| Summary: | 碩士 === 國立陽明大學 === 物理治療研究所 === 91 === Background: Children with spastic cerebral palsy often present with limited gait performance. Muscle weakness and hypertonia were identified as a common phenomenon in these children. A few studies have investigated the relationships between the lower-extremity muscle strength, muscle tone and gait performance in children with spastic cerebral palsy, but with limited evidence. No research could be found in studying the relationships between the trunk muscle strength and gait performance in children with spastic cerebral palsy. It is important to clearly define the relationships between muscle strength, muscle tone and gait performance in children with cerebral palsy. Purpose: The purpose of this study was to investigate the relationships between trunk and low-extremity muscle strength, low-extremity muscle tone and gait performance in children with cerebral palsy. Method: An exploratory research design was employed for this study. Twenty-three children with spastic diplegic or quadriplegic cerebral palsy (mean age=69.4, SD=18.7) were recruited in this study. All subjects were able to ambulate independently for a minimum of four meters without walking aids or braces. The maximum isometric muscle endurance of trunk flexors/extensors and maximum isometric muscle strength and tone of both lower extremities, including hip flexors, hip extensors, hip abductors, hip adductors, knee flexors, knee extensors, ankle dorsiflexors and ankle plantarflexors, were evaluated with a hand-held dynamometer. A VICON 370 motion analysis system was used to examine the gait performance at the self-selected preferred walking. Statistic Analysis: The factor analysis and stepwise multiple regression were utilized to determine the relationships between muscle strength and gait performance in children with spastic cerebral palsy. Results: In the regression model of relationships between low-extremity normalized strength, trunk endurance, lower extremity muscle tone, and gait performance, normalized strength of all 8 main muscle groups in lower extremity significantly influenced speed, speed normalized to leg length, step length, and step length normalized to leg length at preferred speed(R²=0.15~0.25). Trunk endurance and normalized strength of hip adductors and knee flexors significantly influenced 5-minute walk distance at preferred speed (R²=0.15~0.22). In the regression model of relationships between low-extremity agonist versus antagonist muscle strength ratio, trunk extensors versus flexors endurance ratio and gait performance, knee joint strength ratio was the most important influencing factor on gait, including speed, speed normalized to leg length, step length, step length normalized to leg length, single-leg-support phase, double-leg-support phase at preferred speed (R²=0.20~0.43). And trunk endurance ratio significantly influenced 5-minute walk distance at preferred speed (R²=0.17). In the regression model of relationships between low-extremity agonist versus antagonist muscle tone ratio and gait performance, the muscle tone ratio of hip abductors versus adductors was the most important influencing factor on gait. The hip abductor/adductor muscle tone ratio significantly influenced speed, speed normalized to leg length, step length, step length normalized to leg length, gait cycle percentage of single-leg support, percentage of double-leg support, and 5-minute walk distance (R²=0.18~0.38). Conclusions: Muscle strength and trunk endurance indeed influenced gait performance in ambulatory children with cerebral palsy, but the muscle tone didn’t. Both the muscle strength ratio of knee joint and muscle tone ratio of hip abductor versus adductor were the most important influenced factors in gait. Beside the muscle-skeletal system’s factors such as strength, endurance, or tone, there were some others factors have powerful influences on cerebral palsy children’ gait performance. Clinical Relevance: Results of this study revealed that in ambulatory children with spstic cerebral palsy, the low-extremity muscle strength was more related to gait performance than low-extremity muscle tone in these, and the normalized strength of all 8 main muscle groups in lower extremity were highly correlated. It suggested that therapeutic interventions to improve gait performance in ambulatory spastic cerebral palsy should emphasize on the over-all low-extremity muscle strengthening. On the other hand, result of this study support that clinical trunk endurance training program to improve gait performance. And the results of negative correlation between knee joint strength ratio and gait performance remind us should emphasize the strength of knee flexors.
|
|---|
