A Maximum Muscle Strength Prediction Formula Using Theoretical Grade 3 Muscle Strength Value in Daniels et al.’s Manual Muscle Test, in Consideration of Age: An Investigation of Hip and Knee Joint Flexion and Extension

Figure 3

Calculating . : body weight (kg), : acceleration due to gravity (m/s²) = 9.8, : thigh length (m), : thigh weighting factor (men: 0.1; women: 0.1115), : thigh center of gravity distance ratio = 0.42, : lower leg and foot combined weighting factor (men: 0.0725; women: 0.0685), : lower leg length (m), : distance (m) between the greater trochanter and the measurement site, and : distance (m) between the knee joint space and the measurement site.

(a) Hip joint flexion

(b) Hip joint extension

(c) Knee joint flexion

(d) Knee joint extension