Sitting in a chair for long periods of time can be damaging to your body. Exercise physiologist Alex Sheldon explains how occupational health can help to minimise the associated risks using a few simple exercises.
Do humans need to physically prepare for work? If they do, which job roles would require specific physical preparation and conditioning? An infantry soldier running an assault course, carrying 30kg on their back? A builder who spends a significant proportion of their day carrying bricks up and down scaffolding? What about the task that the majority of us do for most of our day, what the majority of us are doing right now while reading this: sitting?
It has been acknowledged that human evolution has been outpaced by human revolution. We now go for a run on the hard concrete streets rather than running, as nature intended, on grass. We spend our days sat in front of the office computer rather than hunting for food. There is no doubt that the modern world has significantly affected injury prevalence.
Four-sign exercise for pelvis | |
Technique 1. Sit on a chair and cross one leg over the other. 2. Place both hands on the inside of your knee. 3. Pull your knee up into your hands. 4. Pull up with 20% of maximum effort, just enough to engage the muscles in your hip. This is a static contraction, so make sure that the leg does not move. Instruction 1. Hold for 20 seconds. 2. Do four sets on each leg. 3. Do this in the morning and afternoon. Before and after periods of activity or inactivity. | |
So, let’s talk specifics. A recent survey suggested that back pain will affect 80% of the UK population at some stage in their lives. Back pain is also a leading cause of absenteeism in the UK workplace (Health and Safety Executive, 2011). Originally, the medical advice for those suffering with pain in any part of their back was “rest”. Now, the advice is to move more frequently (Black, 2008).
Exercise classes such as Yoga and Pilates now form, and are sometimes advertised as, a holistic, comprehensive back-care/rehabilitation programme. Unfortunately, it is not as simple as that.
In a recent interview, Professor Stuart McGill, a leading expert on spinal biomechanics and injury prevention, discussed research where he found that individuals who were “discogenic flexion intolerant” (a common condition among working-age people who spend a lot of their time sat at a desk) reported an increase in symptoms when flattening their back against the floor (a common action in Pilates).
Human structures, including nerves and tendons, are viscoelastic in nature (Kolt et al, 2007), where the greater the velocity of stretch applied to the structure, the less stretch is available, applying greater stress on the structure.
Static leg press exercise for pelvis | |
Technique 1. Sit on a chair, lift your knee towards your chest and put both hands behind the lower thigh. 2. Press your knee down into your hands. 3. Press down with 20% of maximum effort, just enough to engage the muscles in your hip. This is a static contraction, so make sure that the leg does not move. Instruction 1. Hold for 20 seconds. 2. Do four sets on each leg. 3. Do this in the morning and afternoon. Before and after periods of activity or inactivity. | |
Joints require movement to remain healthy as movement is essential to maintain normal viscosity of the synovial fluid, which lubricates joints. Movement is also necessary to maintain healthy joint cartilage and normal muscle tone. Contrary to belief, muscle spasms are low-grade muscular contractions or tightness and are generally not accompanied by sudden pain (muscular “cramp”). Muscular spasms may occur as a result of injury and could lead to muscular fibrosis (Draper et al, 2007).
This could have profound implications for us during our daily working lives. For example, sit for too long using your mouse at your workstation and your median nerve running from your neck to your hand might become “tight”. The muscles that surround the nerve may then go into spasm to help protect the nerve, which over time may result in fibrotic muscles resulting in pain.
A similar situation could also occur in the buttock region, where the piriformis muscle could go into spasm, tethering the sciatic nerve (running close to, and sometimes through, the piriformis muscle), resulting in poor hamstring flexibility and referred sciatic pain.
The “tight” piriformis muscle may restrict movement of the joints of the pelvis, fixing them in abnormally rotated positions, resulting in a leg length discrepancy. This may cause the foot (on the “short leg”) to externally rotate, resulting in a collapsed arch in that foot (McCaw et al, 1991). Abnormal foot motion can increase the risk of developing lower back pain (Dinsdale, 2009).
Slump (ankle) exercise for sciatic nerve | |
Technique 1. Sit on a chair/table that is high enough to allow the feet to hang freely without touching the floor. Slouch down, putting the chin to the chest and lean forward slightly. 2. Slowly straighten your knee and then pull the ankle up to the point where a gentle stretch is felt. This is usually in the back of the leg, but could be anywhere the nerve is tightest, which could include the calf, knee, buttock or even the other side of the body. 3. Point the foot until the tension has reduced and then pull up again to re-engage the tension. Repeat. Instruction 1. Perform at least once per day. 2. If possible, try two to three times per day. 3. Start with two sets of 15 reps and build up to four sets of 30 reps. | |
So, the pain in our backs may not be due to extrinsic factors such as body amour, backpacks or the office chair. Indeed, the genesis of the pain, as we have seen from the above, might not have even been in our back. The pain in our back might be due to what is happening inside our body, our intrinsic biomechanics, where dysfunction in one area (ie piriformis muscle) changes the mechanics of another area (pelvis) requiring abnormal compensation in a further area (foot) changing your dynamics and resulting, finally, in pain in a completely different region (back).
Before you blame your office chair for causing your pain, blame yourself for sitting in it for too long. Sometimes, however, we have no choice but to stay glued to our chairs, so to the right are some exercises that you can do while sat at your PC that will allow you to release muscular spasms, mobilise nerves and move more freely.
In an occupational health setting, biomechanical coaching can help to reduce the instances of recurrent non-contact injuries (those “unexplained” overused injuries that might affect the shoulders, back, hips, knees, ankles or feet) by helping to find the root cause of the injury rather than treating the site of the pain itself, thereby reducing those “frequent flyers” who monopolise both occupational health and NHS resources.
Alex Sheldon is an exercise physiologist working as the health and wellbeing coordinator for the OH unit of South Yorkshire Police. He is also a member of the United Kingdom Biomechanics Coaching Association.
References
Back exercise and performance training podcast. BacFitPro.com – accessed 2 February 2012.
Black C (2008). “Working for a healthier tomorrow”. London, TSO.
Dinsdale N (2009). “How abnormal foot motion can be a major contributor to lower back and pelvic problems”. sportEX dynamics, 19 (1), pp.11-14.
Draper DO, Knight K (2007). Therapeutic Modalities: The Art and Science; and Clinical Activities Manual. USA, Lippincott Williams & Wilkins.
Health and Safety Executive (2011). “Musculoskeletal disorders in Great Britain”. Accessed online 26 March 2011.
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Kolt GS, Snyder-Mackler L (2007). Physical Therapies in Sport and Exercise. Edinburgh, Churchill Livingstone Elsevier.
McCaw ST, Bates BT (1991). “Biomechanical implications of mild leg length inequality”. British Journal of Sports Medicine; 25 (1), pp.10-13.
