Fit-Active-Habits: Measuring Fitness and Physical Activity in Cerebral Palsy

O'Neil M.E.^1,2, Bjornson K.³, Boyd R.⁴, Dallmeijer A.⁵, Thorpe D.⁶

¹Drexel University, Physical Therapy and Rehabilitation Sciences, Philadelphia, United States of America, ²Franciscan Hospital for Children, Research Center, Boston, United States of America, ³University of Washington, Seattle Children's Research Institute, Seattle, United States of America, ⁴University of Queensland, School of Medicine, Department of Pediatrics & Child Health, Brisbane, Australia, ⁵VU University Medical Center, Department of Rehabilitation Medicine, Amsterdam, Netherlands, ⁶University of North Carolina, Department of Allied Health Sciences, Chapel Hill, United States of America

Learning objectives:

1. To review psychometric properties of laboratory and field-based measures of health-related fitness and habitual physical activity (HPA) for persons with cerebral palsy (CP) 2. To present findings on measurement methodology protocols on fitness and HPA outcomes from current research reviewed by or conducted by team members 3. To discuss the methodology for collecting reference values on HPA and fitness for persons with CP and areas of future research 

Description:

Presenters in this symposium will review current “state of the science” in measurement methodology and psychometric properties of measurement for fitness and habitual physical activity (HPA) in persons with CP.

Cerebral palsy (CP) is the most common form of physical disability in childhood and management costs exceed one million dollars (US) over a lifetime. People with physical disabilities such as CP are the least physically active members of society placing them at high risk for the co-morbidities associated with inactivity (obesity, heart disease, Type 2 diabetes). Although the potential health-related benefits of exercise and physical activity are known, recent reviews of health related fitness and physical activity measures for persons with CP reveal limitations in quality research designs and use of appropriate and rigorous measurement protocols. Establishing psychometric properties and systematic protocols for lab and field-based measurements is important to validate use of these measures in determining activity-based intervention effectiveness for persons with CP.

Activity-based physical therapy interventions include strategies to enhance health-related fitness and participation in physical activities in children with CP. Evidence indicates that activity-based intervention strategies have been successfully conducted in laboratory and field-based settings. Although the potential of health-related benefits of exercise and physical activity are known (ie., increased function, improved cardiorespiratory capacity and muscle strength), existing studies lack psychometrically sound measures of both HPA and fitness in persons with CP.

There is a need to examine the validity, reliability, responsiveness, and feasibility of the physiological measures of aerobic fitness before we can identify how physical activity and fitness or changes in physical activity and fitness are linked to improved health related fitness and activity in this population. Lab-based test protocols have been described for measuring aerobic capacity (VO2max) using cycle ergometry and treadmill testing. In addition, tests for measuring anaerobic capacity and isometric muscle strength have been described. There is, however, very little information available about the psychometric properties of these tests and there is no consensus on measurement protocols. In addition, the small number of subjects limits interpretation of data across different Gross Motor Function Classification System (GMFCS) levels and ages (Dallmeijer 2008).

Examination of quantitative instruments to measure field based fitness and HPA levels in persons with CP is a developing field in rehabilitation sciences. In addition, studies that examine relationships among laboratory and field based physical activity and fitness measures are becoming more prevalent in rehabilitation research literature. Lennon (2006) found that physical activity as measured by the Step WatchTM accelerometer was highly correlated to laboratory measures of oxygen consumption in ambulatory children with CP. In 2007, Bjornson and colleagues documented the first published habitual ambulatory activity data using the StepWatchTM accelerometer. In a comparison cohort design, adolescents with CP ages 10-13 years demonstrated significant limitations in their average daily stride rates, percent active walking time and ability to attain high rates of walking activity as compared to youth developing typically. These field based data on physical activity (StepWatchTM accelerometry data) were moderately correlated with self report data on overall physical activity and locomotion as measured by the ASKp-38. Clanchy, Boyd et al (2009) recently reported on the validation of physical activity data as measured by the Actigraph accelerometer compared with oxygen consumption (Cosmed K4B2) in ambulatory children with CP comparing physical activity at different intensities (quiet sitting, brisk walking, ball kicking/throwing). This newly developing body of work offers opportunities to develop more rigorous measurement methodology when examining HPA and health-related fitness in children and adolescents with CP in laboratory and field-based environments. This methodology also needs to be applied to adults with CP.

Implications / Conclusions:

This international rehabilitation research team has made significant contributions to research in measurement and intervention outcomes in studies that aim to improve fitness, HPA and participation in persons with CP. The evidence contributed by continued work of this team will help move the field of physical therapy and rehabilitation sciences forward towards more effective, specific interventions and measures to improve health outcomes and healthy lifestyles for persons with CP.

Keywords:

Measurement; Physical fitness and habitual physical activity; Cerebral palsy habitual

Funding acknowledgements:

This project is funded by a research grant from the American Academy of Cerebral Palsy and Developmental Medicine (2009).

Relevance to WCPT and expected audience:

This symposium is relevant to the theme of this year’s Congress: Moving Physical Therapy Forward. Our panel of presenters represents an international, multidisciplinary research team which examines evidence and best practices in measurement methodology to evaluate and promote fitness and habitual physical activity (HPA) in persons with cerebral palsy. We recognize a renewed emphasis on activity-based physical therapy interventions and a need to identify best measurement practices to evaluate fitness and HPA.

Target audience:

This presentation is targeted towards physical therapists and other rehabilitation providers who focus on measurement outcomes for fitness, HPA, and participation in persons with CP.

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