Abstract
The purpose of this study was to quantify the rotational components of the pelvis, femur, tibia, and subtalar joint, and center of pressure of the body during activities. Five healthy subjects participated in this study.
Subjects stood on their right leg over the gravicoder which output X and Y of the center of pressure, and four gyrosensors which exhibited rotational motion were attached over anterior-superior iliac spine, centrolateral of thigh, centrolateral lower leg and vertical plane to the Henke's line.
Subjects were instructed to perform the following six tasks without moving their right foot over the gravicoder.
1) Rotating the trunk to the right with the knee extended.
2) Rotating the trunk to the left with the knee extended.
3) Inverting the right subtalar joint.
4) Everting the right subtalar joint.
5) Thrusting the right knee anterolaterally.
6) Thrusting the right knee anteromedially.
The signals from each task performed by four gyrosensors and gravicoder were converted to the digital data, and correlation of the data was analyzed.
Common movements were observed in tasks 2), 4) and 6), of pelvis rotate internally, femur and tibia rotate internally, subtalar joint rotate evertly and center of pressure moved medially. On the contrary tasks 1), 3) and 5) showed reverse movement.
Most cases revealed significant level of p < 0.01 [173 out of 180 cases in rotation, 116 out of 120 cases in center of pressure].
Consequently, pelvis, thigh, tibia and subtalar joint rotated with mutual relation and had high correlation with center of pressure of the body.
