Test Setup

The pelvic tuck establishes sagittal-plane position and abdominal contribution before lower-extremity components are added. Pressing the top-side arm into the ground helps activate the abdominals on the left side in the demonstrated setup. The test is performed in a side-lying position with the top hip and knee both flexed to 90 degrees. The bottom-side leg starts at 0 degrees of hip extension with the knee flexed to 90 degrees. Both the backside heel and the top-side arch must contact the ground after the hips are tucked.