Abstract:
Reduced grip strength can affect certain para-rower’s ability to maintain contact to the oar, feather or rotate the oar, and decrease the rower’s overall comfort during extended periods of rowing. Companies, such as Active Hands (1), have made grip aids that intend to serve this purpose but these grip aids are too restrictive and lack quick releases which threatens the lives of the rowers in the incident of a capsize. Although “capsizes are quite rare… on average [there is] one or two every year” (2), in which all rowers safety should be ensured. In our research, we explored how to make a grip aid that does not compromise safety. At first we made a prototype that was a fingerless glove with a rubber cylinder attached that could slide onto the oar to keep the rower connected. Then we visited a para-rower with reduced grip strength at Community Rowing Inc. to get feedback. What we found was reduced grip strength can cause curling of the fingers which makes it difficult to put gloves on, but the security of finger holes and velcro around the wrist was liked. This led to the final design in which we removed excess fabric on the top of the hand and made only the three middle fingers have fabric rising right below the knuckle, then the thumb and pinky only have holes. Overall the design has been successful in increasing grip strength and connection to the oar while not compromising safety.
Problem Statement:
When a rower has reduced grip strength, it makes it harder to hold on to the oars and maintain a solid connection. In order to row efficiently, the rower needs to curl their fingers around the oar and place their thumb on the tip for maximum control. Josh’s index and middle fingers in his right hand have nerve damage, which results in both of them curling and decreased control over them. Our goal was to design a glove that was both easily accessible and stable, but allowed the user to easily escape.
Design Specifications:
| Attribute | Metric | Unit | Value |
| Visibility | time to spot | seconds | < 3 sec. |
| Intuitiveness | time to understand | seconds | < 30 sec. |
| Lightweight | weight | ounces | < 1 oz. |
| Versatility in Size | accessible to different sized hands | small/large | |
| Shape Retention | stretching over time | tautness yes/no | determined over time |
| Oar Accessibility | ease of use | yes/no | yes |
| Max. Force Applied | no breakage | Newtons | ???* |
*An approximate estimate of the force was not possible because the grip aid has not been tested on the water yet.
Our design specifications are diverse ranging from visibility to shape retention; the reason for each is as follows:
- Visibility– Being able to spot the rower’s hand helps a coach to check for proper technique. Furthermore, if it is brightly colored, it is easy to spot and find.
- Intuitiveness– The grip aid should be easily accessed and understood; the design needed to be simple and the user should understand how to use the aid almost immediately
- Lightweight– Bulk would impede the rower’s ability to feather and move naturally with the oar, so the grip aid needed to be light and almost negligible in weight
- Versatility in size– Needed to be accessible to all hand sizes
- Shape retention– To prevent distortion over time and increase durability so the user does not need to continually replace the glove
- Oar accessibility– The grip aid needed to be easily slipped over the oar handle, yet remain flush to the surface of the oar so it didn’t slide off
- Maximum force applied– The oar grip portion of the grip aid needed to be able to withstand a certain amount of force so it didn’t rip off of the glove
Design Concepts:
The grip aid designs we considered targeted the construction of the hand covering and included a fingerless glove, a fingerless glove with fabric extending to below the wrist, and a full glove. Both fingerless glove designs were very similar in construction, complete with a buckle and velcro closure, the only differing factor being the length of the glove. The full glove design completely covered the fingers that would be sewn on to the oar attachment piece; an elastic closure replaced the velcro closures present in the other two designs.
We ultimately chose the ‘extended’ fingerless grip aid, with the rationale that a closure below the wrist would provide more security while maximizing the mobility of the fingers. Upon testing and receiving feedback from Josh, it was concluded that a closure below the wrist was the most effective way to secure the grip aid, but a portion of the fabric from the upper hand needed to be cut out to increase accessibility and ease of use. To that opening, elastic was sewn on the inside to create a bunching effect that allows the cut out to lay flat to the back of the hand.
Detailed Description:
The feathering grip aid is constructed of double layered neoprene which is semi-waterproof and has stretch for a comfortable fit. The glove had material that rises below the knuckle on only the three middle fingers to increase security without decreasing the ease at which the glove is placed on the hand. The velcro is secured around the wrist to ensure an easy release to not compromise safety or feeling of security of the glove on the hand. The rubber oar attachment is secured to the upper palm of the glove to attach to the oar in a comfortable position. The oar attachment has elastic secured to the rubber so it does not slide around on the rubber oar attachment.
Instruction Manual:
- Find a glove pattern that resembles the size of hand that you wish to create the grip aid for.
