BACKGROUND: Sitting cross-legged as an activity of daily living and its kinematics have significantly different demands on the arthroplasty of hip and knee, which can be referred in the design of joint arthroplasty. OBJECTIVES: The purpose of this study was to obtain the kinematics of the lower limb in Chinese people during cross-legged sitting. STUDY DESIGN: This study identified the necessary requirements for joint arthroplasty to carry out sitting cross-legged activity. METHODS: A total of 40 healthy Chinese participants (average age = 23.8 years) performed six cross-legged sitting trials per person. Three-dimensional kinematic data of ankle, knee, and hip joints were collected; the means of the three-dimensional angles of these three joints were calculated. RESULTS: At the hip, the range of motion of the flexion was 101.7°, the abduction reached 43.2°, and the range of motion of the external rotation was 36.4°. At the knee, the range of motion of the flexion was 131.9° and the range of motion of the internal rotation reached 32.4°. At the ankle, the range of motion in three planes was not great. CONCLUSIONS: Such motion ranges were likely to result in prosthetic dislocation. The results would provide valuable references for prosthesis design in the Chinese population.
BACKGROUND: Sitting cross-legged as an activity of daily living and its kinematics have significantly different demands on the arthroplasty of hip and knee, which can be referred in the design of joint arthroplasty. OBJECTIVES: The purpose of this study was to obtain the kinematics of the lower limb in Chinese people during cross-legged sitting. STUDY DESIGN: This study identified the necessary requirements for joint arthroplasty to carry out sitting cross-legged activity. METHODS: A total of 40 healthy Chinese participants (average age = 23.8 years) performed six cross-legged sitting trials per person. Three-dimensional kinematic data of ankle, knee, and hip joints were collected; the means of the three-dimensional angles of these three joints were calculated. RESULTS: At the hip, the range of motion of the flexion was 101.7°, the abduction reached 43.2°, and the range of motion of the external rotation was 36.4°. At the knee, the range of motion of the flexion was 131.9° and the range of motion of the internal rotation reached 32.4°. At the ankle, the range of motion in three planes was not great. CONCLUSIONS: Such motion ranges were likely to result in prosthetic dislocation. The results would provide valuable references for prosthesis design in the Chinese population.