The usefulness of a vibrating wrist strap for restoring the hand after a stroke

The aim of the presented research by scientists from American universities was to test the concept of a vibrating wristband, a portable hand orthosis designed to improve the efficiency of a hand affected by functional impairment after a stroke. The authors referred to it as “TheraBracelet” (possibly short for “therapeutic bracelet”). They focused on demonstrating the feasibility of TheraBracelet and assessing the potential requirements and critical needs for the improvement of the TheraBracelet prototype.

• The tested vibrating wristband has proved to be feasible.
• Stroke survivors have been shown to try it at low cost willingly.
• The TheraBracelet prototype was assessed as overall satisfactory by stroke patients (3.7 out of 5).

Prepared on the basis of:

Feasibility and usability of a wearable orthotic for stroke survivors with hand impairment. Lakshminarayanan K, Wang F, Webster JG, Seo NJ. Disabil Rehabil Assist Technol. 2017 Feb;12(2):175-183.

Study population

10 people (including 4 women; age: 45-82 years) who survived a stroke participated in the study. The time since the stroke was 2-27 years. The functionality of the affected upper limb ranged from 13 to 24 points (out of 24 on the Fugl-Meyer Assessment scale).

Test procedure

The TheraBracelet prototype (described in the next section) was used. The expectations for TheraBracelet and the performance of the prototype were assessed with appropriate pre- and post-prototype surveys. House of Quality analysis was used to identify priority needs for technical improvements to the prototype.

Participants tested the prototype by performing manual dexterity tasks with and without the prototype, such as: writing with a pen or keyboard, pouring water into the cup, adding/ mixing sugar in the cup, and performing manual skill tests in the Box and Block and Purdue Pegboard Tests. Thanks to this research, participants were able to imagine how they might proceed with the prototype in their daily activities and how the prototype would affect their performance.

Use of vibration in the study

TheraBracelet had a vibrating element, thanks to which the skin of the wrist was subjected to vibrations. A piezoelectric vibrator embedded in a conventional sports wristband was used. A white low-pass noise filtered at 500 Hz was used as the source signal. The intensity of vibrations was selected individually according to the sense of a given participant.

Results

It has been shown that stroke survivors are willing to try TheraBracelet at low cost.

The tested prototype was generally satisfactory with an average rating of 3.7 out of 5.

Participants noted the need to increase the availability of clinical knowledge on the long-term efficacy of TheraBracelet. They also expected a lower price, an improvement in the ease of putting on and taking off, and the water resistance of TheraBracelet.

Comment

This study demonstrated the feasibility of a battery-powered vibrating wristband to improve hand function in stroke survivors, as well as making patients themselves interested in using it at low cost. The prototype under study was well received by stroke survivors.

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