserved.