tremendous strength, we decided that using a pulley system was certainly reasonable. (see
Appendix D: User Observation Summary) Since the Shirt Horn claw will allow Elsa to stick her
head and arms through the shirt, she will be able to pull the rope on the pulley system. This rope
will then lift the dynamic claw, releasing the shirt down Elsa’s back. The pulleys will also
provide a mechanical advantage for Elsa in lifting the dynamic claw, as they will redirect
downward force (which the user is able to easily provide) into upward force (which is more
difficult for the user to provide). During user testing, Elsa showed strong capabilities in pulling
down on the rope and releasing the shirt from the claw (see Appendix E: User Testing Summary).
Undressing Device
What is it?
The undressing device is an apparatus designed to assist people with arthrogryposis in getting
undressed as a way to increase independence in these people’s lives. The design includes two
components: the door assembly and the pulley system. A clip is attached to a string in a pulley
system and when the string is pulled, the shirt is pulled up, allowing the user to independently
squeeze out of the shirt.
For measurements of the device and its parts (see Appendix G: Dimensioned Sketches). As this
device was never constructed, no finished images are provided.
How does it work?
The system is prepared by clipping one end of the pulley rope to the back lower end of the user’s
shirt. As the user leans forward and pulls the rope, the shirt is pulled up the back of the user.
Once the shirt reaches the shoulders of the user, the user maneuvers out of the shirt
independently.
Door assembly
Design Concept
The door assembly is an invertedU shaped aluminum structure which fits over the top of the
door for support and includes wooden supports which extend down the face of the door with
extension points to attach the pulley system. The upper part of the assembly is identical to the
door assembly from the Shirt Horn.
Design Rationale
The door assembly is designed to attach the Shirt Horn to the door so that it can be elevated to a
height above Elsa’s head. Therefore, when Elsa pulls down on the rope connected to the pulleys,
the shirt is pulled up her back. As the device could not stand on its own due to its bulkiness, it
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