This exercise is similar to a woodchop type ab exercise. Muscles used include shoulders, lats, biceps, serratus, and obliques. This exercise can also be performed standing on stability discs (dynadisc) or using a lunging motion, both of which would add the benefit of tying in the outer hips as well. Place bar into a fixed position angled into a corner or joint. Hold bar in both hand with arms straight and end of bar at (or slightly above) eye level. Keep knees bent, back arched and abs in as you rotate bar from hip to hip. Weight can be added to end of bar to increase resistance.
This is an introduction to the woodchop type exercises. These exercises work contra-laterally (cross-body) from external oblique (top layer) on one side, to the internal oblique (deep layer) on the other. Start exercise in a lunge-type stance gripping a rope attachment on top pulley of a cable crossover machine. Next, with arms straight, pull rope from over the top of one shoulder to outside the hip on the opposite side. Make sure to keep your belly button pulled in toward your spine and try to exhale slightly as you chop.
This straight arm motion is for the back of the shoulder and the upper back. By performing the exercise in a side lying bridge you also activate the outer hip, oblique and shoulder stabilizers as well.
Start this exercise standing with feet hip width, toes straight and medicine ball on one hip. Next, step forward with the opposite side leg, and rotate ball overhead with arms straight. The lunge should finish with (2) ninety degree angles in the knees, shoulders and hips pointed straight ahead and the ball finished outside the front knee. While this exercise is primarily for the legs, it is an excellent core motion as well. As the ball rotates, the muscles in the abdomen contract not only to aid in pulling the ball, but also to help stabilize the body throughout the motion.