Have you ever sat on a chair, sofa, car seat, movie theater seat, etc, for a couple of hours, and when it comes time to stand up, your back suddenly shoots a sharp pain? You might cry out in pain, or the sensation might travel down your leg causing your legs to buckle under your weight, or your back might feel locked up.
If your answer is yes, then you're definitely note alone!
Now, your next question is, why does it do that? Why isn't my back supporting me the way that it should be? What causes my back to become so weak?
But, is it weak? Or is your back just extremely tight?
You see, when most people think of weak muscles, they think of a set of muscles that they have not used in a long time, causing the muscles to atrophy slightly. In the case of your back muscles, however, more likely than not, they are overworked, causing them to become weak.
Before we dive too deep into how sitting can possibly tighten and weaken your back muscles, let us take a quick look at the anatomy of the core.
A Quick Look at the Core
Take a look at the front and back muscles of your "core" in the image below:
Your first impression may be: These constitute ALL of my core muscles? I thought my core was just my six-pack muscles!
Yes, in fact, your core consists of many team members that extend beyond your "abs," and they all work together to (1) protect your organs, (2) initiate movement, (3) stabilize movement, and (4) transfer force from one extremity to the other. Each has its strengths (e.g., your external and internal obliques allow you to turn your torso and bend sideways; your gluteal muscles play an essential role in stabilizing the curvature in your lumbar spine and sacrum, as well as provide power with each of your stride), and your job is to use each member's potentials wisely. For simplicity, let us group the anterior (front) core muscles as one team member called The Core, and the posterior (back) core muscles as second team member called The Back.
How Muscles Work
Now that you have a general idea of what the core is and what it does, let us explore how muscles work together to support our body and initiate movement. Open and close one hand repeatedly a few times. A healthy muscle fiber should be able to do exactly that: contract (hand closes in a fist), stretch (hand opens wide), and relax (hand relaxes). Now, hold your hand in a fist and gradually clench tighter and tighter until you cannot clench any further. After awhile, your hand and forearm may even start to feel fatigued, sore, numb, and tense.
Do those words feel familiar to you and your back?
Imagine that the tightness of your clenched fist resembles that of The Back. When you stand, sit, and perform daily activities or exercises that do not use each team member of The Core and The Back wisely, the consequence is an imbalance in your muscle groups. Think of how you stand and sit on a daily basis: shoulders slumped forward, The Core disengaged, and The Back rounded. The Core and The Back should work together as a team. Therefore, when one slacks off, the other team member has to pick up the slack. In most of our cases, The Core tends to slack off, and The Back is doing back-breaking work to pick up the slack, overtime clenching more, more, and more.
To put things in perspective, this particular sitting posture puts a significant amount of load on your spine and your spinal muscles than when you standing properly with your spine in a neutral position. Forty percent to 85% more, to be exact. Think of what that means to your poor spine when it takes that much more than it should during most of your waking hours every single day. No wonder The Back becomes so angry at you!
So, let's say you have been sitting with The Back rounded and The Core disengaged for a couple of hours. You decide you'd like to get a glass of water, so you stand up, hauling yourself with The Back because The Core has forgotten how to cooperate. That initial haul causes The Back to clench even more, and while you may be able to get away with it for some months and years, at some point, The Back won't take it anymore and starts screaming (read: shooting pain) at you.
It is tired, beaten, abused. The Back screams at you so loud and "locks up" because it knows that if you start moving about again, you will abuse it.
Other scenarios where this may happen are: when you bend down to tie your shoes and try to get back up, when you sit up from bed in the morning, when you stand up after a period on the sofa, when you straighten up after you've been bending for awhile.
How to Relieve The Back Before Standing Up
Luckily, you can practice preventative measures against The Back throwing a tantrum at you. You may already know this: It is to awaken and train The Core to play as a team member again. The video below is a short practice that can help ease tension in The Back and awaken The Core so that when you are ready to stand up, they are both working together to support the movement and the transfer of weight.