An evaluation of four different measures of abdominal muscle strength: patient, order and instrument variation.

We compared 4 measures of abdominal muscle strength in 24 male subjects aged 20-52 years, 12 without low back pain (LBP) and 12 with LBP. The manometer to knee and manometer to sternum methods involved 2 positions of testing abdominal muscle strength using the adapter sphygmomanometer, a 3rd method was a scheme of graduated sit-ups, and the 4th had the sphygmomanometer bladder replaced by a disposable plastic tube and the subject blowing into …