Using surface electrodes for the evaluation of the rectus femoris, vastus medialis and vastus lateralis muscles in children with cerebral palsy

The purpose of this study was to determine if surface electrodes are adequate in the determination of the activity patterns of the rectus femoris, vastus medialis and vastus lateralis in children with cerebral palsy (CP). Ninety patients with a diagnosis of CP underwent electromyography (EMG) testing. Surface electrodes were placed on the rectus femoris (RF), hamstrings, vastus medialis (VM) and vastus lateralis (VL). Muscle isolation tests revealed no cross-talk of the RF muscle on the vastii electrodes in any subject indicating surface EMG is sufficient for testing RF, VM and VL function in children. Muscle activation patterns during gait showed that the RF and not the VM or VL was active in mid-swing in the majority of cases.