THE EFFECTIVENESS OF LONG SITTING ON HAMSTRING MUSCLE STRETCHING IN YOUNG CHILDREN WITH SPASTIC DIPLEGIA

Abstract

Purpose/Hypothesis: To compare the effectiveness of prolonged passive stretch and repetitive (static) stretch in increasing hamstring extensibility in children with spastic diplegia. We hypothesized that prolonged passive stretch would be more effective than repetitive stretch in improving popliteal angle (PA); step/stride length, cadence and speed during gait; and gross motor skills. Number of Subjects: Participants were 4 children, 3 girls and 1 boy (mean age = 4 yrs 7 months; range = 4 yrs 2– 5 yr 1 month). The children represented Levels I–IV of the GMFCS. Materials/Methods: This study employed a single-subject cross-over design with random assignment of intervention phases. Two methods of stretch, repetitive (Phase B) and prolonged (Phase C) were implemented using an ABAC or ACAB stretching sequence with baseline interspersed between the types of stretch. The initial baseline was 4–6 weeks with the subsequent phases each 4 weeks long for a total of 16–18 weeks. Goniometry, pedograph and GMFM-66 were used to gather data on the popliteal angle (PA), time/distance gait parameters, and motor skills. PA was measured with a stabilization apparatus using an electronic digital inclinometer. Spatiotemporal gait parameters were obtained from pedograph assessments. Data on all outcome measures were collected weekly. The data were analyzed using visual analysis with determination of statistical significance. Results: Both repetitive and prolonged stretch methods were effective in increasing hamstring muscle hypoextensibility. Improvement was observed in 11 of 14 PA measures. The pattern of change in gait measures and GMFM-66 scores was not consistent among the children. Three subjects with a GMFCS level of II or lower demonstrated an increase in step and stride lengths and GMFM-66 scores that was commensurate with their improved PA measures. The subject with a GMFCS level of 1 demonstrated an increase in gait speed and cadence that corresponded with improved PA measures for one of the interventions. Conclusions: The results of this study suggest that the use of prolonged passive and repetitive stretching methods on a short-term basis does not result in differences in their effect on muscle length and gait. There is a suggestion that a critical value in PA may need to be attained before improvements in impairment translate to enhanced function in gait and gross motor skills thereby supporting previous findings. Clinical Relevance: Tight hamstrings are a common limiting factor in postural and functional mobility of children with cerebral palsy. Physical therapists need evidence to guide them in selecting effective methods of stretching. Although no differences were observed between the two methods in the outcomes employed in this study, the single-subject design provided details and information that therapists can use in deciding which stretching program to implement and why. The limitation is that the results cannot be generalized.