By Angela Henderson//
ABSTRACT// The objective of the project discussed in this article is the re-design of an existing standard axillary crutch. The axillary crutch is a versatile prosthetic device, but has limited function and little aesthetic value as a mobility aid for people living with lower limb amputations.
Here, designers work co-creatively with a thirty-four year old female with an above the knee amputation and consult with physiotherapists at the G.F. Strong Rehabilitation Centre. The project considers the goal of improved portability in the axillary crutch through explorations in collapsibility. Tailored solutions for a specific co-creator, such as providing personalized aesthetics in the device, are also defined.
Axillary Crutch, Re-design, Co-creation, Collapsibility, Amputation, Prototyping, Aesthetic, Mobility Aid
INTRODUCTION// This project was part of a medical and assistive care design course at the Emily Carr University of Art and Design. In collaboration with professionals at the G.F. Strong Rehabilitation Center, our team worked to redesign an existing axillary crutch to better meet the needs of our co-creator, a thirty-four year old female living with an above the knee amputation. Through qualitative investigations of such a disability, including co-creative activities with both a disabled individual and medical professionals, we intended to improve upon the design of the axillary crutch.
Methods// In order to investigate and understand the physical and emotional experience of a person with a disability, we engaged in an exercise that meant temporarily disabling a limb over a period of time. Our design team cast their bodies to inhibit limb function and then attempted to go about daily activities. This exercise mentally prepared us to meet with our co-creator, whom we interviewed to understand her needs and desires in a mobility aid and her criticisms of existing products. We visited her home to educate ourselves regarding her daily life, routine and needs from this project. To further investigate mobility aids, we met with medical professionals and conducted a literature search to explore existing options, including pertinent side effects and standard criticisms. We created numerous prototypes which helped direct the physical outcome of the product. Through these methods, several prominent constraints were identified. These included navigating the potential for stress injuries associated with extended axillary crutch use as well as considering portability, collapsibility and crutch aesthetics.
Current Mobility Aids// Mobility aids for people living with lower limb amputations include crutches, hinged prosthetic devices and wheelchairs. Prosthetics, wheelchairs, and crutches have unique functions and enable those living with disabilities to navigate an able-bodied environment. After some investigation, we realized that crutches fall into two main categories: forearm and axillary. A visit to G.F. Strong enabled us to examine both types of crutches, better understanding the benefits and problems associated with each of them. In discussion with a Physiatrist at G.F. Strong we understood that while the forearm crutch enables a longer stride and a faster pace, many patients experience stress on the wrist, resulting in fatigue with extended use. This is particularly common, given that forearm crutches are considered standard for those with permanent disabilities. On the other hand, axillary crutches are considered standard for those with temporary injuries and are discouraged for those with permanent disabilities. While they are easier to use, axillary crutches are associated with brachial plexus injury, a condition colloquially known as Crutch Palsy (Raikin and Froimson, 1997). Understanding the positive and negative elements of the crutch was essential to glean useful information from our co-creator in her experiential understanding of crutch use.
Collaboration// Co-creation and collaboration educates designers while helping them manage constraints (Sanders and Stappers, 2008). The effectiveness of co-creation depends in part on the setting in which one gathers information (Buchenau, 2000). We chose several settings for collaboration and co-creation. An information session with G.F. Strong helped identify universal issues and advantages associated with crutch use, both forearm and axillary. The professional setting of G.F. Strong offered a broad range of information that lent itself to universal design whereas an informal meeting with our co-creator in her home revealed information of a more personal nature; she commented on her experience with frequent axillary crutch use, telling us about the side effects of pain in her shoulders and upper body. She also expressed her need for collapsibility in a crutch to facilitate ease of mobility while traveling; something she does on a routine basis as part of the national Para Olympic basketball team. Finally, the issue of aesthetics came forward. She felt that the current aesthetic of her standard axillary crutch was not only unattractive but impersonal. Her desire for a personalized aesthetic revealed her relationship with her crutches as an extension of her body (Scarry, 1985). Collaboration with G.F. Strong and our co-creator helped us to clearly define our project goals: reducing the potential for stress injuries to the brachial plexus1, increasing mobility through collapsibility and developing a more personalized aesthetic.
Re-designing the axillary crutch with our co-creator provided an opportunity to design for her specific needs. The first meetings revealed her reasons for using the axillary crutch instead of the forearm crutch. The ability to travel a greater distance without tiring and to transition from crutch to hands-free while performing daily tasks was of primary importance. Prototyping based on feedback from our co-creator allowed us to further refine the concept and ask more directed questions. What was her natural inclination when using the axillary crutch, how does this differ when in a stabile position verses in motion? Would a hybrid between the forearm and axillary crutch offer further support? Is there a need for more forearm support?
Research on Axillary Crutches// To further understand the physiology of the brachial plexus, we contacted a kinesiologist. This meeting helped us to not only better understand the potential damage resulting from long term crutch use, but to rethink ways of lessening risk of injury by facilitating neutral posture. We learned that the impact of regular misuse of the axillary crutch affects not only axillary nerves but can also impact the ulnar and radial nerves (Youdas, Kotajarvi, Padgett, and Kaufman, 2005) This information led us to explore alternatives for the underarm piece of the axillary crutch. We also discovered that weight distribution of axillary crutches creates stress on the wrist due to the angle of the crutch handle. Research revealed that the optimal angle for stress reduction to be twelve degrees below horizontal. This creates optimal weight redistribution on the wrist and forearm (Youdas et all.). With this information, we were better prepared to begin the creation of prototypes.
