Maximal ankle dorsiflexion was measured with an equinometer
affixed to the subject’s leg (Fig. 1)39,40. Data from this
electrogoniometric device were processed by a Macintosh G3
series computer software package (Apple Computer, Cupertino,
California), which depicts ankle position in the sagittal
plane as a result of an upwardly directed load applied to the
undersurface of the foot. The site of torque application is directly
under the second metatarsal head, the approximate center
of force transmission in the human foot. The instrument
shows a reading of 0° when attached to a neutral, plantigrade
foot, with subsequent positive change indicating relative dorsiflexion
and negative change indicating plantar flexion. A
predetermined, constant torque of 10 N-m was arbitrarily selected
for use in this experiment. This value represents the
average pressure placed on the foot by two of our orthopaedists
and one rehabilitation medicine specialist while testing
for equinus contracture in an office setting. We had previously
validated the equinometer in our laboratory for such use. The
instrument is accurate to within 1.31°, with a documented
average daily variation in individual subjects of