Modify a play structure and create an area that promotes collaborative play for a child with low mobility and limited trunk support. Specific requests include trunk supported swing, sensory and interactive attachments, and shade.
We are looking to modify the family’s existing play area to make it so that their two kids, one of which needs support to walk / stand, can play together. In meeting with them we learned how their child lays down in a saucer-like swing outside but that this makes it hard for her to see and interact with her brother while playing. They also mentioned the lack of shade and that she struggles with temperature regulation. They have an existing play structure which they are hoping could either be modified or added upon to have the child supported while also allowing her to play freely with interactive games such as tic tac toe. The parents emphasized that when she becomes tired, she tends to “fold” and thus our structure needs to ensure that she remains safe / upright when she eventually tires. They specifically mentioned a harness or means of strapping her down to solve this. They also asked that this area could either be joined or sit adjacent to the existing structure such that her brother can actively play with her as this is an issue for them. In terms of a swing seat, the cost of “medical grade” seats or devices is prohibiting them from changing their existing swing seat to one which can adequately support the child. Similarly, this seat needs to hold her in place while being durable, and ideally one that can be interchanged on their existing swing set.
Swing:
The user needs specific trunk support due to lower mobility that decreases as the user gets tired. We were told that the previous swing gets too hot for the user, so it is important to use a seat that has a higher breathability. We were told that the user was previously in a laying position while using her swing, but the mom wants he to be sitting upright while using her swing. Needs to be strong enough to hold the user up.
Zipline/Sensory Wall:
The user need specific trunk support due to lower mobility that decreases as the user gets tired. We were given a possible harness that we could use that would need to be detachable from the zipline. The mom said that the brother should have have a way to pull the user back and forth on the zipline. There was an old zipline that the family had the we could repurpose parts from.
The sensory wall needs multiple games that the brother can play in collaboration with the user. User likes pulling motions and things that makes sounds.
We started our background research by looking at many examples of accessible playground equipment, mostly focusing on accessible swings since the initial paragraph mentioned a swing. We then found some activities that we thought would be accessible to someone with low mobility, like a water wall and rope pulls. We also researched existing play sets that we could modify, either with a table and bench at the bottom, or with a rope and pulley system to use the slide.
After meeting with our family, we found out that we have a lot of space and existing resources to work with. We learned that their goal was to get her to be able to use the play set with her brother, be involved, and have plenty of shade in the yard. We learned they already have a firefly splashy seat that can be used in our design with a simple mounting mechanism, a standing harness, and an old zip line carriage.
This design allows for an existing five-point harness chair the family already possesses to be clipped into a designed swing frame. The frame will be larger to accompany the size of the chair but with the clips, it will securely hold the seat which securely holds the child.
This design creates a soft but water resistant seat that is designed to fit a child. The material is EVA foam which is the same material used to make Crocs, creating a flexible but durable seating option. The back of the chair is of the same material and has holes to address the temperature issues of the child. Modification will be had to make to make this a five-point harness. The supporting frame will also have to be designed and attached to the foam.
This design addresses the want for the child to be able to be more involved with her sibling on the playground, give her more independent mobility, and provide interactive sensory games. The overall design is a zip-line using an existing carriage and existing harness . Along the zip-line on a lower wall will be sensory games while the side view wall will have a water wall activity and sound wall activity. The materials for these will be second-hand and easily affordable. Attached also to the zip-line will be an adjustable umbrella to protect from heat sensitivity.
Based upon the decision matrix, the route planned to go is the clip on attachment seat as it uses a pre-existing seat that is known to provide safety, ventilation, and support that she needs. The only parts that will need to be manufactured are the frame for the seat as drawn (made out of wood for proper support and balance) and clip attachments that connect to the pre-existing seat.
Our selected design combines three elements to create a playground where collaborative play is enabled by supporting the child. Our selected design includes a new swing-seat which attaches an existing, supportive seat the family had to a solid backing. It also includes what we refer to as the game wall. This features your typical playground games such as tic tac toe as well as sensory games and areas for the child. And finally, our design includes a zipline which will support the child by attaching to an existing harness the family uses to allow her to stand. This harness will clip onto our zipline and allow her to remain upright while playing with the activity wall.
Specific details for each item:
Swing Chair – Similarly to our zipline using the family’s existing harness, our swing will use an existing supportive chair to keep the child upright as she swings. This chair uses a standardized attachment method which uses a slider to securely fasten itself to an array of different supports and devices. The benefit of this is when not in use, the family can remove the chair to avoid deterioration due to being outside. The chair already features a 5 point harness to keep the child securely in place and is custom fit to her body’s dimensions. It is also cushioned and ventilated for comfort. Our selected design uses a replica of the locking mechanism used in this chair to securely fasten the child to our swing chair. This chair will fit around and support the existing chair such that the chair maintains its rigidity and keeps the child upright.
