Introduction
Over the past decades, there has been a prolific amount
of research and development of technology to enhance both the
understanding of neurologic injuries and the application of
evidence-based neurorehabilitation interventions. Surface
electromyography (sEMG) is one such technology that has undergone rapid
advancement in development, but has yet to reach its full translational
potential to help drive neurorehabilitation and maximize recovery.
Understanding this translational gap must consider multiple factors
across a complex landscape of healthcare provision, especially given the
public/private healthcare model in the United States. Successful
deployment of sEMG in clinical environments relies on an interaction of
system design, funding, translational research findings, clinician
training, and user acceptance, among many other factors. While user
acceptance of neurorehabilitation technology is just a small piece of a
much larger puzzle, it is an essential one, and a more explicit
understanding of the perceptions and experiences of individuals with
neurologic injury, such as stroke, is warranted to better understand the
barriers, facilitators, and untapped potential of sEMG technology in
clinical neurorehabilitation,
Stroke is one of the most common neurologic injuries worldwide (1, 2).
Recent global statistics estimate nearly 14 million new instances of
stroke annually; stroke related healthcare costs in the US alone have
topped $750 billion annually and are projected to increase as a result
of the aging population (3, 4).
Further, the psychosocial and functional impacts of stroke are also
significant, leading to stress, isolation, and potential comorbid health
conditions (5, 6).
While neurorehabilitation is a central feature of recovery for
individuals with stroke, outcomes can be disparate and long-term
impairment is common, further influenced by the extent to which stroke
survivors have the geographic, financial, healthcare, and
socio-emotional resources to maximize recovery following their injury (1).
It is because of this significant impact of stroke at both individual
and institutional levels that the field of neurorehabilitation must
engage in a deeper exploration of the translation of advanced healthcare
technologies into clinical settings to enhance our knowledge and
provision of care during recovery from neurologic injuries.
Surface EMG today is used in research and clinical
environments across a wide variety of physiological and engineering
applications relating to rehabilitation, sport performance, occupational
performance, and beyond (7).
More specific to neurorehabilitation, foundational literature in the
mid-twentieth century described sEMG as a useful tool to characterize
neuromuscular patterns, demonstrated the relative contribution of
different muscles in functional movement, and in some cases, assisted in
prognosis of recovery following neurologic injury (8, 9).
Across many subsequent decades, researchers have used sEMG to examine
factors in participants with and without neurologic impairments such as
interlimb coordination, muscle activation and co-activation patterns,
response to biofeedback, and most recently, as a tool to determine
treatment appropriateness and costs in stroke survivors with gait
impairments (7, 10–14).
Despite these advances, a significant body of literature supporting the
use of sEMG, and the establishment of expert guidelines for sEMG
implementation through SENIAM (Surface EMG Non-Invasive Assessment of
Muscles), a lack of clinical translation of sEMG technology has also
been recognized by researchers (7, 15–18).
One potential reason for the slow clinical uptake of
sEMG and related neurorehabilitation technologies may be the paucity of
perspectives in research from clinicians as providers of sEMG assessment
or intervention, and individuals with neurologic conditions and their
caregivers as recipients of sEMG assessment or intervention. Considering
sEMG alongside other neurorehabilitation technologies more broadly, the
literature is lacking a clear picture of how and how often these
technologies are used in clinics across the US, and how technology users
and their caregivers respond to the design, logistics of use, and
output of the devices. However, user and caregiver perspectives are a
key untapped resource in the design and implementation of rehabilitation
technologies such as sEMG, and have the potential to richly
contextualize the barriers and facilitators that affect technology
acceptance and use. For example, within the broader realm of
neurorehabilitation technology, Alt Murphy et al. (19)
recently published a qualitative analysis of participant responses to a
novel wearable sensor garment to monitor physiologic and movement
parameters for individuals with stroke, Parkinson's Disease, or
Epilepsy. The authors reported that responses to the upper body garment
was acceptable, but participants noted challenges with fit and comfort
and felt uncertain about consistent monitoring and privacy (19).
