Lesson
Hip Joint Muscles-Actions
| Action (Plane of Motion) | Abduction (Frontal & Transverse) | Adduction (Frontal & Transverse) | Flexion (Sagittal) | Extension (Sagittal) | External Rotation (Transverse) | Internal Rotation (Transverse) |
| Description of Motion | Abduction of hip joint is 45º. It is free in all positions of lower limb. Abduction greater when knee partly flexed. | Abduction of hip joint is also 45º. It is easier with hip flexed than extended. | With knee in flexion, hip flexion is free until thigh touches anterior abdominal wall. When knee extended, hip flexion is limited by tension in hamstrings. | Hip extension has a greater ROM (30º) when knee is flexed than when it is extended (20º). Two jointed muscles contract at one end better when other end stretched. | Rotation of femur takes place about its mechanical axis (external to the bone) NOT about long axis of shaft. So, the shaft of femur moves posteriorly, and toes point away from midline. Lateral rotation freer and more powerful than medial | Shaft of femur moves anteriorly about mechanical axis of femur, carrying along calf and foot, so toes point towards midline. |
Note: Rotational movement of the thigh in all of above directions
is a complex movement termed ‘circumduction’