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Electro-suit treatment of children with unilateral cerebral palsy alters nonlinear dynamics of walking

      Highlights

      • Children with cerebral palsy received treatment intervention with Exopulse® suit.
      • Trunk acceleration was measured to investigate changes in underlying gait control.
      • 24 weeks of electrical stimulation alters the nonlinear dynamics of treadmill gait.
      • The Lyapunov exponent and complexity was altered in the anterior-posterior direction.
      • Changes were in direction of observations made in healthy individuals.

      Abstract

      Background

      Cerebral palsy (CP) is characterized by spasticity and muscle contracture development and associated with mild to severe motor impairments including reduced gait function. Treatment with the Exopulse® suit has been shown to reduce spasticity of the affected muscles and constitutes a non-invasive alternative to pharmaceutical agents and surgical denervation. The present study investigated the effect of systematic treatment with the Exopulse® suit on the nonlinear dynamics and variability of trunk accelerations during walking in children with unilateral CP.

      Methods

      Twelve patients (mean age: 12 years, range 7–17 years) with unilateral CP (GMFCS level 1 and 2) received 24 weeks Exopulse® suit treatment with patient-specific muscle stimulation. Before and after the treatment, the patients completed 4 min treadmill walking while trunk accelerometry was obtained. The nonlinear dynamics was quantified by the largest Lyapunov exponent and the complexity index from the multiscale entropy and movement variability was quantified by the root mean square ratio. Pre- vs post-treatment differences were evaluated by a paired Student's t-test.

      Findings

      The largest Lyapunov exponent (p-value = 0.041) and the complexity index (p-value = 0.030) of the acceleration in the anterior-posterior direction was significantly lower post-treatment. No other between-trial differences were observed.

      Interpretation

      The present study suggests that 24 weeks of Exopulse® suit treatment alters the nonlinear dynamics but not the variability of the trunk accelerations during walking in children with unilateral CP. The temporal structure of the trunk acceleration in the anterior-posterior direction was altered towards that of healthy individuals.

      Keywords

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