Assessment of physical activity in inactive populations.

The ability to index activity objectively in disabled or impaired activity populations is critical for our understanding of the long-term health consequences of reduced activity. The current research employed the large-scale integrated activity monitor as an objective measure of free living daily activity in 28 subjects with traumatic spinal cord injury. All the spinal cord-injured subjects wore the monitors for 2 d while in-patients at a rehabilitation center. The results indicated that the instruments can accurately index individual physical activity levels in this population, which has drastically reduced activity. Furthermore, group differences in activity were discriminated where paraplegic activity (mean, 32.0 counts X h-1) was significantly greater than quadriplegic activity (mean, 15.1 counts X h-1) (P less than 0.01) despite the markedly low activity levels. The results thus indicate that activity sensors can index individual activity levels at the very low end of the activity spectrum.