Okay… We get it… Sitting is bad for us! How can we combat it?
We’ve established that 1. Sitting down for too long is really bad for us. 2. The environment in which we spend most of our day sitting down in is also bad for us. Check out this post if you haven’t seen it yet.
Now, taking the age old superstition that bad news comes in threes; allow me to round off the third point in this series by taking a look at the proposed detrimental effect that sitting has on our muscular system – our posture.
The brain and body are adaptive mechanisms
If you’ve ever heard the phrase ‘path of least resistance’, you have an understanding of how the brain likes to operate. The brain, which conducts the body (not 100% but to a very high degree… story for another time), has evolved to conserve energy. This is why when we rehearse activities regularly we get better and more energy efficient at them.
The amount of energy it took for you to acquire the fine and gross motor control necessary to tie your shoelaces as a small person, compared to that which controls the seamless autonomous actions you display as a big person, are polar opposites.
Energy conservation is a survival-based strategy. The prime directive of the brain is to promote survival of the individual, and as a human race, survival of the species. To survive, the allocation of energy must be appropriately distributed.
Whilst learning new cognitive and movement skills are incredibly good for our health, as this process strengthens existing, and builds new connections across the brain, a process known as synaptogenesis (1), the brain also wishes to automate our existence as quickly as possible.
Brakes on the brain
Just as the brain has adaptive learning mechanisms, a study carried out by a research group at Lund University in Sweden (2) has now been able to describe a ‘forgetting mechanism’ at the cellular level.
The research study looked at a classic conditioning model where human or animal subjects can learn to associate a certain tone or light signal with a puff of air to the eye. The subjects are forced to blink as a puff of air hits the eye. At the same time, an audible tone or light signal flashes, and eventually, they blink in response to the sound or light without the puff of air.
What the researchers found was that once the initial conditioning has taken place, presenting the sound and light stimulus together actually degrades the learned response, making it worse instead of even more robust.
The researchers show that when a particular association has been sufficiently learnt, when faced with a similar conditioning challenge, neurons called Purkinjie cells in the Cerebellum put the brakes on the learning mechanism. While the Cerebellum is acutely involved in the learning process, it equally holds circuitry that can ignore and forget stimulus. Professor Germund Hesslow suggests that this occurs as the brain wants to save energy. This conservation of energy principle occurs all of the time as new tasks are learned and is in full effect with habituated tasks.
The Cerebellum plays a central role in modulating movement and learning
The posture which we adopt when sat down at work for hours on end, is such a habituated activity and, therefore one we get very, very good at.
The functional assessment and stimulation of the Cerebellum is covered in detail as part of the AMN Level one Practitioner Certification.
Adaptive shortening or altered feedback?
It is widely touted that sitting all day will change your posture. It is said that the hip flexors will shorten, the shoulders round forward and the head sticks out in front of you as in anterior head carriage. But, there isn’t a whole lot of evidence to suggest that adaptive shortening of muscles occurs due to prolonged sitting.
Adaptive shortening is when the muscle fiber length, sarcomere length, and the total number of sarcomeres in muscle tissue, reduces significantly. This has been shown to occur due to complete immobilisation of muscles that were placed in flexion, in plaster casts (3). Sitting however is not immobilisation.
Within the context of AMN we describe posture as ‘the dynamic interplay of skeletal alignment.
Postural muscles are effected by central brain mechanisms such as visual and vestibular pathways, connective tissue tone, feedback from joints above and below the spine, mood and even the enteric and endocrine systems. Prolonged sitting is just one stimulus that may play a role in a multi-faceted phenomena.
The AMN view on posture
Other presentations of true muscle shortening occur in cases such as stroke, where specific patterns of spasticity kick in due to vascular damage in the brain.
What does occur from prolonged sitting, when coupled with poor movement choices, is the adaptive conservation of energy relative to the input or information the brain is receiving from the tissues. You get better at sitting. This is most likely more detrimental to us if we are not off setting that practice with other movements that challenge the body in more extended positions. This dirty little combo may carry some knock on effects to one’s ability to appropriately utilise postural anti-gravity muscles as one is supposed to.
Good movement to sit like a Boss
If the postural system is firing on all cylinders, the spine segmentally stable, the body strong in extended positions, flexible and able to perform complex movement skills – as far as posture is concerned – sitting for extended periods shouldn’t be that much of an issue.
As I have previously mentioned, it is often touted that prolonged sitting will cause an anterior pelvic tilt. If you think about it this is kind of puzzling as most people sit in a posterior pelvic tilt with lumbar and thoracic spinal flexion. How then, is sitting the culprit of an anteriorly tilted pelvis?
