Investigation of the Performance of an Ergonomic Handrim as a Pain-Relieving Intervention for Manual Wheelchair Users

Mapping wheelchair functions and their associated functional elements for stair climbing accessibility: a systematic review

PURPOSE

Wheelchair (WC) design elements are subjected to the accessibility and assistive needs of a person with locomotor disability. In order to pursue a holistic design for a stairclimbing WC, there is a need for literature review on WC functions reported for both stair climbing and plane surface movement.

METHODS

A total of 112 Research articles are reviewed for the purpose of extracting the relationship between WC design elements and the functions associated with them. Stairclimbing technologies are reviewed for their technological assessment in terms of functional elements associated with stairclimbing. Cross-functional mapping between functional elements and their dominant function is performed. Heat map for primary user needs and associated design elements is generated from cross mapping.

CONCLUSIONS

A design gap for user's functional needs is indicated from the review of literature on prototypes and products of WC. The literature in stairclimbing technology is primarily focussed on stair climbing capability and not on the other functional needs, such as safety, ride comfort, seat comfort, manoeuvrability, etc.Implications for rehabilitationFor attaining the goal of an effective rehabilitation, it is important to design and develop an assistive technology that can provide maximum accessibility and functioning for a person with disability. In case of locomotor disability, wheelchair (WC) is the most empowering tool that can assist people in both accessibility and activities of daily living. This review of literature was conducted to draw out the functions fulfilled by a WC, such as safety, comfort, propulsion for its users and the associated WC elements like seat, wheels, backrest, etc., that are required to fulfil those functions.WC being the most important technological intervention in the life of a person who cannot walk should be designed with the highest level of empathy. Therefore, each and every aspect of the user's physical and emotional needs should be catered up to the limits of engineering design. The research on stair climbing technologies has also grown exponentially, fuelled by technological growth in engineering mechanisms, ambient awareness sensors, actuators, etc. The review attempts to envelop such technologies and consolidate them on the basis of their capabilities and efficacies.The virtue of stair climbing has been realized through some novel and innovative mechanisms reviewed in this article that can be integrated with the research in field of functional elements required to carry out primary functions of a disabled person, such as safety, comfort, intuitiveness, etc. This review can help in coupling both of them in a more rational way where a designer who is designing the technology is more empathetic towards the design for accessibility. It can also help user in becoming more confident towards adapting a new assistive technology.

A newly developed hand rim for wheelchair tennis improves propulsion technique and efficiency in able-bodied novices

A new wheelchair tennis hand rim was developed, having a larger contact area and higher friction. How does this new hand rim compare to a regular hand rim regarding submaximal propulsion with a tennis racket during practice in novices? Twenty-four able-bodied novices (12 Regular Rim, 12 New Rim) completed a one-day experiment: pre-test, three practice-sessions and a post-test of 3 × 4 min each on a wheelchair ergometer (1.11 m/s, 7W). The New Rim group compared to the Regular Rim group, had a lower negative work per cycle (-0.83J vs. -2.06J, p = 0.01) at the post-test. There was a significantly larger increase in mechanical efficiency between the pre- and post-test in the New Rim group (2.3-3.4% vs. 2.1-2.5%, p = 0.02) compared to the Regular Rim group. The new rim led to a more ergonomic propulsion technique, with a reduction in negative power and higher mechanical efficiency between the pre- and post-test at submaximal propulsion.

