RESNA 26th International Annual Confence

Technology & Disability: Research, Design, Practice & Policy

June 19 to June 23, 2003
Atlanta, Georgia


THE RETRACTABLE REACHER

Elisha Williams, Meg Casey, Andrea Zariwny, Alyssa Warren, & Christine Oldfield
University of Alberta
Edmonton, AB Canada

ABSTRACT

Thousands of people use reachers for assistance in completing activities of daily living. Standard reachers extend the range of reach of the user, which reduces the user's need to stretch or bend over to obtain objects. Current standard reacher designs have several limitations: most handles are difficult to hold onto because they are bulky and made of a hard plastic, trigger mechanisms require excessive grip strength, not all reachers have locking mechanisms for the pinchers, some reachers are quite heavy (>1 lb.) and it is awkward to retrieve items from the pinchers of the reacher. The purpose of modifying the standard reacher was to decrease the physical demands that a reacher places on its' users by enhancing the universality of the design.

BACKGROUND

Most reachers are designed to assist individuals with their activities of daily living. However, a recent study found that reachers today are most commonly used for picking up remote controls, picking up newspaper off the floor, taking cans or dishes in/out of cupboards, dressing and pulling up socks, and opening/closing drawers (1). In a literature review, we found there were certain characteristics of a reacher deemed to be more favourable than others. These included: lightweight design, forearm support, a locking mechanism, ease of use, and adequate length and strength (1). Today, older adults and individuals who have arthritis, stroke, hip or knee replacements, decreased strength and range of motion, and wheelchair users commonly use reachers. In communicating with older adults in the community, we have determined that there is a need to modify the current reacher design.

STATEMENT OF PROBLEM

Many potential users are unable to operate a standard reacher due to the physical demands it places on the user. Limitations of the standard reacher are as follows: most handles are difficult to hold, trigger mechanisms require too much grip strength, not all reachers have locking mechanisms thus increased endurance of grip strength is required to hold pinchers closed, the reachers are too heavy (> 1 lb.), the pinchers are not flexible enough to pick of a large variety of objects, the magnet on the end of the pinchers is ineffective, and it is awkward to retrieve items off the end of a reacher because it requires a large range of shoulder motion.

RATIONALE

Many individuals experience a loss of independence during their lifespan due to natural or pathological changes to their body. Currently many individuals with limited grip strength or shoulder range of motion find it difficult to use a standard reacher. Therefore, they utilize unsafe practices of standing on a chair to retrieve objects out of reach or depend on others to assist them with self-care tasks such as dressing. By decreasing the physical demands required to operate a reacher more people will be able to use reachers to maintain or regain independence in their activities of daily living in a safe and convenient manner (2). The newly designed retractable reacher incorporates many features that facilitate independence in older adults as well as other populations, including those with disabilities.

DEVELOPMENT

Our reacher was modified according to the measurements and strength of an 80 year old women. See Table 1 (3 & 4). We decided to limit the weight of our reacher to approximately 1 lb. and the length to 75 cm because this was found to be the preferred weight and length of older adults (1). The maximal weight our reacher will be able to pick up is approximately 5 lbs. A heavier object would require our user to have increased strength. We also consider the cost when designing our reacher. Our design uses simple mechanics (spring and cable system) in order to keep the price close to exsiting cost of $30 US.

DESIGN

Table 1: Fifth Percentile of 80-Year-Old Woman

Grip Strength

180N

"Pull" Strength

100N

Hand Width

7.8cm

Forearm Length

24cm

The handle has been redesigned to accommodate a large variety of hand sizes. It will be adjustable to hand width by repositioning the base of the handle by securing 3 screws into preset holes at different heights ranging from 7.5cm to 11.05cm. The handle will also be tapered at the top for easier access to the lever. Plastigrip will be used to rubberize the handle, which will provide a non-slip, comfortable grip. To close and lock the pincher, the user will simply pull a lever towards the handle (Figure 1). For every two degrees the lever is pulled, the pinchers close four degrees. This feature reduces the range the user will have to pull on the lever to close the pinchers. The pinchers automatically lock once the lever stops moving. A sliding switch will be located on the thumb side of the handle and when moved down will retract the shaft (Figure 1). Both the triggers will be labelled and will be different, contrasting colours to the handle so they can easily be seen.

