Comparison of oxygen consumption measurements in children with cerebral palsy to children with muscular dystrophy.

Children with muscular dystrophy (MD) offer a unique opportunity to measure the effect of weakness on gait efficiency as they experience weakness not usually accompanied by other disabilities affecting gait. Oxygen consumption measurements were collected from eight patients with MD and eight patients with cerebral palsy (CP). A statistically significant difference in oxygen cost and oxygen consumption while walking between patients with CP and patients with MD was found despite their common inability to walk similar distances. Oxygen cost and oxygen consumption were elevated within the CP population, whereas all measurements for the MD population were within normal ranges. The measurements show that a patient can have normal oxygen cost and oxygen consumption while walking and yet be functionally limited because of weakness. Caution should be taken when using oxygen cost and oxygen consumption as sole outcome measures for patients with CP, because these measures may be insensitive to changes in strength.