Hamstrings and psoas lengths during normal and crouch gait: Implications for muscle‐tendon surgery

Abstract

Crouch gait, one of the most common movement abnormalities among children with cerebral palsy, is characterized by persistent flexion of the knee during the stance phase. Short hamstrings are thought to be the cause of crouch gait; thus, crouch gait is often treated by surgical lengthening of the hamstrings. In this study, a graphics-based model of the lower extremity was used in conjunction with three-dimensional kinematic data obtained from gait analysis to estimate the lengths of the hamstrings and psoas muscles during normal and crouch gaits. Only three of 14 subjects with crouch gait (four of 20 limbs with knee flexion of 20 degrees or more throughout stance) had hamstrings that were shorter than normal by more than 1 SD during walking. Most (80%) of the subjects with crouch gait had hamstrings of normal length or longer, despite persistent knee flexion during stance. This occurred because the excessive knee flexion was typically accompanied by excessive hip flexion throughout the gait cycle. All of the subjects with crouch gait had a psoas that was shorter than normal by more than 1 SD during walking. These results emphasize the need to consider the geometry and kinematics of multiple joints before performing surgical procedures aimed at correcting crouch gait.

Do dynamic and static clinical measurements correlate with gait analysis parameters in children with cerebral palsy?

“…Hip rotation at the end of stance phase was fairly correlated with spasticity of hip flexors (r s = 0.30) and with contractures of hip adductors (r = À0.38). Both muscles are known as internal rotators of the hip [7,24].…”

Case Reports: The Influence of Selective Voluntary Motor Control on Gait After Hamstring Lengthening Surgery

“…Medial hamstring lengths were estimated by combining kinematic data obtained from gait analysis with a threedimensional computer model of the lower extremity using the approach described by Delp et al [6] and software developed for this purpose (OpenSim 1.9.1 and Open-SMAC 0.9, Simbios; Stanford University, Stanford, CA). The semimembranosus was chosen to represent the medial hamstrings.…”

“…The clinical picture may also include excessive knee flexion during stance (crouch), decreased knee ROM, and a shortened stride length [2,3,6,19,20]. For those cases recalcitrant to nonoperative measures, distal hamstring lengthening surgery has been the mainstay of treatment while addressing concomitant contractures at other levels simultaneously through single event multilevel surgery [10,14].…”

Assessment of the Hip and Knee Flexion Contractures in Cerebral Palsy Patients with Crouch Gait

“…Hamstring release in this condition will further increase the pelvic tilt. Thus, the hamstring release operation should be decided after clinical tests and three-dimensional gait analysis which provides dynamic length measurement of hamstring muscles (2,9,12,13).…”

“…ii) Knee flexion contracture following hip flexion contracture and increased anterior pelvic tilt Anterior pelvic tilt and knee flexion are usually increased in children with CP while standing or during the stance phase of gait (2,7,9,13). Normally, ground reaction force (GRF) passes from the center of the hip and knee while standing.…”