Article

The aim of this article was to compare medial gastrocnemius muscle volume,
physiological cross-sectional area (PCSA), muscle length, fascicle length, and
pennation angle in children aged 2 to 5 years with spastic cerebral palsy (CP)
and in typically developing children. Method Fifteen children with spastic CP (11
males, four females; mean age 45mo [SD 15mo]; five with hemiplega; 10 with
diplega; 10 classified at Gross Motor Function Classification System (GMFCS)
level I, five at GMFCS level II) and 20 typically developing children (11 males,
nine females; mean age 48mo [SD 14mo]) participated in the study. Individuals
with spastic CP were included if they had a minimum range of motion of 0 degrees
ankle dorsiflexion with the knee extended and were excluded if they had had
previous botulinum toxin treatment to the calf muscles or previous calf surgery.
Typically developing children were included if they were able to walk
independently and were excluded if there was a history of previous lower leg
injury or other developmental disorder affecting the lower limb. Freehand
two-dimensional and three-dimensional ultrasound was used to assess muscle
properties of the relaxed medial gastrocnemius muscle at three ankle joint
angles: maximum dorsiflexion, neutral and maximum plantarflexion. PCSA was
calculated as a function of muscle volume and muscle fascicle length and
pennation angle was recorded at the neutral ankle joint angle. Results Medial
gastrocnemius muscle volume was 22% lower in the group with spastic CP than in
the typically developing group, which in the absence of significant group
differences in neutral fascicle length gave rise to an equivalent reduction in
PCSA for the group with spastic CP. Significant positive correlations were found
between muscle volume and age (r=0.63-0.65) and between muscle length and age
(r=0.72-0.81) in both groups. Maximum ankle dorsiflexion angle was also reduced
in the group with spastic CP (8 degrees ) compared with the typically developing
group (26 degrees ). Interpretation The observed reduction in muscle PCSA in the
group with spastic CP would be expected to contribute to the clinically observed
muscle weakness in spastic CP and suggests the need for early intervention in
order to minimize loss of muscle PCSA in spastic CP.
CI - (c) The Authors. Developmental Medicine & Child Neurology (c) 2011 Mac Keith
Press.

Langue : ANGLAIS