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Jaybird180

Body to Bike Ergonomics

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One of the things that I learned during my recent school is that proper motorcycle posture is different from proper seated or walking posture. On a motorcycle the back is hunched over.

What is the mechanism that holds the body up in this position? Well, muscles obviously but which muscles? I've heard people talk of strengthening "core" muscles but when I ride I feel it in my legs and unfortunately back, lower back particularly (EDIT: when I hang off, but only sometimes, usually toward the end of the session).

A little research cleared up a misunderstanding for me, in that muscles contract, moving one movable bone toward a stationary bone, giving us the desired conscious motion. Since muscles contract, I can fathom how I'm using my back muscles to keep me from flopping over the tank when in the riding position, but I cannot fathom how contracting abdominal muscles can assist in postural support.

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Lack of lower back strength when riding is what inspired me to start working out. At first, I just wanted to correct that deficiency. It's amazing how fast you will feel the benefit from working your lower back. Within 2 weeks, I noticed an improvement in my posture (regular posture, not bike posture) and the ability to stand for longer periods of time without fatigue.

If you belong to a gym, try the back hyperextension. If it's too easy, you can hold weight to make it harder. If you don't belong to a gym, just hold some dumbbells and do the Romanian Deadlift. There's tons of info on youtube showing the correct form which will help keep you from getting hurt.

About the abs thing... Yeah, I remember being shown that at CSS and it was an aha moment. I'm like you in that I can't really explain why. But if you know how to activate your abs and do that as you lean forward, you'll feel it there - in your abs - and know they are right.

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Think of the muscles in your back and your abs, as ratchet straps that support your torso. If you don't tighten them evenly, one will be overtightened. In most cases the lower back contracts to far leading to pain and loss of strenght. 

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4 hours ago, Jaybird180 said:

A little research cleared up a misunderstanding for me, in that muscles contract, moving one movable bone toward a stationary bone, giving us the desired conscious motion. Since muscles contract, I can fathom how I'm using my back muscles to keep me from flopping over the tank when in the riding position, but I cannot fathom how contracting abdominal muscles can assist in postural support.

Muscles can contract and generate movement or they can contract without generating movement. Ever do isometrics? The abdominal or core contraction you guys allude to would be an isometric. The muscles strengthen, and there is no movement.

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How can tight abdominals support the upper body from falling forward?

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If your abdominal muscles are weak and you leave them slack and loose when trying to support your upper body, the looseness of the ab muscles will cause your back to hollow (swayback), which forces your lower back to take all the load of holding you up, and the looseness of the ab muscles combined with the tightness of the back muscles will tend to tilt the pelvis (either the cause or the effect of the swayback). Tightening the abs creates a column of support (your entire core, front, sides and back) that allows you to use a broader range of muscles to do the job of supporting your upper body, prevents the pelvis from tilting backwards (hollowing the back) and preventing your lower back from having to do all the work.

Does that makes sense?

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After reading this I got out my big exercise ball (the one big enough to sit on) and started doing hyperextentions and planks.  Both really help and I agree with BSM, it just makes you feel better.  

 

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11 hours ago, Hotfoot said:

... the looseness of the ab muscles will cause your back to hollow (swayback),

Can you explain the above?

11 hours ago, Hotfoot said:

... the looseness of the ab muscles combined with the tightness of the back muscles will tend to tilt the pelvis...

I can see how that could cause pain

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16 hours ago, JohnCBoukis said:

Muscles can contract and generate movement or they can contract without generating movement. Ever do isometrics? The abdominal or core contraction you guys allude to would be an isometric. The muscles strengthen, and there is no movement.

You are correct about this, which I didn't mention. Now can you please tell the class what would be the functional or design purpose for isometric contraction?

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1 hour ago, Jaybird180 said:

You are correct about this, which I didn't mention. Now can you please tell the class what would be the functional or design purpose for isometric contraction?

For stability, which is what Hotfoot, JohnCBurkis and I have tried to explain in various forms. Imagine you are to push a heavy wheeled container along a pavement, not lift, just push. Do you think your abs contract?? (They do!!). Why is that, for stability, because upper body movement will ruin the connection between the work your legs are doing and the load/resistance of the container.

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If you're pushing and you don't tighten your abs, then there will be no opposing structure to allow you to overpower the inertial resistance of the container you're pushing. As the abdominal muscles contract, they can pull the upper torso forward because they connect the hips to the ribcage.

