Exploration of shoulder load during hand-rim wheelchair start-up with and without power-assisted propulsion in experienced wheelchair users

Reinventing the wheel for a manual wheelchair

PURPOSE

Standard manual wheelchairs (MWCs) are inefficient and pushrim propulsion may cause progressive damage and pain to the user's arms. We describe a wheel for a MWC with a novel propulsion mechanism.

METHODS

The wheel has two modes of operation called "Standard" mode and "Run" mode. In Run mode, the wheelchair is propelled forward by pushing a compliant handle forward and then pulling it back, both strokes contributing to forward propulsion. We report the propulsive force and preliminary testing on a rough outdoor circuit by three able-bodied participants.

RESULTS

In Run mode, the peak applied force is reduced to 30% and the maximum force gradient is reduced to 10% of that for standard pushrim propulsion, for the same work output. The travel time for the 1.06 km outdoor circuit is about 60% of that for a brisk walk and about 40% of that for pushrim propulsion. At a propulsion speed of 1 m/s, the cardiovascular effort in Run mode is 56% of that for pushrim propulsion. Automatic hill-hold in Run mode improves safety when ascending slopes. The mechanism has three gears so that it can be used by people with widely varying strength and fitness. Folding the handle away converts the operation to Standard mode with the conventional pushrim propulsion, supplemented by three gears.

CONCLUSIONS

Despite the increased weight, width and friction, the bimodal geared wheels facilitate wheelchair travel on challenging paths. This may bring significant improvement to the quality of life of MWC users.

Evaluation of two power assist systems for manual wheelchairs for usability, performance and mobility: a pilot study

BACKGROUND

Power-assist devices for manual wheelchairs offer benefits, including increased community participation. Several power-assist devices are commercially available, but research on benefits and limitations of devices is limited.

OBJECTIVE

To compare the usability, performance, and mobility of two power-assist device systems for manual wheelchairs in indoor and outdoor environments.

METHODS

This mixed methods pilot study included 11 volunteers with limited wheelchair experience. Participants tested two different power-assist device configurations: (1) the Batec® and (2) the SmartDrive® + Freewheel®. Indoor & outdoor obstacle courses contained relevant skills from the Wheelchair Skills Test, Power Mobility Community Driving Assessment, and Power Mobility Indoor Driving Assessment. The NASA Task Load Index and System Usability Scale assessed participants' perceptions of cognitive demand and usability. A semi-structured interview was conducted to explore participants' experiences.

RESULTS

Substantial differences were found in the NASA Task Load Index, and System Usability Scale scores. Participant interviews and researcher observations revealed each device performed better on some obstacle course elements. Qualitative findings showed a general preference for using the Batec® for long trips outside and off-road terrains, primarily due to the Batec's® perceived better speed control, maximum speed, and simpler braking system. Conversely, the SmartDrive® + Freewheel® was deemed most useful indoors and in tight spaces; due to a smaller wheelchair footprint, better turning radius, and increased device portability.

CONCLUSION

Further studies are required to understand the usability, performance, and mobility of power-assist devices. Moving forward, these findings will inform end users and occupational therapists when procuring manual wheelchair power-assist devices.Implications for rehabilitationPower-assist devices (PADs) for manual wheelchairs increase the potential for community participation.Qualitative findings showed a general preference for using the Batec® for long trips outside and for off-road terrains, primarily due to the Batec's® perceived better speed control, maximum speed, and simpler braking system.The SmartDrive® + Freewheel® was deemed most useful indoors and in tight spaces; due to a smaller wheelchair footprint, better turning radius, and increased device portability.Increasing knowledge and research about PADs will support development of alternative options for manual or power wheelchairs users. PADs may allow manual wheelchair users (MWC) to delay moving to a power wheelchair (PWC), potentially reducing the perceived stigma associated with transitioning to a power wheelchair and impacting health outcomes.

Effect of power-assistance on upper limb biomechanical and physiological variables during a 6-minute, manual wheelchair propulsion test: a randomised, cross-over study

PURPOSE

Use of a power-assistance wheelchair could reduce the risk of musculoskeletal disorders (MSDs), however, a comprehensive biomechanical evaluation of these systems has not been carried out. This study aimed to evaluate and compare biomechanical UL propulsion variables, and physiological exercise-related variables during the use of a wheelchair with rear drive power assist device (RD-PAD) and a standard manual wheelchair (MW).

