Biomechanical Loading as an Alternative Treatment for Tremor: A Review of Two Approaches

Abstract

Background: Tremor is the most common movement disorder and strongly increases in incidence and prevalence with aging. Although not life threatening, upper-limb tremors hamper the independence of 65% of people suffering from them affected persons, greatly impacting their quality of life. Current treatments include pharmacotherapy and surgery (thalamotomy and deep brain stimulation). However, these options are not sufficient for approximately 25% of patients.Therefore, further research and new therapeutic options are required to effectively manage pathological tremor.Methods: This paper presents findings of two research projects in which two different wearable robots for tremor management were developed based on force loading and validated. The first consisted of a robotic exoskeleton that applied forces to tremulous limbs and consistently attenuated mild and severe tremors. The second was a neuroprosthesis based on transcutaneous neurostimulation. A total of 22 patients suffering from parkinsonian or essential tremor (ET) of different severities were recruited for experimental validation, and both systems were evaluated using standard tasks employed for neurological examination. The inclusion criterion was a postural and/or kinetic pathological upper-limb tremor resistant to medication. Results:The results demonstrate that both approaches effectively suppressed tremor in most patients, although further research is required. The work presented here is based on clinical evidence from a small number of patients (n510 for robotic exoskeleton and n512 for the neuroprosthesis), but most had a positive response to the approaches. In summary, biomechanical loading is non-invasive and painless. It may be effective in patients who are insufficiently responsive (or have adverse reactions) to drugs or in whom surgery is contraindicated.Discussion: This paper identifies and evaluates biomechanical loading approaches to tremor management and discusses their potential.

Need for mechanically and ergonomically enhanced tremor-suppression orthoses for the upper limb: a systematic review

“…Users of the WOTAS (#4) claimed that the orthosis is too bulky and leads to muscle fatigue [52]. This led to a cessation of the research on this wearable orthosis as it was not an acceptable solution for the patients [100]. Instead, the group investigated taking a different approach (functional electrical stimulation).…”

Design of a lightweight passive orthosis for tremor suppression

“…The most prevalent approach is an active orthosis [19]. However, none of the presented systems reached the market, because the solutions presented showed drawbacks, such as too much weight and restrictions in degrees of freedom (leading to patient rejection in some cases) [20]. Low patient acceptance can be explained by bad wearability [19].…”

A Novel Robotic Task for Assessing Impairments in Bimanual Coordination Post-Stroke

“…These oscillations may reflect unique underlying injury or impairment in these participants such as the onset of tremor [35] and may necessitate novel strategies for rehabilitation. For example, the application of biomechanical loads to the limbs can reduce tremor [36] and may evolve as a beneficial rehabilitation component for individuals with tremor-like impairments post-stroke.…”