Are you saying that you need to tighten your abs when pushing on the bars? That makes sense but I'm not sure if that would be the same as holding up your posture.

@Hotfoot when you said "swayback", were you referring to overemphasizing the lordosis of the back?

 

Cervical-Lordosis-Diagram.jpg

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2 hours ago, Jaybird180 said:

Can you explain the above?

Image result for photo of old swayback horse

Well, the term swayback comes from horses and usually evokes an image like the one above. In people it's where your belly pooches forward and your butt sticks out, lower back curved too much for good posture. Core strengthening improves this.

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I think the simplest solution would be for you to go ride and try it and see what actual results you get. It shouldn't take a lot of muscle effort to just sit on the bike, but when braking hard or trying to hang off it will take more. During the braking and hanging off times, try doing it with abs slack, and then try tightening your whole core and see what gives you better support and less stress and muscle fatigue on your back.

If you want to get really serious about getting strong, flexible, and comfortable on the bike, get into yoga. I coached a guy recently on body position - he was 2-3x older than everyone else in the group with him and way more flexible and strong on the bike. I mentioned it and he said he started doing yoga and was astonished at the difference it made. I've heard this enough times to take it quite seriously, it definitely seems to work.

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Yeah, it seems like the subject of yoga keeps popping up.

I'll give your experiment a try next time I ride. I guess it's not enough for me to know that something works, I'd like to also know why it works.

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22 hours ago, Jaybird180 said:

How can tight abdominals support the upper body from falling forward?

They do not. The ab contraction is changing the model. It turns out this is a statics problem. Making the torso rigid is transferring the energy elsewhere, from back support applying vertical weight on the seat, to rotational inertia.

21 hours ago, Hotfoot said:

...preventing your lower back from having to do all the work.

7 hours ago, RonniB said:

 because upper body movement will ruin the connection between the work your legs are doing and the load/resistance of the container.

These two are chocolate and peanut butter.

Note that using the back to support the torso transfers the torso weight to the seat. That is what is going to change with the ab contraction.

On the bike, if the abdomen is held rigid and the legs are held rigid (they are pretty rigid as they do not bend like the back), then the body will want to rotate forward, pivoting on the seat. The feet resting on the pegs prevent this rotation. So the weight the back previously put on the seat is now resting comfortably via the feet on the pegs.

Experiment: Sit in a chair or on the bike, flex the abs, and lean far forward. Relax the abs then flex the abs. If you are sensitive enough you may feel the increase and decrease in force on the bottom of your feet, and with each change the opposite feel of force on the seat.

9 hours ago, Jaybird180 said:

You are correct about this, which I didn't mention. Now can you please tell the class what would be the functional or design purpose for isometric contraction?

Here is what I can think of: Functionally isometrics allows us to hold objects. If I hold a plate or a pen in my hand and do not move, that is an isometric. Holding our torso up vertically is similar.

Design wise, one can become infinitely strong without any equipment by doing isometrics. Of course the strength is over a limited motion area, due to being applied at a point or over a very limited range. Also when injury causes immobility one can begin recovery via isometrics. If motion is painful, one can still build the muscle up. 

If one was trapped under an object that is extremely heavy, they may not be able to lift it in one motion. They can slowly lift it, hold it there, then lift it more. This combination of isometrics and motion allows us to do work that taxes us to our limits.

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I had to pickup my wife's bike from the shop tonight. It used to be mine. The ergonomics are very different from my current steed. This one sits very much more upright and the wind is right there at any speed above residential. So I've never  before had to practice abdominal contraction on a bike. But I tried it.

I found that it caused my quads to tighten and I couldn't help but squeeze in my upper thigh. It's got aftermarket rearsets and I as sit here now I'm thinking that if the footpegs were more below me then I would have been applying pressure to them as JCB is discussing above.

So either I don't get it, I have weak abdominals (albeit crunches are relatively easy for me), I'm not applying the idea correctly or something else is happening.

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Then you have to train contracting your abs while relaxing the rest of your body. The key is not absolute strenght, but control. You're not to ride around with permanently tight abs, but to be able to tighten them to resist external forces or to stabilize your own input. This will be done with abs and back in conjunction, you tighten your core, to create a solid base for movement or maintaining your position on the bike.

If you have issues with how to do that, then go to a proper weightlifting gym, not just a gym, and have a coach help you learn the basics of olympic weightlifting. The whole concept of core control is paramount in that area of sports

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