Wheelchair propulsion biomechanics and wheelers' quality of life: an exploratory review

Purpose.?To provide an overview of associations between wheelchair propulsion biomechanics for both everyday and racing wheelchairs, wheeling-related upper limb injuries, and quality of life of manual wheelchair users through a synthesis of the available information.

Methods.?A search of publications was carried out in PubMed and SportsDiscus databases. Studies on wheelchair propulsion biomechanics, upper limb injuries associated with wheelchair propulsion and quality of life of wheelchair users were identified. Relevant articles cited in identified articles but not cited in PubMed or SportsDiscus were also included.

Results.?Wheelchair sports participation has positive impact on quality of life and research in racing wheelchair biomechanics can indirectly promote the visibility of wheelchair sports. The impact of pushrim-activated power-assisted wheelchairs (a hybrid between manual and battery-powered wheelchairs) and geared manual wheels on wheelers' everyday life were discussed.

Conclusions.?The study of wheelchair propulsion biomechanics focuses on how a wheelchair user imparts power to the wheels to achieve mobility and the accumulated knowledge can help to improve wheelchair users’ mobility, reduce physical stress associated with wheelchair propulsion, and as a result, enhance quality of life.     

Analyzing wheelchair mobility patterns of community-dwelling older adults

This study determined and compared wheelchair mobility patterns for older adults during an organized sporting event and within their community. In July 2008, 39 veterans participating in the 28th National Veterans Wheelchair Games (Omaha, Nebraska) completed the study. Of these, 26 were manual wheelchair and 13 were power wheelchair users. We collected wheelchair-related mobility data using wheelchair data-logging devices. Participants were significantly more active using manual wheelchairs during the games than when using their wheelchairs in their homes in terms of distance traveled (4,466.2 vs 1,367.4 m, p < 0.001) and average speed of propulsion (0.76 vs 0.64 m/s, p < 0.001). The trend was the same for power wheelchair users, with respect to distance (7,306.2 vs 3,450.5 m, p = 0.004) and average speed (0.9 vs 0.7 m/s, p = 0.002). This study demonstrates an objective method of evaluating wheelchair use in community-dwelling older adults.     

A review of manual wheelchairs

Purpose: To review the scientific literature published in the last 14 years on the different types of manual wheelchairs. Method: A systematic review of the literature was conducted to find the recent research on manual wheelchairs. Results: The findings of 77 references on pushrim-propelled wheelchairs, crank-propelled wheelchairs, lever-propelled wheelchairs, geared manual wheelchairs and pushrim-activated power-assist wheelchairs are reported. Conclusion: The pushrim-propelled wheelchair is light, easy to steer and has good indoor manoeuvrability but is very inefficient and causes serious upper body overloading so that long-term use leads to steadily deteriorating capability for the user and ultimately a transition to a powered chair. Whilst the latter is less physically demanding, the sedentary lifestyle and decreasing muscle use lead to several secondary health problems. Crank- and lever-propelled wheelchairs and geared pushrim wheelchairs are more efficient and less demanding and may improve the quality of life of the user by expanding the range of accessible environments, reducing upper body pain, increasing independence and avoiding or delaying the ‘debilitating cycle’. However, wheelchairs with these alternative modes of propulsion are often heavier, wider and/or longer and are less easy to steer, brake and fold than the pushrim wheelchair.

• Implications for rehabilitation

• Pushrim-propelled wheelchairs are difficult to drive on outdoor paths (grass and gravel/sand surfaces) and ramps so that users are confined to restricted environments and have limited participation in everyday activities.

• The repetitive strain imposed on the upper body by pushrim propulsion leads to very high prevalence of shoulder and wrist pain in manual wheelchair users.

• Crank-propelled and lever-propelled wheelchairs are more efficient and less straining than pushrim propelled wheelchairs, allowing users to access more challenging environments, prolong independence and improve the quality of life.

