An interventional study of Instrument Assisted Soft Tissue Mobilization in Range of Motion, Articular, Ankle Joint, High Force IASTM Treatment and Low Force IASTM Treatment, sponsored by University of Idaho. Not yet recruiting at 1 site in United States. Open to participants aged 18 Years to 39 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-10.
Sponsored by University of Idaho · Not applicable, Interventional, and Treatment
Instrument-assisted soft tissue mobilization (IASTM) is a technique commonly used in sports medicine to reduce muscle tightness and improve range of motion. The technique involves using a handheld instrument, typically made of metal, to apply pressure and massage soft tissues. The instrument allows clinicians to target specific areas while reducing stress on their hands. Previous research has demonstrated that IASTM may improve range of motion and reduce muscle tightness. However, little is known about how the amount of force applied during treatment influences these outcomes. This study aims to investigate the effects of different IASTM treatment forces on calf muscle stiffness and ankle dorsiflexion (the movement of the foot upward toward the shin). Participants will receive either low-force IASTM (0-5 N), high-force IASTM (10-15 N), or no treatment depending on what group they are assigned to. Treatment force will be monitored using a sensor attached to the IASTM instrument (Figure 1). Changes in tissue stiffness will be assessed using the MyotonPRO, a handheld device that measures the mechanical properties of muscles and other soft tissues. Changes in ankle dorsiflexion will be evaluated using clinical movement tests and motion capture analysis.
The findings may help researchers and clinicians better understand how different IASTM treatment protocols influence tissue stiffness and ankle mobility, potentially contributing to more standardized treatment recommendations.
Participants will complete a single laboratory visit lasting approximately 82 minutes.
Familiarization With Movement Tasks (\~5 minutes) Participants will practice each movement task before data collection.
Weight Bearing Lunge Test (WBLT). The participant stands with one foot behind the other. They hold a dowel for balance in the hand opposite the back foot. The back leg is extended to a straight knee position, with the heel pressed into the floor and the second toe pointed forward. The participant adjusts foot position until they feel a stretch in the calf while keeping the heel on the ground. They then drive the hips forward, bending the front knee until the heel lifts from the ground. The distance between the front and back foot is adjusted as needed to maintain these parameters.
Gait. Participants will walk back and forth across a pressure sensing walkway until they are comfortable with their walking pattern in the laboratory. They will walk at two speeds. The slow pace is as if they have somewhere to be but are not in a hurry. The fast pace is as if they are walking for exercise.
Overhead Deep Squat (OHDS). The participant stands with feet shoulder width apart and toes pointed forward. They hold a plastic dowel overhead with both hands and arms extended. The participant squats as deep as possible and returns to standing in one continuous motion.
Functional Movement Screen (FMS) Ankle Clearing Test. The participant stands with the feet positioned heel to toe and uses a dowel for balance. Keeping the rear heel in contact with the floor, the participant flexes the rear knee forward as far as possible until the heel lifts from the ground.
Restricted Ankle Dorsiflexion Assessment (\~3 minutes) Participants will repeat the FMS Ankle Clearing Test to determine eligibility for the treatment portion of the study. Both ankles will be assessed. A member of the research team will hold a plumb line at the patella to judge knee position. If the knee does not advance past the medial malleolus of the front foot before the rear heel lifts, the ankle will be classified as having a dorsiflexion restriction.
Participants who report pain during the ankle screening will be excluded from further participation and referred for appropriate evaluation.
Participants with bilateral dorsiflexion restrictions will be eligible for the IASTM portion of the study, which tests whether IASTM improves limited weight bearing dorsiflexion. These participants will be randomly assigned to a high force IASTM, low force IASTM, or no treatment control group.
Participants without bilateral restrictions will complete baseline testing only. Including these participants captures a wide range of dorsiflexion capacity. This allows the study to examine relationships among ankle stiffness, ankle mobility, and functional movement.
Myotonometry Preparation and Measurement Site Identification (\~15 minutes) Participants will lie prone on an examination table. A 4 inch diameter foam roller will be placed beneath the anterior ankles and feet to maintain slight knee flexion and a relaxed lower limb. Participants will hold this position for site identification and for all MyotonPRO measurements.
