Fig. 1
From: Use of the sit-to-stand task to evaluate motor function of older adults using telemetry
a. Video recording of sit-to-stand motion. The motion was acquired from the left of the body, and the iliac elevation maximum velocity (IEMV) and knee extension maximum angle velocity (KEMAV) were measured using five color markers placed at the acromion (a; red), iliac crest (b; green), greater trochanter (c; yellow), lateral epicondyle of the femur (d; red), and lateral malleolus (e; green). The height of the chair is adjusted according to the length of the lower extremity. b. Comparison of webcam and VICON MX measurements of knee angle change during sit-to-stand motion. The solid line shows the average of 42 measurements using a webcam and the dashed line shows that with VICON MX. The temporal change of the knee angle was interpolated using 51 points (2 % for each step) to cover the whole sit-to-stand motion. The correlation coefficient (r) between the time series was 0.920 ± 0.089 (n = 42). Error bar: standard deviation