Follow-Up Observation/Shadowing Session

On January 6th, I had the opportunity to shadow PT on two physical therapy visits with two different boys. I had already shadowed these two boys twice in September, so having a few months in between visits allowed me to really see the progress that they have made with her. These were my observations:

Child A – 14 months old; low muscle tone

ChildA

At this point, Child A is now able to sit upright unsupported, which is a huge step forward from where he was just a few months ago. He can also reach for objects while sitting upright and even bang two objects together. Once in a while he gets back into a side-lying position, so PT slowly aids him as he pushes to lift back into an upright position. When he plays upright with a toy, Child A mainly uses his left hand to play while he uses his right hand to stabilize himself to stay sitting up.

A big challenge that PT is dealing with now is getting him to move onto his stomach. She shakes a small toy near him that makes subtle noises, such as a plastic maraca or a ball with a smaller ball inside. When he hears and sees it, he slowly moves towards it by reaching his arms outward while lying on his back. From his left side, Child A does not need much support to sit upright when he is lying on the floor. He has to work a lot harder reaching up from his right side.

ChildA1

PT holds up a plastic ring stacking toy while he is sitting upright. She has him reach towards it and pull off the rings one at a time, then has him put them each back one by one. Child A puts on and takes off each one that PT tells him to and stays sitting upright the entire time. After this activity, she puts Child A on her lap while she sits on a floor mat. She places his legs in a 90 degree position and gently keeps them in this position with his feet planted firmly on the ground. As she holds him in this position, PT uses her other hand to place toys in front of him so that he reaches forward and grasps the toys with his hands.

Seeing this progress from the first session I observed really made an impact on me. It showed me that with enough time, patience and attention, children with hypotonia can progress at a steady pace and advance physically over time.

Child B – 2 years (+ a few months) old; high muscle tone

ChildB

PT holds him and tells him to carefully lean forward into a hands and knees position. He leans forward slowly so that his hands are touching the ground and she carefully lifts him back up. They proceed to do this activity multiple times so that Child B gets used to it.

After this, PT puts Child B’s orthotics on, followed by his sneakers. The orthotics give him added support in the ankle and knee areas. Having a more stable base helps keep the rest of him stable. She then places a weight around his left ankle before trying to get him to walk across the room. He walks across the room towards an iPad playing a favorite song of his while she stabilizes him and slowly guides him there. Once he reaches his goal, Child B sits down on the floor and PT adds a weight to his right ankle. With both weights on, he is aided back across the room and goes into sitting position once again when he gets to the iPad. PT does this exercise multiple times with him, going from one end of the room to the other.

ChildB4

PT pointed out that Child B works more with his right side during every activity. If he pushes off the ground, he always uses his right side as support since it is currently his dominant side. PT is working with him to use his left side too in order to strengthen it so that he has no dominant side and uses both of them equally. Getting rid of this current dominance will help him use both sides during activities.

ChildB1

PT carefully sets him into his walker. He holds on to both sides and walks without the support of PT, but uses the walker to help him. He is able to walk out a fairly long distance on his own. He does not tire easily and pushes himself to keep moving forward for a fairly long time.

ChildB2

Throughout this entire time he has been looking around and taking in his surroundings. As he gets tired, Child B’s legs get less stable and the bottom of his feet are no longer planted firmly on the ground. He uses the walker to hold most of his weight towards the end of his walk. Once he starts fatiguing it is difficult for him to stand up straight. PT makes sure to take short breaks while walking once he gets tired. She continues to give him encouragement and support, telling him that he is doing a great job. She also makes sure that he is holding up his weight with not only his right hand, but his left one as well.

Once again, I was grateful to be able to see theses stages of progress with my own eyes. It showed me that although it might be difficult at times, these children want to progress physically for themselves but do not know how to do so on their. The help of a PT and development tools makes an extremely noticeable difference and I am hoping that my design will have the opportunity to aid in these milestones as well.

