Hamstring TightnessIASTM-HTNCT07838844
IASTM vs. Static Stretching for Hamstring Tightness: Short- and Long-Term Effects
A study testing Instrument-Assisted Soft Tissue Mobilization and Static Stretching in people with Hamstring Tightness, run by GÖKHAN MARAŞ.
Trial summary
This study compares two treatments for people with tight hamstring muscles (the muscles at the back of the thigh): instrument-assisted soft tissue mobilization (IASTM) and static stretching. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Hamstring Tightness
- What is being tested?
- Instrument-Assisted Soft Tissue Mobilization and Static Stretching
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 46 participants
- Where
- No sites listed yet
- Study dates
- Sep 2026to Feb 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 18 years or older
- Hamstring tightness, defined as hip flexion range of motion <65° on the Straight Leg Raise (SLR) test, without neurological signs
- No diagnosed chronic musculoskeletal or systemic disease
- Signed informed consent form
Who cannot join
- Previous trauma or surgical operation involving the lower extremity
- Neurological symptoms radiating to one or both lower extremities due to hamstring injury, spinal pathology, or sciatic nerve involvement
- Ankle instability
- Pregnancy
- Neurological signs elicited during the Straight Leg Raise (SLR) test
- Hyperalgesia, hematoma, varicose veins, or active skin infection in the lower extremity
About this study
Official title: Comparison of the Short- and Long-Term Effects of Static Stretching and Instrument-Assisted Soft Tissue Mobilization on Flexibility, Performance, and Pressure Pain Threshold in Individuals With Hamstring Tightness: A Randomized Controlled Trial
This study compares two treatments for people with tight hamstring muscles (the muscles at the back of the thigh): instrument-assisted soft tissue mobilization (IASTM) and static stretching. Both are commonly used by physical therapists to improve flexibility, but few studies have looked at their effects beyond a few days after treatment ends.
Forty-six adults with hamstring tightness will be randomly assigned to one of two groups. One group will receive IASTM, and the other will receive static stretching. Both treatments will be given 3 times per week for 4 weeks (12 sessions total).
Researchers will measure flexibility (knee extension range of motion), pressure pain threshold, and physical performance (vertical jump and single-leg hop distance) at three time points: before treatment, 3 days after the last session, and 8 weeks after treatment ends. The goal is to find out which treatment provides better short-term and longer-term benefits.
Read the detailed description
Hamstring muscle tightness is a common musculoskeletal condition that can limit hip and knee range of motion, reduce athletic and functional performance, and contribute to other conditions such as patellofemoral pain, patellar tendinopathy, and low back pain. Static stretching has long been used to address hamstring tightness, with systematic reviews suggesting that 6-8 weeks of regular stretching can produce lasting flexibility gains. Instrument-assisted soft tissue mobilization (IASTM) has more recently emerged as an alternative technique, with proposed mechanisms including controlled microtrauma that stimulates an inflammatory response and collagen remodeling in soft tissue.
Most existing studies comparing static stretching and IASTM for hamstring tightness have examined only single-session or short-term (immediate post-treatment) effects. Long-term follow-up data (≥8 weeks) are limited, making it difficult to determine whether treatment-related gains in flexibility, pain sensitivity, and functional performance are sustained over time.
This randomized controlled trial will enroll 46 participants with hamstring tightness, defined as hip flexion range of motion <65° on the Straight Leg Raise (SLR) test with no neurological signs. Participants will be randomly allocated (computer-generated randomization) to one of two equal groups (n=23 each):
Group 1 (IASTM): Participants will receive instrument-assisted soft tissue mobilization applied to the hamstring muscle group using a stainless-steel instrument, scanning technique, distal-to-proximal direction, for 5 minutes per session.
Group 2 (Static Stretching): Participants will receive manual static stretching of the hamstring muscle group, performed in 5 repetitions of 30 seconds of stretch followed by 30 seconds of rest (5 minutes total per session).
Both interventions will be delivered 3 times per week for 4 weeks (12 sessions total) by a physical therapist with over 10 years of clinical experience in orthopedic rehabilitation and manual therapy.
Outcome assessments will be performed by a blinded assessor independent of treatment delivery, at three time points: baseline (pre-treatment), short-term (3 days after the final session), and long-term (8 weeks after intervention completion). Outcome measures include:
- Flexibility: knee extension range of motion during 90° hip flexion, measured with a digital inclinometer
- Pressure pain threshold: measured with a digital algometer over the hamstring muscle bellies (biceps femoris, semitendinosus, semimembranosus)
- Functional performance: vertical jump height and single-leg hop distance
Statistical analysis will include two-way repeated-measures ANOVA to assess time and group-by-time interaction effects, with Bonferroni-corrected post hoc comparisons where appropriate.
