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The ultimate bimanual task - the IKEA Pax wardrobe system with gliding doors [tricks,tips and yeehaw]

Cite this article:
Wolf Schweitzer: Technical Below Elbow Amputee Issues - The ultimate bimanual task - the IKEA Pax wardrobe system with gliding doors [tricks,tips and yeehaw]; published June 16, 2014, 21:54; URL: https://www.swisswuff.ch/tech/?p=2429.

BibTeX: @MISC{schweitzer_wolf_1571433092, author = {Wolf Schweitzer}, title = {{Technical Below Elbow Amputee Issues - The ultimate bimanual task - the IKEA Pax wardrobe system with gliding doors [tricks,tips and yeehaw]}}, month = {June},year = {2014}, url = {https://www.swisswuff.ch/tech/?p=2429}}


The two of us spent about two days purchasing, unloading, assembling and mounting an IKEA Pax wardrobe with gliding doors, containing two 100 x 58 x 230 and four 50 x 58 x 230 units and several inserts.

In terms of off-shelf weight (two packets of 55kg, four packets of 45 kg, a few 18 kg packets and a considerable number of smaller packets that also were not particularly light weight) and bi-manual challenge, I would call this a top class of tasks for an arm amputee.

The product is recognized as one of the hardest to assemble IKEA pieces (for non-handicapped people) - so obviously, an IKEA Pax system with sliding doors is certainly a must have item.

What is this Pax wardrobe?

The cupboards are a relatively light weight and cheap chipboard construction, weighing a total of 2 x (55 + 45 + 45) = 290 kg, adding two insets of 31 kg adding up to 62 kgeach, as well as some 26 shelves of 2,7 kg each totaling 70 kg. The doors weigh about 2 x 20 kg (metal frames) and 4 x 18 kg (for four glass panels each) so a total of 112 kg.

The total weight overall will be an estimated ~540 kg installation. That also means that one will purchase and transport about half a ton of material for this.

None of the materials is elastic or particularly resistant to scratch or indent. That means that whatever it is that you do there, you may want to really think about it first.

The wardrobe system once installed is very elegant, and so it is very cool to have it in place.

Here is how it looked in the end:

CIMG3439

Getting it there is what is the issue though.

Devices used

I used no prosthesis at all (for the most part). The ability to conduct precise subtle nudges when achieving some screw/part squeeze during position critical mounts, or when making sure a very heavy object would not slide, the option to exert massive power through a soft deformable surface while maximizing sensitivity is not even remotely achieved by any prosthetic arm or even research idea currently floating around. Current research and industrial parts for prosthetic arms are light years away for the comprehensive overall requirements here. Here, we are talking about a near 100% reliability, top force pincer grip, versatile deformability and sensitive feedback for very subtle differences (not just for crude differences!) in part placement and alignment. We are talking about examples such as (but not restricted to) nudging a glass door with metal frames weighing ~28 kilograms into its rails while simultaneously aligning it with other parts (rail, distance holders), with a manual precision of less than 4 mm and a non-slip option, a non-hard-surface contact option and an overall non-fail option. And that was just one of the interesting parts of the assembly.

I used a stump sock for a few things. It was most useful to keep down overall abrasion of the stump for trivial tasks such as carrying and setting up light and easy parts. However, for most critical things no stump cover or prosthesis would really help.

And I used the body powered arm with the hook for a couple of things at first, but then gave up. It scratched surfaces, it was not better when squeezing nails or screws into hold positions, and its slip detection was not useful given its overall performance.

Nailing back walls to cupboard frame

IKEA shipped little plastic holders for nails with the main cupboard frame set.

CIMG3426

Using these plastic holders was a lot easier than trying to use the hook, or, a lot worse, trying to hammer on the innocent finger tips of an iLimb hand. Besides, there was no problem when one killed one of these accidentally. The next package contained another one.

Here is how that went:

Fix the frames against the wall

To make sure they cannot keel over, best to fix the frames against the wall.

CIMG3429

Bolting cupboards together

To obtain a flush front, I bolted all cupboards together.

CIMG3427 CIMG3428 CIMG3430

Installing IKEA Pax TONNES sliding doors - top rail plastic stabilizers

A major bitch was getting the plastic stabilizers for the top rail in place. There were other similar things at that difficulty level, such as the bottom door sliders for the non-A front door, or maybe

Over a total width of 200cm, we had to place eight of these gray plastic parts (#112569) by first jamming them between rail and cupboard and then by drilling a screw through pre-fabricated holes in both plastic part and top cupboard shelf.

The accessibility of that angle is bad for two hands. Getting a clear vision and two hands to manipulate stuff at once is virtually impossible. So straight out of the box, this appears to be a major obstacle in this puzzle assembly.

