Postural instability neuropathic subjects at risk of foot ulceration

Diabetic peripheral neuropathy is believed to cause postural instability due to abnormal proprioception. We therefore assessed body sway in 4 groups of patients matched for age and sex: Group A: normal healthy controls (n=9); B: non-neuropathic diabetic subjects (n=9); C: diabetic neuropathy (n=14) and C: diabetic neuropathy + foot ulcer history (n=11). Postural sway control was assessed on a Kistler force plate using a Romberg test, measuring the standard deviation of the centre of pressure in both sagittal and frontal planes on 2 occasions, with the eyes open and closed. Analysis of variance was used to assess inter-group difference. Significantly greater instability was observed in the foot ulcer group (D) compared with all other groups in all studies: eq:- frontal plane, eyes open: A 3.4mm, B 3.3, C 3.8 and D 6.2 (p<0.05). Saggital plate, eyes closed:- A 5.6mm, B 5.8, C 6.9 and D 12.6 (p<0.05). These results are strongly indicative of an effect of severe neuropathy, as present in foot ulcer patients, on body sway control, that could result from loss of proprioception and/or motor weakness. Such instability is likely to have clinical significance and may increase the risk of minor trauma and ulceration.