Vibration stimulation of upper limb in chronic stroke rehabilitation

The goal of American researchers was to evaluate the feasibility of a glove providing mechanical vibrotactile stimulation (VTS) of the hand, as well as the rehabilitation potential of the VTS glove in restoring hand function in people with chronic stroke.

• VTS glove improved skin tactile perception,
• decreased finger spasticity, as well as
• increased the range of motion of the finger, elbow and arm.

Prepared on the basis of:

Wearable vibrotactile stimulation for upper extremity rehabilitation in chronic stroke: clinical feasibility trial using the VTS Glove. Seim CE, Wolf SL, Starner TE. J Neuroeng Rehabil. 2021 Jan 23;18(1):14.

Study population

The study involved 16 people (including 5 women) with chronic stroke with reduced mobility and perception of touch in the paralyzed hand (age: 28-68 years; period from the onset of stroke: 1-13 years).

Test procedure

A randomized, controlled, double-blind study was conducted.

Participants wore an active/ vibrating VTS glove (see next section; test group) or the same but without vibration (control group), three hours a day for eight weeks.

Hand and arm functions were measured at patients’ homes and at local physical therapy clinics weekly. Cutaneous tactile perception was assessed with the Semmes-Weinstein Monofilament Exam (SWME). The perception of pressure on the skin in grams was tested. The lower the masses were felt, the higher the perception was. The level of spasticity – the resistance of passive movement caused by involuntary muscle tension – was assessed using the Modified Ashworth Scale (MAS). Any angular range of motion (AROM) was used to assess motor impairment. In addition, every week, participants filled out appropriate questionnaires on the use of the VTS glove, which included their observations and comments about the device.

Use of vibration in the study

The VTS glove is designed to provide stimulation with vibrational stimuli at home. Users could use it while conducting their daily activities. VTS rehabilitation is therefore effortless and “passive”.

The VTS glove is fingerless with a vibration motor attached to each dorsal phalanx. Provides stimulation of the hand skin and tendons. The stimulation characteristics were targeted at skin mechanoreceptors – in particular Pacinian corpuscles – which respond best at around 250 Hz, operating in the 10-400 Hz frequency range. A convenient variable vibration pattern was used.

Results

The VTS glove improved the results of the SWME test, i.e. the cutaneous tactile perception, moreover, it reduced the spasticity according to the MAS scale in the fingers and slightly increased the range of motion (AROM) of the finger, elbow and arm.

Comment

Eight-week vibrotherapy with the use of the VTS glove significantly improved tactile perception, voluntary movement and spasticity. Thus, vibrational stimulation applied to a disabled limb with a “home” device enables the use of vibrotherapy and the study of its effects outside the clinical environment.

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