Trunk and Head Control During Walking in Patients With Unilateral Vestibular Hypofunction: Effect of Lower Limb Somatosensory Input.

Abstract

The aim of the study was to investigate (a) postural control, especially trunk and head control, in patients with unilateral vestibular hypofunction and healthy controls during walking on firm and foam surface and (b) the difference between the impact of left and right unilateral vestibular hypofunction, and correlation between trunk/head control and vestibular function in the patients. Thirteen patients and 13 healthy controls were recruited. Vestibular function was examined based on the canal paresis value. Participants walked on a treadmill on firm and foam surface. Peak-to-peak trunk (Troll and Tpitch) and head roll and pitch angle (Hroll and Hpitch) were calculated as primary outcome measures. In the unilateral vestibular hypofunction group but not healthy controls, Troll was significantly higher on foam than firm surface (P = 0.03). Tpitch was significantly higher on foam than firm surface in both groups (P = 0.02). Patients had significantly lower Hroll (P = 0.03) and Hpitch (P = 0.02) and lower head-trunk correlation in both medio-lateral (P = 0.05) and anteroposterior direction (P = 0.03) than those in the healthy control group. Patients with unilateral vestibular hypofunction seemed to rely more on lower limb somatosensory input for trunk control especially in the medio-lateral direction compared with healthy controls. Lower head sway and head-trunk correlation may suggest a more independent and successful head control strategy in patients.