HIP ROM BY ANTHONY LETT
In this post we will be looking at the hip joint with a focus on hip extension. Hip Extension Hip extension can be involve both femoral onpelvic and pelvic-on-femoral kinematics. An example of femoral-on-pelvic movements is walking, where the pelvis is relatively stable and the femurs move. Pelvic-on-femoral movements, on the other hand, are often performed to change the position of the pelvis relative to fixed lower extremities. An example would be a subtle posterior pelvic tilt whilst lying supine with knees bent. Adding to the complexity of pelvic-on-femoral movements is the strong association with the kinematics of the lumbar spine. Because the caudal end of the axial skeleton is firmly attached to the pelvis by way of the sacroiliac joints rotation of the pelvis over the femoral heads typically changes the configuration of the lumbar spine. This important kinematic relationship is known as lumbopelvic rhythm Values for “normal� range of motion vary from 10 to 30 degrees. Hip extension with the knee straight is limited first by the one joint hip flexor muscles followed by the iliofemoral ligament, some fibers of the pubofemoral and ischiofemoral ligaments and the capsule of the joint. To sit in full splits, you will often see a dancer for example, externally rotate and adduct the extended rear leg as well as exaggerate the lumbar lordosis in an effort to maximize hip extension range. Extreme lumbar lordosis, external rotation and adduction will slacken the iliofemoral ligament and capsule to maximize ROM. When the knee is fully flexed during hip extension, passive tension in the stretched rectus femoris, which crosses both the hip and the knee, may reduce hip extension.