Muscular injury can occur when soft tissues are exposed to single or recurrent episodes of biomechanical overloading (11), which is characteristic of chronic musculoskeletal pain and thoracic outlet syndrome at work.
Direct US workers’ compensation costs total $51.1 billion, averaging more than one billion dollars per week (12). Soreness and pain accounted for 12 percent of the total cases (12).
Musculoskeletal disorders, often referred to as ergonomic injuries, accounted for 33 percent of all workplace injuries and illnesses requiring time away from work in 2011 (12).
For all occupations, back injury accounted for 42 percent of the musculoskeletal disorder cases and required a median of seven days to recuperate (12).
The most severe myofascial pain syndrome cases occur in the shoulder, requiring an average of 21 days for the worker to return to work, and accounted for 13 percent of the musculoskeletal disorder cases (12).
Studies on muscle activity during computer use are in line with these findings, since they indicate a higher loading of the hand–arm region (extensors of the wrist) than of the neck–shoulder region (trapezius muscle) (13-15).
Holding your arm in one position outside of perpendicular can alter the position of the shoulder blade, especially when holding your arm above your head for long periods of time. This causes the brain to pattern this muscle contraction to a constant state, squeezing your shoulder down to your chest and ultimately leading to compression of this area and thoracic outlet narrowing.
Neck and Upper Extremity Problems—Workplace Stressors—Causes
One category of risk factors for neck, upper back, shoulder, and arm pain, is workplace stress. Workplace stressors include high work demands, high mental processing, high memory demands, performing multiple tasks simultaneously, time pressure, low decision authority, and working too hard for too little pay (16–18).
First , muscle activity might be affected indirectly through a changed workstyle due to these stressors, for example, increased work pace, high forces on the keyboard and mouse, and more awkward and sustained postures (19).
The causes of workplace stressors are highly varied, but one of the common likely mechanisms is that stressors increase sustained muscle activity, which in turn might lead to injury by overexertion and brain patterning. Remember, any activity repeated consistently creates fixed patterns in the brain, whether this involves athletic movements, dance or gymnastics moves, or stressful input or activity in various aspects of daily life, including work and sleep.
If you continue to maintain a muscle in a contracted state, the brain says, “I sense that you are holding the muscle in your shoulder and arm and neck for a long period of time, so obviously you want me to continue to hold that muscle in the constant contracted state.” That’s the way your body and nervous system are designed, so that is what happens.
Neck and Upper Extremity Problems—Workplace Stressors—Work Style
Muscle activity might be affected indirectly through a changed work style due to these stressors (increased work pace, high forces on the keyboard and mouse, and more awkward and sustained postures), which can lead to fatigue and thus eventually cause musculoskeletal complaints (18–19).
Doctors think that continuously increased muscular activity can lead to fatigue and thus eventually cause musculoskeletal complaints. Mental stress combined with too much activity of the muscles of the hands, wrist, shoulders, and neck can lead to a higher risk for musculoskeletal complaints (20).
When you leave your arms resting at an angled position on a desk for long periods, fairly soon you start to feel a burning pain and tension in your shoulders. We all have experienced this when we work with our keyboards, handheld devices, or mouse.
Repetition Strain Injury—Keyboards
Work-related upper extremity disorders that result from keyboarding tasks are common (20). There are many ways your human spring mechanism can be locked up during simple typing at the compute
- You have to hold the arm in a certain position to get your fingers on the keyboard, which strains your pectoralis minor muscle, the coracobrachialis muscle, and the long and short head of the bicep muscle.
- You have the activity of the fingers when you type, putting stress on the muscles involved, which are located in the forearm.
- You have the stress of holding your head in one position, which creates torsion strains as you try to hold your shoulders, arms, and hands to work the keyboard at the same time.
- You have the constant mental stress that affects your shoulders, abdominal muscles, and neck muscles—which is where a lot of us store our mental stress.
- The result can be a complete lockdown of the entire upper half of your body.
Studies have indicated that it is the amount of time that you hold the mouse in one position that is most strongly associated with the incidence of hand/arm symptoms rather than the amount of time you are using a computer keyboard (21).
Another factor is the mental strain of manipulating the mouse in the exact position required, combined with the constant concentration on what you are doing on the screen. You are straining the scalenes of the neck and straining the six muscles, which drag the shoulder into the outlet at the same time. What could be worse?
But if “too long” is a problem, exactly how long is too long?
One research study found an association between use of a mouse device for more than 20 hours per week and risk of possible carpal tunnel syndrome, rather than actual duration of keyboard use (22). I’m not recommending that you should work 20 hours or less a week and then go home. I’m just informing you of what the study reveals.
Companies that require workers to do more than 20 hours a week of the same repetitive work would probably find they could increase productivity and decrease health problems by introducing more variety in their workers’ schedules.
Computer Use Duration
Another study showed an increased risk for developing severe hand–wrist pain in the highest exposure category, which was greater than 30 hours per week of the same repetitive activity (23). One particular study revealed that time spent working with the mouse and the keyboard was an excellent predictor of elbow and wrist/hand pain (23).
So, you are more at risk for arm and hand conditions than for neck and shoulder conditions when you work long hours (22) (23) (24).
Monitor Position and Visual Stressors
Your position in front of a monitor, including height, determines whether you can get your head, neck, and spine in a perfect perpendicular position to lessen the strain on your body’s integrated spring.
I used to have a laptop about 10 years ago, but I could not get my head at the level of the center of the monitor without strain. At the time there was no “Cloud” so I had to bring my iMac back and forth to work. I even carried it with me when I lectured at medical conferences in China, Australia, Dubai, South Africa, Monte Carlo, and other parts of the world.
Think I’m crazy? I don’t mind carrying the iMac to the car for five minutes to ensure I have 5–12 hours of no stress and strain on my human spring throughout the day.
