Hip and Pelvic Kinematic Pathology in Cerebral Palsy Gait

Abstract

The gait of children with cerebral palsy (CP) is heavily influenced by motor control, balance, musculoskeletal alignment, and force-generating ability. The force input and motor aspect of gait resides primarily in the musculoskeletal system of the pelvis and the two lower extremities. The body above the pelvis including the head, arms, and trunk (HAT) is often considered as the transport cargo. This is an overly simplistic view in that motion of the arms contributed to balance and momentum as well as energy conservation. Trunk motion also is important in maintaining balance as well as adding power input through motion in the thoracolumbar spine. There is little understanding or published data on the exact importance of movements of the HAT segment in pathologic gait of children with cerebral palsy. The most common abnormality at the level of the hip is increased internal rotation in children who are GMFCS level I–III functional ambulators. The most common treatment is femoral derotation osteotomy. The ideal age for doing this is late childhood to adolescence (8–14 years old), and the level in the femur where the derotation occurs is not important. Hip flexion contractures or limited hip extension in stance phase is the next most common problem. Lengthening of hip flexors provides minimal improvement and has risk of creating hip flexor weakness. Hip adductor contractures are also relatively common in GMFCS IV and V but less common in highly functional GMFCS I–III ambulators. Pelvic motion is often a compensation for problems related to hip motion. Increased hip flexion contractures causes increased anterior pelvic tilt and may cause increased motion of the pelvis in the anterior tilt direction. The pelvis is also impacted by the lumbar spine in which fixed lumbar lordosis creates anterior pelvic tilt, and lumbar scoliosis may cause a fixed pelvic obliquity. The goal of this chapter will be to consider the pathologic movements and the compensation, which often develop as secondary problems in the gait of children with CP.