Derman K L, Derman E W, Noakes T D
Department of Physiology, University of Cape Town.
S Afr Med J. 1995 Apr;85(4):278-82.
To determine the effects of a locally designed lumbar body support (LBS) on integrated electromyographic (IEMG) activity of the lumbar erector spinae muscles, on heart rate and on ratings of discomfort in patients with low back pain.
Non-randomised controlled trial.
Patients referred from general practitioners and back pain rehabilitation programmes in Cape Town.
Ten patients with low back pain of diverse causes. Values were compared with those in 10 control subjects without low back pain.
Patients and controls lay supine on (in random order) either a flat conventional mattress or a LBS placed on top of the flat mattress, for a 30-minute period (acute exposure), and every night for 2 weeks (chronic exposure).
IEMG activity of the lumbar erector spinae muscles, heart rate, and perception of comfort.
IEMG activity of the lumbar erector spinae muscles did not differ between controls and patients when lying on the LBS on top of the CM after either acute or chronic exposure. However, it was significantly greater (P < 0.05) in patients than in controls when lying on the flat mattress. Subjective ratings of discomfort and heart rates mirrored these changes and were higher in patients only when lying on the flat mattress (P < 0.05). Patients with low back pain also reported that sleeping overnight on the LBS on top of their own mattress significantly reduced discomfort ratings.
When lying on a mattress with a flat surface, patients with chronic low back pain have higher IEMG activity of the erector spinae muscles, higher heart rates and higher subjective ratings of discomfort than do control subjects. These differences disappear when both groups use a specially designed lumbar body support placed on top of the flat surface. These preliminary studies suggest that a lumbar body support should be evaluated in the chronic management of low back pain.
