The ankle jerk is one of the most commonly tested deep reflexes,1 but the effect of the position of the lower limb on ratings of the reflex is unclear. Most commonly, the ankle jerk is assessed with the subject lying supine with the hip abducted and externally rotated, and the knee in moderate flexion before the triceps surae tendon is tapped with the reflex hammer.2 3Alternatively, the subject could sit with the legs dangling freely over the edge of the couch3 or with the knee on a chair with the ankles projecting freely over the edge of the chair.4In a less commonly described position, the subject lies supine but the hip is adducted and the knee extended, and unlike the other positions, the triceps surae tendon is not struck by the reflex hammer, but the palmar surface of …