     

Effectiveness of an Automatic Manual Wheelchair Braking System in the Prevention of Falls

The purpose of this study was to evaluate the effectiveness of an automatic manual wheelchair braking system in the reduction of falls for patients at high risk of falls while transferring to and from a manual wheelchair. The study design was a normative survey carried out through the use of a written questionnaire sent to 60 skilled nursing facilities to collect data from the medical charts, which identified patients at high risk for falls who used an automatic wheelchair braking system. The facilities participating in the study identified a frequency of falls of high-risk patients while transferring to and from the wheelchair ranging from 2 to 10 per year, with a median fall rate per facility of 4 falls. One year after the installation of the automatic wheelchair braking system, participating facilities demonstrated a reduction of zero to three falls during transfers by high-risk patients, with a median fall rate of zero falls. This represents a statistically significant reduction of 78% in the fall rate of high-risk patients while transferring to and from the wheelchair, t(18) = 6.39, p < .0001. Incident reports of falls to and from manual wheelchairs were reviewed retrospectively for a 1-year period. This study suggests that high-risk fallers transferring to or from manual wheelchairs sustained significantly fewer falls when the Steddy Mate automatic braking system for manual wheelchairs was installed. The application of the automatic braking system allows clients, families/caregivers, and facility personnel an increased safety factor for the reduction of falls from the wheelchair.     

The use of an inertial dynamometer to explore the design of children's wheelchairs

In an attempt to provide information for improvements in the design of wheelchairs for children a simulated wheelchair rig has been developed incorporating an original form of dynamometer to examine propulsion factors. 54 children who were experienced users of hand-propelled wheelchairs and 32 able-bodied controls were individually fitted with seats on this test rig and each performed a series of up to fifty subtests. The principal conclusions are that nearly all children who use wheelchairs, even those proficient users with apparently normal arms, are actually weaker than their able-bodied peers; that evidence for changes in wheelchair propulsion design based on the performance of able-bodied subjects or on isometric tests of strength are likely to be misleading; that an improvement of up to 30% in propulsion performance can be obtained by optimal positioning of conventional wheelrims relative to the user; and that this positioning is most crucial for the weaker children, particularly those with cerebral palsy.     

Relationship between wheelchair durability and wheelchair type and years of test

Objective.?To investigate the relationship between the durability of wheelchairs according to American National Standard for Wheechairs/Rehabilitation Engineering and Assistive Technology Society of North America (ANSI/RESNA) Wheelchair Standards and wheelchair type as well as year of test.

Design.?A retrospective study design with a sample of 246 wheelchairs that were tested in accordance with the ANSI/RESNA standards from 1992 to 2008 including four types of wheelchairs: manual wheelchair (MWC), electrical powered wheelchair (EPW), scooters and pushrim-activated power-assisted wheelchair (PAPAW). Unconditional binary logic regression analysis was chosen to evaluate the relationship between test results and test year as well as wheelchair type.

Setting.?Rehabilitation Engineering Research Center.

Main Outcome Measures:?Wheelchair durability test result (fatigue test: pass or fail)

Results.?There was no significant correlation between the year when tested and equivalent cycles. A significant relation was found between test results and wheelchair type (Wald score?=?10.845, degree of freedom?=?3, p?=?0.013) with scooters having a significantly higher pass ratio than MWC (OR?=?15.629, 95% CI?=?2.026–120.579). EPW also had significantly higher pass ratio than MWC (OR?=?1.953, 95% CI?=?1.049–3.636). No significant difference on pass ratio was found between PAPAW and MWC.

Conclusions.?No significant improvements in wheelchair test results during the time frame from 1992 to 2008 were discovered. Wheelchair standard tests should be conducted to assure minimum quality of the wheelchairs and for improving the design of wheelchairs. Although the ANSI/RESNA wheelchair durability test procedures have remained consistent, it does not appear that the introduction of new materials, designs and the availability of test data have improved wheelchair fatigue life.     

A survey of adult power wheelchair and scooter users

Purpose.?Power wheelchairs and scooters have the potential to increase community participation for people with mobility limitations. However, there are also challenges associated with use. The aims of this study were to investigate the characteristics of adults who use power wheelchairs and scooters, explore the process of power-mobility provision and examine the benefits and challenges of use.

