An arm immobilizer prevents bending at the elbow. These are commercially available and cost around $40-$60. They can be used for many things - to prevent movement of an injured arm or prevent further damage to a surgery site. In this use, it is similar to the "Cone of Shame" or "Elizabethan collar" worn by pets to prevent them chewing the stitches. It is a commercial product that is easy to replicate in cheap materials.
One of my daughters had oral surgery and had the bad habit of sucking on her fingers - a bad combination because of damage to the stitches, higher risk of infection, etc. She had to wear "No-No" (brand name) for several weeks while it healed. This is where I first saw the idea. At some point, all we had to do was threaten her with "Do you need your NoNos?" and she would keep her hands out; she still wore them while she was sleeping.
Yesterday (holiday weekend) D1 pushed D3 down the steps. D3 spent four hours at the hospital emergency room getting her lip sewed back together. We even had them put a layer of super glue on top to protect the stitches. By the time we got home, D3 had pulled two of three stitches out (too young to understand long-term consequences). This meant turning around and driving right back to the ER for another four hours of fun (she got the last stitch out before we made it back to the ER). This put the return considerably after midnight; and any store that might carry pediatric arm immobilizers was long closed. When minutes count, two day shipping isn't much of an option. Spending more money wasn't attractive either, as we have just spent $250 on our ER visit co-pay.
These "Arm Immobilizers" were made from stuff I had laying around; I didn't buy anything for this project. They get the job done; D3 can't bend her elbows. This means that she can't get her fingers to her face. Like the commercial model, they are easily removed so that she can go to the toilet or feed herself while being supervised. Total cost for this build would be about $4 (mainly for the Velcro, most of which will be reused).
Step 1: Ingredients & Tools
- Corrugated Cardboard (in this case, a box from a case of pre-grilled hamburgers form a cookout)
- 4 Velcro Cable Wraps
- 36" Sticky-Back Velcro
- Foam Shelf Liner
- Serrated Kitchen knife
- Measuring Tape
Step 2: Measure and Cut the Cardboard.
I measured around D3's bicep - 15 cm circumference. 12 cm circumference at the wrist. 18 cm from bicep to wrist. This means we essentially have a trapezoid with 12cm on one face, 15cm on the other, and a height of 18 cm. Since this difference is not great, I will approximate it as a rectangle 15cm x 18cm.
I give myself an extra couple of cm (the foam padding will add some bulk, hence adds circumference). Corrugated cardboard does not bend smoothly, it is an n-gon approximating a circle. It also does not have to go 100% the way around her arm; but I want it to be close. This brings the dimensions to 18cm x 18cm.
Since D3 has two arms, we need two immobilizers.
It is extremely important that the Length (18 cm) in this case, be measured WITH the corrugation grain of the cardboard. We want the flutes of the cardboard to be going between arm and forearm. This will prevent movement. To put it anther way, cardboard "wants" to fold one way and not the other. The way it doesn't fold becomes the support.
I cut two 18 cm x 18 cm squares.
Step 3: Roll Cardboard Into Tube
Roll the cardboard into a circular shape, rolling WITH the grain (the easy way to roll up cardboard). If it is hard you are doing it wrong.
Step 4: Cut and Attach Foam Shelf Liner
The foam shelf liner helps to cushion the cardboard (sharp edges, paper cuts, etc.). It also serves to have a non-skid grip to keep it from sliding around on the skin. I gave myself some overlap so that it can wrap around the edges. It is best to make sure the cardboard is curved and press the foam into the curve for more accurate measurements.
Staple the foam into the cardboard. Staple from the foam side (that will be touching the skin) so that the pointy parts of the staple are on the outside. We don't want to scrape the skin. Mash the pointy parts of the staples into the cardboard or foam so that they don't scratch or scrape. You could also do this with spray adhesive, glue, tape, etc.
Trim the excess from the corners.
Step 5: Attach Adhesive Velcro
I put a couple strips of hook-polarity sticky-back (adhesive) Velcro on the back.
I normally only use the Industrial Strength adhesive Velcro, but didn't have any available. Stickyback seems OK for this, especially since this is only going to be for a few days.
Ideally, I might use loop-sticky-back Velcro for the immobilizer and hook sew-on Velcro for the straps (or vice-versa), but all I had was sticky-back and Velcro cable ties. I would rather have exposed hook-Velcro than a long strip of bare adhesive.
Step 6: Add Velcro Cable Wrap
The soft side of the Velcro wrap stick better to the hooks of the stickyback Velcro than the hooks of the cable wrap adhere to the soft side of the stickyback Velcro (trial and error).
Staple two cable wraps on each side of the arm immobilizer. Bend down any sharp points. As before, staple from the foam-covered side, through the cardboard, through the cable wrap.
Step 7: Attach to Child
Gently straighten the arm and place it in the immobilizer. Wrap the cylinder around the arm. Wrap the velcro cable wraps around and press into the hook Velcro. It should not be so tight that it cuts off circulation. It only has to be tight enough that the child can not sling it off. Press the skin on the hand and release, the skin should return to a normal color very quickly. If it is taking a long time to return to normal color the immobilizer is too tight.
Make sure that the hook Velcro is on the outside of the arm. It would be very uncomfortable if it was scraping against the ribcage skin (if not wearing a shirt, etc.)
Because I had to use the hook side for the immobilizers, D3 figured out that she could stick her doll's hair on it and "carry" her doll with her, while keeping her hands free.
These arm immobilizers can be made as advanced (and durable) as needed.
I made a prototype of one of these for a girl in Ecuador. An aid worker who worked in her village told me that the girl had Cerebral Palsy and there were not a lot of paved roads in her village. She would push her chair during the day, thus picking up who-knows what on her hands. At night, she would reflexively suck on her hands. She had gotten many severe (life threatening) illnesses from having her hands in her mouth.
I made a 10-minute prototype out of faux leather, pencils (for vertical rigidity), and staples. Each pencil was encased by staples so that they would not shift or escape. It used velcro for the strapping to keep it in place.
The aid worker was very excited about the prototype - they had the materials and willing hands back in Ecuador, but they needed the idea. There was a shoe factory in the village; they would have no trouble modifying the design in leather to her exact measurements (the prototype immobilizer was to my measurements). They could also sew the leather (rather than use staples) and use grommets/laces instead of Velcro strapping. They (and their doctors) and never seen an immobilizer before, and so they had nothing to copy, but now they knew how to keep her arms still.