For the duration of the exercise, you have to work SO hard to keep your shoulder in a stable position. You also need to prevent your body from tipping to the side (anti-lateral flexion), rotating (anti-rotation), or leaning back (anti-extension), so this addresses all aspects of core stability. The toughest part by far is turning around.
It is critical that you maintain proper alignment for the duration of the exercise. You should maintain a neutral spine, your head, torso and hips should remain stacked (the cannister analogy works well), and your knees should remain in line with your toes. Do not allow them to collapse in or fall out. Maintaining proper alignment, and walking in a straight line (versus looking like you are about to fail a field sobriety test) is very tough as the bar with the chains, plus the fact that the weight is on one side of your body (vs the center) really puts you off balance.
- Pack your shoulder.
- Brace your core muscles (especially your anterior core), and really be mindful of engaging your anterior core (including the obliques) on the opposite side of your body of the arm that is supporting the weight. It is easy to become complacent and allow your body to lean sideways. You want the ''pillars'' of your anterior core on both sides of your body working in your favour, not against you. Think of the Jenga game that used to be popular WAY back in the day. Remove strength from one side of the building, and the building will topple over. The human body is no different.
- Actively tuck your rib cage towards your pelvis. This will help keep your ribs from flaring and your lower back from hyperextending, and will help you maintain the ''cannister''position. Thank you Tony Gentilcore for the cannister analogy.
- Take deep breaths into your belly through your nose (360 degrees of air around your spine) and exhale through your mouth
- Pay attention to your feet. When you plant, you want to make sure that you maintain a tripod base (keep the weight on your mid/back of your foot, and keep all of your toes in contact with the floor, especially your big and baby toes). And when you push off, you want to make sure that you press through all of your toes, not just the inside or outside of your foot. This will dramatically improve your stability and ability to perform this exercise.
This is just one of many fantastic carrying variations that I like to use.