Article

AIM: If increased muscle stiffness and contractures in children with cerebral
palsy (CP) are related to impaired muscle growth, reduced muscle growth should
precede or coincide with increased muscle stiffness during development. Here, we
compared the volume of the medial gastrocnemius muscle and the passive
(non-neural) stiffness of the triceps surae musculotendinous unit in typically
developing children and children with CP from birth until 4 years of age. METHOD:
Forty-one children with CP and 45 typically developing children were included.
Freehand three-dimensional ultrasound was used to evaluate the volume of the
medial gastrocnemius muscle. Biomechanical and electrophysiological measures were
used to determine passive and reflex mediated stiffness of the triceps surae
musculotendinous unit. RESULTS: Medial gastrocnemius muscle volume increased with
the same rate in typically developing and children with CP until 12 months of
age, when a significant smaller rate of growth was observed in children with CP.
Passive stiffness of the triceps surae musculotendinous unit showed a linear
increase with age in typically developing children. Children with CP older than
27 months showed a significant increase in passive stiffness. Reflex mediated
stiffness was only pathologically increased in four children with CP.
INTERPRETATION: The deviation of medial gastrocnemius muscle volume, earlier than
musculotendinous unit stiffness, is consistent with the hypothesis. The data also
point out that muscle atrophy and muscle stiffness already develops within the
first 1 to 2 years. This emphasizes the necessity of early interventions to
promote lower limb muscle growth in this population. WHAT THIS PAPER ADDS: Medial
gastrocnemius muscle growth is reduced in children with cerebral palsy (CP)
around 12 months after birth. Triceps surae musculotendinous unit stiffness is
increased in children with CP around 27 months after birth. Reflex excitability
is rarely increased in children with CP. Reduced muscle growth may be involved in
the pathophysiology of contractures.
CI - (c) 2018 Mac Keith Press.

Langue : ANGLAIS