Rehabilitation management of Friedreich ataxia: Lower extremity force-control variability and gait performance

We describe the rehabilitation management during a 12-month period of a 14 year-old. female with Friedreich ataxia. Interventions included task-oriented bimanual reaching activities,.functional strengthening, and gait training using a walker featuring tension-controlled wheels and a reverse-braking system. Herphysical status was assessed with the Nine-Hole Peg Test, single limb stance tune, manual muscle testing, self-reported falls, isometric force control testing, and 3-dimensional gait analysis in a motion-capture laboratory. Although measures of the patient's Nine-Hole Peg Test, single limb stance time, and manual muscle testing reflected minimal changes, her gait speed decreased by 69.4%. However, the force-control targeting of her dominant knee extensors showed a 43.7% increase in force variability that was concomitant with her decline in gait performance. The decrement of her initial gait speed was reduced to 42.9 on replacing the wheeled walker with the U-Step Walking Stabilizer at the end of the intervention period. Although the patient's gait remained significantly impaired, extended use of the U-Step Walking Stabilizer modestly improved her gail performance, and her rate of falls decreased from 10 to 3 per month. Our observations suggest that use of force-control testing as proxy measures of ataxia and tension-controlled gait aids show promise in the management of Friedreich ataxia and merit further investigation.