Hamstring TightnessPIRNCT07153510
"Comparative Effects of PIR and Static Stretching on Hamstring Flexibility" Post-Isometric Relaxation
A study testing Post-Isometric Relaxation and Active Static Stretching in people with Hamstring Tightness and Hamstring Flexibility, run by University of Health Sciences Lahore at 1 site in Pakistan.
Trial summary
Hamstring tightness is a common problem among students and young adults, often leading to reduced flexibility, musculoskeletal discomfort, and risk of injury. Different stretching methods are used in physiotherapy practice to improve muscle length and flexibility. Read more about this study
- Who is it for?
- Ages 18 to 25 yearsHealthy volunteers can take part
- Conditions the study is for
- Hamstring Tightness, Hamstring Flexibility
- What is being tested?
- Post-Isometric Relaxation and Active Static Stretching
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 54 participants
- Where
- 1 sitePakistan
- Study dates
- 1 Apr 2025to 10 Sep 2025
- 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 to 25 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Aged 18-25 years, Active Knee Extension (AKE) test angle > 20°, Willing to participate and provide informed consent
Who cannot join
- Any history of hamstring strain or lower limb injury in the past 6 months, Neurological or musculoskeletal disorders, Participation in other flexibility or stretching programs
Trial locations and contacts
1 site in 1 country.
About this study
Official title: "Comparison of Post-Isometric Relaxation and Active Static Stretching Technique in Improving Hamstring Flexibility Among Allied Health Sciences Students"
Hamstring tightness is a common problem among students and young adults, often leading to reduced flexibility, musculoskeletal discomfort, and risk of injury. Different stretching methods are used in physiotherapy practice to improve muscle length and flexibility. Post-Isometric Relaxation (PIR), a type of muscle energy technique, and Active Static Stretching (ASS) are two commonly applied methods, but evidence comparing their effectiveness in improving hamstring flexibility among Allied Health Sciences students remains limited.
This randomized controlled trial aims to compare the effects of PIR and Active Static Stretching on hamstring flexibility in healthy university students. Participants will be randomly assigned to either PIR or ASS groups and undergo stretching sessions for a specified duration. Hamstring flexibility will be measured using the Active Knee Extension test before and after the intervention. The findings will provide evidence to guide physiotherapy education and clinical practice on the most effective stretching technique for improving hamstring flexibility.
Read the detailed description
Hamstring muscle tightness is one of the most common musculoskeletal concerns in young adults, particularly in students of Allied Health Sciences who often spend prolonged hours in sitting postures during academic activities. Reduced hamstring flexibility is associated with altered posture, restricted range of motion, musculoskeletal discomfort, and a higher risk of lower limb injuries. Stretching interventions are widely used to address muscle tightness, with Post-Isometric Relaxation (PIR) and Active Static Stretching (ASS) being among the most frequently applied techniques in physiotherapy practice.
Post-Isometric Relaxation (PIR) is a form of muscle energy technique that utilizes a submaximal isometric contraction of the target muscle followed by a passive stretch, aiming to induce reflex relaxation and elongation of the muscle. Active Static Stretching (ASS) involves actively holding the muscle in a lengthened position for a fixed duration, relying on voluntary control and sustained tension to improve flexibility. While both techniques are clinically relevant, comparative evidence regarding their relative effectiveness in improving hamstring flexibility among young healthy populations, particularly Allied Health Sciences students, remains limited.
This randomized controlled trial is designed to compare the immediate and short-term effects of PIR and ASS on hamstring flexibility. A total of 54 students who meet the inclusion criteria will be randomly allocated to either the PIR group or the ASS group. Each group will undergo a structured stretching protocol for a specified period under supervision. Hamstring flexibility will be evaluated pre- and post-intervention using the Active Knee Extension (AKE) test, a valid and reliable measure of hamstring length.
The results of this study are expected to provide evidence on whether PIR or ASS is more effective for improving hamstring flexibility in this population. Findings will have important implications for physiotherapy education, clinical decision-making, and injury prevention strategies in young adults.
