Breathing & Your Chair
As a rule, most of us do not pay attention to the simple act of breathing unless you start having trouble doing it or if you find someone on the floor who is not doing it at all. At which time nothing seems more important than getting it back to normal.
Except for those critical moments, have you thought about breathing and the chairs you or your clients sit in as an issue? Probably not but an article by Laura Walter in EHS Today dated Jun 2nd 2009 quoted research by Stephen Feier that looked at general-purpose office chairs and reduced heart rate. His thesis focused on the tidal volume of air and respiratory rate that was influenced by the shape of the chair's back support. He found that heart rate was reduced with a chair back support design that was wider at the base and narrower at the shoulders. It was not clear if the design was indeed the reason that the heart rate decreased by 8 bpm for men and 4 bpm for women or from other factors.
Though this research is inconclusive as to what if any changes occur via a chair that allows more shoulder motion, the concept of unobstructed breathing is an issue that the ergonomist must not overlook. This especially true for clients that have jobs that force them to maintain flexed and/or rigid postures, e.g. jewelry makers, court reporters, engravers or microscope assembly workers. These occupations often find the worker using only their accessory muscles to breath.
The more efficient diaphragmatic breather finds that they have a slight rocking motion as they breath in and out. If you are looking through a microscope or at a fine detail task, this rocking motion interferes with visual acuity so the worker stops deep breathing and only "pants" their breath in order to stay focused. This increases tension in the neck and upper back muscles which can lead to overuse and pain. (See Ergo science below.) Very skilled workers can time their breathing much like a marksman does when shooting at long distance where a fraction of an inch of motion at the end of a rifle could be several feet off its mark when the bullet reaches the target.
Efficient relaxed breathing lowers the stress on the cardiovascular system and, therefore, could lower the heart rate of a worker. A lower heart rate is associated with better circulation and therefore a healthy and properly functioning nutrient pathway. A properly functioning nutrient pathway decreases the chances for tissue breakdown and helps avoid the dreaded MSD.
Topics from the Journals and Websites
"Comparing Stationary Standing with an Intermittent Walking Posture During Assembly Operations," an article from the International Journal of Human Factors in Manufacturing, Volume 18 Issue 6, pgs. 666-677, published online 9-16-08, reported that when comparing workers who stood at one spot for 25 minutes yet were given passive breaks, up to five times in the 25 minutes, reported more discomfort than workers that also worked 25 minutes but walked to a different location instead of taking a break.
Dynamic activity appears to be more relaxing and refreshing than simple sitting down. The conclusion was the result of psychophysical testing as well as stride length, velocity and foot contact measurements between the two groups tested.
The studying indicates that walking has a positive effect on comfort for those who are required to stand to do their jobs. A person given two options would appear to have less discomfort if allowed to move. Sound familiar?
Back School of Atlanta News
Would you like free tuition for any of our workshops?
Back School of Atlanta is now looking for co-sponsors for live courses in 2009 and 2010. The courses are targeted to groups including Occupational and Physical Therapists, Safety Professionals, Risk & Claims Managers, Human Resources Professionals, Occupational Medicine Professionals and Nurse Practitioners. For information on co-sponsorship of a course, please contact Back School of Atlanta for details. Otherwise, watch the website for courses scheduled.
The Government Corner
On May 20th 2009, U.S. Labor Department announced a process where OSHA will strengthen the integrity of their Outreach Training Program.
OSHA has increased their efforts in cracking down on fraudulent trainers in their 36 year old Outreach program by improving how trainers become authorized to teach and ensure that they are in compliance with OSHA program guidelines. This program has more than 16,000 independent trainers who teach their 10-hour course. However, some of these trainers had not complied with the training guidelines and face criminal charges.
Under the OSHA act of 1970, OSHA's role is to assure safe and healthful working conditions for America's workers by setting and enforcing standards, providing training, outreach and education programs.
OSHA has also developed a new process for investigating and processing complaints. There is a "watch list" of outreach trainers who have received disciplinary actions and their names are posted at the OSHA website:
Breathing and VDT Placement
Breathing/respiration has three basic mechanisms for exchanging air in and out of the lungs. 1) Diaphragmatic breathing that uses a large dome shaped muscle that makes the floor of the ribcage. When used, the abdomen moves forwards as you breath in and collapses in as you breath out. 2) The Intercostal Muscles that lift the ribcage up during inhalation and down during exhalation. 3) The Accessory Muscles that attach the upper ribcage to the cervical spine. They have a short excursion range because of the biomechanics of the cervical spine in relationship to the first 3 ribs of the thorax.
