Association between improved trunk stability and walking capacity using ankle-foot orthosis in hemiparetic patients with stroke: evidence from three-dimensional gait analysis

Background Restoration of both normal movement of the pelvis and centre of mass is a primary goal of walking rehabilitation in post-stroke patients because these movements are essential components of effective gait. The aim of this study is to quantitatively analyze the effect of ankle-foot orthosis on walking ability, and to investigate the correlation between improvements in trunk motion and walking capacity.

Methods Walking speed, centre of mass displacement, and pelvic movements were examined in 20 post-stroke hemiparetic patients with and without ankle-foot orthosis using three-dimensional motion analysis.

Results Using ankle-foot orthosis improved walking speed, pelvic rotation and tilt, and lateral and vertical displacements of the centre of mass (P <0.01). Moreover, the gait asymmetry index was significantly decreased (P <0.01), and the Functional Ambulation Categories score improved significantly when patients used an ankle-foot orthosis (P <0.05). There was significant correlation between improvements in the walking capacity and the displacement of the centre of mass in both vertical and lateral directions (P <0.01).

Conclusions Using ankle-foot orthosis improves the walking capacity by improving the stability and concordant of the trunk in hemiplegic patients. The improvement in the walking capacity from using an ankle-foot orthosis may be attributed to its prevention of foot drop and compensation for the instability of the ankle joint.