Evaluation of effect of ankle-foot orthosis use on strength restoration of paretic dorsiflexors

Geboers JFM, Janssen-Potten YJM, Seelen HAM, Spaans F, Drost MR. Ankle-foot orthosis and reduction of strength restoration of paretic ankle dorsiflexion. Arch Phys Med Rehabil 2001;82:856-60. Objective: To assess whether a difference exists in restoration of strength between patients with a recent paresis of the dorsiflexors of the ankle using an ankle-foot orthosis (AFO) and patients without an AFO. Design: Prospective case-control study. Setting: Patients from regional hospitals, tested in a rehabilitation research center. Participants: Twenty-nine patients with a recent (6wk-1yr) peripheral paresis, alternately assigned to a group using an AFO or a control group. There was no significant difference in duration of the paresis and in torque at entering the study (T0) between the 2 groups. Interventions: The use of an ankle-foot orthosis. Main Outcome Measures: Isometric torque production of ankle dorsiflexors, expressed as ratio of paretic and healthy side, in 2 measurement sessions, over a period of 6 weeks (T0-T6) with the ankle in 0° and 30° plantarflexion. Results: Both groups had significant restoration of strength ± standard deviation between T0 and T6 in 30° flexion: non-AFO group 17% ± 15%, AFO group 9% ± 12%. No significant difference existed between the 2 groups (30° p =.56). No significant shift in strength ratio 0°:30° occurred (AFO group p =.82). Conclusion: The use of an orthosis does not influence restoration of strength in patients with a recent peripheral paresis of the ankle dorsiflexors.