Effect of TENS on Spasticity

June 20, 2026 updated by: Korhan Barış Bayram, Izmir Katip Celebi University

The Effect of Transcutaneous Electrical Nerve Stimulation on Spasticity: A Single-Subject Experimental Study

The purpose of this clinical trial is to evaluate whether Transcutaneous Electrical Nerve Stimulation (TENS) is effective in reducing spasticity in adults with post-stroke spasticity. The primary research question is whether TENS can reduce the severity of spasticity. The effectiveness of TENS will be assessed by comparing spasticity-related outcomes measured before, during, and after the intervention. Participants will first undergo a one-hour baseline monitoring period, during which assessments will be conducted at 10-minute intervals. This will be followed by a 30-minute TENS intervention and a two-hour follow-up period, with assessments performed every 10 minutes. One participant will repeat this protocol once daily for three consecutive days, whereas the remaining three participants will undergo the procedure on a single occasion.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Post-stroke spasticity is a common consequence of upper motor neuron lesions and is characterized by increased muscle overactivity and exaggerated stretch reflex responses. It can negatively affect motor function, daily activities, and quality of life in stroke survivors.

Transcutaneous electrical nerve stimulation (TENS) is a non-invasive and widely used rehabilitation modality that may modulate spinal and supraspinal neural mechanisms through activation of sensory afferent pathways. Although previous studies have reported potential benefits of TENS for spasticity management, findings remain inconsistent because of methodological heterogeneity, variability in stimulation parameters, and differences in individual treatment responses.

The purpose of this study is to evaluate the effects of sensory-level TENS on wrist flexor spasticity and spinal motor neuron excitability in individuals with chronic post-stroke spastic paresis. Specifically, the study will examine whether TENS influences clinical spasticity, the duration of any observed effects, the magnitude of treatment-related changes, and the reproducibility of these effects across participants.

Two complementary single-case experimental designs will be used. First, a withdrawal/reversal design (ABABA with washout periods) will be employed to evaluate the causal effects of TENS on outcome measures. Second, a nonconcurrent multiple-baseline design across participants will be used to assess the consistency of intervention effects across individuals.

TENS will be applied over the paretic wrist flexor muscles for 30 minutes using symmetrical biphasic rectangular pulses (100 Hz, 200 μs). Stimulation intensity will be adjusted to a clearly perceived sensory level without visible muscle contraction or discomfort.

The primary outcomes are clinical spasticity, assessed by muscle reaction angle during rapid passive stretch, and spinal motor neuron excitability, assessed by the Hmax/Mmax ratio obtained from flexor carpi radialis H-reflex recordings. Repeated measurements will be performed throughout the experimental phases to evaluate immediate and time-dependent changes associated with TENS application.

This study is expected to provide individual-level evidence regarding the effects and temporal characteristics of sensory-level TENS in chronic post-stroke spasticity.

Study Type

Interventional

Enrollment (Estimated)

4

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

  • Name: Korhan B Bayram, M.D.
  • Phone Number: +905073066695
  • Email: korbay@gmail.com

Study Contact Backup

Study Locations

  • Turkey (Türkiye)
    • Karabağlar
      • Izmir, Karabağlar, Turkey (Türkiye), 35150
        • Izmir Katip Çelebi University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age between 18 and 70 years
  • Post-stroke wrist flexor spasticity scored as Grade 2 or 3 on the Australian Spasticity Assessment Scale (ASAS), specifically selecting patients whose passive stretch resistance (post-catch response) can be easily overcome to ensure accurate and unconfounded electrophysiological evaluation.
  • At least 6 months post-stroke (chronic phase).
  • Provision of voluntary, written informed consent prior to study enrollment.

Exclusion Criteria:

  • Age <18 or >70 year
  • Contraindications to transcutaneous electrical nerve stimulation (e.g., implanted electronic devices, history of epilepsy, or localized skin lesions preventing electrode placement)
  • Concomitant wrist contracture or pain sufficient to impede clinical evaluation
  • Structural abnormalities of the elbow joint obstructing median nerve stimulation
  • Median nerve neuropathy or injury in the affected upper extremity.
  • Non-stable dosage of antispastic medications within the 2 weeks prior to baseline
  • Initiation of medications affecting nerve conduction (e.g., antidepressants, anticonvulsants, anesthetics) within the past month; patients on a stable dose for >1 month remain eligible
  • Botulinum toxin injection in the target spastic muscles within the preceding 3 months
  • History of neurolytic procedures targeting spasticity in the affected limb.
  • History of orthopedic or neurological surgery targeting spasticity in the affected limb
  • Cognitive impairment severe enough to compromise adherence to study protocols
  • Inability to maintain the required testing positions for the upper extremity joints (shoulder, elbow, forearm, and wrist)
  • Pregnancy or breastfeeding
  • Presence of active malignancy at or near the treatment area.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Transcutaneous electrical nerve stimulation (TENS)
Participants with chronic post-stroke wrist flexor spasticity will receive sensory-level transcutaneous electrical nerve stimulation (TENS) applied over the paretic wrist flexor muscles during the intervention (B) phase. TENS will be delivered for 30 minutes using a symmetrical biphasic rectangular waveform with a frequency of 100 Hz and a pulse duration of 200 μs. Stimulation intensity will be adjusted to a clearly perceived sensory level without visible muscle contraction or discomfort. During the baseline (A) phase, no intervention will be administered.
Device: Transcutaneous electrical nerve stimulation (TENS)
Transcutaneous electrical nerve stimulation (TENS) will be applied over the projection area of the paretic wrist flexor muscles (flexor carpi radialis) for 30 minutes. Stimulation parameters will consist of symmetrical biphasic rectangular pulses at a frequency of 100 Hz and a pulse duration of 200 μs. Stimulation intensity will be adjusted to produce a clearly perceived sensory sensation without visible muscle contraction or discomfort.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Angle of Muscle Reaction
Time Frame: From baseline assessment through completion of study participation (1 to 3 days, depending on the assigned experimental design).
The Angle of Muscle Reaction (AMR) is defined as the joint angle at which a catch response is elicited in the wrist flexor muscles (flexor carpi radialis and flexor carpi ulnaris) during passive stretch performed at the highest achievable velocity. Higher values indicate lower spasticity.
From baseline assessment through completion of study participation (1 to 3 days, depending on the assigned experimental design).
Hmax / Mmax ratio
Time Frame: From baseline assessment through completion of study participation (1 to 3 days, depending on the assigned experimental design).
The Hmax/Mmax ratio is an electrophysiological measure of spinal motor neuron excitability obtained from flexor carpi radialis H-reflex recordings. Higher values indicate greater spinal motor neuron excitability.
From baseline assessment through completion of study participation (1 to 3 days, depending on the assigned experimental design).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Izmir Katip Celebi University

Investigators

  • Principal Investigator: Korhan B Bayram, Izmir Katip Çelebi University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 1, 2026

Primary Completion (Estimated)

June 1, 2027

Study Completion (Estimated)

June 1, 2027

Study Registration Dates

First Submitted

June 20, 2026

First Submitted That Met QC Criteria

June 20, 2026

First Posted (Actual)

June 25, 2026

Study Record Updates

Last Update Posted (Actual)

June 25, 2026

Last Update Submitted That Met QC Criteria

June 20, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2026-KAE-0019

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Since all necessary demographic, clinical, and outcome data will be reported and published in a manuscript as per the study methodology, IPD sharing is currently not deemed required.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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