Measurement sites will be identified bilaterally using anatomical landmarks and a flexible measuring tape, following the multipoint mapping protocol described by Duarte et al. (2026).
Posterior lower leg. The distance from the center of the popliteal fossa to the calcaneal tuberosity will be divided into eight equal intervals, which creates seven equidistant reference points.
At the three most proximal points, additional marks will be placed 2 cm medial and 2 cm lateral. These mark the measurement sites for the medial and lateral gastrocnemius.
The next point distal identifies the musculotendinous junction of the gastrocnemius and Achilles tendon.
The three most distal points identify the Achilles tendon measurement sites.
Plantar fascia. The distance from the calcaneal tuberosity to the base of the second and third toes will be divided into four equal intervals, which creates three equidistant measurement sites.
All sites will be marked on the skin with a skin safe marker to ensure consistent probe placement throughout the session.
Baseline Movement Analysis (\~12 minutes)
Participants will perform the following tasks in order:
Slow walking: 10 passes on the 3 meter walkway Fast walking: 10 passes on the 3 meter walkway OHDS: 8 repetitions FMS Ankle Clearing Test: 3 repetitions WBLT: 3 repetitions
All tasks will follow the procedures described during familiarization. Before each task, participants will perform brief calibration trials of approximately 10 seconds, standing still or walking a few strides. After the OHDS, FMS Ankle Clearing Test, and WBLT, participants will rate calf tightness on a 0 to 10 visual analog scale (VAS). On this scale, 0 represents no tightness and 10 represents extreme tightness.
IASTM Treatment or Control (\~12 minutes) Participants with bilateral dorsiflexion restrictions will receive the condition to which they were randomized. The control group will lie prone on the treatment table for 12 minutes without treatment.
All IASTM treatments will be administered by Aletha Lassiter. Water based ultrasound gel will be applied to the treatment area to reduce friction between the instrument and the skin.
High force group: 10 to 15 N at 60 strokes per minute Low force group: 0 to 5 N at 90 strokes per minute
A metronome will guide stroke rate in both groups. A force sensor attached to the IASTM instrument will monitor applied force so it remains within the prescribed range. Both force ranges fall within those reported for trained clinicians using IASTM.
Pressure tolerance screening. Before treatment, a few strokes at the participant's assigned force will be applied longitudinally along the gastrocnemius and soleus, parallel to the muscle fibers. Participants will rate their discomfort on a 0 to 10 VAS, where 0 represents no discomfort and 10 represents intolerable discomfort. Participants who rate discomfort above 8 will be excluded from further participation.
Treatment. Participants who pass the tolerance screening will receive 3 minutes of IASTM per leg, for 6 minutes total. Sweeping strokes will be applied longitudinally along the gastrocnemius muscle belly and soleus, parallel to the muscle fibers. Both legs will receive the assigned condition. The research team will monitor participants for intolerable discomfort throughout treatment.
After treatment, participants will complete a brief questionnaire on their perception of the intervention. They will also provide a separate 0 to 10 VAS discomfort rating for the full treatment of each leg. Excess gel will then be removed from the instrument, and the instrument will be sanitized with an alcohol wipe before the next use.
University of Idaho is the lead sponsor of 16 studies on the registry; 5 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
- You are between 18 and 39 years of age You are able to stand, walk, squat, and lunge barefoot without assistance You are able to read and understand English and provide written
Exclusion Criteria:
- You do not have a current skin infection. You do not have any prior lower extremity surgeries for muscles, bones, or joints.
You do not have a current injury that limits your gait or ability to squat. You are not currently pregnant. You are not taking any anticoagulant medications, or medications that would inhibit your balance, or pain perception.
You do not have an allergy to ultrasound gel.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A single session of instrument assisted soft tissue mobilization applied to the gastrocnemius and soleus of both legs. Strokes are applied longitudinally, parallel to the muscle fibers, at 10 to 15 N and 60 strokes per minute. A metronome paces the stroke rate, and a force sensor attached to the instrument confirms the applied force. Each leg receives 3 minutes of treatment, for 6 minutes total, with water based ultrasound gel as a lubricant.
