Comparison of the effects of foot-toe orthoses on three-dimensional pelvic kinematics in individuals with hallux valgus during gait.

BACKGROUND: Most previous studies focused on the possible relationship between hallux valgus deformity and biomechanical characteristics in the foot and lower leg. Very few investigated the association of pelvic kinematics and hallux valgus during gait according to various foot-toe orthoses for hallux valgus.

OBJECTIVE: To investigate the effect of soft or hard foot-toe orthoses on pelvic kinematics in individuals with hallux valgus deformity during gait.

STUDY DESIGN: This study has a repeated measures design.

METHODS: Three-dimensional range of motion in the pelvic segment was collected from 22 individuals (18 women and 4 men) aged 21 to 52 years (mean 31.7 years, SD 8.7) with hallux valgus. All participants exhibited a hallux valgus angle of more than 20 degree in both feet. A motion analysis system with eight infrared cameras was used to obtain pelvic kinematic data in the hard plastic orthosis, soft silicone orthosis, and without foot-toe orthosis conditions during gait. The two types of hallux valgus orthoses used in this experiment were commercially available products. The participants performed 8-10 walking trials. The walkway length was 6 m. Repeated-measures analysis of variance was used to determine the effects of each orthosis condition on the pelvic kinematic values.

RESULTS: The hard plastic orthosis condition was associated with decreased pelvic motion compared with the soft-type orthosis and no orthosis conditions for depression (F(2,42) = 7.329, P = 0.004), external rotation (F(2,42) = 4.367, P = 0.027), and overall transverse motion (F(2,42) = 4.897, P = 0.019) of the pelvic segment during gait. There were no significant differences in other pelvic motion variables between the without foot-toe orthosis and soft silicone orthosis conditions (P > 0.05).

CONCLUSIONS: The results of this study suggest that the hard-type foot-toe orthosis for hallux valgus reduced pelvic motion and contributed to preventing excessive pelvic movement during gait.