- Conditions
- Hamstring Tightness, Hamstring Flexibility
- Being tested
- Post-Isometric Relaxation, Active Static Stretching
- Keywords
- Hamstring tightness,, Post Isometric Relaxation, Active Static Stretching, Students, Allied Health Sciences
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Post-Isometric RelaxationOther
Participants will undergo Post-Isometric Relaxation technique targeting the hamstring muscles. The technique involves an isometric contraction of the hamstring followed by a passive stretch. Participant will be in supine position; hip at 90° flexion, Isometric contraction of hamstrings for 7 seconds, Followed by 15 seconds of passive stretch, 10 repetitions, 3 times/week for 4 weeks
Active Static StretchingOther
Participants will perform Active Static Stretching exercises for the hamstrings, where the stretch is held actively without assistance.Seated long sitting position. Participant actively stretches hamstrings for 30 seconds. 10 repetitions, 3 times/week for 4 week
| Study group | Role | What they receive |
|---|---|---|
| Post-Isometric Relaxation | Experimental | Participants will undergo Post-Isometric Relaxation technique targeting the hamstring muscles. The technique involves an isometric contraction of the hamstring followed by a passive stretch. Participant will be in supine position; hip at 90° flexion, Isometric contraction of hamstrings for 7 seconds, Followed by 15 seconds of passive stretch, 10 repetitions, 3 times/week for 4 weeks Receives: Other: Post-Isometric Relaxation |
| Active Static Stretching | Experimental | Participants will perform Active Static Stretching exercises for the hamstrings, where the stretch is held actively without assistance.Seated long sitting position. Participant actively stretches hamstrings for 30 seconds. 10 repetitions, 3 times/week for 4 weeks Receives: Other: Active Static Stretching |
What is being measured
The primary outcome is the main question the study is designed to answer.
Hamstring flexibility
Hamstring flexibility, assessed by the Active Knee Extension (AKE) test using a universal goniometer.
Assessment Timeline:
Baseline (Day 0) Post-intervention (End of Week 4)
Measured: 4 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Sep 2025
- Study start1 Apr 2025
- Primary completion1 Sep 2025 (estimated)
- Study completion10 Sep 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- 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
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 54 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Health Sciences Lahore
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tooba Arif, University of Health Sciences Lahore
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07153510
- Sponsor's protocol ID
- UHS/DPS-25/1189
- Acronym
- PIR
- Status last verified
- Aug 2025
- First submitted
- 25 Aug 2025
- Last updated
- 4 Sep 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Arif T, Mehmood W, Arif T. Comparison of post-isometric relaxation and active static stretching in improving hamstring flexibility among allied health sciences students: a randomized controlled trial. Sci Rep. 2026 May 6;16(1):21489. doi: 10.1038/s41598-026-52130-5.
PubMed 42092043
Study at a glance
From the registry record, last updated by the sponsor on 4 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- "Comparison of Post-Isometric Relaxation and Active Static Stretching Technique in Improving Hamstring Flexibility Among Allied Health Sciences Students"
- ClinicalTrials.gov ID
- NCT07153510
- Acronym / sponsor ID
- PIR / UHS/DPS-25/1189
- Conditions
- Hamstring Tightness, Hamstring Flexibility
- Keywords
- Hamstring tightness,, Post Isometric Relaxation, Active Static Stretching, Students, Allied Health Sciences
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 54 participants (actual)
- Lead sponsor
- University of Health Sciences LahoreUniversity, hospital or other
- Study start
- 1 Apr 2025 (actual)
- Primary completion
- 1 Sep 2025 (estimated)
- Study completion
- 10 Sep 2025 (estimated)
- First posted
- 4 Sep 2025 (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.