- Conditions
- Hamstring Tightness
- Being tested
- Instrument-Assisted Soft Tissue Mobilization, Static Stretching
- Keywords
- Hamstring Tightness, Instrument-Assisted Soft Tissue Mobilization, IASTM, Static Stretching, Flexibility, Pressure Pain Threshold, Range of Motion
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Instrument-Assisted Soft Tissue MobilizationOther
Participants will receive instrument-assisted soft tissue mobilization (IASTM) applied to the hamstring muscle group using a stainless-steel instrument in a scanning technique, distal-to-proximal direction, for 5 minutes per session, 3 times per week for 4 weeks (12 sessions total).
Static StretchingOther
Participants will receive manual static stretching of the hamstring muscle group, performed in 5 repetitions of 30 seconds of stretch followed by 30 seconds of rest (5 minutes total per session), 3 times per week for 4 weeks (12 sessions total).
| Study group | Role | What they receive |
|---|---|---|
| IASTM | Experimental | Participants will receive instrument-assisted soft tissue mobilization (IASTM) applied to the hamstring muscle group using a stainless-steel instrument in a scanning technique, distal-to-proximal direction, for 5 minutes per session, 3 times per week for 4 weeks (12 sessions total). Receives: Other: Instrument-Assisted Soft Tissue Mobilization |
| Static Stretching | Active comparator | Participants will receive manual static stretching of the hamstring muscle group, performed in 5 repetitions of 30 seconds of stretch followed by 30 seconds of rest (5 minutes total per session), 3 times per week for 4 weeks (12 sessions total). Receives: Other: Static Stretching |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Knee Extension Range of Motion (Flexibility)
Knee extension range of motion during 90° hip flexion, measured with a digital inclinometer, as an indicator of hamstring flexibility.
Measured: Baseline, 3 days after final session (short-term), and 8 weeks after intervention completion (long-term)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Sep 2026
- Study startSep 2026 (estimated)
- Primary completionFeb 2027 (estimated)
- Study completionFeb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hamstring TightnessStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Two parallel groups (IASTM and Static Stretching) receiving 12 sessions over 4 weeks, with blinded outcome assessment at baseline, short-term (3 days post-intervention), and long-term (8 weeks post-intervention) follow-up.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 46 participants (estimated)
Sponsor and investigators
- Lead sponsor
- GÖKHAN MARAŞ
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, GÖKHAN MARAŞ, Gazi University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07838844
- Sponsor's protocol ID
- IASTM-HAM-2026-01
- Acronym
- IASTM-HT
- Status last verified
- Sep 2026
- First submitted
- 18 Sep 2026
- Last updated
- 24 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of the Short- and Long-Term Effects of Static Stretching and Instrument-Assisted Soft Tissue Mobilization on Flexibility, Performance, and Pressure Pain Threshold in Individuals With Hamstring Tightness: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07838844
- Acronym / sponsor ID
- IASTM-HT / IASTM-HAM-2026-01
- Conditions
- Hamstring Tightness
- Keywords
- Hamstring Tightness, Instrument-Assisted Soft Tissue Mobilization, IASTM, Static Stretching, Flexibility, Pressure Pain Threshold, Range of Motion
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 46 participants (estimated)
- Lead sponsor
- GÖKHAN MARAŞUniversity, hospital or other
- Study start
- Sep 2026 (estimated)
- Primary completion
- Feb 2027 (estimated)
- Study completion
- Feb 2027 (estimated)
- First posted
- 24 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study compares two treatments for people with tight hamstring muscles (the muscles at the back of the thigh): instrument-assisted soft tissue mobilization (IASTM) and static stretching. Both are commonly used by physical therapists to improve flexibility, but few studies have looked at their effects beyond a few days after treatment ends.
Forty-six adults with hamstring tightness will be randomly assigned to one of two groups. One group will receive IASTM, and the other will receive static stretching. Both treatments will be given 3 times per week for 4 weeks (12 sessions total).
Researchers will measure flexibility (knee extension range of motion), pressure pain threshold, and physical performance (vertical jump and single-leg hop distance) at three time points: before treatment, 3 days after the last session, and 8 weeks after treatment ends. The goal is to find out which treatment provides better short-term and longer-term benefits.
Detailed description
Hamstring muscle tightness is a common musculoskeletal condition that can limit hip and knee range of motion, reduce athletic and functional performance, and contribute to other conditions such as patellofemoral pain, patellar tendinopathy, and low back pain. Static stretching has long been used to address hamstring tightness, with systematic reviews suggesting that 6-8 weeks of regular stretching can produce lasting flexibility gains. Instrument-assisted soft tissue mobilization (IASTM) has more recently emerged as an alternative technique, with proposed mechanisms including controlled microtrauma that stimulates an inflammatory response and collagen remodeling in soft tissue.
