Monday, November 14, 2005, 4:00 pm
Patricia Shewokis, PhD (Host Getchell, HNES)
Place McK 337
The long-term effects of practice and FES gait training on joint coordination and muscle
activation in a child with cerebral palsy
Children with cerebral palsy (CP) often lack the ability to produce appropriate muscle activation
patterns for effective joint coordination and efficient ambulation; often resulting in compensatory
gait patterns which may place additional strain on joints, decrease movement efficiency, and
limit mobility. We assessed whether the effects of percutaneous (P-) or surface (S-) functional
electrical stimulation (FES) applied to the ankle musculature while walking can improve lower
limb coordination and gait function of children with hemiplegic or diplegic CP when walking
without FES. In a series of three pilot studies, we implemented FES-based gait training
paradigms using the principles of memory consolidation (Shadmehr & Brashers-Krug, 1997) and
varying amounts of physical practice. Gait training after 1 month with P-FES (n=3) resulted in
modest average improvements in cadence (4.6 hz), stride length (6 cm) and walking velocity (8
cm*s-1). Coordination changes after gait training with P-FES were localized in ankle and knee
displacement with joint displacement shifts (5 – 150) toward children with typical development
(TD) norms. After training 1 month with S-FES (nFES = 2; nCONTROL=2), improvements were
noted primarily in the knee and ankle for the angle-angle and phase-plane portraits with modest
improvements in spatial-temporal variables, especially step length. Results of a 5 month gait
training case study of a nine year-old female with left spastic hemiplegic CP demonstrated the
carry-over effects of S-FES to alter gait patterns, with joint coordination and muscle activity
patterns approaching those of children with TD. Further, the use of S-FES appeared to affect the
antagonistic muscle to which FES was applied. Taken together, the improvements in joint
coordination and gait function through this series of pilot studies may be attributable to the
combined effects of FES-based physical practice (through the provision of sensory feedback and
muscle activation) and memory consolidation principles. In addition, theoretical and clinical
implications for development of rehabilitation gait training protocols using FES-based
interventions are discussed.