the effect of rehabilitation program on heart rate and mechanical efficiency of leg muscles in children with spastic cerebral palsy

introduction: the efficiency of muscular function is directly related to energy consumption. maintaining the dynamic equilibrium and fatigue during walking and other daily activities are the main problems in spastic cerebral palsy patients. recognition of mechanism and muscular function in these patients is important from a clinical and rehabilitational perspective. the objective of this study was to compare mechanical efficiency and some cardiovascular indices in children with spastic cerebral palsy, before and after submaximal aerobic exercise program, and its comparison with normal children. materials and methods : fifteen children with diplegia spastic cerebral palsy aged 9-14 years, voluntarily (experimental group), and eighteen normal children of the same age range (control group) were randomly selected. the aerobic exercise-rehabilitation program was performed with mean hrr% = 46 ± 2.5% for three months and three times per week on the experimental group. the exercise time in each session was 20-25 minutes with an average heart rate of 144 beats per minute. the dependent variables in both groups were measured according to mac master protocol on tantory bicycle ergometer and all variables were compared by means of statistical repeated measure and manova. results: the heart rate (hr) and percentage of heart rate reserve (hrr) in the control group was lower than that of the experimental groups (p<0.05). the net and gross mechanical efficiency of the control group was higher than the experimental group (p<0.05). mechanical efficiency of the cases increased significantly in the end of the exercise-rehabilitation program and the heart rate was decreased (p<0.05) too. conclusion: the cerebral palsy children have high energy cost because of high muscle tone, severe degree of spasticity and involuntarily movements. therefore, they have lower mechanical efficiency and higher heart rate in submaximal work compared to normal subjects. the rehabilitation and aerobic exercise can be effective in improving the physical function of the muscles in cerebral palsy patients and can increase their mechanical efficiency.