The term Kyphosis refers to the forward curve formed from the upper lumbar spine and the top of the thoracic spine. The normal posture standing or sitting properly accommodates this natural curve by balancing it between backward Lordosis curves of the neck and low back. Over time or with certain disease processes, the Kyphotic curve becomes exaggerated and the chest becomes compressed. This compression, much like the posture seen in a full slouch, reduces the ability to breath and exchange air.
The ergonomist must be aware of the need to promote a natural and upright posture as much as possible to help with full and healthy ventilation. Making sure that the VDT is at the proper height to avoid the slouch and compression of the spine is paramount in this aspect of ergonomics. In addition, an upright and properly supported trunk will improve breathing as well. Reaching forward, prolonged reading over a flat surface, microscope work or small font all can contribute to the slouch tendency. Furthermore, the slouched position also adds shear and compressive forces to the spine that put the back extensor muscles at a biomechanical disadvantage that will cause them to quickly fatigue. (1)
The simple ergo break and education in posture can be a valuable commodity in the ergonomist toolbox.
1) Briggs, A. Van Dieen, J. Wrigley, T. Thoracic Kyphosis Affects Spinal Loads and Trunk Muscle Force. Physical Therapy vol. 87 Number 5 pg 595-607
Seasoned Employees: MSDs and the Aging Workforce
The prevalence of MSDs increases as people enter their working years. By the age of 35, most people have had their first episode of back pain. Once in their working years (ages 25 to 65), however, the prevalence is relatively consistent. Musculoskeletal impairments are among the most prevalent and symptomatic health problems of middle and old age. Nonetheless, age groups with the highest rates of compensable back pain and strains are the 20-24 age group for men, and 30-34 age group for women. In addition to decreases in musculoskeletal function due to the development of age-related degenerative disorders, loss of tissue strength with age may increase the probability or severity of soft tissue damage from a given insult.
Other studies though have reported a lack of increased risk associated with aging. An explanation for the lack of an observed relationship between an increased risk for MSDs and aging may be "survivor bias". If workers who have health problems leave their jobs, or change jobs to one with less exposure, the remaining population includes only those workers whose health has not been adversely affected by their jobs.
ANSI/ASSE A10.40-2007 Reduction of Musculoskeletal Problems in Construction
Did you know…?
By the age of 60, most people have lost half of their taste buds. That is why many people in that age group appears to over-salt or otherwise excessively spice their food. It does not however, explain the desire to wear white shoes and black socks with Bermuda shorts and a patterned shirt.
Boost Your Ergonomics Consulting Business
The Back School of Atlanta is pleased to announce the launch of a new service - the Certified Professionals listing on our website, for all of our past graduates aimed at helping grow your ergonomics consulting business.
We will list your name and the city and state of your practice/business for one year. We will also include a link which will allow potential clients the ability to email you without seeing your actual email address and, if you choose, your contact phone number. You can also apply to become a Premium listing so that your expanded listing will always appear at the top.
After the first year, there is a quick recertification process to continue your listing on our site as a Certified Ergonomics Professional.
For more information, please click here.
Let us help support you and your business.
Director Back School of Atlanta
Ergo Websites, Ergo Products, gadgets and doodads
There are times when an employee will return to work after hand or wrist surgery and can function fairly well except for clicking the mouse or using certain function keys. On possible solution is the foot mouse that can be used by the foot rather than the hand. There are several companies making comparable devices with Kinesis making several models including single, double or triple pedal models (shown above). Though using such a device may place some strain on backs and hips, the benefit for the hand during recovery period may outweigh the temporary stress on the lower body. More information can be found at the address below.
This newsletter produced in association with ERGOCATION, LLC.
Please help us meet your needs by clicking here
and e-mailing your comments or ergonomics questions.
In this issue:
• Topics from the Journals and Websites
• Back School of Atlanta News
• The Government Corner
• Ergo Science
• Did you know...
• Boost Your Ergonomics Consulting Business
• Ergo Websites, Ergo Products, gadgets and doodads
Upcoming Back School of Atlanta Workshops:
LEVEL I: Ergonomics Assessment Certification and Musculoskeletal Disorders Prevention Workshop
|Advertise with the Back School of Atlanta:
Place a banner ad or a sponsorship on our site or in our newsletter and reach thousands of potential customers. Click here
for more details.
East Lansing, MI - Sept. 25 & 26, 2009
Los Angeles, CA - Oct. 1 & 2, 2009
LEVEL I: Ergonomics: Practical Applications Certification
Atlanta, GA - Oct. 7 - 9, 2009
LEVEL II: Solutions for an Aging Workforce Certification Workshop
Pembroke Pines, FL - Oct. 24 & 25, 2009
Tempe, AZ - Nov. 5 & 6, 2009
Robert Niklewicz, PT, DHSc, CIE, CEAS
Ronald W. Porter, PT, CEAS
Director, Back School of Atlanta