In the current culture a wave is slowly building that is telling us that sitting is bad, but it might not be clear why. There are many reasons why sitting is detrimental to our health and may be the “new smoking”, but I would like to share the perspective of someone who studies the musculoskeletal system. In order to better understand this complex issue, it helps to start from the beginning.
One of the things that makes humans special is our ability to stand on two legs. It is uncommon in nature and creates in us a unique musculoskeletal system. We have been this way for thousands of years, and are now very stuck in our ways. One of the most unique traits that we possess is that our hips are aligned vertically, not bent at 90 degrees. In order to make it clear, imagine a dog, with the hind legs bent and the spine horizontal to the ground to create a 90 degree bend. Our hips are in line with our spine, which is considered our “neutral” position. Before modern society we spent less time sitting and more time standing or lying prone. We do not have to go very far back in our history to identify the time this change happened.
According to a study from the Mayo Clinic in 1970 only 2 in 10 working Americans were in a light activity occupation (desk job), compared with 6 in 10 in 2003 and I would guess this number is even higher now. The reason I bring this up is to give you some perspective of how rapidly the rate of change has increased within the past 40 years, imagine the drastic differences that have occured in the last 2,000! We expect that our bodies should be used to this and we expect no adverse effects from sitting for long periods time. Unfortunately, this is not true and I hope to give you a better understanding of some of the reasons why sitting is so detrimental.
So we all can start on the same page: I want to ensure we are talking about the same joint. The hips are the connection point of the long bone of the thigh with the pelvis, the bones you feel if you put your hands at your side. As we went through before: the neutral position for the hips is in a standing position, and sitting is referred to as a flexed position. If we sit all day, we are stretching and shortening certain muscles because our hips are not in a neutral position. There are muscles on the front of the hips that connect with the pelvis and lower back that are called hip flexors, and they become very tight when sitting. Then when we stand these muscles try to stretch, and unfortunately can put a lot of pressure on our pelvis and lower back. This could be one reason why greater than 90% of Americans experience back pain. So how do we help this?
Changing the position of our bodies from sitting to standing (and ideally adding intermittent periods of movement to our day) can have immense benefits to our overall health. In addition to a regimen of stretching the hip muscles and working on strengthening, I would suggest someone not sit for longer than 45 minutes without standing. It does not have to be a long bout of standing to significantly improve your overall posture. Hip flexors are not the only things that are affected by sitting.
When we sit it also had a negative impact on our lower back, shoulders and even into our neck. This can all be related to the hips, but can have much further reaching impacts on the whole skeletal system like an evil tidal wave, coursing through our bodies. One of the biggest issues can be that whatever you are sitting on may be too deep. By deep I mean you may have difficulty touching your feet to the ground, or getting your butt all the way back in the chair. In this case I recommend putting a support in back of you such as a pillow. If it is your work chair and cannot be adjusted, I would suggest looking into a new work chair.
Overall, I want to stress that sitting may not be as natural as we think, and our bodies are not adapted to endure the stress that we are currently putting them in. Some other positives to standing are increase in calories burned per hour, increase in focus and positive stresses on the lower leg from the foot to the hip. So if you need to sit, don’t do it for very long and supplement standing when you can.
(Owen N, Sparling PB, Healy GN, Dunstan DW, Matthews CE. Sedentary Behavior: Emerging Evidence for a New Health Risk. Mayo Clinic Proceedings. 2010;85(12):1138-1141. doi:10.4065/mcp.2010.0444.)
reachphysicaltherapy.com 