Article

OBJECTIVE: To evaluate whether the catch in clinical spasticity assessment in
cerebral palsy (CP) is the consequence of a sudden velocity-dependent increase in
muscle activity, resulting from hyperexcitability of the stretch reflex in
spasticity. DESIGN: Cross-sectional study. SETTING: A special school for children
with physical disabilities. PARTICIPANTS: Children with CP (N=20; age range,
5-14y; mean weight +/- SD, 35+/-14kg; mean length +/- SD, 139+/-19cm).
INTERVENTIONS: Spasticity assessment tests (using slow and fast passive stretch)
were performed in the medial hamstrings, soleus, and medial gastrocnemius muscles
of the children by 2 experienced examiners. MAIN OUTCOME MEASURES: Surface
electromyography (EMG) was recorded and joint motion was simultaneously measured
using 2 inertial sensors. The encounter of a catch by the examiner was compared
with the presence of a sudden increase in muscle activity ("burst"). The average
rectified value (ARV) of the EMG signal was calculated for each test. RESULTS:
The study shows a sudden increase in muscle activity in fast passive stretch,
followed by a catch (hamstrings 100%, soleus 95%, gastrocnemius 84%). The ARV in
slow passive stretch was significantly lower. CONCLUSIONS: The results confirm
that in children with CP, an increase in muscle activity is primarily responsible
for a catch in fast passive muscle stretch.
CI - Copyright 2010 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS