Ask the Experts Follow-up Questions with Marty Frame

Body Mechanics November 7, 2018

Today we’re answering follow-up questions submitted during last weeks Ask the Experts webinar

Last week we had a fantastic webinar with one of our favorite faculty members, Marty Frame, on Postures and Body Mechanics for the Non-medical Provider. If you happened to miss it last weekend you register and watch it HERE. You’ll save 25% now through the end of November (and earn an hour of CEU!).

We had a number of questions that came in during the presentation that we didn’t have an opportunity to answer on air but Marty was kind enough to pen the follow-up answers below:

Q: How should one best create a setup where multiple users of different sizes will be working?

A: When there are multiple users at each work station, the goal should be to design the workstation so that it is as easily adjustable as possible and adjustable to the greatest range to accommodate most users. Start with the monitor(s)- Put the monitor on an articulation arm so the height and distance from the employee could be easily changed to accommodate employees of various heights and visual acuity.  The chair is the next item that can usually be adjusted.  Make sure it has as much adjustability as possible with chair height, seat pan depth and lumbar support easily adjustable.  Provide a foot rest for shorter employees.  With multi users I would avoid a keyboard tray as it tends to get in the way and contact the thighs of taller and heavier employees.  If you have short employees consider an adjustable height desk rather than an adjustable height work station that sits on the desk.  This will allow the employee to lower the work station to their comfort.  Lastly with any equipment additions make sure employees know how to adjust the work area and emphasize they must take the time to do so when they work at a particular work station.

Q: What are the effects on the spine with increased heel height?

A: Increased heel heights shift the person’s center of gravity forward so to compensate the person will usually present with an increased lumbar lordosis or sway back posture.

Q: How should one modify lifting when using bad knees?

A: If a person has bad knees they find it difficult to use a squat lifting pattern.  If they have good flexibility in their hamstrings they can use a hip hinging strategy which is bending forward from the hips and maintaining the normal inward curve of their back.  This type of lift takes some practice and unless they have good hamstring flexibility they may not be able to reach floor level. See the video below on hip hinging.   For light items they can use the diagonal lifting pattern. https://www.youtube.com/watch?v=5j6L-o1dwvU

Q: Is it better to carry the aforementioned 11 lbs. on one side vs. in front of you (ie, carrying in a bag of cat food)

A: The best way would be to carry 5.5 lbs. in both hands rather than 11 lbs. in one hand.  Holding the arms close to the side decreases the compression on the back but some of this will be offset by asymmetrical loading of the spine. I would carry the cat litter in one hand if I was strong enough to carry it without deviating my spine out of neutral.  If I could not maintain a neutral spine I would carry it in front of me.

Q: I do have a question re: work/desk chairs. It seems I have run into a lot of situations in the last couple of weeks with employees wanting new desk chairs. After assessment the current chairs they use provide poor lumbar support. The biggest problem for some is that they sit at a desk with a fixed height of 34 inches.

It is difficult to find a chair that can accommodate most workers at this awkward height. They purchased a chair that provided great lumbar support but only was height adjustable to 20 inches which caused issues with the shoulder positioning. I have looked at different drafting chairs and stools but they seem to be too high.

I have suggested they look at modify the desk to make the height more optimal, but they would like to take the chair route since it could be a while for the desk to be adjusted.

My struggle is finding a chair that is capable of allowing more height adjustable options. They want to use Staples as their supplier also which limits selection.

A: Regarding the chair issue at a 34-inch work height.  You probably are not going to find a chair that raises high enough for most folks other than the very tall.  Using anthropometric data elbow height is 7.1 inches from the chair for the 5% female and 11.6 inches for the 95% male.  Assuming the keyboard. Mouse is at elbow height (the chair would have to elevate higher to get the keyboard 2-3 inches below elbow height) the chair would have to elevate to almost 27 inches for the 5% female and 23.4 inches for the 95% male.  I have seen some chairs that elevate to 24 inches but they are the higher priced chairs.  Most chairs are designed for a work height of 29-31 inches and adjust accordingly.  They can possibly purchase chair cushions to raise up the seated surface but then the person gets less lumbar & upper back support and the arm rests may not elevate sufficiently. This is a Kensington chair cushion  Staples Kensington® Memory Foam Seat Rest, Black (82024) which has a two inch height and may help the taller person but not the shorter one.

We’ll be doing our final Ask the Experts webinar of 2018 next month with our Director, Ron Porter and you definitely won’t want to miss it! Keep an eye on your inbox for RSVP dates and information. You can check out more of our previous Ask the Experts webinars HERE.


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