Abstract
A study of 12 cerebral palsied children with internal rotation revealed three patterns of electromyographic activity: (1) Diagnostic pattern--where a simple muscle group stood out as the responsible agent--notably the medial hamstrings; (2) Nondiagnostic pattern--nonrecurring pattern; (3) Nondiagnostic pattern--recurring "mass limb reflex" pattern. In all cases, electromyography was useful for: (1) confirmation of clinical impressions. Electromyographic confirmation of phasic hamstring overactivity gives a firm basis for tendon surgery with expectancy of good results. (2) Detection of the responsible muscle group where clinical methods fail to do so. It detects the "at risk" patients, where follow up with tendon surgery at the appropriate time could be performed with predictable results. (3) Selection of patients who are likely to respond to tendon surgery, and those unlikely to benefit from it. The adductors and internal rotators may play only a secondary role in children whose predominant problem is internal rotation during gait. The medial hamstrings stand out as the most important single muscle group causing this problem. Consequently, it is important to analyze gait problems with the patient walking, and examine electromyographs during walking in the overall assessment of a patient with dynamic gait problem.