Measuring abdominal muscle weakness in patients with low back pain and matched controls: a comparison of 3 devices.

OBJECTIVE: To compare 3 hand held devices used to measure isometric abdominal muscle strength: the adapted sphygmomanometer, the vigorometer and the Penny & Giles myometer. METHODS: Subjects were men, aged 22 to 43 years. Fifteen had a history of low back pain and 18 age matched controls had no low back pain. The test position was a half sit-up at 45 degrees, knees at 90 degrees, feet secured. The single observer applied pressure with one of …