Coactivation During Dynamometry Testing in Adolescents With Spastic Cerebral Palsy

BACKGROUND: Dynamometry has been used extensively to measure knee extensor strength in individuals with cerebral palsy (CP). However, increased coactivation can lead to underestimation of knee extensor strength and, therefore, reduce validity of strength measurements. It is yet unknown to what extent coactivation occurs during dynamometry testing and whether coactivation is influenced by severity of CP, load levels, and muscle fatigue. OBJECTIVES: The aims of this study were: (1) to investigate coactivation in adolescents with and without CP during dynamometer tests and (2) to assess the effect of Gross Motor Function Classification System (GMFCS) level, load level, and muscle fatigue on coactivation. DESIGN: A cross-sectional observational design was used. METHOD: Sixteen adolescents with CP (GMFCS levels I and II: n=10/6; age range=13-19 years) and 15 adolescents without CP (n=15; age range=12-19 years) performed maximal isometric contractions (maximal voluntary torque [MVT]) and a series of submaximal dynamic contractions at low (±65% MVT), medium (±75% MVT), and high (±85% MVT) loads until fatigue. A coactivation index (CAI) was calculated for each contraction from surface electromyography recordings from the quadriceps and hamstring muscles. RESULTS: Adolescents with CP classified in GMFCS level II showed significantly higher CAI values than adolescents classified in GMFCS level I and those without CP during maximal and submaximal contractions. No differences were observed among load levels. During the series of fatiguing submaximal contractions, CAI remained constant in both the CP group and the group with typical development (TD), except for adolescents with TD at the low-load condition, which showed a significant decrease. LIMITATIONS: Electromyography tracings were normalized to amplitudes during maximal isometric contractions, whereas previous studies suggested that these types of contractions could not be reliably determined in the CP population. CONCLUSION: Coactivation was higher in adolescents with CP classified in GMFCS level II than in adolescents with TD and those with CP in GMFCS level I at different load levels. Within all groups, coactivation was independent of load level and fatigue. In individuals with CP, coactivation can lead to an underestimation of agonist muscle strength, which should be taken into account while interpreting the results of both maximal and submaximal dynamometer tests

Effectiveness of functional progressive resistance exercise training on walking ability in children with cerebral palsy: A randomized controlled trial

The objective of the study was to evaluate the effectiveness of functional progressive resistance exercise (PRE) training on walking ability in children with cerebral palsy (CP).Fifty-one ambulant children with spastic CP (mean age 10 years 5 months, 29 boys) were randomized to an intervention (n= 26) or control group (n= 25, receiving usual care). The intervention consisted of 12 weeks functional PRE circuit training, for 3 times a week. Main outcome measures were walking ability and participation. Secondary outcomes were muscle strength and anaerobic muscle power. Possible adverse outcomes were spasticity and passive range of motion (ROM). Muscle strength increased significantly in the training group compared to the control group, but walking ability, participation and anaerobic muscle power did not change. Spasticity and ROM remained unchanged, except for a significant decrease in rectus femoris length in the intervention group. It is concluded that twelve weeks of functional PRE-training does not improve walking ability, despite improved muscle strength. © 2011 Elsevier Ltd

Combined surveillance and treatment register for children with cerebral palsy: the protocol of the Netherlands CP register

Introduction Cerebral palsy (CP) is a childhood onset, lifelong, condition. Early detection and timely treatment of potential problems during the child’s development are important to prevent secondary impairments and improve function. Clinical management of children with CP requires a spectrum of multidisciplinary interventions, which have an impact on short-term and long-term outcomes. However, there is a lack of knowledge about a personalised approach in this heterogeneous population. Various CP registers with different aims have been developed worldwide, which has made an important contribution to our understanding of CP. The purpose of this protocol is to describe the unique design of a combined multidisciplinary surveillance and treatment register for children with CP in the Netherlands, which aims to improve quality of care and to enhance an individual treatment approach.Methods and analysis The Netherlands CP Register combines a multidisciplinary surveillance programme with a standardised protocol for treatment registry. The register systematically collects real-life surveillance and treatment data of children with CP. The register contributes to daily care at the individual level by screening for potential secondary impairments using a decision-support tool, by visualising individual development using a dashboard, and by supporting goal setting and shared decision-making for interventions. The register provides a platform at the national level for quality of care improvement and a comprehensive database of real-life data allowing multicentre studies with a long-term follow-up. People with lived experience of CP, healthcare professionals from different disciplines and researchers collaborated in the development of the register.Ethics and dissemination The Netherlands CP register was submitted to the Medical Ethics Review Committee of VU University Medical Center (Amsterdam, the Netherlands), who judged the register not to be subject to the Medical Research Involving Human Subjects Act. A scientific board reviews requests for dissemination of data from the register for specific research questions