Effects and effectiveness of dynamic arm supports: a technical review

Usability of mechanical assistive technologies for performing activities involving the upper extremities in individuals with impairments: a systematic review

PURPOSE

To conduct a systematic review on the impacts of using mechanical assistive devices on function, performance in activities and participation of persons with upper extremity impairments, and to synthesize the strengths and limitations of these devices.

METHOD

Three independent reviewers conducted systematic searches of articles published between 2003 and 2023 in Compendex, Inspec, Embase, PubMed/Medline, IEEE Xplore, and Web of Science, as well as manual searches on the RESNA website for conference papers over the same period. The methodological quality of articles was appraised using the QualSyst tool.

RESULTS

From the 34 retained studies, 28 mechanical devices were identified and classified into two categories: (1) mobile arm supports (MASs) designed to perform multiple activities, and (2) devices used to assist with a specific activity of daily living (ADL). Overall, MASs helped users to perform manual activities in elevation and/or against gravity. Specific ADL devices allowed users to perform unique activities requiring fine motor skills such as opening a medicine container. Some of these devices have advantages like portability, adaptability, low cost, and ease of use. Limitations most often reported included interference or mobility restraints.

CONCLUSION

This review synthesizes the impacts of mechanical devices on the three domains of the International Classification of Functioning, Disability and Health (ICF) for individuals with upper extremity impairments. Impacts regarding function and performance in activities were more often measured than participation. Future studies should include outcomes related to participation, as taking this aspect into account might favor successful continued use of assistive devices.

Use of a dynamic arm support to drive a power wheelchair: a case report

PURPOSE

Dynamic arm supports (DAS) can assist individuals with severe upper limb disabilities who use a wheelchair to accomplish their daily activities. The objective of this case series was to assess the potential of a DAS to improve power wheelchair (PWC) control in real-life contexts and to describe the integration process. A secondary objective was to explore factors that may influence the DAS integration process.

METHODS

This case series includes four participants fitted with the Kinova DAS O110. A one-year follow-up was planned for each participant with qualitative and quantitative data collection to assess DAS outcomes. Assessment methods were selected to cover the three vantages of assistive technology outcomes assessment: effectiveness, subjective well-being, and social significance.

RESULTS

Among the four participants, one used the DAS to help with his wheelchair control for at least 12 months (successful integration). For him, the DAS led to significantly improved wheelchair skills and an important positive psychosocial impact. He was, however, only able to use the DAS for PWC control (no effects on other daily activities), and could not use it in some contexts because the device increased his PWC width. As for the other participants, they stopped using the DAS for different reasons, including a DAS-related adverse event.

CONCLUSION

This study demonstrated that a wheelchair-bound DAS has the potential to improve PWC use, but successful integration requires specific factors. The service delivery process and the environmental accessibility are crucial for the successful integration of such a device and to avoid safety issues.IMPLICATIONS FOR REHABILITATIONNo study deeply assessed the impacts of dynamic arm support on power wheelchair control, and the associated facilitators and obstacles.A wheelchair-bound dynamic arm support has the potential to improve power wheelchair control for individuals with upper limb disabilities and to lead to positive psychosocial impacts if some conditions conductive to successful integration are met.The service delivery process and the environmental accessibility appear as crucial aspects for the successful integration of a new device, such as dynamic arm support and avoiding safety issues.

The effects of facioscapulohumeral dystrophy and dynamic arm support on upper extremity muscle coordination in functional tasks

This study's objective is to understand the effect of muscular weakness in persons with facioscapulohumeral dystrophy as well as the effect of a dynamic arm support on muscle coordination and activity performance, during activities of daily living. People with facioscapulohumeral dystrophy (n=12, 56.0±14.5 years) and healthy controls (n=12, 55.5±13.4 years) performed five simulated daily activity tasks, while unsupported and supported by the Gowing dynamic arm support. Surface electromyography, kinematics, and maximum force output were recorded. Outcomes were calculated for muscle coordination (muscle synergies), maximum muscle activity, movement performance indicators, and upper limb muscular weakness (maximum force output). Muscle coordination was altered and less consistent in persons with facioscapulohumeral dystrophy compared with healthy controls. The dynamic arm support alleviated muscle efforts and affected muscle coordination in both populations. While populations became more similar, the internal consistency of persons with facioscapulohumeral dystrophy remained unaffected and lower than that of healthy controls. Furthermore, the support affected movements' performance in both groups. The maximum force outputs were lower in persons with facioscapulohumeral dystrophy than controls. Muscle coordination differences were presumably the result of individual-specific in muscle weakness and compensatory strategies for dealing with gravity compensation and movement constraints.

