Why is it now a days more people are getting injured from just sitting around? It’s not like sitting is very strenuous...or... is it?
You don’t need a forceful physical trauma to hurt your back. In fact, most people suffer from low back pain because of repetitive or cumulative microtrauma instead of one large event.
It has become a very common way of life to sit the majority of the day. We sit while driving, sit at work, sit while we eat and sit when we come home to read or relax in front of the TV. That’s a lot of sitting in one day! Unfortunately we know that one of the worst things for your muscles is a static sustained posture (like sitting).
The term for this repetitive or cumulative trauma is called the ‘CREEP’ phenomenon. It is a complicated process of events that makes your back more susceptible to injury with prolonged sitting or slouching.
‘CREEP’ actually stands for Continuous and Repetitive Elongation of the Elastic Properties of Tissue.
Wow, that’s a mouthful! Allow me to explain further.
When we sit and especially when we slouch down in our seat or lean forward into our computer screens, our spine goes into a forward flexed position. This forward flexion stretches the passive structures in our spine that hold everything together. These passive structures are ligaments, tendons and joint capsules that support our joints. In all these passive structures are little nerve endings called mechanoreceptors, which are designed to tell our brain where our body is in space.
Test your mechanoreceptors: standing, close your eyes and lean forward. As you begin to fall forward a stretching force is felt in the back of your ankles. This stretching stimulates the mechanoreceptors in your ankles and sends a message to your brain. Your brain hopefully then responds by signalling your leg to take a step forward. If you didn’t have any mechanoreceptors then the leg would respond too late and you would fall right to the ground. Hopefully that didn’t happen and you can thank your mechanoreceptors for saving your face.
In another example, just imagine trying to do the splits. The ligaments and tendons in our hips feel this extreme stretch and the mechanoreceptors send a signal to our brain to contract our muscles so that we don’t go any further. Without proper mechanoreceptors our joints would go way too far resulting in a tear in the tissue and damage to our joints. Another term for this feedback loop is call ‘Proprioception’ – and it basically means knowing where your body and joints are in space. Without proprioception our tissue would get injured.
Now back to our example of someone sitting at work all day. When we sit in a forward flexed position for an extended period of time the passive supporting structures (remember these are the ligament, tendons and joint capsules that help with proprioception) send a signal to our brain to turn on our back stabilizing muscles. After a while these muscles either fatigue or go into spasm, both of which leave the spine unstable.
Over time the reflex that signals the muscles to turn on becomes less intense so there is actually less contraction of the supporting muscles. Without the muscular support the passive structures in our spine are overstretched and micro strains occur in the tissue. These micro tears are cumulative and result in increase laxity in the spine which leads to injury. So it isn’t the sheer force of the load that is put on the spine that injures your back, it is actually the long duration of a relatively low load that causes low back pain.
Studies have demonstrated that there is also an inflammatory reaction that takes place after being in a prolonged flexed position. The micro strain is signalling the body that it needs to heal itself and therefore over the next several hours inflammatory cells will come into the area to try and repair the tissue. This increase in inflammation will lead to increased pain and stiffness. Have you ever noticed that you are sore the next day after traveling or sitting all day? It is because there is actually inflammation in the spine and it builds as you sleep so you wake up feeling stiff and sore.
The other aspect of CREEP refers to cyclical loading, in other words - repetitive bending. An example is someone who works on an assembly line, repetitively bending down to lift a small carton over and over again. It isn’t that the item they are lifting is very heavy, it’s the fact that the bending action is being repeated and the forces on the spine all add up. The spine experiences the same process as with sustained sitting - the passive structures over time will get overstretched and lose its proprioceptive function which eventually leads to the failure of the stabilizing muscles and results in a back injury.
So what can you do if you sit all day or have a job that is very repetitive?
Here are some steps to avoid low back injury associated with CREEP
1. One of the best things to avoid injury is to really strengthen your spine stabilizing muscles (your core.) This will improve your muscle endurance so that they can support your spine over longer periods of time. There is a lot of misinformation about core training, so seek the advice of someone who is ‘core certified,’ like a trainer, doctor or other physical therapist.
2. Take frequent breaks. Get up and stretch every 30 minutes.
3. Drink plenty of water. It will keep your tissue hydrated and also force you to get up and walk to the bathroom more frequently.
4. After a prolonged forward flexion position. Stand upright and place your hand on your low back. Now gently bend backwards to reverse the pressure on the spine – repeat this 5-10 times.
5. If you have a repetitive job, minimize the amount of reaching and forward flexion you have to do. Get an ergonomic assessment done of your workspace and see if modifications can be made to avoid repetitive loading. Other solutions include rotating jobs throughout the day so that you engage different muscles.
6. Be careful not to overstress the spine with heavy loading after prolonged sitting or repetitive bending. Your spine will be a lot more susceptible after a long day of sitting so be careful heading home and then shovelling snow, raking leaves or even going straight to the gym to lift weights. Your stabilizing muscles will be fatigued and leave your spine susceptible to injury.
7. Add lastly, regularly visit a your Chiropractor, Massage therapist or Physiotherapist to get some manual work done on your low back before the symptoms even appear and remember, prevention is key!
Take care of those backs!
Dr. Lara
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