Variable-ratio pushrim-activated power-assist wheelchair eases wheeling over a variety of terrains for elders11A commercial party with a direct financial interest in the results of the research supporting this article has conferred or will confer a financial benefit on the author or 1 or more of the authors

A Comparison Between Conventional and Terrain-Specific Adaptive Pushrim-Activated Power-Assisted Wheelchairs

Pushrim-activated power-assisted wheels (PAPAWs) are assistive technologies that provide on-demand propulsion assistance to wheelchair users. In this study, we aimed to develop an adaptive PAPAW controller that responds effectively to changes in environmental conditions (e.g., type of surface or terrain). Experiments were conducted to collect kinematics of wheelchair motion using a frame-mounted inertial measurement unit (IMU) while performing a variety of wheelchair activities on different indoor/outdoor terrains. Statistical characteristics of velocity and acceleration measurements were extracted and used to develop a terrain classification framework to identify certain indoor and outdoor terrains. The terrain classification framework, based on random forest classification algorithms and kinematic features, was implemented and tested in our laboratory-developed PAPAW. This computationally efficient terrain classification framework was successfully implemented and tested in real-time. The power-assist ratio of each wheel was adjusted based on the type of terrain (e.g., more assistance was provided on outdoor terrains). Our findings revealed that propulsion effort (e.g., peak input torque) on asphalt was significantly reduced when using adaptive controllers compared to conventional PAPAW controllers. In addition, subjective views of participants regarding the workload of wheelchair propulsion (e.g., physical/cognitive effort) supported the positive effects of adaptive PAPAW controllers. We believe that the adoption of terrain-specific adaptive controllers has the potential to improve the accessibility of outdoor terrains and to prevent or delay upper extremity joint degeneration or pain.

A Comparison Between Conventional and User-Intention-Based Adaptive Pushrim-Activated Power-Assisted Wheelchairs

Pushrim-activated power-assisted wheel (PAPAW) users ideally require different levels of assistance depending on activity and preference. Therefore, it is important to design and develop adaptive PAPAW controllers to account for these differences. The main objective of this work was to integrate a user intention estimation framework into a PAPAW and develop personalized adaptive controllers. We performed experiments to gather kinetics of wheelchair propulsion for a variety of daily life wheelchair activities. The propulsion characteristics (i.e., pushrim forces) were used to train intention estimation models and characterize implicit user intentions when performing daily life wheelchair maneuvers. These intentions included moving straight forward, performing a right/left turn, and braking. The intention estimation framework, based on random forest classification algorithms and kinetic features, was implemented and tested in our laboratory-developed PAPAW. This computationally efficient framework was successfully implemented and tested for each participant in real-time. Our results revealed that the real-time user intention predictions were similar to the offline models. The power-assist ratio of each wheel was adjusted based on which user intention was identified. Data collected from four participants provided evidence regarding the effectiveness of using adaptive intention-based controllers. For instance, the propulsion effort was significantly reduced when using an adaptive PAPAW controller. Subjective views of participants regarding the workload of wheelchair propulsion (e.g., physical/cognitive effort) were also gathered. Our findings suggest that rankings of different controllers varied among different participants and across different wheelchair maneuvers, indicating the need for customized adaptive controllers to fit different users' activities and preferences.

Comparison of Manual Wheelchair and Pushrim-Activated Power-Assisted Wheelchair Propulsion Characteristics during Common Over-Ground Maneuvers

Pushrim-activated power-assisted wheels (PAPAWs) are assistive technologies that use force sensor data to provide on-demand propulsion assistance to manual wheelchair users. However, available data about kinetic and kinematic of PAPAW use are mainly limited to experiments performed on a treadmill or using a dynamometer. In this work, we performed experiments to gather kinetics of wheelchair propulsion and kinematics of wheelchair motion for a variety of over-ground wheelchair maneuvers with a manual wheelchair with and without PAPAWs. Our findings revealed that using PAPAWs can significantly reduce the propulsion effort and push frequency. Both linear and angular velocities of the wheelchair were significantly increased when using PAPAWs. Less force and push frequency could potentially reduce risk of chronic upper limb injury. Higher linear velocity could be desirable for various daily life activities; however; the increase in the angular velocity could lead to unintended deviations from a desired path. Future research could investigate PAPAW controllers that amplify the desired intentions of users while mitigating any unwanted behaviours.