Testing Size: Making a Half-Scale MDF Mock Up

At this point, I decided to push forward with my latest 3D print advancement in order to scale it up. The 3D print is only about 5 inches long, which is helpful in identifying the form but not so much the function. I wanted to see how stable the piece would be in a larger scale, as well as to see exactly how big the final product should be. This latest print has a simple curved form that varies in thickness from one end to the other. It is able to be placed in four different positions while staying upright and each position is useful for different activities. The main position it stays in allows it to subtly rock and spin since the widened base has a slight curve, which is enough to initiate movement while keeping safety in mind:

Form6bForm6a

I proceeded to take the CAD file for the model into a program called 123D Make, which allows you to turn your 3D model into a two dimensional build plan. The program takes the three dimensional form you have created and slices it into layers upon your direction. I was able to choose the direction and width of the slices it would be made up of based on the material it was cut from. In addition, I hollowed out the inside so that I could fill the end piece with sand in order to test the shift in weight when placed in different positions.

In order to choose the size of the larger scale model, I researched the average measurements of a child in the age range of my user group. It turned out that the average height is about 31″, so I decided that the overall length of my first test piece would be 36″. I figured it should be a little bit larger than the child so that they can sit on it and interact with it without it being too overwhelming to them. Since the CNC has limitations due to the material choice, I had to create an 18″ half scale model. It would still allow me to test the function on a larger scale than the 3D print and pave the way for future iterations.

I chose MDF as the material to use for the model because it comes in large sheets that are easy to sand once the pieces have been assembled. After setting up the material onto the CNC, it was time to start cutting out the pieces. 123D Make works with the CNC router so the new file had to be transferred to the machine, allowing it to then follow the line paths that were programmed.

After all the pieces were cut out of the MDF sheets, the assembly process began.

I had to remove all of the unnecessary material from the interior and exterior of each part. I numbered them in size order to keep track of the way in which they would be glued together.

I was left with only the pieces required for my model and I continued to work on each one by hand. I used a hand file to clean up all of the edges to give the overall piece a smoother finish at this stage. Although somewhat time-consuming, it saved me time later on in the construction process.

During the sanding process, my thesis advisor, Professor Stan Rickel, and I discussed the best way of going about assembling the pieces. It required multiple wooden dowels to be placed through pre-drilled holes in order to keep the pieces from shifting during the gluing process.

I proceeded to widen the pre-drilled holes after all of the sanding was complete so that there would be room to apply wood glue around the dowels to keep them securely in place without falling out. I then split the parts into two piles and glued the pieces into two separate halves. This would enable me to fill the piece with sand before gluing the two halves together. I hoped that the sand would create the weight-shifting ability I wanted in the final design, however, the MDF was too heavy a material for it to really make much of a difference. I would like to test it out with a foam model, which would allow the sand to make more of a difference due to its lighter quality.

Both halves were carefully glued and clamped to ensure a close fit. I left them to dry overnight, added the sand to one half in the morning and then glued the whole piece together. I gave the piece more time to dry this time since the next step would entitle sanding down the entire surface to shape and smooth the exterior.

I clamped the entire piece securely onto a table in the industrial design studio’s sanding room. Using a hand grinder, I went over each section of the piece so that there would be a continuous surface over all of the glued pieces. I had to continuously rotate the model and re-clamp it to ensure an even surface all around. In the end, the room was completely covered in MDF dust from the excess material removed and my piece had been sanded down to the necessary form.

When the time came to finish the surface of the piece by removing all of the sanding marks, Stan happened to be in the industrial design studio with furniture designer Wendell Castle. Wendell uses a wood stacking technique similar to this in many of his pieces, so he took the time to give me advice on how to complete mine more efficiently. I carefully removed the markings from the hand grinder so that the curves would have a better flow and a smoother surface.

After the piece was completed, I began to take notes of its qualities. A thinner wall would be better, allowing there to be more hollow space inside for the sand to partially fill and allow a more noticeable shift in weight. When it came to size, this definitely help me see a more realistic scale of the final design. Even though it was just a half scale representation of what the final form would be, it allowed me to see that at full scale the piece would be too large. Instead of 36″ long, it would be sufficient for the piece to be minimized to approximately 25″ long. A smaller size will allow it to be used properly without being excessively large. In addition, no extra material will be wasted and the proportion to the child will be more in scale.