Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Marjolijn Ketelaar is active.

Publication


Featured researches published by Marjolijn Ketelaar.


JAMA Pediatrics | 2007

Exercise Training Program in Children and Adolescents With Cerebral Palsy: A Randomized Controlled Trial

Olaf Verschuren; Marjolijn Ketelaar; Jan Willem Gorter; Paul J. M. Helders; Cuno S.P.M. Uiterwaal; Tim Takken

OBJECTIVES To delineate the natural history of pityriasis rosea in black children and to compare our findings with those of the American, European, and African literature on pityriasis rosea. Textbook and journal article descriptions of pityriasis rosea usually offer information about the presentation and clinical course of this condition in white patients. DESIGN Prospective observational study. SETTING The general pediatric clinic, adolescent clinic, and emergency department of Childrens Hospital of Michigan, Detroit, from June 2003 through May 2005. PATIENTS We followed up 50 black children with pityriasis rosea from the time of diagnosis through follow-up visits at 1, 2, and 4 weeks. Detailed observations were made and digital photographs taken at each visit. MAIN OUTCOME MEASURES Duration of illness and pigmentary sequelae. RESULTS Similarities with the medical literature were found regarding season of onset and prevalence of pruritus and of a herald patch. Our patients had more frequent facial involvement (30%) and more scalp lesions (8%) than usually described in white populations. One third had papular lesions. The disease resolved in nearly one half of patients within 2 weeks. Residual hyperpigmentation was seen in 48% of patients. Hypopigmentation developed in 29% of patients with purely papular or papulovesicular lesions. CONCLUSIONS Pityriasis rosea in black children differs in several ways from textbook descriptions. Physicians may use this information to better counsel patients about the course and potential sequelae of this condition.


Clinical Rehabilitation | 1998

Functional motor abilities of children with cerebral palsy: a systematic literature review of assessment measures

Marjolijn Ketelaar; A. Vermeer; Paul J. M. Helders

Objective: To provide an overview of functional assessment measures for children with cerebral palsy, supporting the selection of measures and the interpretation of results from measures. Methods: Instruments were selected on the basis of a literature search of the Medline, Sportdisk and PsychLIT databases. Issues reviewed: Instruments were reviewed with respect to target group, purpose, nature, type and psychometric properties. Results: In the literature 17 instruments that are used in paediatric rehabilitation and paediatric physical therapy to assess the functional motor abilities of children with cerebral palsy were found. While there is an urgent need for measures that can evaluate change in functional abilities, it was found that most measures are developed and validated for discriminative purposes. Conclusions: Although instruments developed within the lastdecade meet psychometric criteria more adequately than those developed previously, it is concluded that only two evaluative assessment measures, the Gross Motor Function Measure (GMFM) and the Pediatric Evaluation of Disability Inventory (PEDI), fulfil the criteria of reliability and validity with respect to responsiveness to change.


American Journal of Physical Medicine & Rehabilitation | 2008

Exercise programs for children with cerebral palsy: a systematic review of the literature.

Olaf Verschuren; Marjolijn Ketelaar; Tim Takken; Paul J. M. Helders; Jan Willem Gorter

Verschuren O, Ketelaar M, Takken T, Helders PJM, Gorter JW: Exercise programs for children with cerebral palsy: a systematic review of the literature. Am J Phys Med Rehabil 2008;87:404–417.The purpose of this literature review, regarding all types of exercise programs focusing on cardiovascular fitness (aerobic and anaerobic capacity) and/or lower-extremity muscle strength in children with cerebral palsy (CP), was to address the following questions: (1) what exercise programs focusing on muscle strength, cardiovascular fitness, or a combination are studied, and what are the effects of these exercise programs in children with CP? (2) What are the outcome measures that were used to assess the effects of the exercise programs? (3) What is the methodological quality of the studies?We systematically searched the literature in electronic databases up to October 2006 and included a total of 20 studies that were evaluated. The methodological quality of the included trials was low. However, it seems that children with CP may benefit from improved exercise programs that focused on lower-extremity muscle strength, cardiovascular fitness, or a combination. The outcome measures used in most studies were not intervention specific and often only focused on the International Classification of Function, Disability and Health body function and activity level. There is a need to determine the efficacy of exercise programs to improve the daily activity and participation level of children with CP and increase their self-competence or quality of life.


