Oar sling for crutch users: Week 3 progress report

Group partners: Zainab and Kiki

This week, once we received our new parts on Friday we were able to move forward with our next prototype that we will be showing CRI on Wednesday. We cut a foot-long piece of the PVC pipe and then cut it in half to recreate the channels, and glued a piece of wood to connect the outer sides of the two halves. We lined up the wood so that it would be level (or close to level) with the edges of the pipes on one side, and thus have a sort of dip for the shoulder to rest in while using. While it wasn’t exactly level, we still managed to do so. We also received the shoulder brace, which took a few minutes to figure out (I found the instructions actually more confusing than just going off of the picture), which in addition to the cross-chest strap and arm band had an additional piece like a flap which velcroed onto the shoulder covering, under which you could theoretically place an ice pack (it was to “adjust pressure”). We ended up taking this flap piece off and then separating the velcro bits, which we found to be very effective. Then we cut the flap into a strip to glue onto the top of the wood, and attached the velcro ends onto the straps to hold the oars into the channels. We also nailed the flap strip into the wood because we found that the velcro straps were pulling at it significantly when they were being taken off. We then glued the straps onto the bottom of the wood, one at each end (as opposed to both centered) in an attempt to further distribute the weight. Then we wanted to add the foam on the bottom of the oar channel/wood/strap component like our previous prototype, but since this one would also have the shoulder brace under it we thought we might be able to use less foam. We used the same foam from our previous prototype (literally, took it off and re-used it) but sliced the strips in half so they would be thinner and less bulky, then hot glued them to the bottom of the wood and pipes. Finally, we hot glued the foam to the shoulder brace to connect both the oar holding device to the brace.

Upon testing, we found that again the main problem was balancing the oars. Putting on the brace itself was a bit tricky and definitely required two hands, at least for me), and actually I needed help from Zainab connecting the armband piece. Once on, the oars were simple enough to put in and strap in (although the strap on the far side behind me was harder), and from then it was a matter of repeated adjusting, testing, and readjusting to find the perfect balance point. However, once I did find a spot that worked, it stayed pretty secure and did not tilt too much, even while moving — both forwards and backwards, and up and down. I actually hopped a little and the oars still stayed secure. Moving from side to side did cause the oars to tilt up or down more significantly, but I wonder if actually constantly moving forward would help keep the oars from tilting. And another main issue was keeping the oar carrier on the right place on my shoulder — it slipped forwards a little, and the oars felt considerably heavy balanced on that one exact point on my shoulder.

Obviously, there is a lot to work on but I think we have still made considerable progress. We look forward to showing CRI what we have and getting their feedback!