- Trace and cut the pattern (back, front, and side flap) to exact size. Further trace on the glove front where you would like to cut out the back of the hand, making sure there is at least a ¾ inch border around from the fabric to the cut.
- Transfer any markings, such as places to sew for finger holes.
- Pin patterns to fabric, trace with chalk, and cut
- Use push pins to pin the patterns to the WRONG side of the fabric; the wrong side is the color that will be on the inside of the glove.
- Use fabric scissors to cut the pattern from the fabric
- Transfer markings again.
- Align fabric back and front pieces and pin together
- The back should show the right color, the front should show the wrong color.
- Sew along where the bottom of pinkie hole would be to the end of the wrist on the left
- Always be sure to backstitch to reduce rips and tears
- Sew around the markings for finger holes; this will create a small raised edge when flipped inside out.
- Sew from the top of the index finger to the top of the thumb hole
- Align the flap with the right edge of the wrist portion of the pattern and pin; they should be flush and there should be three pieces of fabric total to sew together
- Sew from the bottom of the thumb hole to the end of the wrist on the right
- Stretch and pin elastic around the opening on the front
- This will cause a ballet flat type of effect and pull the glove flush to the skin and ensure it stays there
- Be sure to remove pins as you go, otherwise they’ll pick you and you’ll be sad
- Sew on velcro to the corresponding flaps on the wrist portion
- Oar attachment
- First the following materials must be measured out of elastic, neoprene, and rubber with 30 or 40 elasticity
- Next the neoprene and rubber should be sewn together. The the elastic will be sewn into place onto the rubber.
- Lastly the neoprene and rubber can be sewn together to make a final cylinder that will be sewn onto the glove.
- Sew the oar attachment to the glove
- Place the glove on a model hand and pin in place the oar attachment with the neoprene material of glove and oar attchment touching
- Hand sew the neoprene of the oar attachment securely onto the glove, being careful to go through all materials of the neoprene
Methodologies and Results:
The main method we used to progress with our design was trial and error. Almost every week we would create a new design and then test it to see how it felt and performed on the oar and hand. Originally we created a glove that extended to the wrist with a full velcro closure but found this to be too bulky and restricting on wrist movements. We then moved away from the extended glove design and shortened it down to the palm to increase wrist mobility, although the feedback from our CRI partner expressed interest in the extended glove design. We then reverted back to this extended design and fine-tuned it by removing the bulk of velcro and neoprene material. Although when the bulk of the material was removed we noticed this caused gaping so we then added elastic inside to reduce gaping and increase security. We decreased the amount of velcro being used to only secure the wrist and only have the middle three fingers be secured by material while the thumb and pinky have holes for easier access to put on the hand.
Final Design and Shortcomings:
Generally speaking, our final design aligns well with our design specifications. The grip aid itself is highly visible and constructed of bright orange neoprene, lightweight, and intuitive enough that the user can see it is a glove and figure out the closure [EDIT]. The glove easily slides onto the oar and stays put because rowing motion is back and forth rather than side to side. The glove can be made into different sizes depending on the size of the user, but it is impossible to create a ‘one size fits all’ for this device. In regards to shape retention, the neoprene stretches a small amount and over time would lead to the glove becoming too large.
A major shortcoming of the grip aid is the neoprene it is constructed out of. It works well for the fingers and the back of the hand because it is structured, but provides a little stretch. However, for the palm, it is too bulky and causes unwanted bunching where the rower needs to feel the oar. For the future, a mixture of materials should be explored to find a breathable substitute for the fabric on the palm of the hand. Furthermore, the oar attachment is a hand sewn on to the glove, which naturally makes it weaker and more susceptible to tears and ripping. In this case, an industrial sewing machine, or something much more study should be used to adhere the rubber to the glove.
Response to Design:
We have corresponded with Josh, our community partner, and the feedback as of now has been wonderful. He likes the open back feature of our newest prototype and we are currently following up with him to make sure the prototypes we send to CRI fit his hands. Furthermore, we’d like to follow up to look at the durability of the grip aids over time to see which component breaks down fastest. We will also hopefully be speaking to a woman at MIT with access to an industrial sewing machine to learn techniques that will help reinforce the rubber oar grip.
Citations:
- “Home – The Active Hands Company.” The Active Hands Company. N.p., n.d. Web. 07 Dec. 2016. <http://www.activehands.com/>
- “CamboisRowing Club.” Cambois Rowing Club – Frequently Asked Questions. N.p., n.d. Web. 07 Dec. 2016. <http://www.cambois-rowing.org/FAQ.aspx>