Orthotics & Prosthetics and Athletes

Orthotics and Prosthetics Experts Use New Materials to Let Injured Athletes Play

Athletes can play even with fractured bones, thanks to new light-weight braces. The braces are made from a combination of plastic and carbon that is heated to become soft and then molded into perfect-fitting shapes.

BLACKSBURG, Va.--When the star player of a sports team gets hurt, the whole team can suffer. Now, a new, high-tech approach to protect fragile bones can get injured players back into the game.

No matter what the sport, players who play hard-to-win, often lose to injuries. Keith Doolan, an athletic trainer for men's basketball at Virginia Polytechnic Institute and State University in Blacksburg, says, "The most common injuries we'll see are a lot of sprains or strains of ligaments or muscles."

But injuries don't have to send players packing. Experts in orthotics and prosthetics are developing new injury braces using state-of-the-art materials that help some injured players stay safely in the game.

Traditional heavy, bulky casts aren't fit for playing, but breakthroughs in materials science help make braces lighter-weight, stronger and made-to-fit in a flash.

Phillip Johnson, an orthotist and prosthetist at New River Valley Orthotics & Prosthetics in Blacksburg, says, "With the lighter material and the ability to make them very quickly, we can use them quickly and get the player back into play."

The braces are made from a combination of plastic and carbon that is heated to become soft and then molded into perfect-fitting shapes that allow players to play while offering full protection to injuries.

"When something's naturally lighter, it's more comfortable. It's easier to wear," Johnson says.

A running back on the Virginia Tech football team used a brace made from new materials to play with a fractured bone in his arm and it worked perfectly.

BACKGROUND: When Virginia Tech's star running back fractured his ulna (an arm bone) three weeks before a big game, students in the engineering department worked with their professor to develop a better bracing system to provide better support for the athlete. They used a polypropylene/carbon fiber composite to mold a prototype, and found that the prototype was stiffer and stronger than the current braces that are commercially available.

WHAT ARE COMPOSITES? A composite material combines two or more separate materials to build a single construct that combines the best properties of both, such as the silicon-germanium-arsenide composites used to build ultra-fast semiconductor chips. More common materials, such as concrete, paper, cardboard, plywood, fiberglass and bricks are all composites. The first manmade composite was probably the adobe brick. Mud or clay can be shaped and dried into a hard block, but it has little load-bearing strength. Mixing in dried grass or straw makes the bricks tougher. Reinforced concrete, in which steel rods are encased in a matrix of concrete to improve strength and load-bearing properties, is used in bridges and buildings. Tiny carbon nanotubes are beginning to serve the same purpose in building structures.

ABOUT FRACTURES: A fractured bone is the same thing as a broken bone. They occur because a bone area is unable to support the energy placed on it. That energy can be acute, as from a car crash or a two-story fall, or chronic and low-energy repetitive activity. The latter is responsible for stress fractures, an overuse injury commonly seen in athletes. The increased demand places on the bone causes it to remodel and become stronger in areas of higher stress, but if the repetitive demands become too great, a stress fracture can result.

HOW BONES HEAL: The 206 bones in the body renew themselves continually through a process known as remodeling, which is also how fractures heal. Complex chemical signals prompt cells called osteoclasts to break down and remove (by absorbing it) old bone. Other cells called osteoblasts deposit new bone. When a bone breaks, inflammatory cells rush to destroy invaders and isolate injured tissue, causing pain, swelling and heat at the breakage site for a few days. Tiny new blood vessels (capillaries) begin growing into the site, and new cells grow, too. New connective tissue bonds fractured bone ends and the remodeling process begins.

DON'T SMOKE! Research has shown that smoking cigarettes can significantly slow down healing time for bone fractures -- it can take more than two months longer. Bones are nourished by blood carrying nutrients, minerals and oxygen. Smoking elevates the levels of nicotine in the blood, causing the vessels to constrict by as much as 25 percent, decreasing blood flow and therefore the levels of nutrients supplied to the bones.

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Source: ScienceDaily