Keith Cronin & Ryan Kendrick
This single case report does however help to shed some light on the mechanism. In this case, a subject with neurological deficit resulting in a partial foot drop (very weak dorsiflexion and eversion) was examined using the BodiTrak system which evaluates centre of pressure. He was asked to do a single leg standing task with eyes closed.
In the untaped condition (left) the COP measurement shows that the subject tries to maintain a neutral COP. As soon as his COP moves slightly laterally ( to the left of the centre line and into inversion), he does not have the strength to correct and loses his balance. In the taped condition (right), the subject actually rests in slight inversion (COP is slightly to the left of the centreline) which would normally result in a loss of balance. With the tape in situ he is able to rest on the tape and even correct using the recoil if he goes into inversion improving his single leg standing time significantly.
Unfortunately due to time constraints, he was not tested in the lengthened position but the neurological deficit would suggest that any mechanism is likely to be mechanical. This is illustrated further in the wrist case study below where the nerve has been transected with a knife so the only possible mechanism is a mechanical one.