Here is what I did as the one handed person of the two of us setting all of this up:

  • First, place the gray plastic bit in place and wedge it into position.
  • Check visually that hole of plastic aligns with hole of board, in terms of position of the gray plastic part along the rail. That is, get the horizontal position right.
  • Then I held the plastic part in place with my stump while jamming the screw into the hole.
  • Then I would slide the plastic part a small bit sideways, to jam the screw laterally. That way, it would stay in place without further aid. That was when I took the photo (below).
  • With this situation, I could easily fetch the power drill to put the screw in for good. However, there are no second chances for that: you so much as wiggle, or cough, or sneeze, or touch the screw sideways, and it may all fall down so you have to start over again with this.

So you will not want to go about power drilling here with any tremor of intent.

Just gently jammed in place, ready to be power drilled:

CIMG3438

Shelf pins

The little IKEA shelf pins (#115344) are not trivial. The screw distends the plastic foot but does not seem to actually hold the pin in place. So it is possible given enough force to pull them out. Yet, friction may make rotation hard or impossible at least when attempted manually. I thus used pliers to gently convince the pins to look up, after installing them with the power drill.

CIMG3431

 

Stump skin damage

Two days of extensive weight and assembly work caused visible injuries also to my hosed arm (photos).

However, one has to judge the damage in overall context:

  • The extent of bruising and abrasions when moving and mounting furniture tends always to match the overall exposure.
  • These will heal easily and within a few days.
  • The other arm, trunk and legs also were similarly used up.

Living office life with a "bionic" arm delivers less results, is far more costly and far less satisfying. Just wearing a myoelectric arm for a bit more than half a day of office work (and not even lifting 3 kg) causes injuries that are more painful, and take longer to heal, as I documented recently [link]. So if ever you feel like congratulating me for being brave in setting up all the stuff here, please do not forget to then send flowers to the people that endure the real pain and damage caused by "bionic" prostheses - because then, those are our real heroes.

CIMG3441 CIMG3443 CIMG3444

 

Summary

Purchase, transport and assembly of this puppy is all but trivial for a person with arm amputation. However, it can be done.

You want to approach this type of project with a comprehensive attitude. You want to give it your best and invest yourself in it. You will want to deliver a lot of grip force, torque, subtle nudging and adequate pushes and pulls.

The combination of relatively extreme subtleties (e.g., shelf pins, but also many other parts), rather brittle surfaces and parts (panels are too easily indented or scratched, glass panels, connectors may break off quite easily if pushed wrongly) and relatively high weights are, as far as I see it, outside the grip specifications of any prosthetic device that I know of. Sure, placing nails or screws can be done with a hard precision push and grip device such as a hook, that also allows for rather good force and touch feedback. A V2P can be tweaked to grab glass and metal parts without scratching to some extent, but at 25 kg and more, limits of grip strengths are reached.

Using the stump allows for very subtle force feedback nudging, very subtle pushes, soft  surface damage free carrying and shelf or door part assembly, and so on. On top, a few of the assembly steps were harder bimanually than properly sequenced and done with one hand. Trying them bimanually would then be very frustrating while starting with one hand would lead to different and at times better mount solutions, as exemplified above by illustrating the plastic stabilizer installation for the gliding doors' top rail mount. That is because accessibility for this wardrobe puzzle is difficult for some work steps.

Task completion time or task speed - as measured by some people for testing hand or gripper performance - is of absolutely no concern here. Much rather, the responsiveness of a prosthetic arm, and its suitability to the tasks actually performed, are of real interest. Also, tricks to get things done without prosthetic arm are of almost greater interest simply because not wearing the prosthetic is more functional. The top goal is top precision, no damage and a technically correct setup here.

Learning points for bimanual task testers and prosthetic hand device specifiers:

  • not all tasks that people do with two hands are best done with two hands; intelligent re-sequencing may take extra brains but may result in overall better approaches also for people that have two hands;
  • there are some Orthopedic Technicians that promote the attitude that only clients that master difficult "bionic" hands are differentiated and intelligent; I seriously challenge that attitude, as they entirely lack intelligence to understand what this is about here, they entirely lack intelligence to admit to their products' serious flaws and shortcomings, and last but not the least they talk bad about clients; they then lack intelligence to acknowledge theory of grip mechanics which admittedly is not as straightforward as some may wish, and last but not the least, any technician that bills up to around 30% for parts only will be so seriously biased that they cannot but lie in their own financial interest (which, however, does not assemble my furniture);
  • task precision wins way over task speed - an experience I also have for ADL (activities of daily living) when critically analyzing the SHAP Southampton Hand Assessment Procedure [link];
  • the stump may be the best solution (compared to prostheses) - particularly in extreme requirement tasks; something that I already considered when going over theory of grip mechanics a while back [link] and so there does exist a high performance domain - excessive force, excessive subtlety, grip softness - that is better served - functionally - by not wearing a prosthetic arm at all;
  • my stump may retain a few scratches and bruises after being used for "manual" work over two days when mounting a >500kg furniture installation and admittedly that may scare some people off, but to put that into perspective, more excessive and painful stump skin damage happens when wearing "bionic" sockets for light office work for only 1/2 a day or so [link]

Further reading about real work / physically demanding work, and prosthetic arm comparisons, with underlying background

The issue of bimanual heavy work in context of prosthetic arm usage / design / build is discussed in this article in depth:

Publication [link]

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