Trunk muscle strength in relation to balance and functional disability in unihemispheric stroke patients

To evaluate trunk muscle strength in unihemispheric stroke patients and to assess how it relates to body balance and functional disability in this patient group.

This prospective case-comparison study investigated isometric and isokinetic reciprocal trunk flexion and extension strength at angular velocities in 38 unihemispheric stroke patients and 40 healthy volunteers. The Berg balance scale was used to assess balance and stability, and the FIM instrument was used to evaluate functional disability in the patient group. Patients were evaluated as soon as they were able to stand long enough for testing.

Peak torque values for trunk flexion and extension were lower in the stroke patients than in the controls. The differences were significant for trunk flexion and for trunk extension. In both groups, peak torque values for trunk flexors were greater than peak torque values for trunk extensors. There was a significant positive correlation between trunk muscle strength and Berg balance scale score at discharge. Trunk muscle strength was not correlated with FIM total score or FIM motor score, but the locomotion-transfers FIM subscore at discharge was positively correlated with trunk muscle torque values, except for isometric extension.

The findings indicate trunk flexion and extension muscle weakness in unihemispheric stroke patients, which can interfere with balance, stability, and functional disability.