Role of symmetry in gait performance of stroke subjects with hemiplegia

This study examined the symmetry properties of 34 gait variables in a group of 31 hemiplegic subjects. A variable was called symmetric if subjects with the highest speeds had equal values on both sides of the body. If the highest speeds were achieved when the values of the affected side exceeded the unaffected, the variable was called asymmetric. Correlations of the differences and absolute differences with speed were used to detect symmetric and asymmetric variables, as well as variables exhibiting other forms of symmetry. Seven variables were detected but only one showed symmetry itself. Four asymmetric variables and three variables with other symmetry properties were identified. In summary there is only weak evidence that symmetry plays any role in promoting speed in this subject group; in fact asymmetric variables seem more important.