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Old 01-09-13, 22:12
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DirtyWorks DirtyWorks is offline
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Default Seat Height Biomechanics

I was in a temporary situation where I was riding my bike with the seat about 1cm lower for most of a very hilly hour ride.

The major difference being my gluteal muscles (aka **** muscles) really felt sore compared to riding at my original height. I didn't set any personal record, but I wasn't going for one either.

I don't understand why it should be more sore. Does anyone clearly understand why the gluteals would be more sore and can you please post an explanation?

Is it better that they were more sore? I may lower my seat if there's no damning replies. My knees/back/the rest is totally fine and have been for years.
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Last edited by DirtyWorks; 01-09-13 at 22:15.
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Old 01-10-13, 00:06
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veganrob veganrob is offline
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Sure. I'll try.
Two main groups of muscles of the upper leg, quadriceps in front and hamstrings posterior. What is interesting of them both is that span two joints. Originating on pelvis and inserting below knee. This give them each two actions. Quads do flexion at hip and extension at knee. Hamstrings extend at hip and flex at knee. The quads being the largest muscle group in the body are the primary movers in cycling due to extension at the knee. The hamstrings don't provide much synergy here, they are rather weak in this motion. The hamstrings do come into play on the back part of cycling to help bring the pedal around. Consequently the hip flexors provide little help here also. The opposite leg is also now coming over the top to provide the real driving force. With me so far.
The gluteus maximus on the other hand are a weak accessory muscle. They don't do much of anything at all. Walking, jogging, pedaling, They are simply not used. Where they are used is in more forceful exercises. Running faster, uphill, jumping etc. Now what happens when yous saddle is lower than it should be? Your hip angle closes too much at the top of the stroke and your quads are now at their weakest and most vulnerable position. So, in order to achieve the the desired power your glutes are called into action to what it really does not want to do. They are overworked and you get the muscle soreness. Some of that could also be your upper hamstrings.
Another example of how this all works. Squating. If
you go half way down you have the most power and can lift the most weight. Go down to knees at90deg and it gets more difficult. Lower and even more so.
Would I keep my saddle at the lower position and get used to it? No. It most likely was not too high in the first place.
Another position to avoid is saddle too far behind BB. Too much strain on hamstrings.
Hope that helped
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Old 01-11-13, 00:56
Carbonrules Carbonrules is offline
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Good info veganrob.
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Old 01-11-13, 14:33
Flux Capacity Flux Capacity is offline
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I just want to say that the hamstrings are much more involved in hip extension than most people realize. A lot of people only think of the hamstring as being involved in knee flexion, but they work in conjunction with the glutes to flex the hip. In other words, the hamstring are very much involved in the cyclist's down-stroke.

Cycling obviously involves lots of hip flexion, which can be problematic for the psoas which, in turn, can cause problems for the lower back and hamstrings, making the hamstrings work even more during hip extension:

"There is an antagonistic relationship between the psoas muscle and your gluteal muscles. Essentially when the psoas become short and contracted it turns off your glute muscles. Your glutes and your hamstrings are your primary hip extensors. Therefore, when your glutes get turned off, more of the load is placed on your hamstrings which then become susceptible to injury."
http://kinetichealth.ca/resolving-hamstring-injuries/

Last edited by Flux Capacity; 06-17-13 at 17:36.
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Old 01-14-13, 22:41
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DirtyWorks DirtyWorks is offline
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Quote:
Originally Posted by Flux Capacity View Post
I just wanna say that the hammies are much more involved in hip extension than most people realize. A lot of people only think of the hamstring as being involved in knee flexion, but they work in conjunction with the glutes to flex the hip. In other words, the hammies are very much involved in the cyclist's down-stroke.
Thanks for that link. It confirmed what I vaguely recalled.

I think I'm going to lower my saddle a bit and see what happens. I'm picturing a lever that has more force behind the rather complex fulcrum point of the hip as the mechanical explanation. But, that could be totally wrong based on my very, very limited understanding of the biomechanics. Feel free to correct me.

The follow-up question is, how much muscle pain in the "glueteus group" is referred pain from the hamstring group?
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Last edited by DirtyWorks; 01-14-13 at 22:51.
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