The relationship between tight hamstrings and lumbar hypolordosis in children with cerebral palsy

Study Design. Retrospective clinical and radiographic review. Objective. To assess the influence of tight hamstrings an the sagittal alig nment of the thoracic and lumbar spine in children with cerebral palsy. Summary of Background Data. It is postulated that tight hamstrings may prod uce a hypolordosis of the lumbar spine. The abnormal sagittal contour of th e spine may lead to increased stresses in the lumbar spine and subsequent p ain and disability. This is of special concern in children with cerebral pa lsy who often have shortened spastic hamstring muscles. Method. Twenty-one patients were evaluated, with a mean age of 9.4 years. S tanding and sitting lateral spine films were obtained and the lumbar lordos is and thoracic kyphosis were measured using the Cobb method. The popliteal angle was measured to assess hamstring tightness, such that a large poplit eal angle indicates tight ham-strings. Results. We found a statistically significant correlation between the sitti ng lumbar curve and popliteal angle (Pearson correlation value -0.77, P < 0 .01). As the popliteal angle increased, the amount of lumbar lordosis decre ased This correlation was less significant when the patient was standing (P earson correlation value -0.59). Conclusion. This study demonstrates that there is a correlation between tig ht hamstrings, as measured by the popliteal angle, and decreasing lumbar lo rdosis, especially when sitting.