In Vivo Biomechanical Assessment of a Novel Handle-Based Wheelchair Drive

Push-rim wheelchair propulsion frequently causes severe upper limb injuries in people relying on the wheelchair for ambulation. To address this problem, we developed a novel handle-based wheelchair propulsion method that follows a cyclic motion within ergonomic joint ranges of motion. The aim of this study was to measure hand propulsion forces, joint excursions and net joint torques for this novel propulsion device and to compare its performance against traditional push-rim wheelchair propulsion. We hypothesized that under similar conditions, joint excursions of this novel handle-based device will remain within their ergonomic range and that the effectiveness of the propulsion forces will be higher, leading to lower average propulsion forces compared to push-rim propulsion and reducing the risk of injury. Eight paraplegic subjects propelled the new device at two different loads on a custom-made wheelchair-based test rig. Video motion capture and force sensors were used to monitor shoulder and wrist joint kinematics and kinetics. Shoulder and wrist loads were calculated using a modified upper-extremity Wheelchair Propulsion Model available in OpenSim. The results show that with this novel propulsion device joint excursions are within their recommended ergonomic ranges, resulting in a reduced range of motion of up to 30% at the shoulder and up to 80% at the wrist, while average resultant peak forces were reduced by up to 20% compared to push-rim propulsion. Furthermore, the lower net torques at both the shoulder and wrist demonstrate the potential of this novel propulsion system to reduce the risk of upper-extremity injuries.

TECHNOLOGY TRANSFER ASSISTANCE PROJECT BRINGS VA HEALTH CARE IDEAS TO LIFE

Clinicians and staff of the Department of Veterans Affairs Health Care System (VA), who provide services to veterans, have invented many devices and methods for improving veterans' lives. However, translating those inventions to the market has been a challenge due to limited collaboration between the clinical inventors and the scientists, researchers, and engineers who can produce the prototypes necessary for licensing the technology. The VA Technology Transfer Program office and the Human Engineering Research Laboratories, a research laboratory with experience with developing prototypes and licensing technology, jointly developed a program called the Technology Transfer Assistance Project (TTAP) to bridge the gap between clinical inventors and prototypes ready for licensing. This paper describes TTAP and provides examples of the first inventions that were developed or enhanced through TTAP.

Scoping review of propelling aids for manual wheelchairs

Manual wheelchair (MWC) users face a variety of obstacles limiting their participation. Different MWC models and new add-on components intended to improve propulsion may impact users' function and participation, although there is a lack of research on this topic. The aims of this study were to: 1) identify MWC propelling aids (PA) that are reported in the literature; 2) classify the outcomes used to evaluate the influence of PA according to the International Classification of Functioning, Disability and Health (ICF); and 3) summarize evidence for the influence of PA. A scoping review was conducted in 2017 using Pubmed, Medline, Embase, CINAHL, Compendex, IEEE Xplore, RESNA and ISS proceedings, Google, and Google Scholar. The content of each manuscript was assessed by two independent reviewers. A total of 28 PA (19 human-powered; 9 power-assisted) were identified from 163 manuscripts. The three most cited ICF subdomains were "Activity & Participation" (n = 125), "Body Function" (n = 100), and "Personal Factors" (n = 55). The findings suggest an overall positive influence of PA on various ICF domains/subdomains, but initial findings should be interpreted with caution. Confirmation of the effect and safety of PA requires higher levels of evidence.

Evaluation of two wheelchair hand rim models: contact pressure distribution in straight line and curve trajectories

Manual wheelchairs are essential for people with disabilities or limited mobility. However, manual propulsion causes biomechanical loads, including contact pressures on the palms of the hands. The hand rim design has received little attention over time, remaining almost unchanged since its creation. This study investigated how two different designs of such devices - one standard and another with a contoured design - influence the contact pressure on the surface of the hands. The procedures included a figure-of-eight shape propulsion task on a regular floor, using both models on a wheelchair. A pressure-mapping system coupled with a pair of fabric gloves recorded the data. The results show that the contoured hand rim provides lower pressure in most of the analysed regions. Considering that manual propulsion is performed during a considerable part of the day as a routine activity, improving the hand rim interface may benefit the user's comfort and safety during wheelchair use. Practitioner summary: The design of the hand rim used in wheelchair propulsion influences the contact pressure on the hands. Conventional round tube rims tend to concentrate high levels of pressure on the distal phalanges and metacarpal regions. A contoured design generally provides better stability and promotes the distribution of pressure. Abbreviations: AT: assistive technology; kPa: kilopascal.