Developmental Medicine & Child Neurology | 2007

Goal attainment scaling in paediatric rehabilitation: a critical review of the literature

Duco Steenbeek; Marjolijn Ketelaar; Krys Galama; Jan Willem Gorter

The aim of the study was to review the psychometric properties and use of goal attainment scaling (GAS) in paediatric rehabilitation research. We performed a critical literature review searching: (1) all studies whose main focus was to assess the psychometric properties of GAS in paediatric rehabilitation; and (2) all effect studies in paediatric rehabilitation that used GAS as one of the outcome measures. Three articles in the first group and six in the second group met the inclusion criteria. None of the studies had investigated the content reliability of the scales. Interrater reliability had been investigated in one study and had been found to be good. Only one trial had assessed the content validity of the developed scales, which was found to be acceptable. Comparisons showed that GAS, because of its idiosyncratic nature, measures different constructs from those measured by some related instruments. Low concurrent validity was found. All included studies reported good sensitivity to change. We conclude that the literature supports promising qualities of GAS in paediatric rehabilitation. GAS is a responsive method for individual goal setting and for treatment evaluation. However, current knowledge about its reliability when used with children is insufficient. There is a need for further development of GAS and its application for children of different ages and disabilities, across therapists of different disciplines.


Archives of Physical Medicine and Rehabilitation | 2009

Capacity, Capability, and Performance: Different Constructs or Three of a Kind?

Laura Holsbeeke; Marjolijn Ketelaar; Marina M. Schoemaker; Jan Willem Gorter

OBJECTIVES The present study focused on motor activities of young children with cerebral palsy (CP) and examined the relation between motor capacity (what a person can do in a standardized, controlled environment), motor capability (what a person can do in his/her daily environment), and motor performance (what a person actually does do in his/her daily environment). DESIGN The relations between motor capacity, motor capability, and motor performance were calculated by using Pearson correlations and visualized by scatterplots. SETTING A cross-sectional study of a hospital-based population of children with CP. PARTICIPANTS Subjects were children with CP (N=85) aged 30 months (Gross Motor Function Classification System levels I-V). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Motor capacity, motor capability, and motor performance were assessed with the Gross Motor Function Measure and 2 scales of the Pediatric Evaluation of Disability Inventory, respectively. RESULTS Correlations between motor capacity, motor capability, and motor performance were high, between 0.84 and 0.92, and significant (P< .001). But when comparing children with the same level of motor capacity or motor capability, large ranges at the level of motor performance were found. CONCLUSIONS Results imply that motor performance levels are only partly reflected by the motor capacity and motor capability levels in young children children with CP. Contextual factors (physical and social environment) and personal factors (such as motivation) influence the relations between capacity, capability, and performance. This information is essential in making decisions about the focus of therapy to maximize a childs independent functioning in daily life.


Disability and Rehabilitation | 2008

Reliability of hand-held dynamometry and functional strength tests for the lower extremity in children with Cerebral Palsy

Olaf Verschuren; Marjolijn Ketelaar; Tim Takken; Marco van Brussel; Paul J. M. Helders; Jan Willem Gorter

Purpose. To evaluate the intertester reliability of two methods for measuring lower-limb strength in children with cerebral palsy (CP). Method. Twenty-five subjects with CP (7 – 17 years of age) participated in this study. Lower-limb muscle strength was measured on 2 occasions using a Hand-held Dynamometer (HHD; break-method and make-method) and a 30-sec Repetition Maximum (RM) during three functional strength tests for the lower extremities. Reliability was measured using the intraclass correlation coefficients (ICCs), the standard error of measurement (SEM) and the coefficient of variation (CV). Results. The intertester reliability of strength measurement using a HHD was questionable with ICC values ranging from 0.42 – 0.73 for the break-method, and from 0.49 – 0.82 for the make-method. The SEM and CV (%) values ranged from 27.9 – 58.9 and 22.2 – 35.3% for the break-method, and from 30.6 – 52.7 and 16.2 – 56.2% for make-method. The intertester reliability of strength measurement using the 30-sec RM was acceptable with ICC values ranging from 0.91 – 0.96, and SEM and CV (%) values ranging from 1.1 – 2.6 and 10.9 – 39.9% for the functional exercises. Conclusion. The intertester reliability of measuring muscle strength of the lower extremities using a hand-held dynamometer is questionable. The intertester reliability of the 30-sec RM for the lower extremity is acceptable.


