Resist-a-balls thread on ErgoWeb List ***************************** ***************************** From: Deanna Harrison To: Multiple recipients of list ergoweb-l Date: Friday, September 11, 1998 10:18 AM Subject: Resist-a-balls Does anyone have any information, experience or literature on the use of "resist-a-balls" (large, inflatable vinyl exercise balls) in the workplace, specifically, as an alternative to a chair?  We have have had a request from an employee wanting to use one at their computer workstation instead of their "ergonomic" chair. Any feedback would be much appreciated. Deanna Harrison, CPE BCTEL Human Factors deanna_harrison@bctel.com * * * * * From:     Jim Priebe[SMTP:jump@kcdata.com] Reply To:     jump@kcdata.com Sent:     Friday, September 11, 1998 7:48 PM To:   Multiple recipients of list ergoweb-l Subject:  Re:  Resist-a-balls Deanna, Resist-a-Balls are used by some physical therapists in the treatment of low back injuries.  The purpose is to help the patient gain lumbar and abdominal strength while relearning proprioception (position sense) of the trunk/pelvis complex. A big NAY on using the ball as a seat.  You may as well have the person sit in a $5.00 fiberglass bucket seat. The ball will offer absolutely NO lumbar support NOR proper pelvic positioning.  The only way a person could sit with neutral spinal posture on a ball would be by actively contracting the trunk musculature while concentrating on proper posture (the purpose of the short duration exercises).  This requires static muscle contraction, which becomes fatiguing in a very short time (5-10 min).  The result would be a worker with a slumped, flexed posture, looking kind of goofy sitting on a big ball. This posture would create increased intervertebral disc pressures and place the spinal musculature in it's weakest, least efficient range (fully stretched).  In effect, the weight of the body would be hanging on the ligamentous support of the spine - a condition to be avoided. I could go on with a long list of negatives and can't think of one positive for use of the ball as a seat.  The properly adjusted (key point) ergonomic seat is the best bet.  You may do well to interview the worker to determine if there are particular problem they have with the chair.  Perhaps they are not familiar with the various adjustments and how to adjust it appropriately for their size. Think of the play toy this might become in a work setting . . . :-) Jim Priebe, O.T.R. Occupational Health & Ergonomic Specialist Liberty Hospital Occupational Medicine Dept. 2525 Glenn Hendren Drive Liberty, MO  64068 Phone (816) 792-7254 * * * * * From:     Greg Hart[SMTP:hartg@humaneffort.com] Sent:     Thursday, September 17, 1998 1:50 PM To:   Multiple recipients of list ergoweb-l Subject:  Re:  Resist-a-balls Jim Priebe wrote: >A big NAY on using the ball as a seat.  You may as well have the person sit >in a $5.00 fiberglass bucket seat.  The ball will offer absolutely NO lumbar >support NOR proper pelvic positioning.  The only way a person could sit with >neutral spinal posture on a ball would be by actively contracting the trunk >musculature while concentrating on proper posture (the purpose of the short >duration exercises).  This requires static muscle contraction, which becomes >fatiguing in a very short time (5-10 min).  The result would be a worker >with a slumped, flexed posture, looking kind of goofy sitting on a big ball. >This posture would create increased intervertebral disc pressures and place >the spinal musculature in it's weakest, least efficient range (fully >stretched).  In effect, the weight of the body would be hanging on the >ligamentous support of the spine - a condition to be avoided. Having just completed a scientific review of over 2000 literature citations regarding sitting, seating, fundamental biomechanics and muscle physiology and presenting a portion of the results at two conferences, I can categorically say that your assertions are based on some very dubious assumptions.  First of all, I would like to see the proof that lumbar support is required to have spinal health, especially within the context of normal human function.  The muscle fatigue you describe is an artifact of deconditioned type 1 muscle fibres that have been resting against lumbar or other back support since they first hit the couch in front of the television at age two.  These tissues train very quickly and it is possible to sit unsupported and comfortable for as long as one thinks sitting should be tolerated at all (another topic).  The ball would more likely stimulate dynamic variation in trunk muscle contraction since it is slightly unstable in a multitude of directions.  