Evaluation of the catch in spasticity assessment in children with cerebral palsy.
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.


METHODS
Cross-sectional study.


METHODS
A special school for children with physical disabilities.


METHODS
Children with CP (N=20; age range, 5-14y; mean weight +/- SD, 35+/-14kg; mean length +/- SD, 139+/-19cm).


METHODS
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.


METHODS
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.
van den Noort
Josien C
JC
Department of Rehabilitation Medicine, Research Institute MOVE, Vrije Universiteit University Medical Center, 1007 MB Amsterdam, The Netherlands. j.vandennoort@vumc.nl
Scholtes
Vanessa A
VA
Becher
Jules G
JG
Harlaar
Jaap
J
D000293:Adolescent; D002547:Cerebral Palsy / Q000503:physiopathology* / Q000534:rehabilitation; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D009128:Muscle Spasticity / Q000503:physiopathology* / Q000534:rehabilitation; D018482:Muscle, Skeletal / Q000503:physiopathology*; D010808:Physical Examination; D026741:Physical Therapy Modalities; D012026:Reflex, Stretch