Evolution of Muscular Oxygenation during a Walking Test in Preterm Children

Area of Science:

• Pediatric Exercise Physiology
• Neuromuscular Function
• Developmental Pediatrics

Background:

• Understanding the functional capacities of preterm children is crucial for their long-term health.
• Peripheral muscular oxygenation and gait characteristics are key indicators of physical performance.
• The 6-minute walking test (6MWT) is a standard measure for assessing functional exercise capacity.

Purpose of the Study:

• To compare peripheral muscular oxygenation and gait characteristics during a 6-minute walking test (6MWT) between preterm and full-term children.
• To investigate potential differences in muscle oxygen utilization and movement patterns.
• To identify if prematurity is associated with altered functional performance during submaximal exercise.

Main Methods:

• A cohort of 45 prepubescent children (12 preterm, 33 full-term) underwent a 6-minute walking test (6MWT).
• Near-infrared spectroscopy (NIRS) measured muscle oxygenation (oxyhemoglobin, deoxyhemoglobin, total hemoglobin) in the calves.
• The OptoGait system monitored gait variables, including walking speed and stride length.

Main Results:

• Preterm children demonstrated significantly lower walking distance during the 6MWT compared to full-term children (-9% difference).
• An increased oxygen extraction in peripheral muscles, indicated by rising deoxyhemoglobin, was observed in preterm children from the third minute of the test.
• Preterm children exhibited significantly slower walking speed and shorter stride length, indicating altered gait patterns.

Conclusions:

• Children born preterm show diminished walking performance and greater peripheral muscle oxygen extraction during the 6MWT.
• These findings suggest potential muscular maladjustment and reduced functional capacities in preterm children.
• The observed differences may contribute to increased muscular fatigue in children with a history of prematurity.