Abstract
The purpose of this study was to know the individual differences in the motion pattern of the joints of the lower limb during running at various speeds. Three subjects (who were an excellent sprinter, a post-trained runner and an untrained ordinary adult) were employed in this study. Running was performed in the darken room on the motor-driven treadmill, speeds of which were from 200m/min to 500 m/min. The light-trace photographs of three points of lower limb were collected by means of an ordinary camera and a black and white 35mm film. The light-trace was interrupted every l/45 second. Three small lamps were fixed on the hip, knee and ankle joints of the left leg. The typical photographs were shown in Fig. 1 and 2. From those photographs, the vertical displacement of knee and ankle joints, the duration time of one cycle, the step frequency, the step length, and the foot speed were calculated respectively at each speed of running. The results were as follows; 1.General tendency. Towards highest speed, the step frequency was frequent, the step length was lengthened, the vertical displacements of knee and ankle joints became larger and the motion of the foot became faster. 2.Individual differences. There were several distinct differences between the trained runner and the untrained adult. Namely, the triaged runner carried his knee more upwards, made his longer step (consequently lower step frequency) and move his foot more rapidly just before the contact on the ground than untrained at the same speed of running