Device: Instrument Assisted Soft Tissue Mobilization
A single session of instrument assisted soft tissue mobilization applied to the gastrocnemius and soleus of both legs. Strokes are applied longitudinally, parallel to the muscle fibers, at 0 to 5 N and 90 strokes per minute. A metronome paces the stroke rate, and a force sensor attached to the instrument confirms the applied force. Each leg receives 3 minutes of treatment, for 6 minutes total, with water based ultrasound gel as a lubricant.
Device: Instrument Assisted Soft Tissue Mobilization
Participants lie prone on the treatment table for 12 minutes without treatment. This matches the duration of the IASTM session.
A single session of instrument assisted soft tissue mobilization applied bilaterally to the gastrocnemius and soleus muscle bellies. One trained clinician delivers all treatments using the convex edge of the RockBlades 2.0 Mallet (RockTape, Durham, NC), a solid surgical stainless steel instrument fitted with a force sensor. Real time force feedback keeps applied force within the assigned range, and a metronome paces stroke rate. Sweeping strokes are applied longitudinally, parallel to the muscle fibers, with water based ultrasound gel as the lubricant, for 3 minutes per leg (6 minutes total). A pretreatment tolerance screening excludes participants who rate discomfort above 8 on a 0 to 10 VAS. No stretching, warm up, exercise, or other manual therapy accompanies treatment. The protocol is distinguished from other IASTM interventions by quantified, controlled force, a fixed stroke rate, and a single session dose.
Change in Weight Bearing Ankle Dorsiflexion Range of Motion
Ankle dorsiflexion is the ability to bend the ankle so the shin moves forward over the foot. It is measured with the Weight Bearing Lunge Test. The participant stands in a split stance, keeps the back heel on the floor, and bends the front knee forward as far as possible until the front heel begins to lift. An inertial measurement unit (a small motion sensor) on the shin records the angle of the shin relative to vertical at the moment the heel lifts. \[Confirm this is how the angle is derived.\] Each leg is tested 3 times, and the mean of the 3 trials is used. Values are reported in degrees, and higher values indicate greater ankle mobility. Change is calculated as the post-treatment value minus the baseline value
Time frame: Baseline and immediately after the intervention or control condition (within 30 minutes, same session)
Change in Dynamic Stiffness of the Calf Muscles, Achilles Tendon, and Plantar Fascia
Tissue stiffness is measured with the MyotonPRO (Myoton AS, Tallinn, Estonia). This handheld device applies a brief, painless mechanical tap to the skin and records how the underlying tissue oscillates in response. Participants lie face down on an examination table with a foam roller under the front of the ankles to keep the knees slightly bent and the legs relaxed. The probe is held perpendicular to the skin.
Time frame: Baseline and immediately after the intervention or control condition (within 30 minutes, same session)
Plan to share: Yes — Deidentified individual participant data will be shared for all enrolled participants. The dataset includes: Participant age, sex, height, and mass; Ankle dorsiflexion restriction status and group assignment (high force IASTM, low force IASTM, control, or baseline only); Weight bearing ankle dorsiflexion angles from the Weight Bearing Lunge Test for each leg and trial; MyotonPRO dynamic stiffness values for each measurement site and leg; Joint angles from the Overhead Deep Squat; Walking speed and gait variables at slow and fast speeds; Calf tightness and treatment discomfort ratings; Data are provided for each available time point (baseline, pretreatment, and post-treatment), along with a data dictionary that defines each variable and its units. Names, dates of birth, contact information, and testing dates will be removed before sharing.
Supporting information: Study protocol, Statistical analysis plan, Analytic code
Time frame: Data will be available beginning 6 months after publication of the primary results and will remain available for at least 5 years.
Access criteria: Deidentified individual participant data, a data dictionary, the study protocol, the statistical analysis plan, and analytic code will be publicly available to any researcher, without restriction, through osf.io
Data sharing details ↗ · osf.io
Start is estimated for Dec 2026; primary completion for Dec 2027, 12 months later.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
University of Idaho