Disability and Rehabilitation | 2007

Comparing contents of functional outcome measures in stroke rehabilitation using the International Classification of Functioning, Disability and Health

Vera P. Schepers; Marjolijn Ketelaar; I.G.L. van de Port; J.M.A. Visser-Meily; Eline Lindeman

Purpose. To examine the content of outcome measures that are frequently used in stroke rehabilitation and focus on activities and participation, by linking them to the International Classification of Functioning, Disability and Health (ICF). Method. Constructs of the following instruments were linked to the ICF: Barthel Index, Berg Balance Scale, Chedoke McMaster Stroke Assessment Scale, Euroqol-5D, Functional Independence Measure, Frenchay Activities Index, Nottingham Health Profile, Rankin Scale, Rivermead Motor Assessment, Rivermead Mobility Index, Stroke Adapted Sickness Impact Profile 30, Medical Outcomes Study Short Form 36, Stroke Impact Scale, Stroke Specific Quality of Life Scale and Timed Up and Go test. Results. It proved possible to link most constructs to the ICF. Most constructs fitted into the activities and participation component, with mobility being the category most frequently covered in the instruments. Although instruments were selected on the basis of their focus on activities and participation, 27% of the constructs addressed categories of body functions. Approximately 10% of the constructs could not be linked. Conclusions. The ICF is a useful tool to examine and compare contents of instruments in stroke rehabilitation. This content comparison should enable clinicians and researchers to choose the measure that best matches the area of their interest.


The Journal of Pediatrics | 2012

Identification of facilitators and barriers to physical activity in children and adolescents with cerebral palsy.

Olaf Verschuren; Lesley Wiart; Dominique Hermans; Marjolijn Ketelaar

OBJECTIVE To explore facilitators and barriers to participation in physical activity and sport in youth with cerebral palsy (CP). STUDY DESIGN This was a qualitative study involving in-depth focus group interviews with 33 ambulatory youth with CP and their parents. The interviews were conducted until informational redundancy was achieved. RESULTS Youth with CP and their parents reported personal and environmental facilitators and barriers to participation in physical activity. Seven major themes related to personal and environmental factors were identified. CONCLUSIONS This study suggests that various personal and environmental factors play a key role in determining the extent to which youth with CP participate in physical activity. The facilitators and barriers identified provide important theoretical insights into how and why youth with CP and their parents might change their physical activity behavior.


Developmental Medicine & Child Neurology | 2009

Use of the GMFCS in infants with CP: the need for reclassification at age 2 years or older

Jan Willem Gorter; Marjolijn Ketelaar; Peter Rosenbaum; Paul J. M. Helders; Robert J. Palisano

The stability of the Gross Motor Function Classification System (GMFCS) over time is described in 77 infants (41 boys, 36 girls) with cerebral palsy (CP; mean age 19.4mo [SD 1.6 mo]; 27 unilateral spastic, 42 bilateral spastic, eight dyskinetic type) and in the same children at follow‐up at age 2 to 4 years. The overall level of agreement over time (linear weighted kappa) was 0.70 (95% confidence interval [CI] 0.61−0.79). The overall percentage of children whose GMFCS level changed one or two levels was 42%, of which the majority were reclassified to a less functional level (McNemar’s Chi2 test p=0.11). The chance that children initially classified in the combination of GMFCS Levels I, II, and III would subsequently be classified in the same level in early childhood was 96% (positive predictive value [PPV] 0.96, 95% CI 0.85−0.99), whereas the PPV for the combination of Levels I and II was 0.88, 95% CI 0.70−0.96. These findings indicate that GMFCS classification in infants is less precise than classification over time in older children. In conclusion, children can be classified by the GMFCS early on, but there is a need for reclassification at age 2 or older as more clinical information becomes available.


Physical Therapy | 2011

Muscle Strengthening in Children and Adolescents With Spastic Cerebral Palsy: Considerations for Future Resistance Training Protocols

Olaf Verschuren; Louise Ada; Désirée B. Maltais; Jan Willem Gorter; Aline Alvim Scianni; Marjolijn Ketelaar

Resistance training of the lower limbs is now commonly used in clinical practice in children and adolescents with spastic cerebral palsy (CP). However, the effectiveness of this type of training is still disputed. The most recently published systematic review with meta-analysis included interventions such as electrical stimulation and resistance training and found insufficient evidence to support or refute the efficacy of these exercises in children with CP. Thus, the aim of this article is to evaluate the extent to which training protocols from the most recent randomized controlled trials are in keeping with the evidence for effective resistance training in children who are developing typically, as reflected in the training guidelines of the National Strength and Conditioning Association. Recommendations for resistance training protocols, based on this evidence and appropriate to children with CP, are provided to help guide both future research and clinical practice for resistance training in children with CP.

Collaboration


Dive into the Marjolijn Ketelaar's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Olaf Verschuren

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Tim Takken

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar

Annet J. Dallmeijer

VU University Medical Center

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge