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How Extended Periods of Sitting Can Lead to Long Term Lower Back Pain

How Extended Periods of Sitting Can Lead to Long Term Lower Back Pain
By Sherwin A Nicholson

Lower back pain occurs in the majority of the population occasionally, with only a minor effect on our everyday routine. We may experience minor aches and pains towards the end of our busy day and will merely require rest with perhaps an over the counter anti-inflammatory pill. Most of us fall into this category and rarely have any serious issues beyond this.

However, there is an ever growing demand or desire to work longer hours, commute longer distances or spend more time sitting at the game, office, or on the 'screen'. As much as we believe that we are becoming more productive with our lives and for others, there is a physical cost to this need.

Whether during work, at the computer for extended hours, or while watching a favourite sports event, your lower back is gradually bearing an increasingly significant toll from this lack of movement and support.

This is a serious concern to be more aware of. While one appreciates that sitting allows for much needed rest and recovery, it is actually contributing to an increased risk of lower back pain. For a more in depth understanding, it helps to learn what happens with your back first while standing, and then while sitting.

When standing, the extrinsic and intrinsic muscles of your back along with your abdominal muscles contract and relax continuously to maintain your posture, neutral curve and normal pelvic tilt. These muscles comprise all of the muscles of your back from the base of your cranium to your pelvis. It is the deeper, smaller and less visible intrinsic muscles that run along your entire spine which make several corrections and adjustments every second while you stand in order to maintain balance and posture.

Upon sitting, there is a large shift in the requirement of these muscles to provide support. When seated on a chair which has a back rest, the intrinsic muscles and abdominals are no longer active. They cease in their role to adjust for your lower back as it rests. This may seem like a preferred alternative to standing as it naturally feels more comfortable.

However, without adequate lumbar support from these muscles, your neutral curve is lost and disc imbalance occurs. Here, the weight of the upper body bears down on your lower discs more than as in standing. The distribution of weight on each disc becomes uneven and disc bulge occurs. The extrinsic and intrinsic muscles (which are smaller and shorter) become weaker and overstretched. The use of a back rest also reduces circulation to the muscles as you lay against them.

Most of us tend not sit upright correctly and over time, may slouch while seated. Here, the pelvis assumes a posterior tilt, adding further disc imbalance and risk of injury. Placing our hands and arms on the dining table, keyboard or steering wheel whichever it may be, allows us to relax our upper body further. Doing this exacerbates the curve in our spine as we bear down more of our upper body weight. Our normal, balanced, and S-shaped, lumbar curve that we have while standing becomes C-shaped.

Other muscles such as the abdominals and transverse abdominus relax, resulting in additional reduced support. Hamstring and quadricep muscles become progressively shorter (and weaker) from chronic lack of use. This causes these muscles to pull on the pelvis during activity thereby reducing pelvic mobility. With less pelvic mobility, the lower back compensates by bending and moving more than intended, adding stress and discomfort when we are engaged in daily activity. Extended periods of sitting lead to shortened and weaker hip flexors, especially the psoas muscles. A tight psoas is a well known contributor to lower back pain as they are directly attached to each lumbar vertebrae. The discomfort from these tight muscles are more noticeable while standing or actively moving. Muscles tend to shorten when either under used or over used. Rarely do they return to their original or optimal length unless stretched.

Without proper treatment, this discomfort may cause some people to rely on the use of medication, inadequate stretches, incorrect methods of exercise or merely accept such pain as minor but tolerable. If there is no change to ones sitting habits, the muscles and discs will continue to bear this load and suffer. This can lead to long term lower back pain.

Virtually all of the muscles groups required to support and protect the lumbar spine while both standing or in motion are affected by the simple act of sitting. Sitting may provide some needed relief, but it is important to be conscious about the effect it has on the lumbar spine. By changing our sitting habits and finding methods in which we can be better physically conditioned, we can reduce or minimize any discomfort or risk of lower back injury while seated. Lower back pain from extended periods of sitting can be reduced or eliminated by following specific exercises and stretches. To avoid chronic pain felt from sitting, a back program can be used to address this.

Sherwin Nicholson, Honours B.Sc. in Human Biology, 20 years Medical Research, Toronto General Hospital - Max Bell Research Centre. SN Health Resources.
Our site provides a wealth of exercise related information for lower back pain. This includes an effective long term exercise guide specifically targeted to relieving acute and chronic back pain issues.

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