Trunk Muscle Activity during Exercises Performed on Land and in Water

Abstract

When healthy adults perform abdominal hollowing, abdominal bracing, and pelvic tilt exercises in water, most trunk muscles display substantially lower EMG activity when compared with performing the same exercises on land (e.g., abdominal bracing for RA = 20% MVC for land and 10% MVC for water). It is possible that with hydrostatic pressure and buoyancy, trunk muscles play less of a stabilizing role in the aquatic environment, which minimizes their EMG activity levels. Regardless of the mechanism, patients with back pain may find it easier to perform trunk muscle exercises in an aquatic environment first then progress to the land environment because EMG activity may be gradually increased.