Frequent news items report that wearing backpacks causes back pain in children and adults. Some of the usual theories proposed for why backpacks cause pain is "overstuffing them" or carrying them too high or low. Complicated and expensive packs are developed as remedies. Another of the often-repeated theories is that carrying things on your back makes you arch your back. However, none of these are the reason for back pain when carrying packs. It is not the pack that causes the pain or the arching. It is a very simple matter of allowing your back to arch and slouch backward instead of standing straight against the load.

Look at the photo, above left, of the backpacker. The upper arrow shows how his upper body is tilting backward instead of being straight from mid-hip to shoulder. The lower arrow shows how the lower body (the hip) is tilting forward in front and sticking out in back, instead of being straight from mid-hip to the top of the leg bone. Between the two arrows, his lower back is overly arched and pinched. The weight of his upper back plus the weight of his pack is pressing down on the joints and soft tissue of the lower back. This is how overarching causes lower back pain. It is not the backpack, but the body position while carrying it. The other hiker without the backpack standing near the sign is also overly arching the lower back.

Lower back arching (hyperlordosis) may occur automatically when standing, and may seem "natural," but it is not healthy. Wetting your pants is natural too, but you have to learn to control it. To reduce the unhealthy overarching (hyperlordosis), you just use your muscles to stand right. Try this:

• To feel the problem of overarching, stand up and lift your ribs to allow your upper body to lean backward. Allow your hip to tilt down in front and stick out in back. You may feel a familiar pressure in the lower back.
• Straighten your lower body by tucking your "tailbone" under you so that your hip is straight from the top of the upper leg bone to the middle of the crest of the hip bone, not tilted.
• Straighten your upper body by bringing ribs back down to level. Do not slouch or round forward; just stand straight without lifting your ribs.
• The motion of tucking the hip and pulling the upper body straight is like doing an abdominal crunch standing up.
• Your "tailbone" tucks under you so it is not tilted out in back, and the large inward curve of the lower back becomes a small inward curve.

Whenever you are carrying a backpack, standing, walking, running, or exercising, use the same hip tilt to normalize your spine position and prevent overarching. Overarching is not healthy and is poor body ergonomics to walk around or exercise with your behind stuck out in back. The muscles you use to hold your spine from overarching are your abdominal muscles. You get a free built-in abdominal muscle exercise just by standing in healthful position. The next post will cover how to get better exercise and prevent back pain when carrying things in front.