Evaluation of the usability of an actively actuated arm support

Dynamic arm supports can be used to increase the autonomy of people with upper limb disabilities, but their usability is often poorly documented. The objective of this study is to evaluate the usability of an actuated arm support (AAS), namely the Gowing power-assisted arm support. Nine participants with neurological disorders restricting their upper limb capacities (DASH = 63.51 ± 7.72) completed various tasks (Upper Extremity Performance Test for the Elderly (TEMPA)) with and without the AAS. Users' satisfaction (Quebec User Evaluation of Satisfaction with assistive Technology (QUEST)) and perceived benefits of the device (semi-structured interviews) were assessed. Large (effect size ≥ 1.15) and statistically significant (p < .05) improvements were found in the TEMPA functional rating, range of motion, strength, precision of gross movements and prehension patterns subscales while using the AAS. Two third of the participants were quite or very satisfied with the arm support (QUEST > 4/5) and interviews were positive about its usefulness in daily living activities. Our study demonstrated that the use of an AAS could result in significant improvements in the autonomy of people with upper limb disabilities.

Feasibility and effectiveness of a novel dynamic arm support in persons with spinal muscular atrophy and duchenne muscular dystrophy

Background

Neuromuscular disorders (NMD) commonly affect the upper extremity. Due to muscle weakness, performance of daily activities becomes increasingly difficult, which leads to reduced independence and quality of life. In order to support the performance of upper extremity tasks, dynamic arm supports may be used. The Yumen Arm is a novel dynamic arm support specially developed for people with NMD. The aim of this study is to evaluate the feasibility and effectiveness of the Yumen Arm in persons with Duchenne Muscular Dystrophy (DMD) and persons with Spinal Muscular Atrophy (SMA).

Methods

Three persons with DMD and three persons with SMA participated in this study. All participants conducted a set of measures with and without the Yumen Arm. Outcome measures were: active range of motion of the arm and trunk (i.e. Reachable Workspace, Functional Workspace, and trunk movement), fatigue (OMNI-RPE), Performance of Upper Limb (PUL) scale and some additional activities of daily living. User experiences were collected using a questionnaire.

Results

The Yumen Arm could be used by all participants. Results showed a median increase in active range of motion (4% relative surface area), and a median increase of function ability (>11% PUL score) when using the Yumen Arm. In addition, three out of four (data from 2 participants was missing) participants indicated that activity performance was less fatiguing when using the Yumen Arm. Four out of five (data from 1 participant was missing) participants indicated that they would like to use the Yumen Arm in their daily lives.

Conclusion

This study is one of the first studies describing a range of objective measures to examine the effectiveness of a dynamic arm support. Based on these measurements we can conclude that the Yumen Arm effectively improves arm function in NMD patients, however the effectiveness varies a lot between individual subjects. We provided detailed recommendations for the improvement of the Yumen Arm, and possible also for the development of other dynamic arm supports. This study showed a lot of variability between individual subjects, which emphasizes the importance of tuning dynamic arm supports based on individual user characteristics, such as scoliosis, functional capacity and muscle strength.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12984-021-00868-6.

Daily Life Benefits and Usage Characteristics of Dynamic Arm Supports in Subjects with Neuromuscular Disorders

Neuromuscular disorders cause progressive muscular weakness, which limits upper extremity mobility and performance during activities of daily life. Dynamic arm supports can improve mobility and quality of life. However, their use is often discontinued over time for unclear reasons. This study aimed to evaluate whether users of dynamic arm supports demonstrate and perceive quantifiable mobility benefits over a period of two months. Nine users of dynamic arm supports were included in this observational study. They had different neuromuscular disorders and collectively used four different arm supports. They were observed for three consecutive weeks during which they were equipped with a multi-sensor network of accelerometers to assess the actual use of the arm support and they were asked to provide self-reports on the perceived benefits of the devices. Benefits were experienced mainly during anti-gravity activities and the measured use did not change over time. The self-reports provided contextual information in domains such as participation to social life, in addition to the sensor system. However self-reports overestimated the actual use by up to three-fold compared to the accelerometer measures. A combination of objective and subjective methods is recommended for meaningful and quantifiable mobility benefits during activities of daily life.

Mobile arm supports in Duchenne muscular dystrophy: a pilot study of user experience and outcomes

PURPOSE

This pilot study examined whether two different types of non-powered mobile arm supports (MAS) enhanced upper limb function and independence with activities of daily living (ADLs) in people with Duchenne muscular dystrophy (DMD).