MATERIALS AND METHODS

Twenty-two adults with spinal cord injury were recruited. RD-PAD (SmartDrive system) was fitted to their own MW. An instrumented wheel was used to measure handrim forces, and gas exchange and heart rate were monitored. Participants performed repeated out and back runs for 6 min on a straight outdoor course.

RESULTS

Distance covered was significantly greater with the RD-PAD (538 ± 104 m versus 470 ± 124 m). Peak mechanical effort during the propulsion phase was significantly lower with the RD-PAD (p < 0.001). Heart rate, metabolic equivalent of task (MET), tidal volume, minute volume, oxygen consumption, and peak oxygen consumption were all significantly lower with the RD-PAD (p < 0.001).

CONCLUSIONS

The results showed that use of RD-PAD increased the distance covered by MW users and reduced the energy costs of propulsion. The biomechanical results indirectly suggest that RD-PAD may reduce the risk of MSD.Implications for RehabilitationUsing the SmartDrive system as propulsion assistance increases the travel autonomy.The SmartDrive system reduces the biomechanical constraints propelling the wheelchair on a slope and low slope.SmartDrive the system reduces the physiological solicitation related to the propulsion of wheelchair.

Hand-rim biomechanics during geared manual wheelchair propulsion over different ground conditions in individuals with spinal cord injury

Geared manual wheelchair wheels, a recently developed alternative propulsion mechanism, have the potential to alleviate the high upper extremity demands required for wheelchair propulsion and help decrease the risk of secondary injuries in manual wheelchair users. The objective of this study was to investigate the effects of using geared manual wheelchairs on hand-rim biomechanics of wheelchair propulsion in individuals with spinal cord injury (SCI). Seven manual wheelchair users with SCI propelled their wheelchairs equipped with geared wheels over tile, carpet, and up a ramp in low gear (gear ratio 1.5:1) and standard gear (gear ratio 1:1) conditions. Hand-rim kinetics and stroke cycle characteristics were measured using a custom instrumented geared wheel. Using the geared wheels in the low gear condition, propulsion speed (P = 0.013), peak resultant force (P = 0.005), peak propulsive moment (P < 0.006), and peak rate of rise of the resultant force (P = 0.035) decreased significantly in comparison with the standard gear condition. The significant increase in the number of stroke cycles when normalized to distance (P = 0.004) and decrease in the normalized integrated moment (P = 0.030) indicated that although a higher number of stroke cycles are required for travelling a given distance in the low gear than the standard gear condition, the low gear condition might be less demanding for the upper extremity. These results suggest that geared wheels could be a useful technology for manual wheelchair users to independently accomplish strenuous propulsion tasks including mobility on carpeted floors and ramp ascension, while reducing the risk factors contributing to the incidence of secondary upper extremity injuries.

Glenohumeral joint dynamics and shoulder muscle activity during geared manual wheelchair propulsion on carpeted floor in individuals with spinal cord injury

This study investigated the effects of using geared wheels on glenohumeral joint dynamics and shoulder muscle activity during manual wheelchair propulsion. Seven veterans with spinal cord injury propelled their wheelchairs equipped with geared wheels over a carpeted floor in low gear (1.5:1) and standard gear (1:1) conditions. Hand-rim kinetics, glenohumeral joint dynamics, and muscle activity were measured using a custom instrumented geared wheel, motion analysis, and surface electromyography. Findings indicated that the propulsion speed and stroke distance decreased significantly during the low gear condition. The peak hand-rim resultant force and propulsive moment, as well as the peak glenohumeral inferior force and flexion moment, were significantly less during the low gear condition. The peak and integrated muscle activity of the anterior deltoid and pectoralis major decreased significantly, while the normalized integrated muscle activity (muscle activity per stroke distance) was not significantly different between the two conditions. Propulsion on carpeted floor in the low gear condition was accompanied by a reduced perception of effort. The notable decrease in the peak shoulder loading and muscle activity suggests that usage of geared wheels may be beneficial for wheelchair users to enhance independent mobility in their homes and communities while decreasing their shoulder demands.

Rehabilitation: mobility, exercise & sports; a critical position stand on current and future research perspectives

BACKGROUND

Human movement, rehabilitation, and allied sciences have embraced their ambitions within the cycle of "RehabMove" congresses over the past 30 years. This combination of disciplines and collaborations in the Netherlands has tried to provide answers to questions in the fields of rehabilitation and adapted sports, while simultaneously generating new questions and challenges. These research questions help us to further deepen our understanding of (impaired) human movement and functioning, with and without supportive technologies, and stress the importance of continued multidisciplinary (inter)national collaboration.

