This paper explores the use of biofeedback to improve gait in Parkinson's disease (PD) and, in particular, reports on the design and testing of a new vibratory orthosis. The orthosis causes a rhythmic vibratory stimulus to be applied to one or other side of the lumbar region. The stimulus is synchronized with stepping through the use of heel-located switches; each switch controls the stimulus to the corresponding side of the body. In the experimental evaluation it was hypothesized that step-synchronized, vibratory stimulation applied to the lumbar region will lead to an increase in walking velocity in patients with idiopathic Parkinson's disease. Subjects were asked to carry out walking trials under two conditions. In one condition, the vibratory orthosis was active; in the other condition the vibratory orthosis was inactive. Walking velocity was measured over a straight, 10 m walkway. A comparison between the two conditions using a paired t-test showed a significant increase in walking velocity when the vibratory orthosis was active, compared with the inactive condition. It was speculated that use of the vibratory orthosis, which stimulates proprioceptive receptors, may lead to an improvement in gait, stability and may support gait re-education in PD patients. It was also suggested that the results may inform future ideas for rehabilitation of similar neurological diseases.