Even if much of the work is  somewhat static in nature, upright trunk posture requires less that 3% MVC to maintain. You mention disc pressure.  As I am sure you know, discs gain nutrition through the regular exchange of nutrients through the endplates.  This exchange is facilitated by increases and decreases of compression.  Might this be an advantage of the ball with all its dynamic instability and the tendancy of users to lightly bounce? Your comments about the danger of the slumped posture are accurate, but an office chair produces these postures in large percentages of the cases. There is even evidence that lumbar support promotes lumbar flexion bias. The contention that unsupported posture=slumped posture is one of the great legends of modern ergonomics. I could go on with a long list of negatives and can't think of one positive for use of the ball as a seat.  The properly adjusted (key point) ergonomic seat is the best bet.  You may do well to interview the worker to determine if there are particular problem they have with the chair.  Perhaps they are >not familiar with the various adjustments and how to adjust it appropriately >for their size. > >Think of the play toy this might become in a work setting . . . :-) Your comments indicate a cultural bias against the concept of "play" in the workplace and the fear of appearing "goofy".  Such cultural biases are significant barriers to understanding normal human function as well as applying compatible techniques in the workplace. By the way, as a result of my research, I began experimenting with sitting on a ball (price was right at $34 CDN!) while doing computer work.  I have been using it almost exclusively for nearly a year.  I can offer the personal anecdote of complete comfort, enjoyment and neutral spine posture. Besides that I bounce a little from time to time and if I want to do some exercise it is very convenient. Greg Hart Human Effort * * * * * From: "Priestley, Wesley G." To: Multiple recipients of list ergoweb-l Subject: RE: Resist-a-balls Date: Fri, 18 Sep 1998 08:22:50 -0700 Hello everyone, Allow me to go against the tide a bit here:  Use of the larger size Swiss balls or other inflatable exercise balls may not be a totally bad idea.  There are some advantages for intermittent use although I have to agree with Mr. Priebe in his overall assessment that the disadvantages are several.  In sitting, the lumbar "forward sway" (lordosis) needs to be maintained.  This can be accomplished on a ball by rolling the hips forward on the ball, forcing the pelvis into an anterior tilt.  This is the same concept employed in backless knee chairs of days past.  It does not however, prohibit a slump posture which occurs when the hips are rolled to the back of the ball.  Also, the dynamic action of the spine is greatly increased compared to the static forces imposed in normal chair sitting. Every time you move you bounce.  Each move side to side induces intervertebral motion. Finally, the EMG or neuromuscular activity of the paraspinal muscles is far greater in this type of "unstable" sitting, eventually being more conducive to a strengthening effect.  That is why we use the thing in the first place in clinics for stabilization exercises.  Using the ball versus a good office chair produced a definite fatigue in my own back after about 20 minutes.  In summary, I would certainly use caution in the recommendation of such sitting but I would not rule it out.  Especially for intermittent sitting in an otherwise healthy individual whom I can instruct in the principles of its proper use.  But long term or as the only seating option....nah. Wes Priestley Senior Physical Therapist Worker Evaluation & Restoration Center University of Tennessee Medical Center Knoxville, TN * * * * * From: "Peter M. Budnick" To: Multiple recipients of list ergoweb-l Subject: Re: Resist-a-balls Date: Fri, 18 Sep 1998 15:09:29 -0700 I'd like to submit a word of caution regarding the "ball" type chairs. Greg Hart wrote: > [...] > The ball would more likely stimulate dynamic variation in trunk muscle > contraction since it is slightly unstable in a multitude of directions. > [...] In response, Wesley G. Priestley wrote: > [...] > Finally, the EMG or neuromuscular activity of the paraspinal > muscles is far greater in this type of "unstable" sitting, eventually > being more conducive to a strengthening effect. > [...] Am I correct in assuming that it would be relatively easy to fall or roll off one of these "balls" when compared to a "5-star" base design common to office seating? If so, any potential positive effects due to the unstable nature of the device aside, I would *never* recommend their use in the workplace, precisely because they are unstable.  