Sydney Therapies

More Than Everything You Wanted To Know About Muscles – Mar 7th 2009

©Pete Malicki

Before you say you don’t care about muscles, you do. I know you do. You may not be interested in working out 8 times a day and looking like the Governator, but you do care about how your muscles feel. Right?

If you’re a big computer-user, they’re probably sore, or at the very least prone to soreness. This is because they are overused.

But how can they be overused when you’re simply sitting there, moving nothing but your fingers? Surely your muscles are resting while you’re stationary?

Incorrect.

Let me break it down by explaining how muscles work. Muscles do only two things: contract, and dilate (or relax). Contracting muscles requires energy, whereas relaxing them is a passive process and uses no energy at all. Every movement you make is a combination of certain muscles relaxing and others contracting, even pushing movements. If you pushed a car up a hill, you would be getting your strength from a bunch of different muscles contracting.

When you stand up, your postural muscles contract – to varying degrees – to keep you from falling over. If they didn’t contract you would collapse to the ground like the proverbial sack. Likewise when you’re sitting, kneeling, crouching, etc. Unless you’re lying down, there are probably dozens of muscles working at any one time.

What this tells us is that when we sit in front of a computer, numerous muscles are working just to hold your posture. Do this for 8 hours and they’ll know about it. Humour me for a moment. Take a small weight, such as a water bottle, and hold it in your hand. Keep your upper arm flat against your ribcage and flex your elbow joint so you’re holding the water bottle up near your shoulder. Now hold it there for 8 hours. Seriously, hold that water bottle up against your shoulder all day, and see how your arm feels.

Because that’s what your neck muscles are doing. Between them, they have to support a 5 kg head all day. That’s a lot of work. Still wondering why you have a headache, or neck pains? Remember: the worse your posture is, the harder many muscles will have to work.

Now that I’ve pointed out how much work your muscles do when you’re sitting idle, I’d like to explain why you actively need to do something about this, as in, why it won’t make itself better. The human body is an amazing machine and can withstand years of poor dietary habits, alcoholism, smoking, drug use, whatever, but what it doesn’t like is prolonged poor posture.

In order to maintain your body’s range of motion, your muscles need to be put through their maximum range of motion. What I mean by that is, if you are super flexible and can do the splits, you have to practise them often or else you’ll lose the flexibility and won’t be able to do them. While the body has an extraordinary capacity to heal itself, it has no capacity to increase its flexibility without stretching.

When you sit in the same posture all day, such as at a computer, there are numerous muscles which are staying in a contracted state (ie, not stretched out). As you sit here reading this, look down at your lap. See how your thighs are at right angles to your abdomen (well, depending on your level of slouch)? In this position, the hip flexors and rectus abdominis are partially contracted. If you don’t stretch them out, they will lose their flexibility and straightening your body will become difficult.

Case in point. Ever seen an elderly person who walks stooped over, with their chest all the way forwards? This person cannot stand straight because they simply lack the range of motion to do so. Chances are, they’ve spent the last few decades sitting in a chair playing solitaire (I’m thinking of my grandpa here, who fits the example perfectly) and rarely straighten. This could happen to you.

If you don’t push the limits of your flexibility, you will lose it. The body may be fantastic at healing itself, but have you ever seen someone do the splits without either stretching or severely injuring themselves (I’ve seen the latter – shudder)?

So when you sit at the computer there are a series of muscles which are constantly contracted and hence are likely to lose their flexibility: the sternocleidomastoid, splenius group, levator scapulae and trapezius (if you lift your shoulders), pectoralis minor, anterior deltoids, rectus abdominis, hip flexors, piriformis, hamstrings… the list goes on! Given enough time, these muscles being shortened will change your posture, and over a longer span of time the effects can be irreversible. Three decades of poor neck posture and the vertebrae slip, then fuse in anatomically incorrect positions. Horrified?

The point of all of this is stretch, or get some kind of bodywork done. If you have headaches, muscle pains, or difficulty straightening bits, do it soon! I reiterate: the body can heal itself brilliantly, but it won’t magically increase the flexibility of all those muscles I mentioned. You’re going to have to do it actively.

But I made a promise. This article was supposed to be more than everything you know about muscles. I’ll throw in a few little factoids for you, because they’re fun. Feel free to stop here if you’ve had enough.

1) The biceps, those nice big muscles in the upper arms, aren’t all that strong. You know those guys who work out at the gym and wander around sporting massive upper arms? Chances are, it’s not the biceps giving them the bulk.

See, the biceps’ major function is actually to rotate the wrist so the palm is facing up (supination). While there are several different muscles responsible for flexing the elbow, the biceps are not the strongest. The brachialis, a deeper muscle, is the prime flexor of the elbow. That’s the one which does most of the work and when it bulks up, it pushes the more superficial biceps up and makes them look bigger. True story.

2) You can’t flex a muscle. This is an anatomists pet hate. When someone says, ‘I’m going to flex my biceps,’ (spoken in the Governator’s voice) they are contracting their biceps. You flex joints, you contract muscles. Get it right!

3) Muscle bulk alone does not determine strength. The body has things called motor neurons, which are nerves controlling which innervate (control) certain number of muscle fibres. When you contract your biceps, it is not all or nothing. Only some of the motor neurons will kick in. The harder the contraction, the more motor neurons will active.

When people get stronger, their motor neurons activate in sync better. Women can gain up to 50% more strength without a change in muscle bulk, simply because their nervous system is more coordinated. Interesting, huh?

4) When muscles contract, they contract in one direction only. They pull on tendons, which in turn pull on bones and create movement. Slightly less interesting, huh?

5) Almost every muscle in the body has more than one function, as in, it moves its corresponding joint in more than one way.

6) Different muscle fibres have different amounts of ‘fast twitch’ or ‘slow twitch’ fibres, the former being more explosive and the latter being more endurable. A pro sprinter will have a higher percentage of fast twitch muscles, whereas a marathon runner will have more slow twitch. Different muscle groups have different proportions of each kind of fibre. In the calves, the bigger, more superficial gastrocnemius has more fast twitch and is likely to be big in a sprinter, tennis player, etc, whereas the deeper, narrower soleus has a lot of slow twitch fibres, and will be bigger in those who do endurance exercises. You’ll see a marathon runner has skinny legs, but the calves are still solid.

Alright, I think I’ve done my job. That’s more than you could possibly have wanted to know!