METHODS

This position stand provides answers that were conceived by the authors in a creative process underlining the preparation of the 6th RehabMove Congress.

RESULTS

The take-home message of the RehabMove2018 Congress is a plea for continued multidisciplinary research in the fields of rehabilitation and adapted sports. This should be aimed at more individualized notions of human functioning, practice, and training, but also of performance, improved supportive technology, and appropriate "human and technology asset management" at both individual and organization levels and over the lifespan.

CONCLUSIONS

With this, we anticipate to support the development of rehabilitation sciences and technology and to stimulate the use of rehabilitation notions in general health care. We also hope to help ensure a stronger embodiment of preventive and lifestyle medicine in rehabilitation practice. Indeed, general health care and rehabilitation practice require a healthy and active lifestyle management and research agenda in the context of primary, secondary, and tertiary prevention.IMPLICATIONS FOR REHABILITATIONContinued multidisciplinary (international) collaboration will stimulate the development of rehabilitation and human movement sciences.Notions from "human and technology asset management and ergonomics" are fundamental to rehabilitation practice and research.The rehabilitation concept will further merge into general health care and the quality there-off.

Urologic provider experiences in transitioning spina bifida patients from pediatric to adult care

PURPOSE

The lack of precedent in transitioning from pediatric to adult care poses a challenge to providers for patients with spina bifida (SB). The purpose of this study was to summarize perceptions about best practices for the care of adult spina bifida patients.

MATERIALS AND METHODS

A national survey was electronically distributed to 174 urologists who are current members of the Spina Bifida Association Network and AUA Working Group on Urologic Congenitalism. De-identified voluntary responses were assessed for implementation of and barriers to interdisciplinary adult SB clinics, continuity of care, and practices for transitioning from pediatric to adult care.

RESULTS

The response rate was 40% with urologists practicing pediatrics, genitourinary reconstruction, female pelvic medicine and general urology. Patients undergoing transition or who have transitioned were seen in a multidisciplinary clinic (14%), regular adult clinic (34%), combined adult-pediatric multidisciplinary care (20%), or pediatric multidisciplinary clinic (28%). A majority believed transitioning to adult care should occur at 18 (24%) or 21 years (22%). In the absence of acute changes, providers followed adult SB patients annually with upper tract imaging (typically renal ultrasound) and serum creatinine. Acute urologic changes were preferentially managed with urodynamic testing and cystoscopy. Providers identified a need for multidisciplinary care in adult life, with neurosurgery/neurology (87%), social work (84%), and orthopedics (73%).

CONCLUSIONS

Potential solutions to improve the urologic care of this population suggest additional national provider resources, standardized guidelines, multidisciplinary collaboration, access to care, and an advanced-training pathway to improve care of adult patients with spina bifida.

Shoulder kinetics during start-up and propulsion with a manual wheelchair within the initial phase of uninstructed training

PURPOSE

Wheelchair locomotion is constraining for the upper limbs and involves a set of motor tasks that need to be learnt by a novice user. To understand this integration process, we investigated the evolution of shoulder kinetics during start-up and propulsion within the initial phase of low-intensity uninstructed training.

MATERIALS AND METHODS

Seventeen novice able-bodied subjects performed a 120-min uninstructed practice distributed over 4 weeks. During the initial and final sessions, upper limbs kinematics and hand-rim kinetics were continuously collected. Inverse kinematics and dynamics coupled to a three-dimensional linked-segment model were used to compute shoulder net moments.

RESULTS

Participants increased the speed of the wheelchair with practice. In average, an increase of shoulder net moments and mechanical work during the push phase was observed. Conversely, during the recovery phase, participants slightly increased shoulder power but maintained a similar level of shoulder loading. However, individual evolutions allowed the definition of two groups defined as: "increasers", who increased shoulder loading and mechanical work versus "decreasers", who managed to limit shoulder loading while improving the wheelchair speed.

CONCLUSION

These findings underline that individual adaptation strategies are essential to take into account when designing a rehabilitation protocol for wheelchair users. Implications for Rehabilitation The learning process of manual wheelchair locomotion is essential for the assimilation of motor tasks leading individuals to select their propulsion technique. Novice users display different learning strategies: some people increase shoulder loading very early but others spontaneously manage to increase the wheelchair speed while maintaining a constant level of shoulder loading. Wheelchair rehabilitation programs should be individualized to take into account the subject-specific learning strategy.