The impact of functional electrical stimulation to the lower leg after a single botulinum toxin injection in children with a spastic equinus gait due to cerebral palsy
Cerebral palsy (CP) is a common neurological condition seen in children which results in childhood disability. Damage to the developing brain results in abnormal muscle tone and decreased force generation, which leads to loss of independent function. Previous studies investigating interventions targeting the typical equinus gait pattern seen in spastic CP have reported inconclusive and widespread outcomes. Objectives The objectives of the study were to determine (1) the effect of functional electrical stimulation (FES) after a single botulinum toxin injection into the triceps surae muscle as a functional orthosis on various gait parameters and economy of movement; (2) caregivers’ perceptions of the impact of the intervention on their child’s function and participation, and (3) optimal timing intervals for introducing FES after a botulinum toxin injection. Method Single-subject research with a multiple baseline approach was conducted on five ambulant subjects (average age 5.1 years, SD=1.4) in the Cape Metropole with a dynamic equinus gait due to hemiplegic CP. Two-dimensional gait analysis, isometric dynamometry, Energy Expenditure Index (EEI), and a caregiver questionnaire were used to gather data on walking speed, ankle angles at initial contact of gait, isometric plantarand dorsiflexior muscle strength, energy expenditure during gait, as well as caregiver perception on participation changes. Statistical analysis was conducted by means of ANOVA tests and graphic data illustrations. Results A statistically significant pre- to post intervention (FES after botulinum toxin) change was found for plantarflexor muscle strength. This effect was partially maintained over the withdrawal phase. Caregivers felt the intervention to have a positive influence on their children’s walking speeds, as well as on age-appropriate function and participation. Selfselected walking speed, dorsiflexor muscle strength, and ankle angles at initial contact did not change significantly. A 32-day interval between between botulinum toxin and the FES programme resulted in the most pronounced improvements in terms of walking speed, EEI scores, and plantarflexor muscle strength. Conclusion FES to the lower limb, 32 days after botulinum toxin into the triceps surae, applied for 30 minutes per day, five times a week over a total of four weeks, seemed to improve selected gait parameters as well as caregiver perception of impact on function and activities of daily living. However, further research is needed.