Activity Wall – Our activity wall will be held in the ground by (3) 4″x”4″x 5′ posts which will be set in 0.6 cubic feet (14in of height) of concrete (1, 80 lb bag of quikrete) and dug into the ground at a depth of 2 feet with the remaining 10 inches being filled in with dirt. These will be set 4 feet apart from each other giving us a wall length of 8ft. To make these “wall” like, (5) 5/8″x6″x 8′ will be cut in half and affixes to the post starting at 3.5 inches from the ground and equally spaced 0.5″ apart to the top of the posts. The center of the wall will feature a frame which houses a tic tac toe board. This frame will be exactly 20″x20″x6″ and will be made of (2) 2″x6″x20″ pressure treated planks that will be cut in half to (4) 1″x6″x20″. We will do the same for a 2″x6″x18″ plank which will make up dividers inside our frame to keep the blocks from sliding into one another. This model features (9) 3″x3″ blocks which will be made from excess wood from the posts which support the wall. The center of these blocks will be drilled out and slid onto 3 metal bars (each with 3 blocks on it). These bars will run through our dividers to create a 3×3 grid on which they can play tic tac toe. The dividers will sit 2″ from the front of the frame which will be mounted from the post that sits right behind the center of the wall to allow acessibility while also minimizing how far the blocks stick our from the frame. Other activities along the wall include a “rope-pull” which will begin 4″ from the edge of the tic tac toe frame. A series of holes will be cut into the walls through which we will feed varying lengths of braided rope. Each rope will be knotted at both ends and will be fed through two separate holes in the 5/8″x6″x4′ planks such that the knots prevent the rope coming through the hole creating an interactive zone for the child to play. This zone will span 30″ until the left edge of the activity wall. The right section of our activity wall will feature a xylophone and a sliding section. THe xylophone will be mounted in the final 12″ of the wall and will have a mallet anchored to the wall to allow it to remain hanging when not in use (to prevent losing it). The sliding seciton will feature a section of sliding locks that when pulled will open another corresponding lock.
Zipline – Our zipline will be placed right alongside our activity wall such that the child will be able to use the activity wall while supported by her existing harness which will clip into our zipline carriage. The zipline will consist of two 4″x4″x8′ posts spaced 10ft apart. To these posts we will use the zipline kit included in our bill of materials to anchor the included cable and affix the included carriage which will be what allows the child to “walk” along and use the activity wall.
This analysis was used to examine the tension on our zipline cable. This was necessary for two reasons: first, that we could ensure the cable we bought was sufficiently strong to support the weight of the child and the harness. Secondly to determine the tension and height at which the cable needed to be affixed to the posts in order to allow the child to be in contact with the ground while playing (tension the cable such that the child is not floating on the zipline). With our listed parts and a weight of 36 lbs we calculated the tension on our cable at it’s largest point to be 35lbf. Using this, we were able to determine the tension in the cable needed to be 37lbf in order to maintain the lowest point at a height of 2.8ft off the ground.
This analysis examined the swing to determine the force extered on both the swing set and cables with our adapted swing seat in order to ensure both the security of the clips and seat but also the rigidity of the chain and support. Modeling the swing at it’s lowest point (where the tension is greatest) as a statics problem, we determined with a combined weight between the chair and child of 50 and a safety factor of 2.5, we determined the force exerted on each cable to be around 31.25 lbs.
This analysis centered on a cost benefit analysis and a shear analysis of our clip. Both these factors are important when considering this project. Our cost analysis centered on both the material and the time investment while we also considered factors such as the cost of alternative developmental therapy, and a direct comparison to similar supportive swingsets. We found the analysis found that the net benefit of our project was in the range of ~$5000.
We also spent a little bit of time examining the shear and moment forces that would be acting on the clips that secure our chair into the swing.
Swing:
The safe way to use the chair that we designed and built is to attach the 5-point harness seat into the clips on the chair’s frame and check the clips to see if they connected securely. Then, harness the user into the seat. Lastly, push the back of the swing like you would a normal swing.
Zipline / Waterwall:
The safe way to use the the zipline is to check the connections on the posts to see if they are still secure and tightened. Next, attach the harness to the carriage and that the carriage is attached to the zipline cable. Put the user in the harness and secure tightly. Either push the user along the length of the cable or let the user walk along the length of the cable.
Activity Wall:
The activity wall is intended to be used while the user is on the zipline. The activities are simple to use such as pulling ropes through holes, hitting a mallet on the xylophone, rolling cubes for tic-tac-toe.