Practice-based skill acquisition of pushrim-activated power-assisted wheelchair propulsion versus regular handrim propulsion in novices

Background

Regular handrim wheelchair (RHW) propulsion is straining for the upper extremities and wheelchair users often experience overuse problems. A recent advancement in wheelchair technology that could assist users is the pushrim-activated power-assisted wheelchair (PAPAW). PAPAWs are challenging to control, yet it is unclear how people learn to use a PAPAW. The purpose of this study is to examine early skill acquisition through practice in PAPAWs and compare it with RHWs.

Methods

Twenty-four able-bodied novices were randomly allocated to either the RHW group or the PAPAW group. The experiment consisted of five sessions with three blocks of 4 min steady-state practice at 1.11 m/s and 0.21 W/kg. Finally, a transfer to the other mode was made. Data were collected with a drag-test, breath-by-breath spirometry, and a motion capture system. The last minute of each four-minute block was used for analysis. A mixed analysis of variance (ANOVA) was used to test for group, time, and interaction effects.

Results

Both groups improved their (assisted) mechanical efficiency, reduced their stroke rate, right-left and forward-backward deviation on the treadmill, and had a lower rate of perceived exertion (RPE) over time. (Assisted) mechanical efficiency was higher for the PAPAW group than for the RHW group and RPE was lower. However, left-right and forward-backward deviation was also found to be higher in the PAPAW group.

Conclusions

At the group level the energetic cost of RHW and PAPAW propulsion can be lowered through low-intensity practice in novice users. The PAPAW is more ‘efficient’ than the RHW given the reduced energy requirement of the user from the motor assist, but more difficult to control. Future studies on PAPAWs should focus on the control needs of the user and their interaction with the power-assist technology.

Pain, fatigue, function and participation among long-term manual wheelchair users partnered with a mobility service dog

PURPOSE

To assess the effects of a mobility service dog (MSD) on pain, fatigue, wheelchair-related functional tasks, participation and satisfaction among manual wheelchair users over a nine-month period.

METHOD

A longitudinal study with repeated assessment times before and three, six and nine months after intervention was achieved. Intervention consisted in partnering each participant with a MSD. The setting is a well-established provincial service dog training school and participants homes. A convenience sample of 24 long-term manual wheelchair users with a spinal cord injury was involved. Outcome measures were: Wheelchair User's Shoulder Pain Index (WUSPI), Rate of Perceived Exertion (RPE), vitality scale from the SF-36, grip strength, Wheelchair Skills Test (WST), Canadian Occupational Performance Measure (COPM), Reintegration to Normal Living Index (RNLI), Life Space Assessment, Psychosocial Impact of Assistive Devices Scale (PIADS) and Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0).

RESULTS

Shoulder and wrist pain as well as fatigue decreased significantly over time with the use of a MSD as evidenced by scores from WUSPI, RPE and SF-36 (feeling less worn out). Manual wheelchair propulsion skills (steep slopes, soft surfaces and thresholds) improved significantly over time as confirmed by the WST. Participation increased significantly over time as revealed by the COPM (for five occupations) and the RNLI (for five items). Satisfaction with the MSD was high over time (QUEST: nine items) and with a high positive psychosocial impact (PIADS: 10 items).

CONCLUSION

MSD represents a valuable mobility assistive technology option for manual wheelchair users. IMPLICATIONS FOR REHABILITATION   For manual wheelchair users partenered with mobility service dog  • Shoulder pain and fatigue significantly decreased and continued to decrease between the third and sixth month and the ninth month.   • Performance with propelling the wheelchair up steep slopes increased from 41 to 88% and on soft surfaces increased from 53 to 100% after 3 months, respectively.   • Occupational performance satisfaction was significantly increased for mobility in relation with the transfers, navigating in a natural environment and picking up objects.   • High satisfaction towards psychosocial competency, psychosocial adequacy and self-esteem were reported at months three, six and nine.

Evidence-Based Strategies for Preserving Mobility for Elderly and Aging Manual Wheelchair Users

Elderly and aging manual wheelchair (MWC) users have increased risk for accelerated loss of function and mobility that greatly limits independence and affects quality of life. This review paper addresses important issues for preserving function and mobility for elderly and aging individuals who use a MWC by presenting the current available evidence and recommendations. These include recommendations for maximizing function, by decreasing pain, improving the ability to self-propel, and prolonging mobility and endurance through ergonomics, individualized wheelchair selection and configuration, and adaptations for increasing the capacity to handle the daily mobility demands through training, strengthening, and exercise. Each recommendation is supported by current research in each relevant area.

