Immediate Effects of Two IASTM Tools on Lower-Leg Tissue Stiffness and Ankle Mobility

September 16, 2026 updated by: Žiga Kozinc, University of Primorska

Acute Effects of Instrument-Assisted Soft Tissue Mobilization Using Lower-Cost and Higher-Cost Tools Lower-Leg Tissue Stiffness and Ankle Dorsiflexion Range of Motion in Healthy Adults: A Randomized Controlled Trial

This randomized controlled trial will investigate the immediate effects of instrument-assisted soft tissue mobilization (IASTM) performed with two different commercially available tools on posterior lower-leg tissue stiffness and ankle dorsiflexion range of motion in healthy young adults. Participants will be randomly allocated to one of three parallel groups: IASTM using a higher-cost tool, IASTM using a lower-cost tool, or passive rest without IASTM.

Tissue stiffness at predefined posterior lower-leg sites and ankle dorsiflexion range of motion will be assessed before and immediately after the intervention or equivalent rest period. A single lower limb will be assessed in each participant. Participants receiving IASTM will additionally rate the pleasantness of the intervention and their perceived relaxation after the intervention.

The study will determine whether IASTM produces immediate changes in tissue stiffness and ankle dorsiflexion compared with passive rest and whether these effects differ between the two IASTM tools.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Healthy adults aged 18 to 30 years will be randomly allocated to one of three parallel groups: higher-cost IASTM, lower-cost IASTM, or passive control. Only one lower limb will be assessed in each participant; the contralateral limb will not serve as a control.

Before and immediately after the intervention or control period, tissue stiffness will be assessed using MyotonPRO (Myoton AS, Tallinn, Estonia) at four predefined locations: the medial gastrocnemius, lateral gastrocnemius, soleus, and Achilles tendon. Gastrocnemius measurement locations will be identified at one-third of the respective anatomical reference distances described in the protocol. The soleus measurement will be performed medially at one-third of the distance from the medial malleolus toward the medial femoral condyle. The Achilles tendon will be assessed 2 cm proximal to the calcaneus. Two consecutive measurements will be obtained at each site at each assessment, and their mean will be used for analysis.

Ankle dorsiflexion range of motion will be assessed using a digital inclinometer positioned on the lateral aspect of the lower leg during a weight-bearing lunge performed while maintaining the assessed knee extended and the heel in contact with the floor.

Participants in either IASTM group will receive a six-minute standardized treatment of the posterior lower-leg region. The first minute will consist of familiarization with the instrument, desensitization, and application of IASTM cream. This will be followed by five minutes of treatment using long gliding strokes along the direction of the muscle fibers, with the instrument held at approximately a 45-degree angle. Treatment intensity will be adjusted to produce slight pain or moderate discomfort. The treatment protocol will be identical between IASTM groups except for the tool used.

Participants allocated to the control group will rest passively for an equivalent six-minute period without receiving IASTM. Participants receiving IASTM will rate intervention pleasantness and perceived relaxation immediately after treatment using 0-to-10 numerical rating scales.

Study Type

Interventional

Enrollment (Estimated)

45

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

Study Locations

  • Slovenia
    • Urban Municipality of Koper
      • Izola, Urban Municipality of Koper, Slovenia, 6310
        • University of Primorska, Faculty of Health Sciences, Izola
        • Contact:

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

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age 18 to 40 years
  • Healthy volunteer
  • Willing and able to provide written informed consent

Exclusion Criteria:

  • Current or previous lower-limb injury
  • Neuromuscular disorder
  • Neurological disorder

