Muscle Recruitment and Coordination following Constraint-Induced Movement Therapy with Electrical Stimulation on Children with Hemiplegic Cerebral Palsy: A Randomized Controlled Trial

Abstract

Objective: To investigate changes of muscle recruitment and coordination following constraint-induced movement therapy, constraint-induced movement therapy plus electrical stimulation, and traditional occupational therapy in treating hand dysfunction.

Methods: In a randomized, single-blind, controlled trial, children with hemiplegic cerebral palsy were randomly assigned to receive constraint-induced movement therapy (n = 22), constraint-induced movement therapy plus electrical stimulation (n = 23), or traditional occupational therapy (n = 23). Three groups received a 2-week hospital-based intervention and a 6-month home-based exercise program following hospital-based intervention. Constraint-induced movement therapy involved intensive functional training of the involved hand during which the uninvolved hand was constrained. Electrical stimulation was applied on wrist extensors of the involved hand. Traditional occupational therapy involved functional unimanual and bimanual training. All children underwent clinical assessments and surface electromyography (EMG) at baseline, 2 weeks, 3 and 6 months after treatment. Surface myoelectric signals were integrated EMG, root mean square and cocontraction ratio. Clinical measures were grip strength and upper extremity functional test.

Results: Constraint-induced movement therapy plus electrical stimulation group showed both a greater rate of improvement in integrated EMG of the involved wrist extensors and cocontraction ratio compared to the other two groups at 3 and 6 months, as well as improving in root mean square of the involved wrist extensors than traditional occupational therapy group (p<0.05). Positive correlations were found between both upper extremity functional test scores and integrated EMG of the involved wrist as well as grip strength and integrated EMG of the involved wrist extensors (p<0.05).

Conclusions: Constraint-induced movement therapy plus electrical stimulation is likely to produce the best outcome in improving muscle recruitment and coordination in children with hemiplegic cerebral palsy compared to constraint-induced movement therapy alone or traditional occupational therapy.

Trial registration: chictr.org ChiCTR-TRC-13004041.

Fig 1. Intention-to-treat flowchart.

Fig 2. Test of surface electromyography.

Fig 3. Changes in root mean square measured in the subjects' wrist extensors (a) and flexors (b) on maximum isometric voluntary contraction of the involved hand (mean ± SD).

CIMT-ES group, constraint-induced movement therapy plus electrical stimulation group; CIMT group, constraint-induced movement therapy group; OT group, occupational therapy group.

Fig 4. Changes in integrated electromyography measured in the subjects' wrist flexors (a) and extensors (b) on maximum isometric voluntary contraction of the involved hand (mean ± SD).

CIMT-ES group, constraint-induced movement therapy plus electrical stimulation group; CIMT group, constraint-induced movement therapy group; OT group, occupational therapy group.

Fig 5. Changes in cocontraction ratio measured in the subjects' wrist on maximum isometric voluntary contraction of the involved hand and uninvolved hand (mean ± SD).

CIMT-ES group, constraint-induced movement therapy plus electrical stimulation group; CIMT group, constraint-induced movement therapy group; OT group, occupational therapy group.

Fig 6. Simple scatter of changes between upper extremity functional scale scores and integrated electromyography (μV·s) of involved wrist extensors (a) and flexors (b) at six month on maximum isometric voluntary contraction of the involved hand.

Fig 7. Simple scatter of changes between grip strength (in mmHg) and integrated electromyography (μV·s) of involved wrist extensors at six month on maximum isometric voluntary contraction of the involved hand.