Development of an Index for Drop-Foot Severity of DPN Patients

Abstract

PURPOSE: Currently, the population percentage of diabetics suffering Diabetic Peripheral Neuropathy (DPN) and foot-drop gait anomaly was estimates as 15% in the United States. The onset of foot-drop could not be detected until symptoms could be observed visually, patient falling or patient experiencing painful gait issues and medical tests. This research showed that by utilising the plantarpressure characteristics of DPN drop-foot gait, a set of index could be developed for the severity of DPN. METHODS: The protocol involved the recruitment of older diabetic adults who were confirmed to have diabetic peripheral neuropathy (DPN) at two local hospitals in Malaysia. Also, older diabetic adults who have no DPN were recruited. Soft targets were placed on the plantar surface at the heel and at the second metatarsal areas. A set of prototype stencils were used to position the targets. Subjects wore shoes with in-sole pressure sensors (TekScan) and walked on a straight line for roughly 20 steps and repeated six times. Based on the heel target position, the plantar distance covered from heel-down along the foot-path for a specific period of time was calculated and was called Plantar distance at the heel (PDH). Then, the amount of time it took to cover a quarter of the foot-path from heel-down and the amount of time it took to cover the foot-path from the second metatarsal head to toe-off were called Time at heel (TAH) and Time at push-off (TAP), respectively. The results of the study are provided in Table I. The PDH covered by DPN subjects were significantly larger those of non-DPN subjects in all cases. By taking the ratio between PDH and TAH, an index could be determined successfully. CONCLUSION: With the discovery of these measures, drop-foot anomaly could be determined at an early stage; thus, DPN patients could have access to orthotics promptly, hence avoiding falling and other adverse effects such as plantar ulcer development, reluctance to walk and lack of enthusiasm for physical exercise.