Mission requirements or limited transportation for service members sometimes means units must depend on themselves to move their supplies and gear. Understanding good load-bearing techniques to reduce stress can be a useful injury prevention tool. Remember these tips when you need to carry a heavy load.
Where you carry a load on your body affects both how much energy you expend and how you walk. A practical choice is to carry a load as close as possible to your center of gravity. In general, a woman has a lower center of gravity compared to a man, typically around their hips, or approximately 55% of their height (men’s is approximately 57% of their height, or higher up the body, between the belly button and sternum). The backpack and double pack methods have been shown to use less energy than most other forms of load carriage. A double pack causes less forward lean of the trunk, which can reduce your risk for back pain. Though double packs can be useful in some military situations (for example, medics carrying their aid bags in front), they can also inhibit movement and limit your forward field of vision, making it difficult to see obstructions and traps.
Pack frames and hip belts reduce shoulder stress. Overall, when a portion of the load is carried on the waist through use of a hip belt, there is less discomfort than there is with shoulder load carriage.
A low- or mid-back load placement might help you with stability on uneven terrain, particularly during unexpected stumbles. And you might find that high load placement is best for even terrain because you can hold your posture closer to what it would be without a load.
Shifting loads from one part of your body to another during a march can improve your comfort and allow you to carry loads for longer periods of time. You can load shift by using various strap adjustments to redistribute the load to other muscles or other portions of previously loaded muscles.
- Sternum straps attach horizontally across both shoulder straps at mid-chest level. Tightening a sternum strap shifts the load toward the center of your body. When you loosen a sternum strap, the load shifts outward.
- Hip belts and shoulder straps have adjustments that should allow you to place more of the load on your hips or shoulders. When you reduce the shoulder strap tension (by loosening the straps), more of the load rests on your hips. With the shoulder straps tighter, more of the load is placed on your shoulders.
- Load-lifter straps attach the tops of the shoulder straps to the pack frame. When you tighten this the strap, it pulls the top of the load upward and forward over the base of support; however, when you loosen the strap, the top of the load falls lower.