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Higher-Cost IASTM
Participants will receive a standardized six-minute IASTM intervention to the posterior lower-leg region using the higher-cost IASTM tool. The first minute will include familiarization, desensitization, and application of IASTM cream, followed by five minutes of standardized treatment.
Procedure: Instrument-Assisted Soft Tissue Mobilization Using a Higher-Cost Tool
A six-minute standardized IASTM intervention applied to the posterior lower-leg region using a higher-cost IASTM tool. The first minute consists of familiarization, desensitization, and application of IASTM cream, followed by five minutes of long gliding strokes along the direction of the muscle fibers. The instrument is held at approximately 45 degrees and treatment intensity is adjusted to slight pain or moderate discomfort.
Active Comparator: Lower-Cost IASTM
Participants will receive the same standardized six-minute IASTM intervention to the posterior lower-leg region using the lower-cost IASTM tool. Treatment duration, technique, instrument angle, treated region, and intensity will be matched to the higher-cost IASTM group.
Procedure: Instrument-Assisted Soft Tissue Mobilization Using a Lower-Cost Tool
The same six-minute standardized IASTM intervention as in the higher-cost tool condition, performed using a lower-cost IASTM tool. Treatment duration, treated region, stroke direction, instrument angle, and target intensity are standardized between the two IASTM interventions.
No Intervention: Passive Control
Participants will rest passively for six minutes without receiving IASTM. Measurements will be performed before and immediately after the rest period using the same procedures as in the intervention groups.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change From Baseline in Medial Gastrocnemius Stiffness
Time Frame: Baseline and immediately after the 6-minute intervention or rest period
Tissue stiffness will be measured using MyotonPRO and expressed in N/m. Two consecutive measurements will be obtained at each assessment and averaged.
Baseline and immediately after the 6-minute intervention or rest period
Change From Baseline in Lateral Gastrocnemius Stiffness
Time Frame: Baseline and immediately after the 6-minute intervention or rest period
Tissue stiffness will be measured using MyotonPRO and expressed in N/m. Two consecutive measurements will be obtained at each assessment and averaged.
Baseline and immediately after the 6-minute intervention or rest period
Change From Baseline in Soleus Stiffness
Time Frame: Baseline and immediately after the 6-minute intervention or rest period
Tissue stiffness will be measured using MyotonPRO and expressed in N/m. The measurement site will be located medially at one-third of the distance from the medial malleolus toward the medial femoral condyle. Two consecutive measurements will be obtained and averaged.
Baseline and immediately after the 6-minute intervention or rest period
Change From Baseline in Achilles Tendon Stiffness
Time Frame: Baseline and immediately after the 6-minute intervention or rest period
Achilles tendon stiffness will be measured using MyotonPRO and expressed in N/m at a predefined site 2 cm proximal to the calcaneus. Two consecutive measurements will be obtained and averaged.
Baseline and immediately after the 6-minute intervention or rest period
Change From Baseline in Ankle Dorsiflexion Range of Motion
Time Frame: Baseline and immediately after the 6-minute intervention or rest period
Ankle dorsiflexion range of motion will be measured in degrees using a digital inclinometer positioned on the lateral aspect of the lower leg during a weight-bearing lunge with the assessed knee maintained in extension and the heel in contact with the floor.
Baseline and immediately after the 6-minute intervention or rest period

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Perceived Pleasantness of IASTM
Time Frame: Immediately after the 6-minute IASTM intervention
Participants receiving IASTM will rate the pleasantness of the intervention on an 11-point numerical rating scale ranging from 0 to 10, with 0 representing the lowest possible pleasantness and 10 representing the highest possible pleasantness.
Immediately after the 6-minute IASTM intervention
Perceived Relaxation After IASTM
Time Frame: Immediately after the 6-minute IASTM intervention
Participants receiving IASTM will rate their perceived relaxation after the intervention on an 11-point numerical rating scale ranging from 0 to 10, with 0 representing the lowest possible relaxation and 10 representing the highest possible relaxation.
Immediately after the 6-minute IASTM intervention

Collaborators and Investigators

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

Sponsor

University of Primorska

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)

October 1, 2026

Primary Completion (Estimated)

December 15, 2026

Study Completion (Estimated)

January 15, 2027

Study Registration Dates

First Submitted

September 10, 2026

First Submitted That Met QC Criteria

September 10, 2026

First Posted (Actual)

September 16, 2026

Study Record Updates

Last Update Posted (Actual)

September 17, 2026

Last Update Submitted That Met QC Criteria

September 16, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • UPFVZ-IASTM-2026

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data underlying the results reported in the publication will be made available upon reasonable request. After publication of scientific manuscript, the data will also be uploaded to a trusted repository (Zenodo.org).

IPD Sharing Time Frame

Data will become available following publication of the main study results and will remain available for at least 5 years.

IPD Sharing Access Criteria

Data will be made available to researchers upon reasonable request to the corresponding author. Requests should include a brief description of the proposed analysis and intended use of the data. Data will be shared following approval by the study investigators and, where applicable, completion of an appropriate data-sharing agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ANALYTIC_CODE

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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