Measurement of nocturnal body motility: behaviour of osteoarthritic patients and healthy controls.

Nocturnal body motility has been compared in a sleep laboratory between patients with osteoarthritis and healthy age-, sex- and weight-matched controls using a Bio-medical timer and bedleg force transducers connected to a Disa polygraph. Four motility variables were derived (duration of movement; duration adjusted for sensitivity; number of movements; number of 30-s epochs containing movements) enabling an assessment of nocturnal body motility in the two groups. There was a trend for osteoarthritic patients to move more than controls during sleep on all variables measured, although this did not reach statistical significance. Temazepam elixir (0.4 mg/kg body weight/night) reduced all four motility variables in both osteoarthritic patients and controls, although only the reduction of the number of 30-s epochs containing movements (P less than 0.05) in the control group attained statistical significance.