Biomechanics · functional reading

Hip mobility

Hip mobility refers to the range and quality of movement of the hip joint, which connects the pelvis to the femur: flexion and extension, moving the thigh away from and toward the midline, and rotations.

Scientific basis

The hip is a highly mobile joint that allows movement in all three planes. In the seated position, it is flexed: the angle between the pelvis and the femur goes from about 180° standing to about 125° sitting.

Pelvic mobility and hip mobility are coupled; a restriction of one can change the relative contributions of the other depending on the task and the person.

Blue Portance / SBNFA™ reading

In the SBNFA™ framework, the hips are the regulator: they drive the adjustments, with independence between right and left. A seat does not regulate posture; it makes available, or not, the degrees of freedom the hips need to carry out these adjustments.

Contribution to the analysis of sitting

Seating analysis observes whether the position leaves both hips free to move independently and to vary their support; it does not measure joint ranges of motion.

Not to be confused with

Pelvic mobility, the orientation of the pelvis that the hips drive; sacroiliac joint, the joint between the sacrum and the iliac bone; flexibility: joint mobility is not, here, a stretching goal.

Sources and scope

Kouyoumdjian (2023): involvement of the hip-spine relationship in hip arthroplasty surgery (Revue de chirurgie orthopédique et traumatologique) (in French)

An established biomechanical notion. This entry does not offer an exercise program; any limitation of mobility calls for an evaluation by a health professional.