Could you imagine seeing me get on a plane with an iMac in an overhead bag with the stand sticking out of the bag? Well, that’s what I did—and I only had a problem with one flight attendant, on a flight to Malaysia, during a period of many years.
That was because they could not figure out how to get the videos to feed into my PowerPoint slides, as I lectured on walking and running patterns that cause chronic conditions.
People in my building see me going in and out of the elevator with this bag with my iMac hanging out the top. They frequently ask me why I’m doing this. I explain that looking down at a laptop causes strain on my integrated spring mechanism that can lead to compressive syndromes, such as thoracic outlet syndrome. I tell them that I’m writing a book on the topic.
That’s when they ask me for my business card, because so many have neck pain, upper back pain, shoulder pain, and numbness. They wonder if it’s thoracic outlet syndrome. Too often, I still see them taking their laptops with them to work. Well, sooner or later, they will likely experience the discomfort of thoracic outlet syndrome. That’s the point when they will take out my card and contact me for an appointment.
How You Can Abide by the Laws of Gravity
- Never touch your back to the back of the chair.
- Give your recliner to someone you don’t like.
- Relax to let your reflexes determine perfect stress-free, strain free, equilibrium posture.
- Your body parts should either be perpendicular or horizontal to gravity, and joints should be at 90-degree angles.
- Keep your feet on the floor or on a footrest, if they don’t reach the floor.
- Rest your arms on the armrest to lift your shoulders off your chest.
- Make sure the chair has an even platform.
- Do not cross your legs at the knees or the ankles.
- Get up and walk around every 25 minutes.
- Never twist your back against the chair.
- Distribute your body weight evenly on both hips.
- Don’t use a laptop.
- Plug the laptop into a full-size monitor that allows you to view the screen at eye level.
- When you are done with the mouse and keyboard, take your hands off and rest your arms and hands on the arm rest of the chair.
This is an excerpt from a chapter in Dr Stoxen’s #1 best seller The Human Spring Approach to Thoracic Outlet Syndrome. The book is available on Amazon.com in these 13 counties US UK DE FR ES IT NL JP BR CA MX AU IN on Kindle. The book is available on Amazon.com in these 7 counties US UK DE FR ES IT JP in paperback.
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12. U.S. Department of Labor. Bureau of Labor Statistics. “Nonfatal Occupational Injuries and Illnesses Requiring Days Away from Work, 2011.” November 2012.
Full text link http://www.bls.gov/news.release/pdf/osh2.pdf.
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Full text link http://occmed.oxfordjournals.org/content/55/3/168.long
16. B. H. W. Eijckelhof, M. A. Huysmans, J. L. Bruno Garza, B. M. Blatter, J. H. van Dieën, J. T. Dennerlein, A. J. van der Beek The effects of workplace stressors on muscle activity in the neck-shoulder and forearm muscles during computer work: a systematic review and meta-analysis Eur J Appl Physiol. 2013; 113: 2897–2912.
Full text link http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3828497/
17. Karasek R1, Brisson C, Kawakami N, Houtman I, Bongers P, Amick B. The Job Content Questionnaire (JCQ): an instrument for internationally comparative assessments of psychosocial job characteristics. J Occup Health Psychol. 1998 Oct;3(4):322-55.
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20. Bloemsaat JG1, Meulenbroek RG, Van Galen GP. Differential effects of mental load on proximal and distal arm muscle activity. Exp Brain Res. 2005 Dec;167(4):622-34. Epub 2005 Aug 3. http://www.ncbi.nlm.nih.gov/pubmed/16078028
21. IJmker S1, Huysmans MA, Blatter BM, van der Beek AJ, van Mechelen W, Bongers PM. Should office workers spend fewer hours at their computer? A systematic review of the literature. Occup Environ Med. 2007 Apr;64(4):211-22. Epub 2006 Nov 9.
http://www.ncbi.nlm.nih.gov/pubmed/17095550/Full text link http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2078461/
22. Andersen JH1, Thomsen JF, Overgaard E, Lassen CF, Brandt LP, Vilstrup I, Kryger AI, Mikkelsen S. Computer use and carpal tunnel syndrome: a 1-year follow-up study. JAMA. 2003 Jun 11;289(22):2963-9. http://www.ncbi.nlm.nih.gov/pubmed/12799404
23. Lassen CF1, Mikkelsen S, Kryger AI, Brandt LP, Overgaard E, Thomsen JF, Vilstrup I, Andersen JH. Elbow and wrist/ hand symptoms among 6,943 computer operators: a 1-year follow-up study (the NUDATA study). Am J Ind Med. 2004 Nov;46(5):521-33.
24. Kryger AI1, Andersen JH, Lassen CF, Brandt LP, Vilstrup I, Overgaard E, Thomsen JF, Mikkelsen S. Does computer use pose an occupational hazard for forearm pain; from the NUDATA study. Occup Environ Med. 2003 Nov;60(11):e14.
Full text link http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1740406/
Dr Stoxen is a #1 International Best Selling Author. He is the president of Team Doctors®, Treatment and Training Center Chicago, one of the most recognized treatment centers in the world. He is a much sought-after speaker giving over 1000 live presentations and has lectured at over 70 medical conferences to over 50,000 doctors in more than 20 countries. He’s been asked to be the keynote speaker to specifically lecture on his human spring approach to thoracic outlet syndrome and other medical conditions. After his groundbreaking lecture on the Integrated Spring-Mass Model at the World Congress of Sports and Exercise Medicine he was presented with an Honorary Fellowship Award by a member of the royal family, the Sultan of Pahang, for his distinguished research and contributions to the advancement of Sports and Exercise Medicine on an International level. (Full Bio) Dr Stoxen can be reached directly at email@example.com