Most existing studies comparing static stretching and IASTM for hamstring tightness have examined only single-session or short-term (immediate post-treatment) effects. Long-term follow-up data (≥8 weeks) are limited, making it difficult to determine whether treatment-related gains in flexibility, pain sensitivity, and functional performance are sustained over time.
This randomized controlled trial will enroll 46 participants with hamstring tightness, defined as hip flexion range of motion <65° on the Straight Leg Raise (SLR) test with no neurological signs. Participants will be randomly allocated (computer-generated randomization) to one of two equal groups (n=23 each):
Group 1 (IASTM): Participants will receive instrument-assisted soft tissue mobilization applied to the hamstring muscle group using a stainless-steel instrument, scanning technique, distal-to-proximal direction, for 5 minutes per session.
Group 2 (Static Stretching): Participants will receive manual static stretching of the hamstring muscle group, performed in 5 repetitions of 30 seconds of stretch followed by 30 seconds of rest (5 minutes total per session).
Both interventions will be delivered 3 times per week for 4 weeks (12 sessions total) by a physical therapist with over 10 years of clinical experience in orthopedic rehabilitation and manual therapy.
Outcome assessments will be performed by a blinded assessor independent of treatment delivery, at three time points: baseline (pre-treatment), short-term (3 days after the final session), and long-term (8 weeks after intervention completion). Outcome measures include:
- Flexibility: knee extension range of motion during 90° hip flexion, measured with a digital inclinometer
- Pressure pain threshold: measured with a digital algometer over the hamstring muscle bellies (biceps femoris, semitendinosus, semimembranosus)
- Functional performance: vertical jump height and single-leg hop distance
Statistical analysis will include two-way repeated-measures ANOVA to assess time and group-by-time interaction effects, with Bonferroni-corrected post hoc comparisons where appropriate.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Two parallel groups (IASTM and Static Stretching) receiving 12 sessions over 4 weeks, with blinded outcome assessment at baseline, short-term (3 days post-intervention), and long-term (8 weeks post-intervention) follow-up.
| Arm | Type | Receives |
|---|---|---|
| IASTM | Experimental | Other: Instrument-Assisted Soft Tissue MobilizationParticipants will receive instrument-assisted soft tissue mobilization (IASTM) applied to the hamstring muscle group using a stainless-steel instrument in a scanning technique, distal-to-proximal direction, for 5 minutes per session, 3 times per week for 4 weeks (12 sessions total). |
| Static Stretching | Active comparator | Other: Static StretchingParticipants will receive manual static stretching of the hamstring muscle group, performed in 5 repetitions of 30 seconds of stretch followed by 30 seconds of rest (5 minutes total per session), 3 times per week for 4 weeks (12 sessions total). |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age 18 years or older
- Hamstring tightness, defined as hip flexion range of motion <65° on the Straight Leg Raise (SLR) test, without neurological signs
- No diagnosed chronic musculoskeletal or systemic disease
- Signed informed consent form
Key exclusion criteria (6 listed)
- Previous trauma or surgical operation involving the lower extremity
- Neurological symptoms radiating to one or both lower extremities due to hamstring injury, spinal pathology, or sciatic nerve involvement
- Ankle instability
- Pregnancy
- Neurological signs elicited during the Straight Leg Raise (SLR) test
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Instrument-Assisted Soft Tissue MobilizationParticipants will receive instrument-assisted soft tissue mobilization (IASTM) applied to the hamstring muscle group using a stainless-steel instrument in a scanning technique, distal-to-proximal direction, for 5 minutes per session, 3 times per week for 4 weeks (12 sessions total). | Other | IASTM |
| Static StretchingParticipants will receive manual static stretching of the hamstring muscle group, performed in 5 repetitions of 30 seconds of stretch followed by 30 seconds of rest (5 minutes total per session), 3 times per week for 4 weeks (12 sessions total). | Other | Static Stretching |
Primary outcome
Change in Knee Extension Range of Motion (Flexibility)
Time frame: Baseline, 3 days after final session (short-term), and 8 weeks after intervention completion (long-term)
Knee extension range of motion during 90° hip flexion, measured with a digital inclinometer, as an indicator of hamstring flexibility.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Sep 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A study testing Instrument-Assisted Soft Tissue Mobilization and Static Stretching in people with Hamstring Tightness, run by GÖKHAN MARAŞ.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 24 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Knee Extension Range of Motion (Flexibility) (time frame: Baseline, 3 days after final session (short-term), and 8 weeks after intervention completion (long-term)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Sep 2026.