The impact of orthoses on gait in children with Charcot-Marie-Tooth disease.

BACKGROUND

Charcot-Marie-Tooth disease (CMT) results in distal muscle weakness that leads to gait difficulties in both the stance and swing phases, thus limiting function in the community. A primary purpose of ankle foot orthoses (AFOs) is to improve gait function; however, little is known about what AFOs are prescribed and how they benefit children with CMT.

RESEARCH QUESTION

To determine the impact of previously prescribed AFOs on gait in children with CMT using comprehensive gait analysis techniques.

METHODS

We examined strength, passive range of motion and gait (kinematics, kinetics and temporal-spatial) for barefoot and AFO walking on 15 children with a diagnosis of CMT. Participants used their prescribed AFOs, the design of which varied depending on the patient. Comparisons between barefoot and AFO walking were completed for selected ankle, knee and hip kinematics and kinetics and temporal-spatial parameters. Subgroups were also evaluated based upon specific ankle kinematics relevant to AFO prescription.

RESULTS

AFOs resulted in increased walking velocity (0.91, SD 0.31 to 1.13, SD 0.23 m/sec, p = 0.001) and improved ankle kinematics (dorsiflexion in mid-swing: -11, SD 10 to 0, SD 5 degrees, p = 0.0001) and kinetics (peak plantar flexor moment in stance: 0.71, SD 0.30 to 0.85, SD 0.29 Nm/kg, p = 0.001). In patients with increased equinus in swing, AFOs resulted in improved ankle kinematics. In patients with increased dorsiflexion in terminal stance, AFOs did not provide the support that was needed to improve gait function.

SIGNIFICANCE

AFOs enhance gait function in children with CMT by improving walking velocity and selected ankle kinematics and kinetics. It is important that the AFO design be aligned with the patient's specific joint level impairment and associated gait dysfunction. Comprehensive gait analysis techniques can measure differences between barefoot and AFO function and help to clarify the most appropriate AFO prescription for an individual child.