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Shorter cranks for quad tendonosis?
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Got pulled off the bike by my doc for a flair of quad tendonosis that hit at the end of the season. I've done the stretch and roller thing for this before with good results but it killed my offseason last year and is doing same this year. I've never been a masher on the bike and usually spin around 90 rpm. No power numbers, that will be next investment.

I'm thinking that shorter cranks might help..... Should have me pushing with a less acute knee angle at the top. I'm on 172.5mm now and thinking 165mm. I know the crank length thing has been done on here before but wondered if anybody had used for quad tendonopathy specifically? I have a brand new Shiv that is currently an expensive wall hanging so thoughts appreciated :)
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Re: Shorter cranks for quad tendonosis? [mktri] [ In reply to ]
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I don't have a concrete answer about this but you need to share a little more information. What is your height, weight and inseam. If you are looking to open up the knee angle, go on down to 145mm cranks, there will not be any power loss but there would definitely be a big gain in knee angle. During the off season is a good time to start this and then in the Spring time as you start to increase your power and time, change the front chainring out to a 54 or 55 to keep the same "feel" of a higher work load.
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Re: Shorter cranks for quad tendonosis? [mktri] [ In reply to ]
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If you raised your saddle 7.5mm then wouldn't you have nearly the same knee angle as the 165mm crank at the top of the pedal stroke where you are starting to put out your highest power?
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Re: Shorter cranks for quad tendonosis? [mktri] [ In reply to ]
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FWIW: My quad tendinitis flareups are always caused by cleat alignment issues.
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Re: Shorter cranks for quad tendonosis? [rijndael] [ In reply to ]
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rijndael wrote:
FWIW: My quad tendinitis flareups are always caused by cleat alignment issues.

This. Check your cleat position, knee position and hips.
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Re: Shorter cranks for quad tendonosis? [John Cobb] [ In reply to ]
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John, thanks for the reply...... I'm 5'11", 170lb with 32 in inseam.
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Re: Shorter cranks for quad tendonosis? [mktri] [ In reply to ]
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Go shorter for sure. It can't hurt and might help.
How short should you go? Who knows. I never see the point in making small changes with this, I would start considering at 165mm and go down from there. It will take some time to get used to, but being that you are a spinner it shouldn't be bad. You may have to lighten up your gearing in one place or another. Good luck!

Jonathan Blyer,
ACME Bicycle Co., Brooklyn, NY
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Re: Shorter cranks for quad tendonosis? [jonblyer] [ In reply to ]
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I've had patella tendonitis and recently move from 172.5 to 150mm cranks. My knee has improved.. But. I'm a masher and have noticed a drop in power. When I try to hit my old power numbers my breathing and heart rate go too high.
What would be nice is if I could afford the new look cranks so I could adjust to see what MY sweetspot is.
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Re: Shorter cranks for quad tendonosis? [bluntandy] [ In reply to ]
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It's worth trying. The major change will be hip angle and the knee angle when you reach the most powerful portion of your stroke. It will also change the knee angle during the point at TDC, which could also aggravate an injury issue. But I agree with others, that I'd look at cleat position, Q factor and cleat angle. Even foot support, shoe size/fit.

I don't think there's much disadvantage to shorter cranks for a TT/tri. Some for road & MTB.

It is possible that your overall efficiency could drop slightly as the stroke length per revolution is reduced, though it is proportionally the same. I haven't seen any studies to show this to be true.

I compare the difference to running on flat ground vs. an incline. The total length of each leg extension at the same pace would increase so you might actually become more efficient in net power output as determined by the sum of your pace AND elevation gain... or a normalized graded pace.

As mentioned above, if you go too far out of the "sweet spot" then the force per pedal stroke will utilize too many muscle fibers and you'll effectively be operating at a higher intensity level for the same power output.

The trick is to maintain the same foot speed.


TrainingBible Coaching
http://www.trainingbible.com
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