Hamstring tightness is a common problem among students and young adults, often leading to reduced flexibility, musculoskeletal discomfort, and risk of injury. Different stretching methods are used in physiotherapy practice to improve muscle length and flexibility. Post-Isometric Relaxation (PIR), a type of muscle energy technique, and Active Static Stretching (ASS) are two commonly applied methods, but evidence comparing their effectiveness in improving hamstring flexibility among Allied Health Sciences students remains limited.
This randomized controlled trial aims to compare the effects of PIR and Active Static Stretching on hamstring flexibility in healthy university students. Participants will be randomly assigned to either PIR or ASS groups and undergo stretching sessions for a specified duration. Hamstring flexibility will be measured using the Active Knee Extension test before and after the intervention. The findings will provide evidence to guide physiotherapy education and clinical practice on the most effective stretching technique for improving hamstring flexibility.
Detailed description
Hamstring muscle tightness is one of the most common musculoskeletal concerns in young adults, particularly in students of Allied Health Sciences who often spend prolonged hours in sitting postures during academic activities. Reduced hamstring flexibility is associated with altered posture, restricted range of motion, musculoskeletal discomfort, and a higher risk of lower limb injuries. Stretching interventions are widely used to address muscle tightness, with Post-Isometric Relaxation (PIR) and Active Static Stretching (ASS) being among the most frequently applied techniques in physiotherapy practice.
Post-Isometric Relaxation (PIR) is a form of muscle energy technique that utilizes a submaximal isometric contraction of the target muscle followed by a passive stretch, aiming to induce reflex relaxation and elongation of the muscle. Active Static Stretching (ASS) involves actively holding the muscle in a lengthened position for a fixed duration, relying on voluntary control and sustained tension to improve flexibility. While both techniques are clinically relevant, comparative evidence regarding their relative effectiveness in improving hamstring flexibility among young healthy populations, particularly Allied Health Sciences students, remains limited.
This randomized controlled trial is designed to compare the immediate and short-term effects of PIR and ASS on hamstring flexibility. A total of 54 students who meet the inclusion criteria will be randomly allocated to either the PIR group or the ASS group. Each group will undergo a structured stretching protocol for a specified period under supervision. Hamstring flexibility will be evaluated pre- and post-intervention using the Active Knee Extension (AKE) test, a valid and reliable measure of hamstring length.
The results of this study are expected to provide evidence on whether PIR or ASS is more effective for improving hamstring flexibility in this population. Findings will have important implications for physiotherapy education, clinical decision-making, and injury prevention strategies in young adults.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Post-Isometric Relaxation | Experimental | Other: Post-Isometric RelaxationParticipants will undergo Post-Isometric Relaxation technique targeting the hamstring muscles. The technique involves an isometric contraction of the hamstring followed by a passive stretch. Participant will be in supine position; hip at 90° flexion, Isometric contraction of hamstrings for 7 seconds, Followed by 15 seconds of passive stretch, 10 repetitions, 3 times/week for 4 weeks |
| Active Static Stretching | Experimental | Other: Active Static StretchingParticipants will perform Active Static Stretching exercises for the hamstrings, where the stretch is held actively without assistance.Seated long sitting position. Participant actively stretches hamstrings for 30 seconds. 10 repetitions, 3 times/week for 4 weeks |
Who may qualify
- Ages
- 18 to 25 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Aged 18-25 years, Active Knee Extension (AKE) test angle > 20°, Willing to participate and provide informed consent
Key exclusion criteria (1 listed)
- Any history of hamstring strain or lower limb injury in the past 6 months, Neurological or musculoskeletal disorders, Participation in other flexibility or stretching programs
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 |
|---|---|---|
| Post-Isometric RelaxationParticipants will undergo Post-Isometric Relaxation technique targeting the hamstring muscles. The technique involves an isometric contraction of the hamstring followed by a passive stretch. Participant will be in supine position; hip at 90° flexion, Isometric contraction of hamstrings for 7 seconds, Followed by 15 seconds of passive stretch, 10 repetitions, 3 times/week for 4 weeks | