Defining gastrocnemius length in ambulant children

This paper describes a system to calculate gastrocnemius muscle length from three dimensional kinematic gait data and anthropometric measurements of children taken from MRI scans. As well as describing the simple model that may be applied to existing gait data, the anthropometric data for 15 able-bodied children is presented. The model is then used to describe gastrocnemius muscle lengths and the effect of different pathologies on muscle lengths by looking at cohorts of able-bodied children, children with a hemiplegic or diplegic pattern of cerebral palsy, a child undergoing tendo Achilles lengthening and a child with burns to his lower limbs. The results show the importance of using muscle lengths as part of a clinical assessment and the need to take the effects of skeletal growth into account when developing models for use in a paediatric population.