Full length article Orthotic correction of lower limb function during gait does not immediately influence spinal kinematics in spastic hemiplegic cerebral palsy Stefan Schmid a,b, *, Jacqueline Romkes c , William R. Taylor a , Silvio Lorenzetti a , Reinald Brunner c,d a ETH Zurich, Institute for Biomechanics, Zurich, Switzerland b Bern University of Applied Sciences, Health Division, Bern, Switzerland c University of Basel Children’s Hospital, Laboratory for Movement Analysis, Basel, Switzerland d University of Basel Children’s Hospital, Orthopaedic Department, Basel, Switzerland A R T I C L E I N F O Article history: Received 15 December 2015 Received in revised form 8 August 2016 Accepted 11 August 2016 Keywords: Spine Foot equinus Ankle-foot-orthosis AFO Leg length discrepancy CP A B S T R A C T Background and purpose: Foot equinus and leg length discrepancy (LLD) are common problems in hemiplegic cerebral palsy (hCP), both causing secondary deviations of pelvic motion during gait. It can therefore be assumed that the spinal deviations observed in hCP patients are secondary as a compensation for the position of the pelvis arising from the disturbed leg function. This study investigated the effects of correcting lower extremity function by orthotics on spinal gait kinematics in hCP patients. Methods: Ten adolescent hCP patients and 15 healthy controls were included. Using a validated and previously used enhanced marker set, sagittal and frontal plane spinal curvature angles as well as general trunk and lower extremity kinematics were measured while walking barefoot as well as with an orthotic correction (only hCP patients) using a 12-camera motion capture system. Results: The hCP patients in both the barefoot and orthotic conditions indicated clinically relevant greater lumbar lordosis angles (d  0.96, p  0.071), smaller thoracic kyphosis angles (d  0.84, p  0.142) and differences in frontal plane lumbar curvature angles (d  1.00, p  0.105) compared to controls. However, these angles were not influenced by the successful restoration of a normal heel-to-toe gait pattern and the correction of any LLD using lower extremity orthotics. Conclusions: Spinal gait deviations in adolescents with mild hCP seemed not to result secondarily from foot equinus or LLD, but probably from structural deformities such as hip flexor contractures. Future research should address long-term effects of an AFO treatment as well as the relationship between spinal kinematics and severity of disease. ã 2016 Elsevier B.V. All rights reserved. 1. Introduction Cerebral palsy (CP) results from a static lesion of the brain in utero, during delivery or within the first two years after birth [1]. The overall prevalence was reported to be 2.4 per 1000 children aged 3–10 years [1]. About 25% of all cases present an involvement of one side of the body and are classified as hemiplegic CP (hCP) [1]. The most common gait problem in hCP patients is the foot equinus, caused by calf-muscle spasticity and dorsiflexor weakness, which results in a toe-walking pattern on the affected side [2,3]. Biomechanical studies showed that unilateral toe- walking leads to secondary deviations such as increased pelvic rotation and anterior pelvic tilt as a result from hip flexion, internal rotation and adduction [4,5]. In addition, hCP patients often develop a structurally shorter leg on the affected side [6], which has been shown to cause pelvic obliquity in children without associated neuromuscular diseases [7]. Considering these effects, it is therefore not unreasonable to assume that the spinal deviations in hCP are caused secondarily due to foot equinus and leg length discrepancy (LLD). Primary deviations (resulting directly from the brain lesion) are unlikely since innervation of the trunk muscles is known to remain almost normal in hCP and patients develop good * Corresponding author at: ETH Zurich, Institute for Biomechanics, HCP H 23.2, Leopold-Ruzicka-Weg 4, 8093 Zürich, Switzerland. E-mail address: stefanschmid79@gmail.com (S. Schmid). http://dx.doi.org/10.1016/j.gaitpost.2016.08.013 0966-6362/ã 2016 Elsevier B.V. All rights reserved. Gait & Posture 49 (2016) 457–462 Contents lists available at ScienceDirect Gait & Posture journal homepage: www.else vie r.com/locate /gait post