Article

Children with cerebral palsy often walk with reduced knee extension in terminal
swing, which can be associated with short length or slow lengthening velocity of
hamstrings muscles during gait. This study investigated the role of two factors
that may contribute to such short and slow hamstrings: walking speed and
spasticity. 17 children with spastic cerebral palsy and 11 matched typically
developing children walked at comfortable, slow, and fast walking speed.
Semitendinosus muscle-tendon length and velocity during gait were calculated
using musculoskeletal modeling. Spasticity of the hamstrings was tested in
physical examination. Peak hamstrings length increased only slightly with walking
speed, while peak hamstrings lengthening velocity increased strongly. After
controlling for these effects of walking speed, spastic hamstrings acted at
considerably shorter length and slower velocity during gait than normal, while
non-spastic hamstrings did not (all P<0.001). These data are important as a
reference for valid interpretation of hamstrings length and velocity data in gait
analyses at different walking speeds. The results indicate that the presence of
spasticity is associated with reduced hamstrings length and lengthening velocity
during gait, even at constant walking speed.

Langue : ANGLAIS