Analysis of gait features variation pre and post SEML surgery in CP by means of GPS and MAP

Introduction: Gait Analysis (GA) is often used in the assessment of the gait abilities of children with motor disorders, such as cerebral palsy (CP) and to quantify improvements/variations after a treatment [1]. A GA clinical report is generally difficult to read and requires a specific training of the clinicians. To simplify overall GA data interpretation, some synthetic descriptors were devel- oped, as the Gait Profile Score (GPS) and Movement Analysis Profile (MAP) [2]. GPS compares the measured GA features to a normality dataset, quantifying the overall deviation from normality. In MAP, each gait feature is compared to the respective normality, therefore a deviation index is available for each feature. Such analysis is useful to quickly identify, quantify and interpret gait variations in subjects with CP that underwent a treatment such as SEML surgery, that involves bone repositioning and muscle/tendon lengthening at the level of the femur and hamstring group. Research question: What are the changes in gait profiles in subjects with CP, who received SEML surgical treatment. Methods: GA exams of 12 children with CP (age 12.8 ? 2.2 years, 9 males, 3 females), pre and post SEML treatment, were collected in the Motion Analysis Laboratory of VUmc, Amsterdam, NL. Datasets consisted in 9 bilateral gait features, as required to compute GPS [2] (pelvic tilt, obliquity and rotation; hip flexion, abduction and rotation; knee flexion; ankle dorsiflexion and foot progression), obtained as average of 5 walking trials. For each subject, GPS and MAP indices were computed for both sides. A total of 24 hemisides were examined. Variations in gait features were quantified by post-pre difference in all parameters. Results were then averaged across the subjects. Statistical t-test was used to assess differences pre-post. To interpret results, a Minimally Clinical Important Difference (MCID) of 1.6 degrees was considered for GPS [3]. Results: Absolute values of pre-post differences were higher than the MCID for all parameters, except pelvic rotation. An improvement towards normality was observed in all the param- eters, with the exception of pelvic tilt and hip flexion for which a worsening was observed. Average values and SDs for the selected indices are represented through bar graphs in the figure.