Hamstring and psoas length of crouch gait in cerebral palsy: a comparison with induced crouch gait in age- and sex-matched controls

Tae-Yon Rhie,Ki Hyuk Sung,Kyoung Min Lee,Moon Seok Park,Chin Youb Chung

doi:10.1186/1743-0003-10-10

Abstract

BackgroundPrevious studies have shown that hamstring lengths are often not short in patients with cerebral palsy, which raises concerns over the benefits of distal hamstring lengthening in patients with crouch gait. In this study, the authors measured lengths of hamstrings and psoas muscles in normal subjects mimicking crouch gait and compared these with lengths in cerebral palsy patients with crouch gait.MethodsThirty-six patients with cerebral palsy and crouch gait were included in this study, and in addition, 36 age- and sex-matched normal controls were recruited. Hamstring and psoas muscle lengths in patients were evaluated using gait analysis and interactive musculoskeletal modeling software. Muscle lengths were also measured in the normal control group during normal gait and while mimicking crouch gait, and these were compared with those of cerebral palsy patient with crouch gait.ResultsNo significant differences were observed between maximum hamstring (p=0.810) and maximum psoas (p=0.456) lengths of patients and controls mimicking crouch gait. However, patients showed significantly shorter excursions of hamstring (p=0.022) and psoas (p=0.036) muscles than controls, whereas no significant excursion differences were observed between controls during normal gait and mimicking crouch gait.ConclusionsNormal controls mimicking crouch gait and cerebral palsy patients with crouch gait demonstrate similar muscle length patterns. However, mimicked crouch gait did not reproduce the excursion pattern shown by patients with crouch gait, which suggests that reduced hamstring and psoas excursion is an innate characteristic of pathologic crouch gait.

Highlights

Previous studies have shown that hamstring lengths are often not short in patients with cerebral palsy, which raises concerns over the benefits of distal hamstring lengthening in patients with crouch gait
There were no significant differences in the maximum length of hamstring and psoas muscle between patients and normal controls with crouch gait (p=0.810 and 0.456, respectively)
Three patients with crouch gait had a maximum hamstring length that was shorter than controls mimicking crouch gait by more than 1SD

Summary

Introduction

Previous studies have shown that hamstring lengths are often not short in patients with cerebral palsy, which raises concerns over the benefits of distal hamstring lengthening in patients with crouch gait. Cerebral palsy (CP) is a group of disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain Musculoskeletal surgery, such as, single event multilevel surgery, is widely performed in cerebral palsy and focuses on improving gait function and pattern. Hoffinger et al found that the hamstring lengths during stance phase in most of patients with crouch gait were longer than resting length and that hamstrings functioned as hip extensor during a significant portion of stance phase [9] They suggested that surgeons should be careful to avoid hamstring overlengthening to prevent an increased anterior pelvic tilt and consider lengthening the iliopsoas. Muscle length is not static, and can be affected by the position, that is, muscle lengths in patients with crouch gait and those in normally developing children may not be comparable because body positions differ

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