Abstract
Background: This systematic review summarizes the current evidence about the effectiveness of wearable assistive technologies for upper limbs support during activities of daily living for individuals with neuromuscular diseases.
Methods: Fourteen studies have been included in the meta-analysis, involving 184 participants. All included studies compared patients ability to perform functional tasks with and without assistive devices.
Results: An overall effect size of 1.06 (95% CI = 0.76-1.36, p < 0.00001) was obtained, demonstrating that upper limbs assistive devices significantly improve the performance in activities of daily living in people with neuromuscular diseases. A significant interaction between studies evaluating functional improvement with externally-assessed outcome measures or self-perceived outcome measures has been detected. In particular, the effect size of the sub-group considering self-perceived scales was 1.38 (95% CI = 1.08-1.68), while the effect size of the other group was 0.77 (95% CI = 0.41-1.11), meaning that patients’ perceived functional gain is often higher than the functional gain detectable through clinical scales.
Conclusion: Overall, the quality of the evidence ranged from low to moderate, due to low number of studies and participants, limitations in the selection of participants and in the blindness of outcome assessors, and risk of publication bias.
Significance: A large magnitude effect and a clear dose-response gradient were found, therefore, a strong recommendation, in favor of the use of assistive devices could be suggested.
1. Introduction
1.1. Background
Severe muscular weakness and chronic disability caused by neuromuscular diseases (e.g., muscular dystrophy, spinal muscular atrophy, spinal cord injuries or stroke) or neurodegenerative diseases (i.e., multiple sclerosis, amyotrophic lateral sclerosis) lead to the unavoidable loss of the possibility to perform even simple actions, such as walking, eating, and changing limbs posture. Patients suffer the consequences in terms of independence, quality of life, and self-esteem, given their need to continuously rely on assistance from their caregivers. This is particularly true for upper limbs, where independence is not primarily linked to essential tasks (e.g., eating, drinking, get dressed), but to simple actions not necessary for survival, but which increase the quality of life (e.g., pull up the glasses, scratch, use the mouse, etc.). To independently regain a lost motor function might be therefore a special experience towards a more independent daily life. Technological advancements might be a way to compensate patients’ muscular weakness through the use of Assistive Devices (ADs), which empower the user in the execution of daily life activities, and which are designed to maintain or to improve the functional capabilities of individuals with disabilities. ADs for lower limbs, such as wheelchairs and electric wheelchairs, have been successfully developed and diffused to deal with the deambulation issue. On the other side, the support of upper limbs related activities is more challenging. However, with the increased life expectancy, upper extremities functions became more and more important to be supported. Non-ambulant patients with neuromuscular disorders identified arm functions as their highest priority, indicating repositioning at night, bring hands to mouth, shift while seated, using the wheelchair joystick and the keyboard of a computer, and personal hygiene as priority functions to be regained (Janssen et al., 2014). The currently existing assistive devices to support upper limbs functions can be categorized in (i) end-effector devices, and (ii) exoskeletons. As for end-effector devices, they present a single interaction point between the user and the AD, usually located at forearm or hand level. The main disadvantage of robotic manipulator devices is the impossibility to control upper limb joints directly: the change in position of the interaction point results in unexpected movements of shoulder and elbow joints. As for exoskeletons, they are external structures worn by the patient, with joints and links placed in correspondence of human joints and bones. Patients usually prefer exoskeleton solutions, given that these devices not only help to execute the desired task, but they increase the perception of a self-executed movement. In a study conducted by Rupal et al. (2017) with 118 participants, 96.8% prefer to use an exoskeleton over other mobility aids, and 84.1% like the idea that exoskeletons should be made available in care homes (Rupal et al., 2017). In addition, from a survey conducted by the authors at Lignano Sabbiadoro (Italy) on June 2015, during the annual meeting of the UILDM Association (Italian Association of Muscular Dystrophy), 10 out of 15 interviewed patients affected by muscular dystrophy answered that they prefer exoskeleton solutions for possible upper limbs assistive devices. ADs driving technology can be either passive, working through pre-stored mechanical energy, or active, working with motors, and therefore able to exert greater forces or to control movements more precisely. However, even if a remarkable number of works have been published dealing with the development of innovative electromechanical technologies (e.g., Ragonesi et al., 2013; Jung et al., 2014; Dunning et al., 2015; Sin et al., 2015; Dalla Gasperina et al., 2018), scientific evidence for the benefits of these technologies is still lacking, which could justify costs and effort. When dealing with Assistive Devices, or in general with complex technologies, the demonstration of the effectiveness of their use is rather difficult to be demonstrated following the canonical research studies design [i.e., Randomized Control Trial (RCT) design], even if some effort in this direction is currently ongoing (Antonietti et al., 2019). This is due to several reasons, such as the difficulty to demonstrate the validity of the proposed approach independently from the users’ placebo effect (e.g., it is impossible to perform a blind session), the high cost of the technology and therefore the impossibility to recruit many volunteers contemporary, and the Ethical Committee procedures for non CE-marked devices. A recent systematic review on devices to assist and/or rehabilitate upper limbs made a quite large classification of different devices used, showing an intense research work towards the development of new technologies, which however are rarely methodologically properly tested, and therefore they have difficulties to effectively reach end-users (Onose et al., 2018). […]

