A sit-to-stand movement is one of the most common activities of daily life and researches discriminating that patterns between the normal and the abnormal sit-to-stand movement patterns are important in rehabilitation setting. We analyzed the pattern of normal sit-to-stand movements by the use of the motion analysis system developed in Korea. The purpose of this study was to provide basic kinematic and kinetic data for an analysis of normal sit-to-stand movement and to find the clinical usefullness and reliability of the motion analysis system used in this study.

We selected 10 healthy males within ⁑10% of ideal body weight, and used two-dimensional approach of sit-to-stand movement. We set five transition points during sit-to-stand movement in our study, and observed course-of-time shift in angles of hip, knee and ankle joints, Then one session of a sit-to-stand movement was classified into four stages.

We also calculated maximum flexion moments per body weight in hip and knee joints which represented minimum extension toques required for normal sit-to-stand movements. These maximum flexion moments were compared with the actual maximum extension torques.

The results were as follows

1) The kinematic of sit-to-stand movement showed initial flexion follwed by later extension in hip joint, and continuous extension in knee joint, and initial dorsiflexion followed by later platar flexion

2) The largest proportion among all stages of sit-to-stand movement was stage 4.

3) The maximum flexion moment per body weight was 0.81 Nm/kg in hip joint and 1.02 Nm/kg in knee joint.

4) The percentage of the maximum flexion moment to actual maximum extension torque was 29%, in hip joint and 33% in knee joint. This result represented that about 29% and 33% of the actual maximum hip and knee extension torques were needed to fulfill a sit-to-stand movement.