The Influence of Muscle Contraction on the Cardiac Autonomic System

Population: 16 children with cerebral palsy, GMFCS 1-3.16 children typically developed, matched for age. All children aged 6-12 yrs who understand simple commands. Tools: 1. Polar monitor to record heart rate, attached to chest, in use throughout testing 2. Dynamometer- for assessing muscle strength. 3. Weights Method: Each child will be tested once. Both tools will be demonstrated and tried out before actual testing. With Polar watch attached: 1. 5 min sitting at rest, 2. knee muscle strength assessment with the dynamometer, 3. 15 minutes rest 4. Isometric and isotonic knee muscle contraction at 30% of childs' maximal strength as has assessed by the dynamometer. The child will asked to perform each for 3 minutes, with 5 minutes rest in-between All will be perform in both legs.