A systematic review on the pros and cons of using a pushrim-activated power-assisted wheelchair

OBJECTIVE

To determine the (dis)advantages of transition to a power-assisted wheelchair, and derive the clinical implications for its use or prescription.

DATA SOURCES

Relevant articles published prior to May 2012 were identified using PubMed, Cochrane Library, REHABDATA, CIRRIE and CINAHL databases.

REVIEW METHODS

Clinical or (randomized) controlled trials, published in a peer-reviewed journal, comparing power-assisted wheelchair use and hand-rim or powered wheelchair use were eligible. Data quality and validity were assessed by two reviewers independently using the Checklist for Measuring Quality developed by Downs and Black.

RESULTS

A systematic search yielded 15 cross-over trails with repeated measurement design and one qualitative interview. Methodological quality scored between 9 and 15 points out of the maximum score of 32. Ten studies measuring body function and structure reported reduced strain on the arm and cardiovascular system during power-assisted propulsion compared to hand-rim propulsion. Twelve studies measuring activities and social participation reported precision tasks easier to perform with a hand-rim wheelchair and tasks which require more torque were easier with a power-assisted wheelchair. Social participation was not altered significantly by the use of a hand-rim, powered or power-assisted wheelchair.

CONCLUSION

Power-assisted propulsion might be beneficial for subjects in whom independent hand-rim wheelchair propulsion is endangered by arm injury, insufficient arm strength or low cardiopulmonary reserves. Also, subjects who have difficulty propelling a wheelchair in a challenging environment can benefit from power-assisted wheelchair use. Caution is warranted for the additional width and weight in relation to the usual mode of transportation and access to the home environment.

Comparison of shoulder load during power-assisted and purely hand-rim wheelchair propulsion

BACKGROUND

Repetitive forces and moments are among the work requirements of hand-rim wheelchair propulsion that are related to shoulder injuries. No previous research has been published about the influence of power-assisted wheelchair propulsion on these work requirements. The purpose of our study was therefore to determine the influence of power-assisted propulsion on shoulder biomechanics and muscle activation patterns. We also explored the theoretical framework for the effectiveness of power-assisted propulsion in preventing shoulder injuries by decreasing the work requirements of hand-rim wheelchair propulsion.

METHODS

Nine non-wheelchair users propelled a hand-rim wheelchair on a treadmill at 0.9 m/s. Shoulder biomechanics, and muscle activation patterns, were compared between propulsion with and without power-assist.

FINDINGS

Propulsion frequency did not differ significantly between the two conditions (Wilcoxon Signed Rank test/significance level/effect size:4/.314/-.34). During power-assisted propulsion we found significantly decreased maximum shoulder flexion and internal rotation angles (1/.015/-.81 and 0/.008/-.89) and decreased peak force on the rim (0/.008/-.89). This resulted in decreased shoulder flexion, adduction and internal rotation moments (2/.021/-.77; 0/.008/-.89 and 1/.011/-.85) and decreased forces at the shoulder in the posterior, superior and lateral directions (2/.021/-.77; 2/.008/-.89 and 2/.024/-.75). Muscle activation in the pectoralis major, posterior deltoid and triceps brachii was also decreased (2/.038/-.69; 1/.015/-.81 and 1/.021/-.77).

INTERPRETATION

Power-assist influenced the work requirements of hand-rim wheelchair propulsion by healthy subjects. It was primarily the kinetics at rim and shoulder which were influenced by power-assisted propulsion. Additional research with actual hand-rim wheelchair users is required before extrapolation to routine clinical practice.

Experiences with Using a Pushrim-Activated Power-Assisted Wheelchair for Community-Based Occupations: A Qualitative Exploration

Background. Occupational therapists strive to engage individuals in occupation and enhance community access through wheelchair prescription. Previous research with pushrim-activated, power-assisted wheelchairs identifies a reduction in the physical demands of manual wheelchair propulsion but limited evidence exists regarding user evaluation in context. Purpose. This study explored the experience of using a power-assisted wheelchair in the community. Methods. Eight individuals who used both a power and manual device participated in focus groups after trialing a power-assist wheelchair for three weeks. Data were analyzed using a qualitative description approach. Findings. Three themes emerged from our analysis: relative advantages and disadvantages; environmental factors that affect accessibility; and evaluation of mobility device. Implications. Participants perceived the power-assist as improving performance and accessibility compared with the manual wheelchair, increasing the potential scope of occupations and environments, but not replacing their power mobility device. Sufficient time for adjustment of both user and device was important.

