Physical Strain: A New Perspective on Walking in Cerebral Palsy

Astrid C. Balemans*, Eline A. Bolster, Merel Anne Brehm, Annet J. Dallmeijer

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Objectives: To describe (1) physical strain of walking, (2) the proportion of participants walking above the anaerobic threshold, and (3) 4 phenotypes of physical strain of walking on the basis of deviations in aerobic capacity and walking energy cost (EC) in children and adolescents with cerebral palsy (CP). Design: Cohort study. Setting: Academic medical center. Participants: A sample (N=57) of participants (n=37; mean age, 13.5±4.0y) with CP (Gross Motor Function Classification System [GMFCS] levels I [n=13], II [n=17], and III [n=7]) and typically developing (TD) participants (n=20; mean age, 11.8±3.5y). Interventions: Not applicable. Main Outcome Measures: Oxygen consumption (Vo 2walk), speed, and EC were determined during walking at a comfortable speed. Peak oxygen consumption (Vo 2peak) and anaerobic threshold were measured during a maximal cycling exercise test. Aerobic capacity was reduce if lower than the 10th percentile, and EC was increased if higher than 3SD. Physical strain was defined as follows: (Vo 2walk/Vo 2peak)×100. Results: Participants with CP had a higher physical strain (GMFCS level I, 55%±12% GMFCS level II, 62%±17%; GMFCS level III, 78%±14%) than did TD participants (40%±11%) (P<.001). Forty-three percent of participants with CP showed a Vo 2walk at or above their anaerobic threshold as compared with 10% of TD participants (P=.007). Phenotypes showed that a reduced Vo 2peak (n=9) or an increased EC (n=9) lead to an 18% to 20% higher physical strain, whereas a combination (n=12) leads to a 40% increase. Conclusions: Children and adolescents with CP walk at a high physical strain, approximating intense exercise and a considerable proportion walks close to or above their anaerobic threshold, probably explaining fatigue and reduced walking distance. Both an increased EC and a reduced Vo 2peak contribute to high physical strain in children or adolescents with CP. The different causes of high physical strain in individuals with CP require different intervention strategies.

Original languageEnglish
Pages (from-to)2507-2513
Number of pages7
JournalArchives of Physical Medicine and Rehabilitation
Issue number12
Publication statusPublished - 1 Dec 2017

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