The shaft of the reacher will telescopically retract to half of its original length. A rubber stopper located near the end of the proximal portion of the shaft will be released when the sliding switch is moved down triggering the spring to retract the reacher. In order to return the reacher to its original length, the user will pull the movable (distal) end of the shaft back to the starting position. To accommodate for wear and tear of the spring, the user can tighten the spring at the end of the handle. A damper is placed at the end of the proximal shaft in order to control the speed of retraction (Figure 1).

The pinchers will open to 90° and will pivot 360° to allow the user to adjust the pincher to their preferred angle (Figure 1). Redesigning the pinchers to be wider, longer, and smoother than a standard reacher allows the user to retrieve a larger variety of objects. Current reacher magnets appear ineffective therefore we have incorporated a stronger and wider magnet mounted on the end of the upper pincher to pick up objects such as coins and jewellery.

The reacher will also have a removable forearm support (Figure 1). This feature will decrease the stress on the small joints of the wrist and hand and help to counterbalance the weight of the distal end of the reacher by distributing it across the forearm. The support will be made from a mouldable plastic for optimal fit around the forearm of the user. It will spiral around the forearm and will be able to pivot around the end of the reacher in order to maintain continuous support for all planes of motion.

EVALUATION

This reacher contains all seven universal design principles (5). This affordable and effective design appeals to all ages and many levels of physical ability. The retractable reacher is flexible because it will accommodate for all kinds of users: left/right handed, one handed, small/large hands, and weak/strong grip and arm strengths. The locking and retractable mechanisms are simple to use. As previously mentioned, there are many features that provide perceptual stimulation, these include: colour contrasted triggers, labelled switches, different triggers for different functions (a lever and a switch), rubberized handle, and mouldable forearm support. The reacher is safe to use because all mechanical mechanisms are enclosed in the shaft or the handle of the reacher. Minimal physical effort including range of motion, strength, and repetitive actions are required. Lastly, appropriate size and weight of the reacher allows for easy manipulation regardless of the user's body size, strength, range of motion, posture, and means of mobility.

DISCUSSION

Using these principles as the basis of our design, our reacher is practical for everyone! Many of the commonly experienced disabilities older adults and other populations face are addressed by our modifications to current standard reachers. Current reachers meet the needs of many users but have some limitations such as requiring large hands, the ability to maintain a strong grip, and a large range of shoulder extension. By retracting and locking, our reacher limits the amount of shoulder range of motion the user must undergo to retrieve an item from the pinchers of the reacher and decreases the grip strength endurance a user must possess. Overall, these modifications will facilitate the ability of the user to independently complete many activities of daily living.

REFERENCES

  1. Chen, L., Mann, W., Tomita, M. and Burford, T. (1998). An evaluation of reachers for use by older persons with disabilities. Assistive Technology, 10, 113-125.
  2. Barger, A., Funkhouser, K., Gravitz, T., Jusko, H., Lokke, S., McCullen, L., Nguyen, D. and Moyers, P. (2000). Potential variables affecting the use of reachers by the elderly. Physical and Occupational Therapy in Geriatrics 17(3), 51-63.
  3. Voorbij, A. and Steenbekkers, L. (2001). The composition of a graph on the decline of total body strength with age based on pushing, pulling, twisting and gripping force. Applied Ergonomics, 32, 287-292.
  4. Kothiyal, K. and Tettey, S. (2001). Anthropometry for design for the elderly. International Journal of Occupational Safety and Ergonomics, 7(1), 15-34.
  5. Connell, B., Jones, M., Mace, R., Mueller, J., Mullick, A., Ostroff, E., Sanford, J., Steinfeld, E., Story, M. and Vanderheiden, G. (1997) What is universal design: the principles. Retrieved November 16, 2002 from the World Wide Web: http://www.design.ncsu.edu/cud/univ_design/princ_overview.htm

ACKNOWLEDGMENTS

We would like to thank Dr. Ken Fyfe and Tyler Tamell of the University of Alberta for their explanations regarding the mechanical systems for this project.

Elisha Williams
#316 155 Royal Rd.
Edmonton, AB Canada T6J 2E9

Figure 1: Retractable Reacher Design
details of components of the retractable reacher.

 

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