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Biomechanics(4 posts)

BiomechanicsBC
May 28, 2002 4:16 PM
Why do pro cyclists, such as Cipollini and Ullrich, have such large Vastus medailis muscles and yet experts say this muscle is only contracted in the last 20 degrees of knee extension. Bicycling only extends this much when standing out of the saddle, so why is thier muscle so large?

Thanks,

Bradley
My take on this...PODIUMBOUNDdotCA
May 28, 2002 4:56 PM
I just took a crash-course in anatomy this weekend to be a fitness instructor so my guess is the experts are wrong. At least to a degree... the normal population or normal cyclists only use the vastus medialis for 20 degrees of their pedal stroke. But for whatever reason Cipollini and Ulrich have either genetically or through training strengthened this muscle and use it to create all their power. If you look at Ulrich when he won the Tour and how powerful he was it proves the point. Then Cipollini is the best sprinter in Tour history so far. Also if you look at the very highest end sprint speed skaters they have huge vastus medialis muscles to.

Time to shut up and go work my vastus medialis.

Cheers,
Nick Corcoran
PodiumBound.ca
years at Uni studying this but...hayaku
May 29, 2002 3:31 AM
I can't give you a concise answer.

any agonistic muscle (Muscle making a joint move) will be used in the extention (In the case of the quadricep muscles, straitening the knee) of that joint. However, muscles that are highly stretched at the time of flexion cannot produce as much power as muscles that are short.

Try bicep curls with a heavey weight, starting with a strait arm, then try starting with your elbow half bent at the start of the exercise. The muscle fibers have more of each other to assist in the action when the muscle is shorter. another example is to squat until your Gluteus maximus hits the deck then come up slowly. It's a lot more difficult to extend at the bottom that it is at the top.

In the case of the Vastus medialis it can produce power throughout the movement but more power at the end of the extention. I was doing weights at Uni and was always amazed at how much different muscles of the leg would burn at different angles of extention.

Well anyway, I hope you can understand my rambling.
M.
re: BiomechanicsLeisure
May 30, 2002 4:03 AM
I think any time you're talking about the limits of human ability (pro athletes), you're going to see muscles developed all over the place, even when the relative role those muscles play in the exercise is minor. I can remember a lot of muscles I never specifically worked that supposedly (according to my anatomy/biomechanics courses) were not supposed to get very large, but got huge anyway when I started to really peak-out in weightlifting. A lot of muscles running up the middle of my back, my serratus anteriors, my trapezoids... Also, I believe there is a certain extent to which muscle development in some parts of the body tends to go along with increased muscles growth through the entire body. Whether it's local muscle development stimulating system-wide develoment or just increased metabolite absorption, etc, would make an interesting debate in and of itself. During college, I NEVER worked my calves, but when I was weightlifting they developed incredible size and definition. A lot of lifters I knew would plateau with assorted muscle groups, and never were able to make more progress until they started to seriously work other large muscle groups. Peaking out with arm muscles until working out more leg muscles was a common example.