Area health and back experts agree that two straps are better than one when it comes to carrying around a backpack.

Lisa Day, a chiropractor at Elbert Chiropractic Clinic, 622 Burnett Ave., said learning to carry the best type of backpack for the back and carrying it in the correct manner can save students backaches and pains, headaches, muscle weakness and tingling.

The backpack with the double strap is the better one because of the even weight distribution,Œ Day said. One-strap backpacks pull you one way or another.Œ

She said the pulling of ligaments can lead to muscle pains, tingling and muscle weakness.

The spine has a natural curve to it and all along the spine there are nerves that come out and run to the different parts of the body, Day said. Tingling and tight muscles occur when the spine gets pulled into an unnatural curve, because nerve openings are closed.

If it¡s left misaligned for a long period of time it can cause damage,Œ she said. The nervous system controls everything in your body.Œ

Day said most of the nerves in the body run from the brain down the spinal cord to the rest of the body. The body¡s billions of nerve fibers supply every cell, tissue, organ and system of the body with messages from the brain.

Neal Bentley, chiropractor at Advanced Chiropractic, 712 5th St., said one-strap backpacks and carrying a backpack on one shoulder could create other problems.

He said the weight on the shoulder can put traction on nerves in the shoulder. Traction occurs when the shoulder is relaxed and there is a heavy weight that tugs on the nerve route.

It is a pulling type of injury instead of a pinch,ΠBentley said.

Joint problems and nerve problems result from a traction type of injury, he said. Bentley said serious damage can result when someone¡s shoulder is totally relaxed when carrying a backpack and then there is a sudden jolt. This could happen just by missing a step.

He said long-term effects could include scar tissue formation.

Heavy backpacks are another problem.

Ten students at Lied Recreation Center took the time to have their bags weighed on the scales in the locker rooms. The average weight was 10.3 pounds. The heaviest bag weighed 20.6 pounds and the lightest bag weighed 5 pounds.

Books aren¡t the only thing students are carrying in their backpacks any more. Most students lug their lunches, workout clothes, cell phones and purses.

Laura Lyons, senior in exercise and sports science, had a backpack that weighed 8.2 pounds.

Anything more gets too heavy,Πshe said.

Janae Raymond, junior in management, carried around a backpack that weighed 11.5 pounds that day and she said it hurts her back to carry more.

Day said students should not carry backpacks that weigh more than 15 to 20 percent of their weight. If a backpack is too heavy, she said, the person carrying it will lean forward, which causes another type of unnatural spinal curve.

Tim Derrick, assistant professor of health and human performance, said it¡s important to keep the weight in backpacks down.

Switch books out if you¡re going home or back to the dorms between classes,Œ Derrick said.

For those students who have no alternative to carrying a heavy load, Day gave tips for choosing a backpack with has recommended design features and then properly loading and wearing the backpack.

When buying a backpack, she said, find one with two straps that are wide, padded and S-shaped. Also, buy a backpack that is made of a lightweight material.

Look for backpacks with a waist or chest strap and built-in back supports. These will keep the backpack close to your body and will help you keep your balance.

If students do carry single-strapped backpacks, Day recommended slinging the strap over a different shoulder each week.

She also recommended:

‹ Placing heavy items in the backpack first.

‹ Lifting the pack with your leg muscles and keep it close to the body.

‹ Adjusting the straps so the backpack does not hang more than four inches below the waistline.