Abstract
1 . An operation for strengthening the lateral abdominal muscles in children after poliomyelitis is described. It consists of transposition of the proximal part of the gluteus maximus, the tensor fasciae latae and the ilio-tibial band ("the pelvic deltoid" of Henry) to a chosen rib.
2. The results of this operation in eight consecutive cases of paralytic scoliosis, pelvic obliquity and thoraco-pelvic instability are assessed.
3. A "strong" motor allows the child to lift the pelvis against gravity, whereas with a "weak" motor the child is unable to do so efficiently. However, even a "weak" musculotendinous tendinous unit helps invariably in restoring the thoraco-pelvic stability, just as a weak "hamstring-into-patella" transplant stabilises the knee.
4. Those motors (gluteus maximus with or without tensor fasciae latae) that contract vigorously and move the free end of the ilio-tibial band for at least three centimetres on direct faradic stimulation with a bipolar electrode during the operation become ultimately strong and most efficient.
5. The unreliability of the clinical test of tensor fasciae latae in small children is discussed, and the advantage of using the gluteus maximus as the motor for the musculo-tendinous unit is emphasised.
6. Using the proximal half (or less) of the gluteus maximus for strengthening the lateral abdominal muscles does not seem to affect appreciably the strength of hip extension. This phenomenon may be explained with reasonable probability by the existence of a twofold insertion of that muscle.