Methods.?A cross-sectional survey design was used to recruit power wheelchair or scooter users, aged over 18 years, or their carer, living in New South Wales, Australia. The survey was distributed by mail and e-mail.

Results.?Two hundred and two usable surveys were returned, 25% were power wheelchair users (median age: 57 years, IQR: 40–69) and 74% were scooter users (mean age: 81 years, IQR: 72–85). Only one-third of users (33%) consulted a health professional prior to purchasing their device. Benefits included increased independence and quality of life. Challenges included environmental barriers and accidents. A sizeable proportion of respondents (21%) reported accidents in the previous year, often resulting in personal injury and damage to their device.

Conclusion.?Power-mobility devices have many benefits for users, but can also have negative outcomes, like accidents resulting in injuries. Further high quality studies need to be conducted to determine whether the positive benefits outweigh the negative outcomes such as accidents and injuries.     

Comparison between performances of three types of manual wheelchairs often distributed in low-resource settings

Purpose: This study was conducted to compare the performance of three types of chairs in a low-resource setting. The larger goal was to provide information which will enable more effective use of limited funds by wheelchair manufacturers and suppliers in low-resource settings. Methods: The Motivation Rough Terrain and Whirlwind Rough Rider were compared in six skills tests which participants completed in one wheelchair type and then a day later in the other. A hospital-style folding transport wheelchair was also included in one test. For all skills, participants rated the ease or difficulty on a visual analogue scale. For all tracks, distance traveled and the physiological cost index were recorded. Data were analyzed using repeated measures analysis of variance. Results: The Motivation wheelchair outperformed Whirlwind wheelchair on rough and smooth tracks, and in some metrics on the tight spaces track. Motivation and Whirlwind wheelchairs significantly outperformed the hospital transport wheelchair in all metrics on the rough track skills test. Conclusion: This comparative study provides data that are valuable for manufacturers and for those who provide wheelchairs to users. The comparison with the hospital-style transport chair confirms the cost to users of inappropriate wheelchair provision.

• Implications for Rehabilitation

• For those with compromised lower limb function, wheelchairs are essential to enable full participation and improved quality of life. Therefore, provision of wheelchairs which effectively enable mobility in the cultures and environments in which people with disabilities live is crucial. This includes low-resource settings where the need for appropriate seating is especially urgent.

• A repeated measures study to measure wheelchair performances in everyday skills in the setting where wheelchairs are used gives information on the quality of mobility provided by those wheelchairs.

• This study highlights differences in the performance of three types of wheelchairs often distributed in low-resource settings. This information can improve mobility for wheelchair users in those settings by enabling wheelchair manufacturers to optimize wheelchair design and providers to optimize the use of limited funds

     

Important wheelchair skills for new manual wheelchair users: health care professional and wheelchair user perspectives

Purpose: The purpose of this project was to identify wheelchair skills currently being taught to new manual wheelchair users, identify areas of importance for manual wheelchair skills' training during initial rehabilitation, identify similarities and differences between the perspectives of health care professionals and manual wheelchair users and use the ICF to organize themes related to rehabilitation and learning how to use a manual wheelchair. Method: Focus groups were conducted with health care professionals and experienced manual wheelchair users. ICF codes were used to identify focus group themes. Results: The Activities and Participation codes were more frequently used than Structure, Function and Environment codes. Wheelchair skills identified as important for new manual wheelchair users included propulsion techniques, transfers in an out of the wheelchair, providing maintenance to the wheelchair and navigating barriers such as curbs, ramps and rough terrain. Health care professionals and manual wheelchair users identified the need to incorporate the environment (home and community) into the wheelchair training program. Conclusions: Identifying essential components for training the proper propulsion mechanics and wheelchair skills in new manual wheelchair users is an important step in preventing future health and participation restrictions.

• Implications for Rehabilitation

• Wheelchair skills are being addressed frequently during rehabilitation at the activity-dependent level.

• Propulsion techniques, transfers in an out of the wheelchair, providing maintenance to the wheelchair and navigating barriers such as curbs, ramps and rough terrain are important skills to address during wheelchair training.

• Environment factors (in the home and community) are important to incorporate into wheelchair training to maximize safe and multiple-environmental-setting uses of manual wheelchairs.