We started our ideation process by sketching. Figure one shows a concept we developed regarding collapsibility and stress injuries. This process of ideating through sketching created new ideas throughout the project. With a range of ideations and feedback from our co-creator, we began to connect drawn concepts to physical forms through prototyping.
We began prototyping underarms pieces (Fig. 2) to reduce impact on the brachial plexus and encourage neutral posture. These components were designed to be tested with an adjustable trial prototype (Fig. 3). To further reduce stress, we focused on the potential for impact on the forearm and wrist.
The adjustable trial prototype (Fig. 3) enabled us to map the ergonomics of our co-creator’s body while static. To further understand her interaction with a mobility aid, we then mapped the ergonomics of her body while dynamic. With this information, we began to build a product prototype (Fig. 4). The process of mapping and prototyping with our co-creator narrowed the project’s ergonomic goals (Buchenau, 2000).
After testing underarm pieces with our co-creator, we received extensive feedback. She stated that none of the prototypes felt as natural to use as the current underarm piece of her standard axillary crutch; she highlighted where there may be potential modification in the design, commenting on the comfort of a more minimal form. With this feedback we met the physiotherapists at G.F. Strong. In discussion with our co-creator’s physiotherapist, we came to understand that we did not need to focus on a re-design for the underarm piece of the crutch since our co-creator did not use her underarm crutch in a way related to stress injuries. With this feedback, we were able to narrow the constraints of the project. Our objectives became clearly defined as working to increase mobility through collapsibility, and personalizing the aesthetic.
Testing the product prototype (Fig. 4) based on our previous ergonomic findings revealed that the addition of the forearm support meant the crutch was actually less functional. When testing the prototype during construction, we found that we were more inclined to hold the crutch close to our person in both a stabile position and while in motion – similar to what a new crutch user would do. As a result, when this prototype was tested with our co-creator, she saw very little relevance in the placement of the forearm piece. However, the added support of a forearm crutch was of interest to her and she saw the potential in exploring a hybrid of forms. Additionally, we recognized the need for a new prototype that would facilitate adjustment much like our first prototype (Fig. 3). Ultimately, we recognized the need to work without compromising the functional elements of our co-creator’s existing crutches. With this non-negotiable constraint, and our co-creator’s hopes for increased mobility through collapsibility and personalized aesthetics, we were able to focus on combining these elements into a new prototype (Fig. 5).
A New Prototype// With clear constraints in mind, we focused on paring down the form to meet our new design criteria. Investigating the underarm, forearm and handle as they relate to the body meant experimentation with form through the use of wet clay. Holding the clay in our hands, we were able to see the form of the hand as it related to holding the handle of the crutch, as well as the curves of the body in relation to the underarm. This enabled us to pare down the form of the crutch in a way that fit the ergonomics of the body. To facilitate collapsibility, we used an existing mechanism in the height adjust on the standard axillary crutch. We employed this same mechanism in locking the collapsible crutch into an open and closed position.
As the form became pared down, becoming more comfortable and portable, we incorporated the collapsing mechanism to construct a final testable prototype (Fig. 5). At this stage we met with both our co-creator and the physiotherapists from G.F. Strong to present them with our work. It appeared that while the issue of comfort required further modifications, the collapsible component held significant potential as a viable solution. While this prototype has fulfilled the requirements for the studio deliverables, this collaboration will continue as we work to find a solution to meet the needs of a woman living with a disability.
CONCLUSION// The process of design involves gleaning information from a variety of sources. A source of valid information in the process of re-designing a mobility aid is medical literature which facilitates a better understanding of the issues surrounding these devices. Meanwhile, collaboration with medical professionals allows one to better understand this information by tapping the vast anecdotal experience and knowledge on the subject. Finally, through collaboration with the end user, one is able to achieve a more personalized and practical understanding of the issues surrounding product design. Through these sources, a designer is better able to understand the broad issues at hand, and gradually narrow the focus to a personalized, usable end product.
Buchenau, M., Fulton Suri, J. E. (2000). Experience Prototyping. Proceedings of the 3rd Conference onDesigning Interactive Systems. ACM Press.
Raikin, S., Froimson, M. (1997) Bilateral Brachial Plexus Compressive Neuropathy (Crutch Palsy). Abstract. Retrieved from: http://www.ncbi.nlm.nih.gov/pubmed.9057152?log$=activity. March 31, 2010
Sanders, E., Stappers, P. (2008). Co-creation and the New Landscapes of Design. Co-Design, 5-18
Scarry, E. (1985) The Body in Pain: The Making and Unmaking of the World. Oxford University Press, 278-286.
Youdas, J., Kotajarvi, B., Padgett, D., Kaufman, K. (2005) Partial Weight-Bearing Gait Using Conventional AssistiveDevices. Abstract. Retrieved from:http://www.ncbi.nlm.nih.gov/pubmed/15759217?log$=activity. March 31, 2010.
Figure 1. Angela Henderson (2009)
Figure 2. Angela Henderson (2009)
Figure 3. Angela Henderson (2009)
Figure 4. Angela Henderson (2009)
Figure 5. Angela Henderson (2009)
FOOTNOTE: brachial plexus is an arrangement of nerve fibers, running from the spine, formed by the ventral rami of the lower four cervical and first thoracic nerve roots (C5-T1). It proceeds through the neck, the axilla (armpit region), and into the arm. (http://en.wikipedia.org/wiki/Brachial_plexus)