• Functional electrical stimulation;
  • hereditary spastic paraparesis;
  • spasticity;
  • stiffness;
  • walking;
  • weakness

Objectives:  To investigate in people with spastic paraparesis (SP): 1) the factors contributing to foot drop and reduced toe clearance while walking; 2) short-term effects of bilateral functional electrical stimulation (FES) of the common peroneal nerve.

Materials and Methods:  Long term (>0.5 years) users of FES with SP were compared to matched controls (N = 11 per group). Ankle strength and plantarflexor stiffness and walking kinematics were objectively recorded. The effects of FES on: 1) perceived efficacy; 2) muscle torque and ankle motion; 3) clinical outcome measures and walking kinematics were assessed. Results were compared using an analysis of covariance.

Results:  Ankle weakness and stiffness is higher among people with SP. Higher plantarflexor stiffness is associated with reduced swing phase dorsiflexion; higher toe clearance while walking is associated with increased hip flexion. FES increases dorsiflexor torque, improves toe clearance and dorsiflexion in swing phase, and significantly improves walking speed (p < 0.05).

Conclusions:  There are multiple causes of tripping in people with SP; FES reduces foot drop and improves walking speed.