Within- and between-day stability of treadmill walking VO sub(2) in children with hemiplegic cerebral palsy. Stability of walking VO sub(2) in children with CP

• Published in: Gait & posture 2005-01, Vol.21 (1), p.80-84
• Main Authors: Keefer, D J, Tseh, W, Caputo, J L, Apperson, K, McGreal, S, Morgan, D W
• Format: Article
• Language: English
• ISSN: 0966-6362
• DOI: 10.1016/j.gaitpost.2004.01.004

Within- and between-day stability in locomotor energy use was quantified in 13 children with hemiplegic cerebral palsy (CP). During testing, subjects were familiarized with the laboratory environment (Session 1), performed three 5 min level treadmill walks (Trials 1-3) at 0.67 ms super(-1) (Session 2), and completed a single 5 min walk (Trial 4) at 0.67 m s super(-1) (Session 3). In Sessions 2 and 3, heart rate (HR) was assessed and expired air was collected and analyzed to determine VO sub(2). Data analyses revealed no significant difference (P>0.05) in either net VO sub(2) (ml kg super(-1)min super(-1)) or EEI sub(HR) (bm super(-1)) across the three trials performed in Session 2 and between average measures of net VO sub(2) and EEI sub(HR) quantified in Session 2 and those obtained in Session 3. Mean within-day coefficient of variation (CV) values for net VO sub(2) and EEI sub(HR) were 8.6%+/-8.5% and 13.9%+/-7.8%, respectively. Analysis of between-day variability and energy expenditure revealed a between-day CV value of 13.1% for net VO sub(2) and 24.0% for EEI sub(HR). In addition, significant inverse relationships between Gross Motor Function Measure (GMFM) scores and within- (r=-0.61) and between-day (r=-0.58) CV values for net VO sub(2) were detected. Viewed in concert, these data suggest that fairly stable within- and between-day measures of locomotor energy expenditure during level treadmill walking can be achieved in subjects with hemiplegic CP if testing is preceded by a short period of treadmill accommodation. However, children with greater motor dysfunction may require an extended period of treadmill accommodation to reduce trial-to-trial variability in walking energy use.