Roadcycling.com?s Chad Asplund, MD explains why a man who finished the Giro d?Italia with a broken shoulder blade and the 2003 Tour de France with a broken collarbone would abandon the Tour with only a bruise on his lower back. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /?>

Tyler Hamilton abandoned the 2004 Tour de France at the feed station 79K into stage 13 secondary to a back injury.   According to a Phonak team spokesman, ?<?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" /?>
Tyler crashed badly in
Angers and we didn't talk much about it, but he had a large and painful bruise on his lower back and was just in too much pain to continue.
Tyler couldn't get out of the saddle when he was climbing...it's really too bad."

Before the start of stage 13,
Hamilton explained to Roadcycling.com how much he was being affected by the crash. "All the muscles around [my back] are swollen," he said. "It's basically blocking my lower back, which when you're climbing, you need to use your lower back a lot. Yesterday it put a limit on my power. The team did a fantastic job for me, it's just that I wasn't ready.?

Why would a man who finished the Giro with a broken shoulder blade (scapula) and last year?s Tour with a broken collarbone (clavicle) abandon the Tour with only a bruise on his lower back?   The contusion to his lower back musculature greatly diminished the function of his ?core muscles? and greatly stripped him of his climbing power and ability to ride efficiently and effectively.

These core muscles lie deep within the torso. They generally attach to the spine, pelvis and muscles that support the scapula. When these muscles contract, they stabilize the spine, pelvis and shoulders and create a solid base of support. They are then able to generate powerful movements of the extremities.   The core is the foundation for all other movement. The muscles of the torso stabilize the spine and provide a solid foundation for movement in the extremities. If you have poor core function, you lack a solid base of support from which to generate power. This results in an inefficient pedaling form with power loss and improper muscle recruitment.

Your core musculature allows you to transfer power from your arms through your middle to your legs, holding your torso stiff so you can provide maximum power from your quads as you push against the pedals. "You can tell immediately when the core fatigues," Vern Gambetta of Gambetta Sports Training Systems in
Sarasota, Florida told Roadcycling.com. "The force from your pedal stroke sends you bobbing back and forth instead of propelling you forward."

?When your core is strong you can climb in bigger gears. A strong core increases your power transfer from your arms to your legs, especially when you're pushing out of the saddle? , says Chris Carmichael, Lance Armstrong's personal coach. Again, the stronger your core, the longer you can ride without fatigue. Andy Pruitt, director of the
Boulder
Center for Sports Medicine in
Colorado, added that "The [core]