The document discusses the angle of inclination of the femur bone in the human body. It notes that the average angle is 125-135 degrees in adults and that this angle decreases with age. The angle can be affected by certain diseases and conditions like rickets that cause deformities in bones. The angle provides important information to physicians and plays a role in gait and movement.
The angle of inclination of the femur changes across the life span, being substantially greater in infancy and childhood (see Fig. 10-2B)
and gradually declining to about 120 in the normal
elderly person.
The acetabulum does not fully cover the head superiorly, and the anterior torsion of the femoral head (angle of torsion) exposes a substantial amount of the femoral head’s
articular surface anteriorly. Articular contact between
the femur and the acetabulum can be increased in the
normal non–weight-bearing hip joint by a combination
of flexion, abduction, and slight lateral rotation
(see
Fig. 10-9B). This position (also known as the frog-leg
position) corresponds to that assumed by the hip joint
in a quadruped position and, according to Kapandji,
9
is
the true physiologic position of the hip joint
The ligament is a triangular band attached at one end to both sides of the peripheral edge of the acetabular notch.
The ligament then passes under the transverse acetabular ligament (with which it blends) to attach at its other end to the fovea of the femur; thus, it is (Fig. 10-11)
checks extension, adduction (superior fibers), and abduction (inferior fibers). In addition, because this ligament limits hip extension, it allows maintenance of the upright posture by reducing the need for muscle contractions
Optimal articular contact occurs with combined flexion, abduction, and lateral rotation
has less reinforcement and thus more potential for failure.
The zone of weakness of the femoral neck is particularly susceptible to the bending forces across the area and can fracture either when forces are excessive or when compromised bony composition reduces the tissue’s ability to resist typical forces