Use of power assist wheels results in increased distance traveled compared with conventional manual wheeling

OBJECTIVE

To evaluate the impact of power assist wheels on the distance traveled by manual wheelchair users and analyze potential cofactors in the magnitude of response and to test the hypothesis that wheelers would travel significantly further with power assist wheels.

DESIGN

A 16-wk A (Preintervention)-B (Intervention)-A (Postintervention) repeated measures design. Seven women and 13 men (age, 43 +/- 15 yrs) full-time wheelers participated. During the pre- and postintervention phases (4 wks each), participants used their own unaltered manual wheelchairs. During the 8-wk intervention phase, the manual wheels were replaced with power assist wheels. Daily distance was measured with bicycle-style odometers. A composite score of laboratory wheelchair tasks was used to classify wheelchair performance. Mixed model repeated measures analysis of variance analyzed changes across phases of the trial. A post hoc analysis tabulated the amount of days wheelers exceeded their individual daily averages in each phase by two SDs.

RESULTS

Wheelers traveled significantly greater distances during the intervention phase compared with pre- or postintervention phases regardless of baseline wheelchair performance. Wheelers who demonstrated higher baseline wheelchair performance traveled lesser average distances in the first 2 wks after receiving power assist wheels than in the subsequent 6 wks. Wheelers exceeded their individual daily averages per phase on a significantly greater number of days during the intervention phase.

CONCLUSIONS

Power assist wheels enabled wheelers to travel farther and to travel beyond their usual distances on more days. Further studies may be strengthened by taking into account the 2-wk "adjustment phase" for power assist wheels.

Comparison of shoulder muscle electromyographic activity during standard manual wheelchair and push-rim activated power assisted wheelchair propulsion in persons with complete tetraplegia

OBJECTIVES

To compare spatio-temporal propulsion characteristics and shoulder muscle electromyographic activity in persons with cervical spinal cord injury propelling a standard pushrim wheelchair (WC) and a commercially available pushrim-activated power assisted wheelchair (PAPAW) design on a stationary ergometer.

DESIGN

Repeated measures.

SETTING

Motion analysis laboratory within a rehabilitation hospital.

PARTICIPANTS

Men (N=14) with complete (American Spinal Injury Association grade A or B) tetraplegia (C6=5; C7=9).

INTERVENTION

Participants propelled a standard pushrim WC and PAPAW during 3 propulsion conditions: self-selected free and fast and simulated 4% or 8% graded resistance propulsion.

MAIN OUTCOME MEASURES

Median speed, cycle length, cadence, median and peak electromyographic activity intensity, and duration of electromyographic activity in pectoralis major, anterior deltoid, supraspinatus, and infraspinatus muscles were compared between standard pushrim WC and PAPAW propulsion.

RESULTS

A significant (P<.05) decrease in electromyographic activity intensity and duration of pectoralis major, anterior deltoid, and infraspinatus muscles and significantly reduced intensity and push phase duration of supraspinatus electromyographic activity at faster speeds and with increased resistance were seen during PAPAW propulsion.

CONCLUSIONS

For participants with complete tetraplegia, push phase shoulder muscle activity was decreased in the PAPAW compared with standard pushrim WC, indicating a reduction in demands when propelling a PAPAW.

Participation in community-based activities of daily living: comparison of a pushrim-activated, power-assisted wheelchair and a power wheelchair

PURPOSE

The purpose of this study was to evaluate pushrim-activated, power-assisted wheelchair (PPW) performance among dual-users in their natural environment to determine whether the PPW would serve as a satisfactory alternative to a power wheelchair for community-based activities.

METHODS

A concurrent mixed methods research design using a cross-over trial was used. The outcome measures used were number of hours reported using the different wheelchairs, Quebec User Evaluation of Satisfaction with assistive Technology (QUEST), Functioning Everyday with a Wheelchair (FEW), Psychosocial Impact of Assistive Devices Scale (PIADS) and Canadian Occupational Performance Measure (COPM).

RESULTS

The number of hours spent participating in self-identified activities was not significantly different. Only the Self-Esteem subscale of the PIADS identified a statistically significant difference between the PPW and power wheelchair conditions (p = 0.016). A clinically important difference for Performance and Satisfaction was suggested by the COPM, in favour of the power wheelchair.

