STRENGTH DIFFERENCES IN TRAUMATIC LIMBS WITH LENGTH INEQUALITY

Abstract

606 A variety of physical characteristics of children, including leg length inequality, may be related to the risk of sustaining a sports injury. Isokinetic muscle strength testing is a popular clinical tool for evaluating muscle function after injury and is used as an indicator for return to activity, such as competitive sport or recreation. To determine muscle strength deficiencies, our purpose was to quantify isokinetic muscle strength of the lower extremities of children who had a leg length discrepency (LLD) due to a femur fracture. Muscle strength data was collected on the hip, knee and ankle joints of eleven recreationally active children who had an LLD due to a traumatic femur fracture. Tests were supine hip flexion/extension at 30 degrees/s, seated knee flexion/extension at 60 degrees/s and prone ankle plantar/dorsiflexion at 30 degrees/s. The testing session included 5 maximal repetitions for each movement. T-tests were used to determine differences between the injured and uninjured and the short and long limbs. 15% deficit was clinically significant. Only hip flexion was significantly stronger in the injured limb. However, only 4 of 11 had clinically significant deficits. We found no strength differences between short and long limbs. No consistent pattern of weakness was seen following femur fracture. An absence of deficiencies would indicate a return to more vigorous activity, such as competitive sport or recreation. This test should be used with other clinical assessments to help determine the extent of lower limb functions.