K.A. Neely, MSOP

_{December 2022}

Clinical Question

Does the use of a myoelectric elbow or elbow-wrist-hand orthosis increase the functional capabilities of the affected upper extremity in chronic hemiplegic patients?

Background

Chronic upper-extremity (UE) neuromuscular impairment affects millions of people in the United States. Flaccid and spastic paralysis of the UE can result from stroke, traumatic brain injury (TBI), brachial plexus injuries (BPI), as well as many other etiologies, and this condition leaves patients unable to perform volitional elbow, wrist, and/or hand motion.^1-10 Impairments are chronic if they persist for longer than 6 months. The ability to complete activities of daily living and functional tasks decreases without control or range of motion of the elbow, wrist, and hand in the affected arm. Deficits in the upper extremities greatly impact and reduce quality of life and level of independence.¹ Motor learning-based (MLB) therapy with repetitive activity-based intervention has been shown to improve functional outcomes, but with reduced function in the affected extremity, participation in these therapies is limited.^2-4

Myoelectric upper-extremity orthoses (MUEO), such as the MyoPro (Myomo, Boston, MA), are sometimes used in MLB therapy. These orthoses are custom made for each patient and use EMG signals to recognize volitional muscle contraction. Built-in motors help complete motion at the hand or elbow as indicated from the sensed contraction. A MUEO is intended to help train the user to activate and relax muscles corresponding to desired motion and strengthen the otherwise unused arm, increasing functional use of the paretic extremity and participation in MLB therapies. Small sample studies have been conducted regarding the effect of a MUEO on rehabilitation outcomes in a variety of populations with upper-extremity impairment. An analysis of available literature was conducted to evaluate if evidence exists to indicate a MUEO positively impacts rehabilitation and functional use of a paretic UE.

Search Strategy

Databases Searched: O&P IQ, PubMed, CINAHL

Search Terms:  Myoelectric” AND (“orthosis” OR “orthotic” OR “orthoses”) AND (“upper extremity” OR “upper limb” OR “arm” OR “hand”) NOT (“prosthetic” OR “prosthesis” OR “protheses”)

Inclusion/Exclusion Criteria:   2010-present, English, Peer-Reviewed Journal paper

Synthesis of Results

A total of six articles were included (Table 1). One study evaluated patients with BPI,⁸ five evaluated stroke patients,^2,4-6,9 and one included TBI patients.⁴ All patient populations presented with chronic weakness and diminished function of the UE. Sample size for the included studies ranged from n=9⁶ to n=34.⁵ Studies varied in duration of use with the MUEO from one day^2,9 to multiple months-long phases of therapy.^4-6,8 Almost all studies compared outcomes using the device to a baseline taken prior to use of the device.

Outcomes included Fugl-Meyer (FM) assessment scores,^2,4-6 Modified Ashworth Scale (MAS) results,^4,6 Box and Blocks (BB) test scores,² measurements of range of motion,^4,8-9 and muscle strength,⁸ DASH scores,⁸ Chedoke scores,⁴ and subjective patient reports.⁴ Key findings from these studies consistently show improved functional outcomes with increased FM scores, increased ROM, and/or increased ability to complete tasks or decreased perceived disability (DASH, Chedoke, BB, functional tasks).^2,4-6,8-9 Findings also suggest an influence of patient compliance on sustained improvement once released from therapy or in-clinic phases.^4,6

Potential limitations of the evidence presented include: (1) small sample size studies, including only one randomized controlled trial; (2) a lack of comparison to a traditional therapy control; (3) data analyzed containing multiple iterations or versions of the MUEO device; (4) the outcome measures used may not be valid representations of functional mobility.

Clinical Message

While individual study sample size was small, results remained consistent across multiple studies. Results in short-term studies indicate that a MUEO supports the affected extremity and increases functional capabilities while wearing the device. Available literature from longer-term studies indicates that in addition to supporting the weakened extremity, motor-learning-based therapy completed using a MUEO effectively increases functional capabilities in the affected upper extremity for chronic upper extremity impairment caused by stroke, TBI, or BPI beyond that seen in traditional therapy alone. The available literature shows that discontinued use of therapeutic intervention with the device results in loss of the marked increased functional capabilities.

^{Please address correspondence to: neelykal@gmail.com}