CONCLUSIONS

Additional knowledge was gained about the benefits of PPW technology. Participants were able to continue participating independently in their self-identified community activities using the PPW, and identified comparable ratings of satisfaction and performance with the PPW and the power wheelchair. For some individuals requiring power mobility, the PPW may provide an alternative to the power wheelchair.

Comparison between performance with a pushrim-activated power-assisted wheelchair and a manual wheelchair on the Wheelchair Skills Test

PURPOSE

To test the hypothesis that people using a pushrim-activated power-assisted wheelchair (PAPAW) can accomplish a wider range of wheelchair skills than when using a manual wheelchair (MWC).

METHODS

We studied 30 able-bodied participants, using within-participant comparisons. Participants used a manual wheelchair equipped with both PAPAW and regular MWC rear wheels, and rear anti-tip devices (Arc-RADs) that permitted wheelie-like function. We trained participants to perform the wheelchair skills of the Wheelchair Skills Training Program (WSTP, Version 2.4). From the Wheelchair Skills Test (WST, Version 2.4), we calculated pass-fail success rates for the 50 individual skills and a total percentage WST score.

RESULTS

The mean (+/-SD) total WST scores were 89.3 (+/-7.0)% for the PAPAW and 88.8 (+/-8.4)% for the MWC, with a mean difference of 0.6 (+/-5.6)% (p = 0.59). Qualitative observations suggested that skills requiring a higher force on the pushrim (e.g., incline ascent) were performed more easily with the PAPAW, whereas skills requiring greater control of the wheelchair (e.g., wheelie-dependent skills) were performed more easily with the MWC.

CONCLUSION

Overall wheelchair skill performance with the PAPAW is not superior to that when using the MWC. The PAPAW may be helpful for specific skills that require more wheel torque, but the additional torque appears to be disadvantageous when performing skills that require greater control.

Methodological challenges confronting researchers of wheeled mobility aids and other assistive technologies

PURPOSE

To identify gaps in assistive technology (AT) research and solutions, with a focus on wheeled mobility.

METHODS

Literature review.

RESULTS

AT researchers have identified a need to move beyond determining whether a device works well in the laboratory or is perceived favorably by users. The vital next step in AT research is to determine the effects of AT when used for day-to-day activities by typical consumers. Four challenges affect AT research on everyday mobility: (1) the heterogeneity of the population using AT, the environments in which AT is used, and the devices themselves; (2) the dependency of empirical research on objective data for valid causal inference; (3) the need for detailed information to capture the interaction between the person, the device, and the environment in which it is used; and (4) the extent to which success or failure of AT is dependent on the personal perspectives of the individual using the device. These challenges are being addressed by AT researchers through use of new measures, novel data collection methods, and by linking quantitative with qualitative data.

CONCLUSIONS

AT researchers are adapting traditional research designs and analytic methods to examine that effects of AT on everyday life.

Manual wheelchairs: Research and innovation in rehabilitation, sports, daily life and health

Those with lower limb disabilities are often dependent on manually propelled wheelchairs for their mobility, in Europe today some 3.3 million people. This implies a transfer from leg to arm work for ambulation and all other activities of daily living (ADL). Compared to the legs, arm work is less efficient and more straining, and leads to a lower physical capacity. Also, there is a major risk of mechanical overuse. Problems of long-term wheelchair use are not only pain or discomfort, but also a risk of a physically inactive lifestyle. Subsequently, serious secondary impairments (obesity, diabetes and cardiovascular problems) may eventually emerge. Wheelchair quality, including the ergonomic fitting to the individual may play a preventive role here, but also other modes of physical activity, and the understanding of training, rehabilitation, active lifestyle and sports on health and wellbeing. The 'International Classification of Functioning, Health and Disability' (ICF) model, a stress-strain-work capacity model, as well as the ergonomics model that relates human-activity-assistive technology are instrumental to the concepts, structure and aims of research in assistive technology for mobility. Apart from empirical developments and innovations from within wheelchair sports, systematic research has played a role in wheelchair development and design in three important areas: (1) the vehicle mechanics, (2) the human movement system and (3) the wheelchair-user interface. Current practical developments in design and technology are discussed. A position stand on the key-issues of a current and future research agenda in this area is presented.

Wheelchair evaluation for the older adult

This article focuses on basic principles of seating and wheelchair evaluation for the general population. The discussion includes wheelchair options, components, and accessories. Basic principles to guide the clinician in the process of selection for maximum function are addressed.

