Validation of Using Smartphone Built-In Accelerometers to Estimate the Active Energy Expenditures of Full-Time Manual Wheelchair Users with Spinal Cord Injury

This study explores whether smartphones can accurately measure energy expenditure (EE) in manual wheelchair users with spinal cord injury (SCI). It compares smartphone measurements to a gold-standard method, indirect calorimetry, to see how well they match up. Twenty participants with SCI performed daily activities while wearing a smartphone on their arm and using a gas analyzer to measure oxygen consumption. The study then used this data to create mathematical models to estimate EE from the smartphone's accelerometer data. The study found that smartphones can be a promising, low-cost way to estimate energy expenditure in wheelchair users with SCI during daily activities, offering a more accessible alternative to expensive laboratory equipment.

• 1
  The models that included all variables or only linear variables showed comparable performance, with a correlation of 0.72 between estimated and measured energy expenditure.
• 2
  A model using only non-linear variables was less accurate overall but performed better for specific tasks, suggesting different types of data are useful for different activities.
• 3
  The first three predictors in the models contributed the most to their accuracy, indicating that a few key smartphone accelerometer variables can provide a good estimate of energy expenditure.