Contents lists available at ScienceDirect Gait & Posture journal homepage: www.elsevier.com/locate/gaitpost Short communication O 050 - Gait and muscle characteristics in a girl with hereditary spastic paraplegia: A clinical case study H. Adams a, ⁎ , N. De Beukelaer b , C. Huenaerts a , B. Hanssen b , L. Bar-on b , S.H. Schless b , A. Van Campenhout c , E. Ortibus d , N. Peeters b , K. Desloovere a,b a Clinical Motion Analysis Laboratory, University Hospitals Leuven, Department of Orthopedics, Leuven, Belgium b KU Leuven, University of Leuven, Department of Rehabilitation Sciences, Neuromotor Rehabilitation Research Group, Leuven, Belgium c UZ Leuven, Department of Orthopedic Surgery, Leuven, Belgium d Development and Regeneration, KU Leuven, University of Leuven, Leuven, Belgium ARTICLE INFO Keywords: Hereditary spastic paraplegia Muscle characteristics Gait Cerebral palsy Spasticity 1. Introduction While the etiology of hereditary spastic paraplegia (HSP) clearly differs from spastic cerebral palsy (SCP), the phenotype of 3SPGA-HSP and bilateral SCP children show much similarity. Hence, HSP children are commonly treated as SCP children. However, the HSP gait pattern and its relation to muscle impairment (spasticity, weakness and mor- phology) has only rarely been studied. A detailed assessment of pa- thological gait and muscle impairment of the HSP child, compared to typically developing (TD) and bilateral SCP children, may help to de- fine HSP-specific characteristics that can support the clinical decision- making. The gait and muscle impairment of an 11-year old girl, with HSP (3SPGA gene mutation, age of onset: 5.5 years) was compared to TD children as well as to children with bilateral SCP, matched for age and gross motor function classification system (GMFCS1). 2. Research question Do 3D gait analysis (3DGA), muscle morphology and instrumented spasticity assessment (ISA) provide sufficient information for pa- thology-specific characteristics and treatment, distinguishing this HSP- patient from a SCP-cohort? 3. Methods The HSP-patient and five age/GMFCS-matched SCP children re- ceived 3DGA, including kinematics and kinetics (Vicon, AMTI-for- ceplates). Apart from the standard clinical exam (Modified Ashworth Scale (MAS), range of motion (ROM) and muscle strength) spasticity was quantified with ISA, integrating dynamometry (torque), kinematics and EMG while stretching the medial gastrocnemius (MG) at low ve- locity (LV) and high velocity (HV) [1]. 3D freehand Ultrasound mea- surement (3DfUS) was used to acquire muscle length normalized to muscle-tendon-unit length (nML), normalized muscle volume (nMV) and mean echo intensity (EI) [2]. 4. Results This HSP gait pattern is characterized by increased knee flexion at initial contact, pathological first and second ankle rocker and increased plantar flexion in swing phase, which is a frequently observed pattern of SCP children (Fig. 1). Lower limb spasticity is confirmed by both objective (ISA) and subjective (MAS) spasticity assessment. MAS is slightly higher (MAS = 3) compared to the GMFCS I-matched SCP- group (median-MAS = 2). ISA reveals high torque when stretching MG at high velocity, indicating a large neural component. The HSP-patient and the SCP-group showed similar results for muscle structure, where EI was increased and nML and nMV were decreased compared to TD https://doi.org/10.1016/j.gaitpost.2018.06.077 ⁎ Corresponding author. E-mail address: heleen.1.adams@uzleuven.be (H. Adams). Gait & Posture xxx (xxxx) xxx–xxx 0966-6362/ © 2018 Elsevier B.V. All rights reserved. Please cite this article as: Adams, H., Gait & Posture (2018), https://doi.org/10.1016/j.gaitpost.2018.06.077