Relative and Absolute Angles Computed from Pathologic Gait Data

The paper proposes a preliminary study upon the angular differences that occur between the sound and prosthetic lower limbs of a trans-tibial amputee patient. Based on landmark spatial coordinates measured during gait movement, the paper presents firstly the computation of the absolute and relative angles of the thigh and shank in all three anatomical planes. The relative angles were computed for knee and hip joints and not for the ankle joint due to the limited movement in the prosthetic limb. The spatial coordinates of the anatomical landmarks were measured using an ultrasound based motion system and further processed in order to obtain the angular parameters. At the end of the study, angles and angular velocities were presented for the sound and prosthetic limbs, underlining the differences that occur and the compensatory mechanisms.