3D body segment oscillation and gait analysis for vestibular disorders.

OBJECTIVE: To investigate the patterns of gait and locomotion in three dimension space in patients with vestibular disorders.

METHODS: A 3D motion analysis system was employed to evaluate locomotor pattern and body's oscillation during gait under different conditions (normal, slow, fast speeds walking with eye open and normal speed walking with eyes closed) of nine patients with vestibular disorders. Twenty-one markers placed on the subject to record kinematics and locomotions of the head, spine and pelvis segments while walking. For each locomotor trial, the walking speed, locomotor patterns as well as the absolute angular dispersions of six segments around the roll, pitch and yaw axes were calculated to assess the equilibrium strategies of head, trunk and pelvis. Data was also recorded in 10 healthy subjects as control.

RESULTS: Patients' cadence is faster, and the stride time at normal walking speed is shorter than that of the controls (p<0.05). The body sway has also been documented some impairment in patients. With respect to the control, patients' oscillation of trunk around yaw axis at fast speed is less (p<0.05), which means the patient seems need less shoulder torsional movement. Moreover, the most prominent changes in patients are the sway of hip in roll, which is significant less than controls at fast (p<0.01), slow speed (p<0.01) and in eye-closed condition (p<0.05).

CONCLUSION: Our investigation corroborates those reports that higher velocities would be helpful for the increased gait stability in patients with vestibular disorders. And the body always try to keep the stability of head during gait, even under vestibular deficit conditions.