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Co-contraction during passive movements of the knee joint in children with cerebral palsy

Samuel R Pierce1, Mary F Barbe, Ann E Barr

  • 1Research Department, Shriners Hospital for Children, 3551 North Broad Street, Philadelphia, PA 19140, USA. srpierce@mail.widener.edu

Clinical Biomechanics (Bristol, Avon)
|September 18, 2007
PubMed

Insights

Co-contraction is common in children with cerebral palsy during passive knee movements. This muscle activity may affect spasticity assessments, highlighting the need for careful interpretation of passive movement tests.

Area of Science:

  • Pediatric Neurology
  • Movement Disorders
  • Rehabilitation Medicine

Background:

  • Co-contraction is a recognized impairment in pediatric cerebral palsy (CP).
  • Its occurrence during passive movements, relevant for spasticity assessment, remains understudied in children with CP.

Purpose of the Study:

  • To investigate the frequency of co-contraction during passive knee movements in children with CP.
  • To explore the relationship between reflex activity and co-contraction during these movements.

Main Methods:

  • Electromyography (EMG) was used to measure muscle activity in 20 children with CP.
  • Continuous passive knee movements were performed at various speeds (15, 90, 180 degrees/s).
  • Vastus lateralis, medial hamstrings, and co-contraction activity were quantified across the range of motion.

Main Results:

  • Co-contraction was frequently observed across all tested movement directions and speeds.
  • Significant positive correlations were found between vastus lateralis, medial hamstrings activation, and co-contraction.
  • These correlations persisted across all tested velocities during passive knee flexion and extension.

Conclusions:

  • Co-contraction is a prevalent finding during passive knee movements in children with CP.
  • The presence of co-contraction may confound spasticity measurements relying on passive movement assessments.
Abstract

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