The forces acting on the mandibular and occipital supports of the Milwaukee brace were measured in eleven patients undergoing treatment for idiopathic scoliosis. Special dynamometers were designed to measure three mutually perpendicular force components in both mandibular and occipital pads. Measurable loads were present during all activities. In the standing position, the average total tractive force was 1.94 kilograms. An increase in loads was noticed when the patients adopted the recumbent position, the average total traction was 3.08 kilograms when lying on the right side and 5.06 kilograms in the supine position.
Exercises increased all force components, as did deep breathing or coughing, where individual force components up to seventeen kilograms were recorded. Removal of the thoracic pad induced a significant increase in forces in all patients. The highest loads were recorded in a patient who ultimately required operative treatment for progression of the curve.