An Electromyographic Investigation of the Rectus Abdominis in Abdominal Exercises

Abstract

The upper and lower rectus abdominis (RA) were studied electromyographically through a series of 10 strenuous abdominal exercises and a trunk flexion isometric strength test. Intensity of contraction was greatest in the basket hang, followed by three variations of the hook sit-up. The curl-up and the inclined, arched back and conventional sit-ups came next in intensity, while the V-sit and controlled backward lean were the least strenuous exercises tested. In the upper RA several of the exercises elicited greater MAPs than were elicited by the maximal isometric effort involved in the trunk flexion test. The apparently strenuous nature of the basket hang, which is primarily a movement of thigh rather than trunk flexion, implies that this exercise may be useful in the abdominal training of highly conditioned athletes.