• The ICF has application to understanding manual wheelchair rehabilitation for wheelchair users and therapists for improving the understanding of manual wheelchair use.

     

Evaluation of manual wheelchairs by individuals with spinal cord injuries

Purpose.?The aim of this study was to investigate how adults with spinal cord injury assess their satisfaction regarding various aspects and use of their manual wheelchair.

Method.?The Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0) together with seven additional questions was sent to 205 adults with SCI.

Results.?One hundred and twenty-four responses were available. The QUEST 2.0 showed a high level of satisfaction with manual wheelchair properties. However, the respondents were less satisfied with the services offered. Ease of use and comfort were identified as most important. Eighty-nine percent of the respondents rated their level of satisfaction as ‘quite satisfied’ or ‘very satisfied’ in ease of using a manual wheelchair compared with 68% of the respondents that were ‘quite satisfied’ or ‘very satisfied’ with the level of comfort. A greater satisfaction of ease in propulsion indoors compared with sitting comfort in various activities was found.

Conclusions.?A discrepancy was shown between users not being as satisfied with comfort in sitting in various activities as opposed to satisfaction with propulsion. This indicates the need for increased knowledge and developments concerning individual solutions, incorporating comfort as well as ease of use of a manual wheelchair.     

The influence of verbal training and visual feedback on manual wheelchair propulsion

Purpose.?To determine if verbal training with visual feedback improved manual wheelchair propulsion; to examine propulsion differences between an individual with paraplegia and an individual with tetraplegia.

Method.?Quasi-experimental study: Nine manual wheelchair-using adults participated in propulsion assessments and training. Baseline propulsion performance was measured on several tasks on different surfaces. Participants were trained on a wheelchair treadmill with verbal and visual feedback to increase push length, reduce push frequency and to modify propulsion pattern. Handrim biomechanics were measured with an instrumented wheel. Changes in propulsion were assessed. Differences in propulsion characteristics between a participant with paraplegia and a participant with tetraplegia were examined.

Results.?Push length increased (p < 0.05), push frequency decreased (p < 0.01) and peak (p < 0.05) and average (p < 0.01) forces increased immediately after training. These changes were not sustained over time. Graphic representations showed differences in propulsion characteristics between a participant with paraplegia and a participant with tetraplegia.

Conclusions.?Verbal training may produce changes in push biomechanics of manual wheelchair users. Longer training periods may be needed to sustain propulsion changes. Findings from this study support other studies that have shown propulsion differences between people with tetraplegia and paraplegia. Propulsion training for populations with upper-extremity impairments warrants further study.     

Evaluation of CIR-Whirlwind Wheelchair and service provision in Afghanistan

Purpose. The Center for International Rehabilitation (CIR) developed a wheelchair provision strategy that combines central fabrication with regional distribution and local service provision by trained practitioners. A field study was initiated in Kabul, Afghanistan to evaluate this plan.

Method. The CIR-Whirlwind Wheelchair (study wheelchair) is an adult size, manual wheelchair designed to be adjustable to accommodate the individual user and durable to withstand rugged terrain. Manufactured in India, the study wheelchairs, with seat cushions, were packaged as kits and shipped to Afghanistan. Local practitioners in Kabul were trained on user assessment, fitting and training, and wheelchair assembly, maintenance and repair. One hundred subjects with previous experience of independently propelling a manual wheelchair participated in the study. This 4-month study entailed three subject visits for initial wheelchair fitting and training and then follow-up at 3 and 10 weeks. Subject training included wheelchair use and maintenance, and wheelchair skill activities.

Results. The study wheelchair was rated favorably by the subjects in all of five categories. Adjustments made to the wheelchairs during the study were typical for maintaining or improving the fit or function of a manual wheelchair. With the exception of brake handles, the need to repair or replace components on the wheelchairs was minimal. The subjects' proficiency at wheelchair skill activities increased throughout the study.