What may be more accurate is that the psoas may become a poor stabiliser of the lumbar spine in the position of its normal lumbar lordosis, as a response to extended periods of sitting and other poor movement choices. However, this should never be taken as rule of thumb. Every presentation will be slightly different, which is why an accurate assessment process is vital to gaining information on the function of muscle recruitment and inhibition. Our AMN Level 1 and 2 Practitioner Certifications provide the student with a systemised approach to dealing with these types of presentations.
So let’s give sitting a bit of breathing space and take a look at a few movements you can integrate into your client’s lives, which can be utilised to:
- Improve the feedback from postural muscles to the brain
- Improve extensor muscle facilitation
This increases the possibility of increasing/expressing strength. It should also improve flexibility.
Movement 1: Thoracic articulation
Welcome to your thoracic spine. This seated (yes seated) mobility drill is part one of four progressions we utilise to reintroduce people to their thoracic spine. The movement comprises of a joint mobility sequence; including articulation of the shoulders.
Why is it effective?
Think of this as an investment of time that will improve communication between the spine and the brain: ultimately improving mobility, thoracic extension, and force output. It can also reduce stress on the lumbar and cervical spine.
By improving how the brain can ‘see’ the body, we are working to clear nociceptive input (for more info check out our coordination blog) and improve the proprioceptive output of the brain to the muscles.
Perform slow articulations for 30 – 60 seconds for 3-5 sets, or frequently throughout the day if you particularly lack motor control of this area.
Movement 2: Quad lean to shoulder extension
Here’s a novel use of the Olympic rings, TRX or whichever suspension system you prefer. The movement progresses from a loaded stretch on the quads, to a pelvic, spine, and shoulder articulation with level change – finishing up with a loaded stretch to the shoulders and biceps.
If you have shoulder pain, especially pain associated with shoulder extension, this movement isn’t for you. But, if you’re good to go and want to open up the front line of the body, give this sequence a go for multiple reps: you will feel taller and more upright afterwards!
Why is it effective?
When we can contract appropriately in lengthened positions, we have control of the tissues and joints; this equates to trust between the nervous system and the muscles.
Loaded stretching increases stimulation to the Golgi Tendon Organ through dynamic ranges of motion in full stretch positions. This acts to build strength while muscles lengthen, which ultimately improves flexibility. (For information on our five step process to achieving flexibility, see here.)
The level changing of the head in space will also stimulate the otolith organs of the vestibular system, which along with the Cerebellum act to facilitate all extensor muscles.
I like to perform this drill slowly with coordinated breathing for a couple of minutes. Start with five repetitions for three to five sets and increase as your range of motion opens up.
Movement 3: Prone flat extension: A.K.A the humbler
This guy is a tough one. It’s actually a drill we use for handstand training. People will often have fairly good control of their pelvis when lying supine on the floor; however, place people on their front and proprioceptive awareness of the pelvis can fly out of the window.
Why is it effective?
This is a prone, isometric position that requires the trainee to pull in to a posterior pelvic tilt without excessively flexing the hips as well as lifting and holding locked out arms off of the floor, whilst keeping the ribs down. This is the exact position required to be upside down on your hands and a great, although difficult drill to build proprioceptive awareness and strength through the core and posterior shoulder musculature.
The gold standard for this movement is multiple sets of sixty second holds. Your starting point is wherever it is. This is a tough movement – Aim to establish your maximum isometric hold time with good form, knock a few seconds off of that time and increase progressively.
The three movements described above can be trained in a circuit fashion and may be useful as part of an integrated treatment and training program to improve posture, strength, and flexibility.
Sitting is certainly bad for us but it shouldn’t bear the entire burden when it comes to altering posture, especially where adaptive shortening is theorised as the source of the problem. Almost all of our clients sit down ALL day, and not all of them have awful posture. It’s just not that simple. Introduce and encourage movement practices that progressively improve communication between the brain and the body, build flexibility and strength.
In other words, include the concepts of complex motion in your own and your clients training.
- Neural Plasticity Foundation for Neurorehabilitation. Jeffrey A. Kleim. Tanas Publishing. www.tanaspub.com
- “Purkinje cell activity during classical conditioning with different conditional stimulus explains central tenet of Rescorla–Wagner model” by Anders Rasmussen, Riccardo Zucca, Fredrik Johansson, Dan-Anders Jirenhed, and Germund Hesslow in PNAS. Published online October 26 2015 doi:10.1073/pnas.1516986112
- Physiological and structural changes in the cat’s soleus muscle due to immobilization at different lengths by plaster casts. Tabary JC, Tabary C, Tardieu C, Tardieu G, Goldspink G. J Physiol. 1972 Jul;224(1):231-44.