Objective
The purpose of this study was to analyse the myotatic reflex characteristics of children with spastic cerebral palsy compared with normal infants and children

Method
Thirty four children with spastic cerebral palsy and 42 normal children were examined. The tendon taps were applied to the patellar and Achilles' tendons and shin using an electric reflex hammer. Compound muscle action potentials (CMAPs) were recorded from hamstring (HAM), rectus femoris (RF), tibialis anterior (TA), and gastrocnemias (GCL) by surface electrodes. The response ratios of HAMs/RF and TA/GCL were determined from CMAP amplitude.

Results
The mean HAM/RF ratios after patellar taps were 0.32⁑0.33, 0.37⁑0.33 and 0.32⁑0.19 in children with cerebral palsy, normal infants, and children over 1 year of age, respectively. The mean TA/GCL ratios following Achilles tap were 0.40⁑0.30, 0.93⁑0.11, and 0.25⁑0.14 in children with cerebral palsy, normal infants, and children over 1 year of age, respectively. All the spastic cerebral palsy children showed muscle responses in RF, HAM, TA and GCL after shin tap, but normal children did not.

Conclusion
The results reflect that the reflex responses are exaggerated in children with spastic cerebral palsy, and it can be used in the early diagnosis of cerebral palsy.