Another study noted similar comfort issues with wearable sensors, but
highlighted that despite the discomfort, participants preferred the
automated data tracking features of the sensors compared to more
time-intensive activities such as completing activity or symptom diaries
(20).
Additional qualitative work with stroke survivors and
clinicians has also explored perspectives and experiences of the
rehabilitation process itself, as well as technologies such as virtual
reality, gaming, robotic exoskeletons, or other wearable devices, but
little work has focused specifically on sEMG (21–29).
One study included gaming as part of a structured, enriched
rehabilitation environment, which garnered positive responses from
participants who noted increased motivation to move as well as friendly
competition between other participants on the unit (29).
Perceptions of virtual reality systems varied, with one study reporting
low rates of side effects but high rates of perceived exertion by
stroke survivors (21),
and another describing how users felt enjoyment and motivation using a
novel technology they would not otherwise have had access to, but felt
that the experiences with virtual reality did not translate into
improved functional carryover (23).
Many studies have examined robotic applications for stroke
rehabilitation, but very few have included survivor perspectives. Those
that have describe user priorities of cost, better movement quality,
endurance, practicality, and appropriate training and support, but also
highlight technology acceptance issues as a potential barrier for
clinical or home use (30–33).
One set of studies investigated the preliminary use of sEMG as a
control mechanism for a gaming system in chronic stroke survivors,
finding significant pre and post intervention sEMG changes, and
qualitative outcomes which indicated most participants would recommend
neurogaming to others for enjoyment, despite a lack of reported
functional carryover (26, 34).
Our recent work has explored rehabilitation clinicians' perspectives of
the use of sEMG in practice with individuals with neurologic
conditions, who noted the potential benefits of objective recovery
tracking, muscle training, and patient motivation, but also acknowledged
barriers to sEMG use such as time, training, and access to funds and
technical support for sEMG equipment (35).
The literature notes that the introduction of novel
healthcare technologies into existing clinical practices can be
challenging, as the process often disrupts engrained care routines (36).
Resistance to new technology integration, as well as distinct ways of
evaluating the utility of technology from professional and lay
perspectives are common (37).
This has consequences for both healthcare providers as well as
patients. For example, healthcare providers have noted translational
difficulties, including challenges with clearly communicating results to
patients and using technology outputs to meaningfully guide treatment
decisions. Patients have expressed uncertainty about the purpose of
technology as a part of their care, and a failure to receive meaningful
results from their providers (37).
Applied to rehabilitation, it is reasonable to expect that there may be
similar challenges when considering the implementation of sEMG
technology, especially considering the introduction of a high-tech,
objective, instrumented assessment tool juxtaposed with clinical
standards that typically involve low-tech, subjective, scaled tools such
as manual muscle testing or dynamometry. Experiences such as these
underscore that clinician training, communication about technology
intent, impact, and translational capacity to assist in healthcare
decision-making are important factors to consider in improving uptake of
technology in clinical settings.
The purpose of this early-stage study was to foreground
the perspectives of stroke survivors and gain a better understanding of
their experiences in neurorehabilitation, the technologies they have
used during their recovery, and their introductory perceptions of one
lab-designed prototype and three commercially available sEMG systems.
Centering these perspectives is critical to understanding the barriers
and untapped potential of sEMG and other neurorehabilitation
technologies that may support the recovery of individuals with
neurologic injuries. This qualitative work complements and builds upon
past milestones in sEMG research across rehabilitation and engineering
fields. It offers a preliminary look at baseline user perspectives to
inform more robust research in the future, and provides a unique
opportunity to leverage user-centered perspectives to support potential
innovations in sEMG design, implementation, and outcomes.
Heather A. Feldner
Christina Papazian
Keshia Peters2 and 
Katherine M. Steele