A method for normalization of oxygen cost and consumption in normal children while walking

Area of Science:

• Pediatric Exercise Physiology
• Biomechanical Analysis
• Clinical Measurement

Background:

• Accurate measurement of oxygen use is crucial for assessing energy expenditure in children, particularly those with walking abnormalities.
• Existing telemetric systems lack statistically validated reference data for oxygen consumption in healthy, nondisabled children.
• Establishing normative data is essential for comparing energy expenditure in children with gait impairments to their peers.

Purpose of the Study:

• To establish statistically valid telemetric measurements of oxygen cost and oxygen consumption in nondisabled children.
• To develop predictive equations for oxygen cost and consumption based on body surface area.
• To create indices for quantifying variations in energy use among children.

Main Methods:

• Collected data from 94 nondisabled children (ages 5-15 years) using the Cosmed K2 oxygen analysis system.
• Measured oxygen cost (mL O2/kg/m) and oxygen consumption (mL O2/kg/min).
• Correlated these measurements with inverse body surface area (IBSA) to derive linear regression equations.

Main Results:

• Developed predictive equations: oxygen cost = 0.256 (IBSA) + 0.052 (r=0.806) and oxygen consumption = 17.635 (IBSA) + 4.956 (r=0.758).
• Established indices to quantify deviations from predicted normal energy expenditure.
• Demonstrated the utility of these indices for comparing energy use across different measurements and over time.

Conclusions:

• The derived equations and indices provide a reliable method for quantifying energy expenditure in children.
• These tools enable objective comparison of energy use in children with walking abnormalities against normative data.
• The developed indices facilitate longitudinal tracking of energy expenditure, accounting for changes in anthropometric variables.