Endurance and Gait in Children with Cerebral Palsy After Intensive Body Weight-Supported Treadmill Training.

Beth Provost, PhD, PT; Kathy Dieruf, PhD, PT, NCS

Summary by Sonya Seif, Mobility Research, 3 Janurary 2008

This study was designed to investigate how intensive body weight-supported treadmill training (BWSTT) affects endurance, functional gait and balance in ambulatory children with cerebral palsy (CP). Six children, aged 6 to 14 years participated in an intensive therapy program in which they received BWSTT in 30-minute sessions, twice a day, for two weeks. Statistically significant changes were noted for walking velocity and energy expenditure. Individual results varied, but at least one child showed detectable improvement for each endurance or functional gait measure.

Within the realm of physical therapy a need exists for the following: a set of relevant and practical outcome measures, algorithms to help make care-giving decisions, and the ability to define the optimum specifications for recipients to "practice" (intensity, specificity, dosing, motivation and feedback). BWSTT, now primarily used in patients with neurological impairments affecting mobility, could be a powerful intervention for children with CP. As conditioning programs become increasingly important to healthy fitness levels in children with disabilities, BWSTT could be an attractive option for improving fitness, function, and endurance levels. Studies have reported clinical improvement in younger and older children, but the majority of these investigations focused on non-ambulatory patients. This study addresses the gap in BWSTT research regarding pediatric CP patients who ambulate independently.

The research questions posed were the following: In terms of clinical measures of endurance, functional gait and balance after an intensive BWSTT program, will there be statistically significant improvements in the children as a group? If not as a group, will individuals show changes? What factors in particular (e.g. age or diagnosis) affect the higher efficacy for certain children? All of the subjects were able to ambulate independently without an assistive device, actively dorsiflex the more involved ankle at least 10 degrees, and follow verbal cues for testing purposes. They rated as Level 1 on the Gross Motor Function Classification System; though walking independently, they were limited in coordination, balance, and speed for advance gross motor skills.

The following clinical assessments were performed pre- and post-therapy: Six-Minute Endurance Walk, Energy Expenditure Index, Ten-Meter Walking Velocity, Gross Motor Function Measure Dimension E, Single Leg Balance Test. With these measures changes in the children's endurance, functional gait, and balance were quantified. The BWSTT was given using the LiteGait I system over a treadmill. A Bisym attachment - a bilateral symmetry scale that measures and displays the amount of weight-bearing support provided on each side (right and left) - was used in conjunction with the LiteGait I. Training started with 30% BW supported at treadmill speeds of 1.5 to 1.9 mph. Over the two-week program support was gradually decreased to 0% (or as close as possible) and treadmill speed increased to 2.3 to 3.1 mph. As previously mentioned, each child received 30 minutes, twice daily, six days per week for two weeks.

Though no group significance was demonstrated, the results of this study are still quite promising. The children who started with the lowest scores improved the most. An interesting observation was that the child who walked more slowly post-training did so because she was paying more attention to achieving a proper gait pattern. Though a small sample size, the authors of this paper felt that the benefits were not affected by age or diagnosis; individuals from both the younger and older age groups and both hemi- and asymmetrical diplegic diagnostic categories showed detectable improvements.

The authors postulated that children who are ambulatory may benefit from BWSTT for several reasons. Jahnsen et al investigated locomotion skills in adults with CP and found that 44% reported deterioration in walking skills, mainly before 35 years of age. Self-reported causes of deterioration included fatigue and lack of adapted physical activity, which may be preventable if ambulatory children with CP engage in an ongoing program of effective treatment strategies such as BWSTT as they mature. In addition, conditioning programs are becoming increasingly important to improve fitness levels of children with disabilities, and treadmill training with BWS may be an option to improve not only function but fitness including endurance levels of children with CP who are ambulatory. The findings of this study support these assertions.