Poor Posture and Pressure on your Spine
Freddie Mercury was right: we’re under pressure. Nothing can be truer when it comes to your spine. It’s because of simple physics: the pressure or load on your back increases as you move away from a neutral posture. Here are the numbers: Standing straight puts 100mm of pressure on the intervertebral discs of your spine; add a forward bend while flexing or rounding your back and you’ve more than double the pressure, or 220mm. Can you see now why reaching your toes in Uttanasana or any standing forward bend before you’re ready isn’t worth the potential harm to your back?
What poor posture means to the ongoing health of your back?
Over time, poor posture causes the discs between the vertebrae to wear down and lose their ability to cushion and act as shock absorbers. The discs are pushed out towards the back from their normal position which causes bulging or herniated discs. These bulging and worn out discs can cause a more serious problem by increasing the pressure on the spinal nerves and the spinal cord itself. The result is pain in the legs, including sciatica, arms, shoulders, and neck, and problems with muscle innervations, movement patterns and the sensation of temperature, pressure and pain.
These same problems can be worsened when sitting, believe it or not. Sitting, in contrast to standing, actually increases the intradiscal load compared to standing; spinal pressure “sits’ around 140mm pressure. If you slouch (I’m talking to you desk slouchers!), spinal pressure increases to 190mm; add some weight and you’ve put a whopping 275 pounds of pressure on your spine. This is why in certain methods of yoga like Iyengar students learn standing poses before sitting ones as a general rule as they’re considered more advanced.
Sitting for long periods of time can definitely cause back pain or worsen an existing back problem. Sitting is a static posture that increases stress on the entire back, shoulders, arms, and legs, and especially the muscles of the spine. Slouching overstretches spinal ligaments and surrounding structures of the spine and nerves, blood supply is interrupted and the back muscles are overstretched.
If you’re not a yogi yet but find yourself slouching or sitting for long periods of time during the day, your yoga can be as simple as doing the following:
Getting up periodically to stand up and take the pressure off your spine
Sit back into your chair so your back is supported. In yoga postures, ground evenly into your support and allow your spine to straighten up
Use a lumbar roll between your lumbar or lower back and your chair. To judge the proper size of the roll, sit back in your chair, place your forearm behind your lower back between it and your chair and lean back. Your forearm is approximately the size of a lumbar roll. This works when driving too.
Move! Joints don’t have much blood flow. Joints get nutrition in and waste out by physical movement. Move freely in your chair instead of sitting still for hours at a time.
For you yogis, body awareness is key to minimizing the pressure on your back. I’m not saying never practice a forward bend or a seated pose but rather know how to practice them safely. Even a seemingly friendly pose like Savasana can do harm. Sure, while lying down you’re at the lowest end of the spinal load spectrum at 25mm. As a teacher, I ask my students to roll to the side before sitting up not simply to avoid feeling dizzy and lightheaded but also to reduce the pressures on the spine. For the record, resting on your side applies 75mm pressure on your back, which is quite a bit less than pulling yourself straight up from lying flat on your back.
So, the take home message is: do the work in other poses which don’t load the spine first to lengthen your leg muscles and hamstrings, and strengthen your back before you throw yourself into a forward bend. Realize which types of poses are right for you. Gentle flexion of the spine isn’t for everybody and that’s ok. Once your body is ready, you’ll be reaping the benefits of practicing Uttanasana instead of causing harm to our back.
Yoga Anatomy: Reducing Shoulder Impingement
Our wonderful shoulders are the most mobile joints in the body and, for anyone who has done any amount of Hatha Yoga flow, we can appreciate how much the shoulders are engaged and challenged in our practices. Given how frequently we load and stress the shoulders in yoga, it is ideal to move the shoulders with intelligence, mindfulness, and attentive care. One aspect of mindful movement and engagement is reducing the onset of shoulder impingement.
Our shoulder joints are made from a ‘ball and socket’ design. The upper arm bone (humerus) has defined structures at its proximal end (closest point to the center of the body). At the proximal end of the shaft, we see that the humerus has boney processes (called tubercles where tendons attach). Moving towards the shoulder joint, the humerus has a neck that transitions into a ‘head’ or the ball portion of the joint. The humeral head inserts into the socket (glenoid fossa or cavity) forming this highly moveable joint. The socket is part of the shoulder blade (scapula bone). There is another part of the shoulder blade with a boney projection called the acromion process which is positioned above the humerus. You call feel the acromion process on yourself by taking one hand over and to the back of the shoulder blade. Run your fingers along the shoulder blade to find a horizontal line of bone – this the spine of the scapula. Run your fingers all the way to the end into your shoulder – where this ends is your acromion process.
Between the acromion process and the tubercle region of the humerus is the ‘subacromial space.’ This is where our attention goes regarding shoulder impingement considerations. Deep above the spine of the scapula runs one of your rotator cuff muscles (supraspinatus muscle), which has its tendon traveling through the subacromial space and attaching onto the greater tubercle of the humerus. To offer some protection to this tendon, there is a small sac of fluid (bursa sac) between the tendon and the acromion process.
When we stand in Mountain pose (arms relaxed), there is ample space in the subacromial space for the supraspinatus tendon and the bursa sac. When we lift our upper arm bone outwards (abduction) or towards certain angles of significant forward movement (flexion), the humerus closes into the subacromial space. For some people, due to bone structure and reduced subacromial space, they are more prone to having the tendon and/or bursa sac being compressed and stressed (aka shoulder impingement). With frequent compression, the tendon and/or bursa sac may develop conditions of inflammation. As with any acute or chronic development of shoulder impingement conditions, you will want to consult a qualified health professional for proper assessment and therapeutic treatment.