A prototype power assist wheelchair that provides for obstacle detection and avoidance for those with visual impairments

Background

Almost 10% of all individuals who are legally blind also have a mobility impairment. The majority of these individuals are dependent on others for mobility. The Smart Power Assistance Module (SPAM) for manual wheelchairs is being developed to provide independent mobility for this population.

Methods

A prototype of the SPAM has been developed using Yamaha JWII power assist hubs, sonar and infrared rangefinders, and a microprocessor. The prototype limits the user to moving straight forward, straight backward, or turning in place, and increases the resistance of the wheels based on the proximity of obstacles. The result is haptic feedback to the user regarding the environment surrounding the wheelchair.

Results

The prototype has been evaluated with four blindfolded able-bodied users and one individual who is blind but not mobility impaired. For all individuals, the prototype reduced the number of collisions on a simple navigation task.

Conclusion

The prototype demonstrates the feasibility of providing navigation assistance to manual wheelchair users, but several shortcomings of the system were identified to be addressed in a second generation prototype.

Effect of a pushrim-activated power-assist wheelchair on the functional capabilities of persons with tetraplegia

OBJECTIVES

To test the differences between a pushrim-activated power-assisted wheelchair (PAPAW) and a traditional manual wheelchair while performing common driving activities and to assess their relative merits for people with tetraplegia.

DESIGN

Repeated measures.

SETTING

An activities of daily living (ADL) laboratory within a rehabilitation research center.

PARTICIPANTS

Fifteen full-time manual wheelchair users with tetraplegia due to a spinal cord injury.

INTERVENTIONS

Participants propelled both their own manual wheelchairs and a PAPAW 3 times over an ADL course. The order in which the 2 different wheelchairs were presented to the participants was randomized.

MAIN OUTCOME MEASURES

Each participant's heart rate was monitored throughout testing by a digital, wireless heart-rate monitor. Time to complete the course was recorded, and participants were surveyed with a visual analog scale after the first, third, fourth, and sixth trials to determine the ease of completing each obstacle and their ergonomic preferences between the 2 wheelchairs. Participants also were observed throughout the trials to determine how much assistance they needed to complete each obstacle course.

RESULTS

After using a Bonferroni adjustment, 4 obstacles (carpet, dimple strips, up a ramp, up a curb cut) were rated as being significantly easier ( P <.001) to complete when using the PAPAW. Participants also showed a significant decrease in mean heart rate throughout all 3 trials ( P =.015, P =.001, P =.003, respectively) when using a PAPAW. The amount of assistance needed by participants, the responses to ergonomic questions, and the overall time to complete the ADL course did not differ significantly between the 2 wheelchairs.

CONCLUSIONS

For subjects with tetraplegia, PAPAWs have the potential to improve functional capabilities during certain ADLs, especially when propelling up ramps, over uneven surfaces, and over thick carpet.

Impact of a pushrim-activated power-assisted wheelchair on the metabolic demands, stroke frequency, and range of motion among subjects with tetraplegia

OBJECTIVES

To determine differences in metabolic demands, stroke frequency, and upper-extremity joint range of motion (ROM) during pushrim-activated power-assisted wheelchair (PAPAW) propulsion and traditional manual wheelchair propulsion among subjects with tetraplegia.

DESIGN

Repeated measures.

SETTING

A biomechanics laboratory within a Veterans Affairs medical center.

PARTICIPANTS

Fifteen full-time manual wheelchair users who had sustained cervical-level spinal cord injuries.

INTERVENTIONS

Participants propelled both their own manual wheelchairs and a PAPAW through 3 different resistances (slight, 10W; moderate, 12W; high, 14W) on a wheelchair dynamometer. Each propulsion trial was 3 minutes long.

MAIN OUTCOME MEASURES

Primary variables that were compared between the 2 wheelchairs were participants mean steady-state oxygen consumption, ventilation, heart rate, mean stroke frequency, and maximum upper-extremity joint ROM.

RESULTS

When using the PAPAW, participants showed a significant ( P <.05) decrease in mean oxygen consumption and ventilation throughout all trials. Mean heart rate was significantly lower when using the PAPAW for the high resistance trial. Stroke frequency was significantly lower when using the PAPAW for the slight and moderate resistances. Overall joint ROM was significantly lower when using the PAPAW.

CONCLUSIONS

For subjects with tetraplegia, PAPAWs reduce the energy demands, stroke frequency, and overall joint ROM when compared with traditional manual wheelchair propulsion.