The effect of a novel square-profile hand rim on propulsion technique of wheelchair tennis players

The purpose of this study was to investigate the effect of a square-profile hand rim (SPR) on propulsion technique of wheelchair tennis players. Eight experienced wheelchair tennis players performed two sets of three submaximal exercise tests and six sprint tests on a wheelchair ergometer, once with a regular rim (RR) and once with a SPR. Torque and velocity were measured continuously and power output and timing variables were calculated. No significant differences were found in propulsion technique between the RR and SPR during the submaximal tests. When sprinting with the racket, the SPR showed a significantly lower overall speed (9.1 vs. 9.8 m s^-1), maximal speed (10.5 vs. 11.4 m s^-1), and maximal acceleration (18.6 vs. 10.9 m s^-2). The SPR does not seem to improve the propulsion technique when propelling a wheelchair with a tennis racket in the hand. However, the results gave input for new hand rim designs for wheelchair tennis.

The influence of speed and grade on wheelchair propulsion hand pattern

BACKGROUND

The hand pattern used during manual wheelchair propulsion (i.e., full-cycle hand path) can provide insight into an individual's propulsion technique. However, previous analyses of hand patterns have been limited by their focus on a single propulsion condition and reliance on subjective qualitative characterization methods. The purpose of this study was to develop a set of objective quantitative parameters to characterize hand patterns and determine the influence of propulsion speed and grade of incline on the patterns preferred by manual wheelchair users.

METHODS

Kinematic and kinetic data were collected from 170 experienced manual wheelchair users on an ergometer during three conditions: level propulsion at their self-selected speed, level propulsion at their fastest comfortable speed and graded propulsion (8%) at their level self-selected speed. Hand patterns were quantified using a set of objective parameters, and differences across conditions were identified.

FINDINGS

Increased propulsion speed resulted in a shift away from under-rim hand patterns. Increased grade of incline resulted in the hand remaining near the handrim throughout the cycle.

INTERPRETATION

Manual wheelchair users change their hand pattern based on task-specific constraints and goals. Further work is needed to investigate how differences between hand patterns influence upper extremity demand and potentially lead to the development of overuse injuries and pain.

Manual wheeled mobility--current and future developments from the human engineering research laboratories

Medical rehabilitation and assistive technology are immersed in a world transitioning to a basis in evidence-based practice. Fortunately, there is a growing body of knowledge related to manual wheelchair mobility to form a basis for clinical decision making. The results from research studies are useful for designing better wheelchairs, fitting and training people appropriately, contributing to evidence-based-medicine and guiding future research. This review describes some of the work related to manual wheelchairs that has and is being conducted within the University of Pittsburgh and the Human Engineering Research Laboratories of the United States Department of Veterans Affairs, and its application.

The natural-fit handrim: factors related to improvement in symptoms and function in wheelchair users

BACKGROUND/OBJECTIVE

People with spinal cord injury (SCI) may spend several decades using a wheelchair as their primary means of mobility. Secondary injury and a decline in independence over time are common with manual wheelchair users who, in turn, may require increased assistance as time passes. The Natural-Fit contoured handrim has been shown to improve symptoms and function in people with SCI who use manual wheelchairs and who have experienced upper extremity pain. The objective of this study was to determine the factors associated with improved symptoms and functions.

PARTICIPANTS

87 people who purchased the ergonomic wheelchair handrims. Participants were predominately men, with a median age of 51 to 55 years, median level of injury T10 to T12, median time in a wheelchair of 15 years, and they had used the contoured rims for 1 to 2 years.

METHODS

This was a mail survey of 217 people who purchased the rims. The survey was mailed out from the manufacturer and was anonymously returned to the physical therapy department of a university. A $10 incentive was offered for returning the survey.

RESULTS

The majority of participants reported improvements in upper extremity symptoms, ease of wheelchair propulsion, and functional status. Longer use of the rims was associated with reported improvement in ease of wheelchair propulsion and reduction in pain in hands and wrists.

CONCLUSION

If a simple modification of the wheelchair can help bring about significant changes in the users' symptoms and function, this modification should be incorporated by people who use manual wheelchairs before decline in function begins. Proactive intervention may alleviate symptoms, help the person maintain maximal independence, and prolong the length of time the individual remains independent.