Functional outcome differences indicated by the angle of righting reaction from a lateral tilted sitting position in subacute severe hemiplegia

This study aimed to clarify the differences in the functional outcomes of severe stroke patients using RR from a lateral tilt sitting position.

This cross-sectional study comprised 51 patients with subacute stroke (age of 69.1 years, 72.2 days from onset, 33 with left hemiplegia). In addition to suffering a severe stroke, their modified Ranking Scale was 5; a mean of 31 was obtained on the Functional Independence Measure of motor items; and they required constant assistance with ADL.

The RR task was performed in a 10° lateral tilt sitting position and the RR angles of the neck, trunk, and lower legs were calculated using Image J. The participants were divided into a home discharge group and another discharge group. Statistical analysis was performed using unpaired t-tests for comparisons between groups. Receiver operating characteristic (ROC) curves were constructed for items with significant differences to calculate the cut-off values for home discharge.

There were 24 participants in the home discharge group and 27 in the other discharge group. For RR toward the paralyzed side, the trunk RR angle was 16.8±4.6° in the home group and 8.5±3.7° in the non-home group; and it was significantly greater in the home group (p0.01, d=2.0, 95% CI: -10.7– -6.0). For RR toward the non-paralyzed side, the trunk RR angle was 14.5±3.8° in the home group and 10.4±3.9° in the non-home group; and it was significantly greater in the home group (p0.01, d=1.0, 95% CI: -6.2– -1.9). The cut-off values for home discharge were a trunk RR angle of 12.5° for RR toward the paralyzed side (area under the curve (AUC): 0.93, sensitivity: 95.8%, specificity: 77.8%), and a trunk RR angle of 13.4° for RR toward the non-paralyzed side.

The difference in functional outcome was found to be related to the RR angle of the trunk, which was greater in the home group, regardless of the tilt direction. The accuracy of the cutoff value was higher for RR to the paralyzed side. It may be feasible to predict whether patients with severe stroke will be discharged home or not, on the basis of the functioning of the trunk on the paralyzed side.

The results indicate that patients with severe subacute stroke who are discharged home exhibit a robust trunk righting reaction. Therefore, an assessment of lateral sitting balance, including RR to the affected side, may be promising in evaluating the balance abilities of stroke patients in physical therapy.