PHYSICAL STRAIN IN DAILY-LIFE OF WHEELCHAIR USERS WITH SPINAL-CORD INJURIES

Forty-three men (age 33 +/- 9 yr) with spinal cord injuries (SCI) were observed during a normal workday while heart rate was recorded contin uously. Physical strain was estimated using the heart rate response ex pressed relative to the individual heart rate reserve (%HRR). The mean physical strain during the day for group I(C4-C8, N = 9), II (T1-T5, N = 6), III (T6-T10, N = 15), and IV (T10-L5, N = 13) was 38 +/- 8, 29 +/- 12, 22 +/- 8, and 23 +/- 5%HRR, respectively. Prolonged periods ( >15 min) of high strain (>60%HRR) that might maintain or improve physi cal capacity were not identified during activities of daily life (ADL) , but only during sports activities. The analysis of activity-related strain revealed. that specific ADL such as making transfers, entering/ leaving car, and negotiating environmental barriers, provoked high lev els of strain, especially in those with quadriplegia. Periods of peak strain (>60%HRR, 43 min) occurred frequently, also predominantly in th ose with quadriplegia. It was concluded that the physical strain durin g ADL is related to the level of lesion and is not of a magnitude and duration that would maintain or improve physical capacity. The periods of peak strain might restrict the mobility and independence of person s with SCI, and, therefore, reduce their quality of life.