REIDER PART 220

180 Chapter 5_Pelvis, Hip, and Thigh

A    B

Figurę 5-26. A, Pelvic flexion. B, Pelvic extension. (Arrows show dircction of motion.)

particularly when accompanied by arthritis or contractures about the hip joint.

Hip

As a ball-and-socket joint, the hip is second only to the shoulder in the rangę and complexity of its potcntial motion. The hip’s potcntial movement is conventionally divided into thrcc movement pairs: flexion-extension, abduction-adduction, and internal rotation-external rotation.

In evaluating hip rangę of motion (ROM), it is important to distinguish movement that occurs in the hip joint itself from complementary or compensatory motion that occurs in the adjacent lumbar spine and between the lumbar spine and the pelvis. This is accom-plished either by stabilizing the pelvis or by taking care to detect accompanying pelvic motion as soon as it occurs. Active and passive ROM at the hips are usually evaluated together. Because the possible motions are complex and potentially confusing, the examiner usually guides the patients active execution of the ROM maneuvers and passively assists when necessary.

Flexion and Extension. Anterior motion in the sagittal piane is defined as hip flexion, whereas posterior motion is defined as extension. These are the hip motions that are most vital to normal ambulation and sitting. Luckily, they are usually the last to be restricted by the stiffness that often accompanies osteoarthritis of the hip. Significant loss of flexion and extension at the hip places inereased stress on the lumbar spine and produces severe gait abnormalities.

Hip flexion and extension are usually assessed with a method called the Thomas test. The Thomas test seeks to control flexion and extension of the pelvis and thereby assess the true ROM arising from the hip joint. This is particularly important owing to the considerable ability of the lumbar spine to mimie hip flexion and extension.

The Thomas test for flexion and extension of the hip is performed with the patient lying supine on the exami-nation table. The patient is encouraged to flex both hips until the knees touch the chest; the examiner assists as necessary (Fig. 5-27A). The patient or the examiner maintains the patients knees positioncd tightly against the patients chest. This maneuver loeks the pelvis in maximal flexion, eliminating the ability of the lumbar spine to extend. The hip to be tested for extension is then releascd and allowed to extend to the table while the opposite hip remains tightly held against the patient’s chest (Fig. 5-27B).