RESNA 26th International Annual Confence

Technology & Disability: Research, Design, Practice & Policy

June 19 to June 23, 2003
Atlanta, Georgia


Jayn McIntosh and Reid Bayly
University of Alberta
Industrial Design
Edmonton, Alberta CANADA


Maintaining independence within the home setting is a common goal for the aging or disabled population. Often small additions to their home setting through after-market products and adaptations can enhance their abilities helping to reach a new level of comfort. The prefix "omni" implies universality and all- encompassing, and the noun "lever" as defined by the Merriam Webster's Collegiate Dictionary, is a rigid piece that transmits and modifies force or motion when forces are applied at two points and it turns about a third. Developing a product based on these principles is the basis for the Omnilever.


Knobs used within a house are designed for people with sufficient strength, manual dexterity, and range of motion in their wrists. The circular knobs are often too slippery or difficult to grasp for those with impairments, as they may lack the grasping ability that is required to grip the knob, and then the strength required to turn them. The problem for the user may arise with medical conditions ranging from arthritis, MS, and generalized weakness, to upper extremity amputations and neurological symptoms such as upper extremity spasticity. Although current lever style handles exist, and laser sensor technology eliminates the need for taps, these are often costly and are not always feasible to install in the home. The concept of the OmniLever is to alter current knob style taps and door handles easily and affordably.

According to the Aids to Independent Living Manual issued by the Canadian Government, "A small piece of wooden dowelling attached with wire is all that's needed" (Government of Canada.1994) Technically this is all that is physically required in order to adapt a knob style handle to a lever style, but is the appearance and installation user friendly? Similar products have been developed to address the concept of knob adaptation using lever style handles, but often they are costly, limited in their availability to special needs stores, they accommodate very specific knob types, and some address traction but do not address reduced hand grasp. Most importantly, all of the products require complicated installation that the limitations of the intended user prevent them from doing it themselves, and fail to address the overall aesthetic concerns of the product.


The main objective of designing knob adaptor was to incorporate solutions to the above mentioned fallacies with the existing products and technology. Focus on incorporating multi-functions for the Omnilever while adhering to the possible limitations of the user were further objectives, as well as material choice, feasibility of production, and possible distribution avenues.


The after-market product that we have designed is called the Omnilever (refer to figure 1). The purpose of this product is to reduce the force required to turn a tap knob, or any other type of knob fixture. Not only is the force required to turn the knob reduced, but also the type of motion and hand position is more advantageous. A rotational force is required to turn a standard knob. This motion requires use of the small muscles of the hand and muscles crossing the wrist. On the other hand, a tangential force is required to turn the lever on the OmniLever. The motion required to produce this force is linear as opposed to rotational. When pushing a lever as opposed to twisting a knob, a person is able to utilize large muscle groups and thereby, conserve energy as well as reduce stress on any one particular joint. Furthermore, the tangential force can be decreased by extending the lever, as was incorporated into our OmniLever. A tangential force enables a person to use larger joints to generate force. Such motion is an inefficient use of energy. This reduces stress on any one particular joint (such as in a twisting motion of the wrist).

Further aspects of the Omnilever include a large tab at the base of the product which allows for easy removal and the tapered internal treads allow for easy installation even for those with physical limitations. The OmniLever is equipped with flexible interior tapered treads as mentioned above, also enable it to be adapted to household knobs of various shapes, sizes and brands, including sink handles, door knobs and even hose valves. An additional feature is a removable snap-in button at the top of each lever, which allows for easy access to doorknobs with keyholes. The button also acts as a colored indicator for hot and cold taps and includes Braille on the top to cater to visually impaired users with an `H' or `C' for hot and cold. The small nature of the OmniLever ensures that it is readily transportable to further adapt to public spaces, which also addresses issues of personal hygiene. The loop through the center makes carabiner attachment a possibility or it can simply be carried in a bag or purse.

The material choice is the commercially manufactured Dycem Rubber. The company currently specializes in Non-Slip products manufactured from polyester plasticizers and polymeric compositions based on a special non-slip formulation, manufactured by the emulsion process. They do not contain latex. Their product line currently includes Aids for Daily Living products such as jar openers and non-slip trays, and is guaranteed safe and user friendly.

The Omnilever would be injection moulded with this rubber with the use of only one mould which makes production affordable and the possibility for mass-production very easy, which thereby decreases the cost for the consumer. An added benefit of the rubber material chosen is its durable and latex-free nature, resulting in an easy to clean product, which even accommodates for those with allergies. Furthermore, this rubber allows for superior grip and traction on the contact surface. Offering a selection of colors would accommodate an array of aesthetic preferences.


The OmniLever addresses many of the functional issues experienced by older adults as well as other physically challenged users when using household knobs. As already mentioned this adaptive device requires only a slight pushing or pulling motion, as opposed to an awkward twisting motion. Those who experience generalized weakness, weakened grip strength, limited range of motion in the wrists, pain, hypersensitivity on the palmer surface of the hand, poor fine motor control, or even amputations of the hand or digits, will find this modification beneficial because it will demand less force in manipulating the faucet. These benefits are particularly pertinent to the aging population, who experience common issues of limited motor control, decreased grip strength, poor range of motion, and joint pain. In addition, people of all ages living with arthritis can benefit from the OmniLever. This device requires less force and supports an ergonomically correct motion by distributing the force across larger joints. For people with arthritis, who often suffer from joint pain and destructive joint flare-ups, the OmniLever can ease and prevent unnecessary exacerbations of their symptoms. The advantage of this product lies in its universality; not only can it address the concerns of the aging and physically impaired populations, but it can also assist even the younger population in everyday self-care activities. Young children often have difficulty using household knobs due to their small hands and limited strength. Our OmniLever enables children to independently use taps and doorknobs by replacing the difficulties of the twisting motion with the push/pull lever, and by avoiding limitations imposed by the standard, large diameter knobs. Finally, apart from the obvious groups, people with carpal tunnel syndrome, Multiple Sclerosis, fibromyalgia, or those who have suffered a stroke or suffered a variety of hand injuries, could greatly benefit on a daily basis by adapting their faucets with the OmniLever.


The Omnilever is a product that has high potential for distribution in large retail centers. Although most current homes are installed with the lever-style handles, there are many- especially in the elder population where doors and taps would benefit from the product. Due to the ease of production, cost efficiency and high demand high, the Omnilever has the potential for retailing at approximately $20.00 CDN/pair.

Further development of the product might include variations in sizing to accommodate greater variance in knob sizes and types, more color variations or translucencies and the possibility of extending the product into a line of ADL products


  1. Government of Canada. Aids to Independent Living: Breaking Through the Barriers. Minister of Human Resources Development. Ottawa, 1994.
  2. Merriam Webster Collegiate Dictionary. November 2002.
  3. Dycem Technologies. November 2002.

Appendix A

Figure 1. Diagram of the OmniLever
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