Correlating mechanical work with energy consumption during gait throughout pregnancy

Area of Science:

• Biomechanics
• Human Physiology
• Pregnancy Studies

Background:

• Assessing walking efficiency during pregnancy is crucial due to physiological adaptations affecting gait and energy expenditure.
• Metabolic energy expenditure measures may be unreliable during pregnancy due to metabolic changes associated with fetal development.
• Mechanical work calculations offer a potential alternative for evaluating gait energetics in pregnant individuals.

Purpose of the Study:

• To investigate the correlation between mechanical work prediction equations and the metabolic energy cost of gait in pregnant women.
• To determine if mechanical work is a reliable indicator of energy expenditure during pregnancy.

Main Methods:

• Thirty-five pregnant women participated, providing informed consent.
• Gas exchange and gait data were collected while participants walked at a self-selected speed.
• External (Wext), internal (Wint), and total (Wtot) mechanical work were calculated, then correlated with oxygen (O2) consumption rates and costs (net and gross).

Main Results:

• Significant positive relationships were found between mechanical energy measures (Wext, Wint, Wtot) and gross oxygen rate and cost.
• No significant relationship was observed between mechanical energy measures and net oxygen rate.
• Net oxygen cost showed significant relationships with Wext, Wint, and Wtot; energy recovery improved with increased gait speed.

Conclusions:

• Mechanical work measures, adjusted for resting energy expenditure and walking speed, can effectively compare metabolic energy consumption in pregnant women.
• These mechanical work metrics may serve as valuable tools for assessing gait changes throughout pregnancy.