Pediatric endurance and limb strengthening for children with cerebral palsy (PEDALS)--a randomized controlled trial protocol for a stationary cycling intervention

Abstract

Background: In the past, effortful exercises were considered inappropriate for children with spastic cerebral palsy (CP) due to concern that they would escalate abnormalities including spasticity and abnormal movement patterns. Current scientific evidence indicates that these concerns were unfounded and that therapeutic interventions focused on muscle strengthening can lead to improved functional ability. However, few studies have examined the potential benefits of cardiorespiratory fitness exercises in this patient population.

Methods/design: The rationale and design of a randomized controlled trial examining the effects of a stationary cycling intervention for children with CP are outlined here. Sixty children with spastic diplegic CP between the ages of 7 and 18 years and Gross Motor Function Classification System (GMFCS) levels of I, II, or III will be recruited for this study. Participants will be randomly assigned to either an intervention (cycling) or a control (no cycling) group. The cycling intervention will be divided into strengthening and cardiorespiratory endurance exercise phases. During the strengthening phase, the resistance to lower extremity cycling will be progressively increased using a uniquely designed limb-loaded mechanism. The cardiorespiratory endurance phase will focus on increasing the intensity and duration of cycling. Children will be encouraged to exercise within a target heart rate (HR) range (70-80% maximum HR). Thirty sessions will take place over a 10-12 week period. All children will be evaluated before (baseline) and after (follow-up) the intervention period. Primary outcome measures are: knee joint extensor and flexor moments, or torque; the Gross Motor Function Measure (GMFM); the 600 Yard Walk-Run test and the Thirty-Second Walk test (30 sec WT).

Discussion: This paper presents the rationale, design and protocol for Pediatric Endurance and Limb Strengthening (PEDALS); a Phase I randomized controlled trial evaluating the efficacy of a stationary cycling intervention for children with spastic diplegic cerebral palsy.

Figure 1

A. The Biodex Cyclocentric Semi-Recumbent Cycle has a wide-based seat with an optional seat belt. The seat is released by a handle located below the front panel allowing it to slide back along the track when the subject pushes forward on the pedal. B. Ten tensioning cords (10 lbs per cord) located at the base of the stationary bicycle provided progressive levels of loading. In this photograph, four of the cords are engaged for a total load of 40 lbs resistance. The arrows point to a location within the "cyclocentric exercise zone" when the seat is positioned for optimal lower limb range of motion during resisted cycling.