Increasing trunk muscle strength improves trunk movement asymmetry during gait in subacute stroke patients

In individuals who have experienced a stroke, the trunk remained relatively still during gait, but with significant asymmetries between the affected and unaffected sides. The purpose of this study was to clarify the factors involved in the improvement of trunk asymmetry during walking in patients with stroke. The study included 52 individuals with subacute stroke. Ambulatory trunk movements can be recorded by an accelerometer attached to the lower back at the L3 vertebra level. The Lissajous index (LI) calculated with the medio-lateral and vertical acceleration values was used to evaluate the trunk asymmetry during gait. A smaller LI would indicate that the gait is closer to being bilaterally symmetrical. Upper- and lower-extremity motor function, the muscle tone, lower-limb muscle strength, standing balance and trunk muscle strength were assessed the patients' physical functions. The LI and physical functions were measured at baseline (T0) and at 1 month (T1) and 2 months (T2) after T0. The LI at T2 was significantly lower than that at T0 (p < 0.05). A multiple regression analysis showed that the effect of trunk muscle strength was significantly greater than those of the upper- and lower-extremity motor functions. The results indicate that the patients with subacute stroke, the improvement of trunk asymmetry during gait was affected by increasing trunk muscle strength.