Restoring a heel-to-toe gait pattern does not influence spinal kinematics in patients with hemiplegic cerebral palsy

Abstract

Introduction: Foot equinus and leg length discrepancy (LLD) are common problems in patients with hemiplegic cerebral palsy (hCP), each causing secondary deviations of pelvic motion during gait [1–3]. It is therefore plausible that the deviations in spinal kinematics observed in hCP patients occur secondarily as a compensation arising from the disturbed leg function and the associated changes in the position of the pelvis. Research question: Does the correction of lower extremity function by orthotics (ankle-foot-orthosis and heel lift) have an effect on spinal gait kinematics in hCP patients? Methods: A total of 10 adolescent hCP patients and 15 healthy controls participated in this study. Participants were equipped with 56 reflective markers (combination of Plug-in-Gait full body and IfB marker sets) and measured during barefoot walking at a self-selected speed using a 12-camera motion analysis system (Vicon). Patients then wore shoes with orthotic corrections on the affected side and were measured again. Thoracic and lumbar spinal curvature angles in the sagittal and frontal planes (primary outcomes) as well as segmental trunk, lower extremity joint angles, and spatio-temporal gait parameters (secondary outcomes) were extracted and parameterized accordingly. Comparisons between populations and conditions were conducted using oneway analyses of variance with Tukey post hoc tests and effect sizes. To evaluate the clinical relevance of a difference, a minimal clinically important difference (MCID) of 58 was used for the angles. Results: The pathological toe-walking gait pattern during the barefoot condition was corrected into a normal heel-to-toe gait pattern when walking with the orthotic corrections. However, this seemed not to influence spinal or general trunk kinematics. Differences could only be found between the hCP patients and the healthy controls (see Figure). Discussion: Spinal gait deviations in adolescent patients with mild forms of hCP seemed to occur not as a secondary effect of a spastic equinus foot or an LLD but due to proximal abnormalities such as hip flexor contractions, which might have been long-term structural adaptations due to passive secondary effects of foot deformity. The question remains, however, whether lower extremity orthotics in younger patients and/or more severe cases of hCP would have different effects on spinal kinematics. In addition, all patients were used to walking with orthotics and might therefore have already adapted their barefoot walking pattern such that possible effects of orthotics have been diluted. Future research should consider investigating long-term effects of orthotics as well as the relation between spinal kinematics and disease severity.