Introducing a safety hazard in an effort to address an ergonomic concern can be tempting, but I'd advise against it, especially in the United States (for liability reasons).  Peter Peter M. Budnick, Ph.D., CPE ErgoWeb Inc.; http://www.ergoweb.com and http://www.ergobuyer.com budnick@ergoweb.com; (801) 323-9444 * * * * * From: "Goggins, Richard W. " To: Multiple recipients of list ergoweb-l Subject: Re:  Resist-a-balls Date: Fri, 18 Sep 1998 15:21:54 -0700 This has been an interesting discussion, but it's starting to seem like one of those cases where we get caught up in considering a solution based on its biomechanical merits and forget about other important factors such as safety.  A couple of postings have been in favor of using the ball because it is "unstable" and would provide for a more dynamic seated posture.  However, unstable also means that sooner or later someone will roll too far on the ball and land on their head. These balls may be fine for your own use, but employers have to provide safe equipment for their employees. Rick Goggins Ergonomist, Policy and Technical Services Washington State Department of Labor and Industries PO Box 44640 Olympia, WA 98504-4640 e-mail: gogr235@lni.wa.gov phone: (360) 902-5450 * * * * * From: Canyonergo@aol.com To: Multiple recipients of list ergoweb-l Subject: Re: Resist-a-balls Date: Sun, 20 Sep 1998 14:13:20 -0700 GOGR235@LNI.WA.GOV writes: << it's starting to seem like one of those cases where we get caught up in considering a solution based on its biomechanical merits and forget about other important factors such as safety >> I have to agree with Mr. Goggins and Budnick that safety should be a VERY important concern regarding this type of issues.  Swiss balls are NOT meant to be used the way it was described in some previous e-mails.  Sitting on a ball instead of a chair may be considered "mis-use of the product" or "unreasonable conduct."  Manufacturers won't assume any liability if some body gets hurt when using the product in an unforeseeable fashion.  (Have you ever seen a warning label such as "Don't sit on this ball" on the ball itself?)  Anyway,the liability may rest on whoever recommends the mis-use of the product.  Be very careful with your recommendation.  It's no fun to be grilled by the plantiff's attorney and the court can very unforgiving. Lee-Jean Lin, CPE Principal Canyon Ergonomics Redondo Beach, CA 90277 (310) 792-0415 (310) 792-0436 fax http://members.aol.com/CanyonErgo/Home.htm * * * * * From: Greg Hart To: Multiple recipients of list ergoweb-l Subject: Re:  Resist-a-balls Date: Mon, 21 Sep 1998 10:59:43 -0700 Rick Goggins wrote: >This has been an interesting discussion, but it's starting to seem like >one of those cases where we get caught up in considering a solution based >on its biomechanical merits and forget about other important factors such >as safety.  A couple of postings have been in favor of using the ball >because it is "unstable" and would provide for a more dynamic seated >posture.  However, unstable also means that sooner or later someone will >roll too far on the ball and land on their head. The reason that the discussion started out along the lines of physiology and biomechanics was because arguments based in those domains were advanced to marginalize this device. >These balls may be fine for your own use, but employers have to provide >safe equipment for their employees. As for the safety issue, which is always a wise point to consider, I am not convinced that the ball presents such a serious risk.  When you are sitting on it, it is not so unstable that you would roll off of it very easily (probably less likely to fall asleep at your desk too!).  Many of the balls have little feet that pop out when no one is on it which prevents it from rolling away. The ball does not need to be necessarily considered as the only seating option and there are many situations where it would be clearly contraindicated.  In the same spirit, it should also merit some serious consideration for its potential advantages.  Research has been done in Europe with children sitting on the ball at school (over an entire school year) and there was no increased reporting of accidents attributed to the use of the ball. Greg Hart, Kinesiologist                                                      fax: 403-215-1444 Human Effort                                     bus: 403-215-1440 Box 23047, Connaught P.O.                web: www.humaneffort.com Calgary, Alberta CANADA T2S 3B1      toll free: 1-888-4EFFORT . . . its author can be excused of dishonesty only on the grounds that before deceiving others he has taken great pains to deceive himself . . . - Peter Medawar (commenting on 'The Phenomenom of Man')