Clinical photography and videotape. Initially, colour
videotapes were used in order to study the movement
patterns by single-frame analysis. As we became more
experienced, the responses were recorded on 35 mm
colour projection slides.
Electromyography. This was performed on three normal
volunteers. Gluteus maximus, gluteus medius, gluteus
minimus, tensor fascia lata and adductor magnus muscle
activities were recorded with the subject at rest and subsequently
with the pelvis in the different positions found
to occur regularly when the test was performed. Three
walking subjects with incomplete paraplegia due to traumatic
fracture-dislocation were also studied.
Assessment of abductor muscle power. With the subject
lying on one side, the strength ofabduction ofthe hip was assessed, using the Medical Research Council grading of