The growth and the development of gastro-soleus contracture in cerebral palsy

Abstract

Introduction: The development of contractures in children with spastic cerebral palsy is an important clinical as well as scientific issue. A common model for the development of contractures suggests that increased muscle tone shortens muscles, which leads to reduced growth of sarcomeres and tighter noncontractile muscle and tendon tissue. However, the spasticity is not the only factor influencing the contracture development. Based on our clinical observation we hypothesize that the body growth might play a key role in development of gastrocnemius contracture. Patients/materials and methods: We performed a retrospective cross-sectional analysis of 3D gait data of 244 children (385 legs) with spastic diplegic CP and equinus gait. Children were subdivided according to age into 6 subgroups (5–6, 7–8, 9–10, 11–12, 13–14 and 15–18 years) to show the changes during the whole period of growth. The height of all the participants at each visit was recorded. A formerly trained Generalized Dynamic Neuronal Network (GDNN) [1], a reliable method of automatic gait pattern recognition and classification, was used to discriminate between dynamic and fixed contracture of gastro-soleus muscle based on the ankle and knee kinematics and moments. The Spearman correlation coefficient was used to show the relationship between the growth and gastro-soleus contracture development. Results: The relative increase of fixed contracture of the gastrosoleus muscle between the age groups correlates positively with the relative increase in height (r=0.9; p<0.05). Therefore, the development of equinus contracture is tightly correlated with growth velocity in children with diplegic spastic CP. Discussion & conclusions: The range of ankle motion is decreasing during childhood [2]. It might sound contradictory but the spasticity of gastrosoleus muscle is decreasing between the ages 6–12 [3] as well. It seems that contracture development is not only moderated by spasticity and the reduction in tone does not prevent the development of contractures in CP [4]. We proved that the development of equinus contracture is tightly correlated with growth velocity in CP. Thereforewewould like to stress the growth spurt as an important period for contracture development as well as prevention.