Article

An ankle-foot orthosis is suggested to actively assist dorsiflexion
of the foot by induction of a positive proprioceptive impact to ankle dorsiflexor
muscles. However, an objective proof is missing.
OBJECTIVES: To assess the
proprioceptive impact of an ankle-foot orthosis application by Hoffmann reflex
recordings of the soleus muscle under static conditions. It was hypothesized that
the use of an ankle-foot orthosis facilitated dorsiflexor motor function and thus
a decreased the soleus Hoffmann reflex. STUDY DESIGN: Experimental study in
healthy volunteers, pre-post test design. METHODS: In all, 20 healthy volunteers
were enrolled in order to assess the proprioceptive impact of orthosis
application. The Hoffmann reflex was recorded before, during, and after orthosis
application. RESULTS: Under orthosis application, the Hoffmann reflex
significantly decreased as compared to before (p < 0.05) and after application (p
< 0.05). CONCLUSIONS: Findings indicate an inhibition of plantarflexors probably
induced by facilitation of ankle dorsiflexors under static conditions. At first
glance, it seems that foot orthoses primarily have a stabilizing effect on ankle
joints in terms of simple mechanical bandages. However, the present results
suggest an additional active impact on proprioceptive control. CLINICAL RELEVANCE: The putative neuromodulatory effect on motor control may support the
application of such ankle-foot orthoses in, for example, drop foot. Furthermore,
the objective assessment of a neurophysiological mode of action of orthoses by
Hoffmann reflex recordings might be an appropriate primary outcome parameter in
clinical trials.
CI - (c) The International Society for Prosthetics and Orthotics 2014.

Langue : ANGLAIS