Effect of Instrument-Assisted Soft Tissue Mobilization on Gastrocnemius Stiffness and Ankle Range of Motion (IASTM-Gastro)

Effect of Instrument-Assisted Soft Tissue Mobilization on Gastrocnemius Muscle Stiffness and Ankle Dorsiflexion Range of Motion

This study will examine whether a technique called instrument-assisted soft tissue mobilization (IASTM) can reduce stiffness in the calf muscle (gastrocnemius) and improve ankle mobility. Muscle stiffness will be measured using a specialized ultrasound method called shear-wave elastography, while ankle range of motion will be assessed using the weight-bearing lunge test. Healthy volunteers will participate in this study, and measurements will be taken before and after a single IASTM treatment. The aim is to determine if this manual therapy technique can produce immediate changes in muscle properties and joint flexibility.

Study Overview

• Status: Completed
• Conditions: Muscle Stiffness
• Intervention / Treatment: Device: Instrument-Assisted Soft Tissue Mobilization

Detailed Description

This interventional study aims to evaluate the acute effects of instrument-assisted soft tissue mobilization (IASTM) on the stiffness of the gastrocnemius muscle and ankle dorsiflexion range of motion. Muscle stiffness will be quantified using shear-wave elastography (SWE), a non-invasive ultrasound technique that measures tissue mechanical properties in real time. Ankle dorsiflexion range of motion will be assessed using the weight-bearing lunge test with the knee extended, a reliable functional measure of ankle mobility.

Participants will undergo baseline measurements followed by a standardized IASTM intervention targeting the gastrocnemius muscle. Post-treatment assessments will be conducted immediately afterward to capture acute changes. The study is designed to improve understanding of how IASTM influences muscle mechanical properties and functional joint mobility. Findings may have implications for the clinical use of IASTM in both rehabilitation and performance contexts.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Slovenia
  • Municipality of Izola
    • Izola, Municipality of Izola, Slovenia, 6310
      • University of Primorska, Faculty of Health Sciences, Izola

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age between 18 and 45 years
• Healthy individuals without current lower limb injury
• No history of surgery to the ankle, knee, or calf
• Able to perform the weight-bearing lunge test without assistance
• Willing to refrain from intense lower-limb exercise 24 hours before testing

Exclusion Criteria:

• Current or recent (past 3 months) lower limb musculoskeletal pain or injury
• Known neuromuscular or vascular disorders affecting the lower extremity
• Use of medications affecting muscle tone or flexibility within 48 hours prior to testing
• Previous adverse reactions to manual therapy or IASTM
• Skin lesions, bruising, or conditions over the gastrocnemius that contraindicate IASTM
• Pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control
Experimental: IASTM; Participants in this arm will receive a single session of instrument-assisted soft tissue mobilization (IASTM) applied to the gastrocnemius muscle. The treatment will be performed using a standardized protocol that includes longitudinal and cross-friction strokes with a stainless-steel tool. The intervention is designed to target the superficial and deep layers of the gastrocnemius and will be delivered for a total of approximately 5 minutes. Post-treatment assessments of muscle stiffness and ankle dorsiflexion range of motion will be conducted immediately following the intervention.	Device: Instrument-Assisted Soft Tissue Mobilization; Participants will receive a single session of instrument-assisted soft tissue mobilization (IASTM) applied to the gastrocnemius muscle using a stainless-steel instrument. The treatment consists of longitudinal and transverse strokes targeting both the medial and lateral heads of the muscle. The procedure will be performed by a trained clinician, following a standardized protocol lasting approximately 5 minutes. The goal is to induce mechanical and neuromodulatory effects on muscle tissue. This intervention is designed to assess acute changes in muscle stiffness (via shear-wave elastography) and ankle dorsiflexion range of motion (via the weight-bearing lunge test).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle stiffness	Stiffness of the gastrocnemius muscle will be measured using shear-wave elastography (SWE), a non-invasive ultrasound technique that quantifies the shear modulus of soft tissue. Measurements will be performed with the participant in a prone position, with the ankle in a standardized neutral position, to ensure consistency. The shear modulus (in kilopascals) will be used as the primary metric of muscle stiffness. Time Frame:	Baseline and Immediately Post-Intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ankle Dorsiflexion Range of Motion	Ankle dorsiflexion range of motion will be assessed using the weight-bearing lunge test with the knee extended. The distance from the great toe to the wall will be recorded at the point where the heel remains in contact with the floor while the knee touches the wall. This test is a reliable and functional assessment of gastrocnemius-related ankle flexibility.	Baseline and Immediately Post-Intervention

Collaborators and Investigators

• Sponsor: University of Primorska

Study record dates

Study Major Dates

• Study Start (Actual): April 24, 2025
• Primary Completion (Actual): May 30, 2025
• Study Completion (Actual): June 15, 2025

Study Registration Dates

• First Submitted: April 11, 2025
• First Submitted That Met QC Criteria: April 11, 2025
• First Posted (Actual): April 18, 2025

Study Record Updates

• Last Update Posted (Actual): May 4, 2026
• Last Update Submitted That Met QC Criteria: May 1, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: IASTM_Gastro

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No