Lower limb muscle endurance and muscle strength in children and adolescents with cerebral palsy

161 Pages·2016·1.99 MB·English

Lower limb muscle endurance and
muscle strength in children and
adolescents with cerebral palsy
Maaike M Eken
The studies presented in this thesis were carried out at the Department of Rehabilitation
Medicine, MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam,
the Netherlands and Rehabilitation Center Heliomare, Wijk aan Zee, the Netherlands.
The work was supported by a grant from the Revalidatiefonds (grant no. R2010142),
JohannaKinderFonds (grant no. 2011-0044) and Kinderfonds Adriaanstichting (grant no.
2011-044).
Financial support for the printing of this thesis has been kindly provided by a non-
commercial grant from, in alphabetic order, Heliomare Research & Development, Lode BV,
OIM Orthopedie, Phelps Stichting and ProCare BV.
THE STANDARD IN ERGOMETRY
Cover Maaike M Eken
Layout Maaike M Eken
Printed by Ipskamp drukkers B.V.
ISBN 978-94-028-0481-2
© Copyright 2016 Maaike M Eken
All rights reserved. No part of this publication may be reproduced or transmitted in any form or
by any means, electronic or mechanical, including photocopying, recording, or any information
storage and retrieval system, without written permission from the author.
VRIJE UNIVERSITEIT
Lower limb muscle endurance and muscle
strength in children and adolescents with
cerebral palsy
ACADEMISCH PROEFSCHRIFT
ter verkrijging van de graad Doctor aan
de Vrije Universiteit Amsterdam,
op gezag van de rector magnificus
prof.dr. V. Subramaniam,
in het openbaar te verdedigen
ten overstaan van de promotiecommissie
van de Faculteit Geneeskunde
op vrijdag 10 februari 2017 om 13.45 uur
in de aula van de Universiteit,
De Boelelaan 1105
door
Maaike Maria Eken
geboren te Jubail, Saudi Arabia
promotoren: prof.dr. J. Harlaar
prof.dr. C.A.M. van Bennekom
copromotoren: dr. H. Houdijk
dr. A.J. Dallmeijer
dr. C.A.M. Doorenbosch

TABLE OF CONTENTS
CHAPTER 1 General Introduction 9
CHAPTER 2 Muscle fatigue during repetitive voluntary contractions: A 23
comparison between children with cerebral palsy, typically
developing children and typically developing adults
CHAPTER 3 Assessment of muscle endurance of the knee extensor 39
muscles in adolescents with spastic cerebral palsy using a
submaximal repetitions-to-fatigue protocol
CHAPTER 4 Co-activation during dynamometry testing in adolescents 57
with spastic cerebral palsy
CHAPTER 5 Relations between muscle endurance and subjectively re- 77
ported fatigue, walking capacity, and participation in mildly
affected adolescents with cerebral palsy
CHAPTER 6 Squat test performance and execution in children with and 95
without cerebral palsy
CHAPTER 7 General Discussion 115
Summary 133
Nederlandse samenvatting 139
About the author 145
Dankwoord 151

Chapter 1
General Introduction
Maaike M Eken
Chapter 1
INTRODUCTION
Walking, running, climbing stairs – people perform these activities rather automatically in
daily life. For this purpose, muscles repetitively generate internal forces in the human body,
to restrain the forces of gravity or accelerate and decelerate body segments for coordinated
joint motions. For individuals with cerebral palsy (CP), it can be more challenging to walk,
run or climb stairs in daily life as it is for people without CP. For them, the muscular load
that these activities require, might be too high to comply with. Proper treatment planning
in a context of rehabilitation medicine, aiming to improve functioning of individuals with
CP, requires accurate information about their ability to generate and sustain muscle force,
needed for most activities of daily life. Therefore, developing knowledge and methods on
how to measure muscle endurance, in addition to muscle strength, of individuals with CP
in a clinically meaningful way will be the main focus of this thesis.
CEREBRAL PALSY
Cerebral palsy (CP) is the most common cause of physical disability in childhood,
caused by a non-progressive lesion of the immature brain 1. In the western world, as the
population studied in this thesis, incidence rates of 1.5 to 2.5 per 1000 live born children
were reported 2, 3. CP refers to a group of conditions with variable manifestations. These
heterogeneous phenotypes are all covered in the definition of CP stated by Bax et al.
(2005): ‘It describes a group of permanent disorders of the development of movement and
posture, causing activity limitations, that are attributed to non-progressive disturbances
that occurred in the developing fetal or infant brain. The motor disorders of CP are often
accompanied by disturbances of sensation, perception, cognition, communication and
behavior, by epilepsy and by secondary musculoskeletal problems’ 4. Though preterm
birth is considered to be the most important risk factor for developing CP 5, full-term
infants account for the majority of cases of CP 6. The lesion can be caused by, for instance,
oxygen deprivation or acquired brain injury, as a consequence of intoxication, hypoxic
ischemia or infection 6, 7.
Classification of CP
Since CP covers a wide variety of clinical presentations, the limitations in activity can
be very divers 1. The severity of the motor impairment caused by CP can be classified
using the gross motor function classification system (GMFCS) 8. The GMFCS identifies
five levels of gross motor function based on their functional performance. In this thesis,
we will focus on the children who walk independently without (GMFCS I and II) or with
(GMFCS III) assistive devices. Children classified in GMFCS level IV and V are not able to
walk independently and use wheelchairs for mobility. Activity limitations increase with
increasing GMFCS levels 9.
The motor disorders caused by CP can be grouped into three subtypes, i.e. spastic,
dyskinetic and ataxic 7, 10. The type of motor disorder largely depends on the location of
10