A short muscle doesn’t equal a strong muscle

Posted on March 3, 2014

6


A mindset I’ve been trying like hell to get people out of is the, “Long =weak; short = strong” muscle view. Where people go, “Ok, this is tight, it must be too strong; I need to stretch it and not strengthen it. Ok, this is weak, it must be too long; I need to strengthen and shorten it.” In a lot of instances, this is true. Not every instance though.

For this post, I’ll ignore the fact this mindset doesn’t include how everything works together (how everything moves), which is what actually matters. Strengthening a bunch of individual muscles and stretching a bunch of other individual muscles gets you as far as Leo at the Oscar’s. You get to be in the conversation, but then you’re D.O.A.

A prominent example illustrating the flaw in something like “This is tight; it’s too strong,” is the gluteus maximus. Atrophied (weak) glutes are readily apparent while standing.

Swayback posture side

Picture from Kendall’s “Muscles: Testing and Function, with Posture and Pain.”

What’s also readily apparent, is many with atrophied glutes are standing in hip extension.

Swayback posture side hip extension line

The glutes are hip extensors. If the hip is in extension, the gluteus maximus is shortened, not lengthened. Yet, they’re atrophied. The muscle is shortened and weak at the same time? Yes.

Muscles contract using filaments, which latch onto one another.

GIF made from this cool video: http://www.youtube.com/watch?v=0kFmbrRJq4w

Shorten, shorten, shorten, lengthen. (GIF made from this cool video: http://www.youtube.com/watch?v=0kFmbrRJq4w )

If these filaments are significantly shortened, they can’t as effectively contract. There’s nothing left for them to latch onto. They’re at this point in the above clip:

No more room to contract.

If they’re chronically, excessively shortened, the muscle can’t do much, if any, work. It can’t produce much, if any, tension (length-tension relationship), leading to atrophy.

Length tension relationship muscle muscular

We’re focusing on the left side of the graph right now.

It’s like when someone gets casted up. The muscles in the cast have a hard time producing any tension. Hence the atrophy once the cast is removed.

Furthermore, if a particular muscle can’t do the work it’s supposed to, other muscles pick up the slack. This is why it’s so common for someone whose glutes are atrophied to have lower back issues. Their lower back is trying to pick up the slack. You see the same thing with hamstring issues. If the glutes aren’t extending the hip like they’re supposed to, other muscles which can have this influence will try to help. Like the lower back and hamstrings.

Some might be thinking, “But aren’t the hamstrings, who extend the hips too, also excessively shortened in this case?” Not usually. Because when the hip is in excessive extension, the knee often is too.

Swayback posture side with knee extension circle

And the hamstrings extend and flex the knee. While they have been shortened into hip extension, they’ve been lengthened into knee extension. The rubber band has been tautened from one end but slackened from the other. The filaments aren’t on top of one another like they are at the glutes. In fact, with atrophied glutes often come hypertrophied hamstrings (and spinal erectors).

In someone like above, it’s common to see the atrophied glutes, see the lack of gluteal contraction during an assessment, and prescribe a bunch of glute exercises. Exercises usually involving a great deal of hip extension. 1) You better make sure the glutes are indeed helping the hip extension. Just because the hip goes into extension doesn’t mean the glutes are working. 2) How much hip extension does this person need? They already have plenty of it. You better make sure you’re not going into excessive extension, along with doing other things to work them back into some hip flexion. Their hips need to be flexed a bit before their glutes can effectively produce tension!

This is why it’s typical those with an anterior pelvic tilt have good gluteal definition.

Neal Left Side (Less Quality)

Neal Side Pelvis Close Up

The extra hip flexion can help the glutes produce more tension. Notice the caption in this graph from ExRx.net:

Length tension muscle ExRx

When the muscle is “slightly stretched” is when it can produce the greatest force. An anterior pelvic tilt can slightly stretch the glutes, leading to greater tension ability, leading to hypertrophy. While significantly shortened glutes often become atrophied; slightly lengthened glutes often become hypertrophied. Shortened, or tightened, muscles aren’t always strong, and lengthened muscles aren’t always weak. Sometimes, the opposite is true.

Enter your email address to follow this blog and receive notifications of new posts by email.