Related Experiment Videos
Electromechanical delay and reflex response in spastic cerebral palsy
K P Granata1, A J Ikeda, M F Abel
1Department of Orthopaedic Surgery, University of Virginia, Charlottesville 22903, USA.
Archives of Physical Medicine and Rehabilitation
|July 15, 2000
Summary
Children with spastic cerebral palsy (CP) have shorter electromechanical delay (EMD) due to increased muscle stiffness. This study quantified EMD and reflex responses, finding significantly reduced EMD in the spastic group compared to typically developing children.
Area of Science:
- Neurology
- Biomechanics
- Pediatrics
Background:
- Spastic cerebral palsy (CP) is characterized by increased muscle stiffness.
- Electromechanical delay (EMD) is the time lag between muscle activation and force production.
Purpose of the Study:
- To quantify and compare EMD and reflex responses in children with spastic CP versus normally developing children.
- To test the hypothesis that increased muscle stiffness in spastic CP shortens EMD.
Main Methods:
- A case-control study design was employed.
- Electromechanical reflex behavior was assessed in 12 children with spastic CP and 12 age-matched controls.
- Data were collected at the University of Virginia's Motion Analysis and Motor Performance Laboratory.
Main Results:
- EMD was significantly shorter in children with spastic CP (40.5 msec) compared to controls (54.7 msec).
- The spastic group exhibited greater reflex activity, faster rate of force development, and increased antagonistic muscle activation.
- Knee flexion angle did not affect EMD in either group.
Conclusions:
- Increased biomechanical stiffness in spastic muscles leads to a reduced EMD.
- Antagonistic cocontraction was observed in the spastic group but did not account for the shortened EMD.