Hip Abductor Muscle Force AN ExPm-:RtMm’:NTAL STUDY OF THE INFLUENCE OF Hm PosITION W’iTt-I PARTICULAR REFERENCE TO ROTATION

To performu its function, the abductor niechanismis of the hip requires: (1) ade-(huatel ’ strong abductor niuscies; (2) adequate length of the femoral lever arm (femmsom’al head, neck, aiid greater trochanter) ; (3) a stable hip joint; (4) a mobile hip joint; amid (5) a paimsless hip joint. Loss or inadequacy of any one of these factors will cause ass abmsormisal gait. Much has been written about the abnormssal gluteal (or giuteuts mssediuis) and amstalgic gaits and their relationship to breakdown of the abductor issechsausisuis. However, a search of the literature failed to disclose amsy imsvestigatioui relatitig function of the abductor niechanisisi to the rotational gait ahnommssalities, such as the toeing-in seen in children. Simsce it has l)eeli established that antalgic and gluteal gait abnormalities corn-pellsate for deficiemicy of the abductor niechanistu, it would seem reasonable that abnommssal rotatiomial gait patterns represent the most efficient use of the hip-abductor msiechamsisiis under cettain circumstances. The purpose of this study was to test this hypothesis by msseasuiimsg, its a static experimisental systemn, the force required to duplicate the futmsctiomi of the abductor msiuscles with the femur amid pelvis in diffem-en