Influence of gait analysis on decision-marketing for lower extremity surgery

Muscle length in severe crouch gait


  1. 1. Hugh Williamson Gait Laboratory, Royal Children’s Hospital;
  2. 2. The University of Melbourne;
  3. 3. La Trobe University;
  4. 4. Gait CCRE, The Murdoch Childrens Research Institute, Melbourne, Australia

Background: Considerable uncertainty remains as to the length of muscle tendon units in crouch gait, particularly, the length of hamstrings has not been defined.

Objectives: To investigate muscle lengths in severe crouch gait.

Design: Retrospective cohort study.

Setting: A tertiary paediatric hospital/gait analysis laboratory.

Participants: A convenience sample of 16 children with spastic diplegic cerebral palsy (Gross Motor Function Classification System Levels II and III) in severe crouch gait attending. Severe crouch gait was defined on sagittal plane kinematics as;greater than 30 0 knee flexion throughout stance phase, 1,2 ankle dorsiflexion > 15 0, and maximum hip extension < ISD above normal range, pelvic position not specified.

Method: Muscle lengths were calculated from 3-dimensional kinematics. Individual muscle lengths were plotted for key sagittal plane motors: psoas, semimembranosus, rectus femoris, vastus intermedius, gastrocnemius, soleus, and tibialis anterior. Individual plots of mean muscle length in stance phase were compared with the normal reference range. Statistical analysis was undertaken using analysis of variance (ANOVA).

Results: In severe crouch gait, muscle lengths showed: uniformly long soleus (not gastrocnemius); long vastus intermedius (not rectus femoris): long hip extensors, and short hip flexors. Pelvic tilt was variable. Hamstring lengths were found to be long, normal, and short (see Table C:2). Hamstring length was strongly related to pelvic tilt (ANOVA p<0.0001). Participants (n=5) with posterior pelvic tilt all had hamstrings functioning in the short range, whereas patients with either a neutral or anterior pelvic tilt had hamstrings that functioned in the excessively long range.

Conclusions: For the first time we have confirmed that crouch gait can be subdivided further by extending the definition to the level of the pelvis. This helps in evaluation and clinical decision-making. Only those patients with a posterior pelvic tilt have functionally short hamstrings and only these patients should be considered for hamstring lengthening surgery. Excessively long muscle groups (quadricepts, hip extensors, and soleus) must be considered in the surgical correction of severe crouch gait: re-tensioning of quadriceps by patella tendon shortening, support of excessively long soleus by a ground reaction ankle-foot orthoses and strengthening of long and weak hip extensors by a strengthening programme, all need to be considered in a comprehensive management programme for severe crouch gait.


  1. 1. Sutherland DH, Cooper L. (1978) The pathomechanics of progressive crouch gait in spastic diplegia. Orthopedic Clinics of North America 9: 143-153.
  2. 2. Sutherland DH, Davids JR. (1993) Common gait abnormalities of the knee cerebral palsy. Clinical Orthopaedics 288: 139-147.
Gal 1 Gal 2
Supporting Organizations
Online Feature Partner
Locations of visitors to this page

© 2010 all rights reserved. maintained by Classic Infomedia