Exploration of paretic gait by differential loading in normals

OBJECTIVE: To determine if the gait patterns of artificially loaded healthy subjects resemble those of patients with weak ambulatory muscles. DESIGN: The gaits of artificially loaded healthy subjects and their controls were compared with the gaits of amputees and paretic patients, using analysis of variance. BACKGROUND: Muscle weakness due to paresis or limb amputation results in a misrelation between muscle power and body weight borne during ambulation. When body weight is increased by artificial loading of a normal subject, a misrelation between muscle strength and body weight results. METHODS: The gaits of paretic patients and artificially loaded normal subjects were recorded in the laboratory, by means of foot-switches. Stride length and stride frequency were used to calculate stride ratio which was used to compare the different gaits. RESULTS: Mean stride ratios of paraparetics, peroneal paretics and healthy subjects who carried load in the hand showed no statistically significant difference, while the ratio for hemiparetics differed significantly from the value for the artificially loaded healthy subjects. Below-knee amputees had a similar stride ratio to normal subjects who carried load on the ankles, while the above-knee stride ratio differed significantly from ankle-loaded normal subjects. CONCLUSION: Paraparetic and peroneal paretic gaits were approximated by the gaits of normal subjects who carried artificial load in the hand while the below-knee amputee gait was mimicked by normal subjects who carried load on the ankles. The two models of artificial loading could not generate any semblance with hemiparetic and above-knee gaits.