The split stance Landmine anti-rotational fly is an extremely effective anti-rotational core exercise that really challenges the obliques. This exercise also strengthens the chest and shoulders.
To perform this exercise, grab a barbell and get into a split stance position. Your feet should be about hip width apart, or slightly wider. Your knees should be slightly bent, and you should be in an athletic position.
Set your elbow so it is in a slightly bent position and maintain this angle for the duration of the exercise. All of the movement should happen via your shoulder, not your elbow.
Before you move the barbell away from the midline of your body, take a deep breath into your belly through your nose (360 degrees of air around the spine), brace your core (imagine that you're about to block a soccer ball with your stomach), and lightly tuck your rib cage down towards your hips (close the space in your midsection).
Also, when the barbell is moving away from the midline of your body, keep your elbow rigid, but relax your arm a little bit so the core muscles will be forced to do the work, versus the arm dominating the exercise. It is important that you do not disengage your muscles as this will make your shoulder vulnerable to injury.
Keep your shoulder down, and draw your shoulder blades together and down towards the opposite hip.
Keep all of your weight on the mid/back of your feet, and make sure that all of your toes are in contact with the ground (particularly your big and baby toes). This is called a ''tripod foot,'' and will dramatically improve your stability and ability to perform this exercise.
Your knees should never collapse in or out.
Once you've performed the desired number of reps, repeat with the opposite arm and change your legs so the opposite leg is ahead.
Maintaining proper alignment is crucial. Your spine should remain in neutral alignment, and your pelvis, spine and torso should remain level and in a fixed position for the duration of the exercise as the point of this exercise is to resist rotation.
You can make this exercise more challenging by moving the arm further away from the midline of the body, or adding additional resistance.
You also have the option of performing this exercise with your feet in a square stance, in a half kneeling position, or in a full kneeling position. Each position offers slightly different challenges and degrees of difficulty.