METHOD

A mixed methods cross-sectional design was used. Participants were four males with DMD, aged 16 to 20 years (M = 18.25 years). Two participants were current MAS users, and two had previously used MAS. To explore experiences of MAS use, semi-structured interviews were undertaken, then transcribed verbatim and analysed thematically. To measure the impact of MAS on arm function and ADLs, participants using MAS completed the Performance of the Upper Limb (PUL) and the DMD Upper Limb Patient Reported Outcome Measure with and without MAS. Participants no longer using MAS only completed the PUL without MAS.

RESULTS

MAS enhanced upper limb function and independence with ADLs in three of four participants. Eating and drinking was most often positively impacted by MAS. Access to informal support for MAS set-up, and ongoing input from a clinician or assistive technology (AT) supplier with MAS expertise, were important enablers to successful MAS use. Barriers to use included inadequate upper limb strength, interference of MAS with wheelchair controls, and AT funding delays.

CONCLUSION

MAS should be considered by individuals with DMD and clinicians working with them as the disease progresses and strength declines. Potential barriers to MAS use need to be addressed to ensure maximum utility. AT funding delays must also be minimized to avoid impact on outcomes of people with DMD.Implications for RehabilitationIndividuals with DMD, and clinicians working with them, may consider MAS to aid achievement of functional goals as the disease progresses and upper limb function declines.Both objective and subjective outcome measures should be used when evaluating the effectiveness of MAS.Consideration should be given to the potential interference of MAS with wheelchair controls and the availability of informal or paid supports (e.g., family, support workers, teachers) to aid MAS use.Efficient and timely funding of MAS is required, as delays may negatively impact outcomes for people with progressive neurological conditions, such as DMD.

Evaluation of admittance control as an alternative to passive arm supports to increase upper extremity function for individuals with Duchenne muscular dystrophy

The degree of upper extremity active range of motion provided by an admittance control robot compared with a commercially available passive arm support for individuals with DMD who have limited arm function was investigated in this study. The reachable workspace evaluation was used to assess active range of motion provided by both devices. A visual analog scale was also used to secure participant-reported outcome measures. The admittance control robot significantly increased reachable surface area scores compared with the passive arm support for the dominant arm (Wilcoxon T = 5, P = .022, r² = 0.263) and for the nondominant arm (paired-samples t test, t(9) = 4.66, P = .001, r² = 0.71). The admittance control robot also significantly decreased participant-reported exertion compared with the passive arm support. Results of this study substantiated the benefits of admittance control for individuals with DMD compared with a commercially available passive arm support.

The perceived functional benefit of dynamic arm supports in daily life

Dynamic arm supports are provided to assist with activities of daily living (ADLs) in people with limited upper-limb function. However, the perceived functional benefit of these devices in daily life is unknown. Insight into the functional benefit may give direction to the development of new devices and may affect the factors that patients and their health care providers consider during the selection process of a device. A cross-sectional study involving 23 Dutch experienced dynamic arm support users was performed in the Netherlands. The study included a questionnaire, an interview, and an observation of ADL task performance in the domestic setting. Twenty participants completed this study. Five users had a large perceived functional benefit, nine a moderate benefit, and five no benefit (one was unable to indicate the benefit). People with limited functional abilities benefited most. Participants varied in the amount of device use, activities the device is used for, and reasons for using (or not using) the device. On an individual level, selection using a selection tool and a good evaluation of the prescription could improve user-device matches.

Surface EMG signals in very late-stage of Duchenne muscular dystrophy: a case study

Background

Robotic arm supports aim at improving the quality of life for adults with Duchenne muscular dystrophy (DMD) by augmenting their residual functional abilities. A critical component of robotic arm supports is the control interface, as is it responsible for the human-machine interaction. Our previous studies showed the feasibility of using surface electromyography (sEMG) as a control interface to operate robotic arm supports in adults with DMD (22-24 years-old). However, in the biomedical engineering community there is an often raised skepticism on whether adults with DMD at the last stage of their disease have sEMG signals that can be measured and used for control.

