If you're shopping for the outdoorsy type in your life, you're probably seeing a lot of backpacks lining the shelves of their favorite stores. But a backpack is one of the most personal things that a person will use in the wilderness, second only to his or her boots.

There are more features to a backpack than might be apparent at first glance. As Dr. Paul Auerbach points out:

(A) poorly fitted backpack can contribute to significant back pain, inefficient travel, or even the ruin of a trip. A backpack that weighs on its carrier can cause muscle spasm, sore neck and shoulders, numbness and tingling in the hands and fingers, sore hips, and irritated skin.

Here are his six tips for getting the right pack:

1. Proper size. It fits the torso closely, in particular the upper part of the body. When the padded waist strap is tightened, the weight of the pack should be distributed evenly across the hips.

2. The shoulder straps should be wide and well padded, to avoid compressing the front of the shoulders and armpits. They should be easily loosened and tightened. There should be a connecting strap that can be opened, closed and adjusted traversing the front of the chest attached to and between the shoulder straps.

3. Adjustable straps to fine-tune the tightness of the waist strap and the proximity of the pack to the back of the wearer are desirable.

4. Multiple compartments allow rational storage, ease of finding carried items, and more even weight distribution than possible with a single-compartment pack. Side pockets, top pockets, tie-down loops, an adjustable top cover, and other features to partition objects into discrete locations while protecting them from the elements are all good to have.

5. The pack should be designed so that it can be donned from a sitting or standing position, using the legs for stabilization. If it can only be put on by hoisting it and slinging it across the back, muscle strain is inevitable.

6. For a child-carrier pack, be certain that it is designed so that an active child can't easily self-extricate and wind up dangling or on the ground.

Read the full article at Medicine for the Outdoors.