Quantification of surface electromyographic recordings for assessment of spasticity

Surface electromyography (sEMG) was used in a group of 100 spinal cord injury (SCI) subjects during a comprehensive protocol to assess the type and severity of their spasticity. Subjects showed the expected range from no spasticity to extreme spasticity with clinical and sEMG criteria. The full range of sEMG responses to passive movement was observed for subjects with an Ashworth score of 3. Plantar stimulation responses, reinforcement maneuver responses and burst activity in relaxation were also evaluated as measures of hyperactivity. sEMGs were more sensitive than were the clinical measures in characterizing the features of spasticity. Use of sEMG data when it does not agree with mechanically derived data is defended. Electrophysiological measures may be usefully applied to provide objective, quantitative data regarding spasticity in SCI subjects and extend the information obtained by clinical examination