Findings

In this study sEMG signals from Biceps and Triceps Brachii muscles were measured for the first time in a 37 year-old man with DMD (Brooke 6) that lost his arm function 15 years ago. The sEMG signals were measured during maximal and sub-maximal voluntary isometric contractions and evaluated in terms of signal-to-noise ratio and co-activation ratio. Beyond the profound deterioration of the muscles, we found that sEMG signals from both Biceps and Triceps muscles were measurable in this individual, although with a maximum signal amplitude 100 times lower compared to sEMG from healthy subjects. The participant was able to voluntarily modulate the required level of muscle activation during the sub-maximal voluntary isometric contractions. Despite the low sEMG amplitude and a considerable level of muscle co-activation, simulations of an elbow orthosis using the measured sEMG as driving signal indicated that the sEMG signals of the participant had the potential to provide control of elbow movements.

Conclusions

To the best of our knowledge this is the first time that sEMG signals from a man with DMD at the last-stage of the disease were measured, analyzed and reported. These findings offer promising perspectives to the use of sEMG as an intuitive and natural control interface for robotic arm supports in adults with DMD until the last stage of the disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12984-017-0292-4) contains supplementary material, which is available to authorized users.

Comparison between sEMG and force as control interfaces to support planar arm movements in adults with Duchenne: a feasibility study

BACKGROUND

Adults with Duchenne muscular dystrophy (DMD) can benefit from devices that actively support their arm function. A critical component of such devices is the control interface as it is responsible for the human-machine interaction. Our previous work indicated that surface electromyography (sEMG) and force-based control with active gravity and joint-stiffness compensation were feasible solutions for the support of elbow movements (one degree of freedom). In this paper, we extend the evaluation of sEMG- and force-based control interfaces to simultaneous and proportional control of planar arm movements (two degrees of freedom).

METHODS

Three men with DMD (18-23 years-old) with different levels of arm function (i.e. Brooke scores of 4, 5 and 6) performed a series of line-tracing tasks over a tabletop surface using an experimental active arm support. The arm movements were controlled using three control methods: sEMG-based control, force-based control with stiffness compensation (FSC), and force-based control with no compensation (FNC). The movement performance was evaluated in terms of percentage of task completion, tracing error, smoothness and speed.

RESULTS

For subject S1 (Brooke 4) FNC was the preferred method and performed better than FSC and sEMG. FNC was not usable for subject S2 (Brooke 5) and S3 (Brooke 6). Subject S2 presented significantly lower movement speed with sEMG than with FSC, yet he preferred sEMG since FSC was perceived to be too fatiguing. Subject S3 could not successfully use neither of the two force-based control methods, while with sEMG he could reach almost his entire workspace.

CONCLUSIONS

Movement performance and subjective preference of the three control methods differed with the level of arm function of the participants. Our results indicate that all three control methods have to be considered in real applications, as they present complementary advantages and disadvantages. The fact that the two weaker subjects (S2 and S3) experienced the force-based control interfaces as fatiguing suggests that sEMG-based control interfaces could be a better solution for adults with DMD. Yet force-based control interfaces can be a better alternative for those cases in which voluntary forces are higher than the stiffness forces of the arms.

Design and pilot validation of A-gear: a novel wearable dynamic arm support

BACKGROUND

Persons suffering from progressive muscular weakness, like those with Duchenne muscular dystrophy (DMD), gradually lose the ability to stand, walk and to use their arms. This hinders them from performing daily activities, social participation and being independent. Wheelchairs are used to overcome the loss of walking. However, there are currently few efficient functional substitutes to support the arms. Arm supports or robotic arms can be mounted to wheelchairs to aid in arm motion, but they are quite visible (stigmatizing), and limited in their possibilities due to their fixation to the wheelchair. The users prefer inconspicuous arm supports that are comfortable to wear and easy to control.

METHODS

In this paper the design, characterization, and pilot validation of a passive arm support prototype, which is worn on the body, is presented. The A-gear runs along the body from the contact surface between seat and upper legs via torso and upper arm to the forearm. Freedom of motion is accomplished by mechanical joints, which are nearly aligned with the human joints. The system compensates for the arm weight, using elastic bands for static balance, in every position of the arm. As opposed to existing devices, the proposed kinematic structure allows trunk motion and requires fewer links and less joint space without compromising balancing precision. The functional prototype has been validated in three DMD patients, using 3D motion analysis.

RESULTS

Measurements have shown increased arm performance when the subjects were wearing the prototype. Upward and forward movements were easier to perform. The arm support is easy to put on and remove. Moreover, the device felt comfortable for the subjects. However, downward movements were more difficult, and the patients would prefer the device to be even more inconspicuous.

CONCLUSION

The A-gear prototype is a step towards inconspicuousness and therefore well-received dynamic arm supports for people with muscular weakness.