Conclusions. Data collected indicates that the study wheelchair performed very well. The data also served to identify those aspects of the wheelchair that may require additional development and testing prior to further production. To gain additional information on long term wheelchair use and performance, the CIR plans to extend this study by interviewing the same subjects at nine and fifteen months from the date they originally received the study wheelchair.     

Energy expenditure,and comfort in a modified wheelchair for people with hemiplegia: A controlled trial

Aim. The aim of this pilot study using non-disabled subjects was to measure energy expenditure, hand position and ride comfort, in a standard dual handrim Sunrise Breezy Wheelchair compared to one modified with a novel ergonomic self propelled steering (ESP) mechanism kit. The clinical reasoning underpinning the engineering design of the ESP kit was to develop a more ergonomically efficient mechanism for wheelchair steering and propulsion for individuals who had sustained cerebral vascular accidents.

Methods. Ten non-disabled males participated in a repeated measures trial by driving two manual wheelchairs – a standard manual dual handrim wheelchair and one fitted with the steering conversion kit. Wheelchairs were randomly assigned, to participants who drove each wheelchair around a designated circuit. Oxygen consumption, carbon dioxide and heart rate were measured as indicators of ergonomic efficiency using a Cosmed analyser. Comfort for each wheelchair was measured using a validated questionnaire.

Results. Heart rate (bpm), oxygen consumption (O₂ ml/min) and exhaled carbon dioxide (CO₂ ml/min) were significantly lower in the modified wheelchair (P < 0.001, P < 0.006 and P < 0.014, respectively). All comfort ratings were reported to be significantly greater in the ESP (P < 0.05).

Conclusions. The ESP conversion kit transforms a standard Sunrise Breezy Wheelchair into one that is ergonomically more efficient and comfortable for non-disabled subjects.     

Effectiveness of an automatic manual wheelchair braking system in the prevention of falls

The purpose of this study was to evaluate the effectiveness of an automatic manual wheelchair braking system in the reduction of falls for patients at high risk of falls while transferring to and from a manual wheelchair. The study design was a normative survey carried out through the use of a written questionnaire sent to 60 skilled nursing facilities to collect data from the medical charts, which identified patients at high risk for falls who used an automatic wheelchair braking system. The facilities participating in the study identified a frequency of falls of high-risk patients while transferring to and from the wheelchair ranging from 2 to 10 per year, with a median fall rate per facility of 4 falls. One year after the installation of the automatic wheelchair braking system, participating facilities demonstrated a reduction of zero to three falls during transfers by high-risk patients, with a median fall rate of zero falls. This represents a statistically significant reduction of 78% in the fall rate of high-risk patients while transferring to and from the wheelchair, t (18) = 6.39, p < .0001. Incident reports of falls to and from manual wheelchairs were reviewed retrospectively for a 1-year period. This study suggests that high-risk fallers transferring to or from manual wheelchairs sustained significantly fewer falls when the Steddy Mate automatic braking system for manual wheelchairs was installed. The application of the automatic braking system allows clients, families/caregivers, and facility personnel an increased safety factor for the reduction of falls from the wheelchair.     

The experiences of using an anti-collision power wheelchair for three long-term care home residents with mild cognitive impairment

Purpose.?Presented are three case analyses of long-term care home residents with cognitive impairment who tested an anti-collision power wheelchair. We discuss technology design and research implications for this population.

Method.?Case studies involved 371?h of participant observation and 7?h of open-ended interview with residents (n?=?3), family members (n?=?3) and clinical staff (n?=?11). Thematic analysis generated themes related to technological, psychological and social aspects of residents' inclination and disinclination towards power mobility use.

Results.?Themes examined the discordance between others' and residents' reports of anti-collision power wheelchair use; a facet of response bias; unanticipated implications for independence and dependence; and implications of device design for self-presentation.

Conclusions.?Technology alone is insufficient to help residents to fully benefit from the autonomy that a wheelchair intervention can provide: close attention is required to the social and organisational factors of institutional life. For technology to be acceptable, the design must meet the functional and aesthetic needs of users. Considerations in the design of future power wheelchairs for residents with cognitive impairment include capabilities to drive on uneven surfaces, effort-reducing driving modes, improved user interface usability, and acceptable driving speed, size and appearance.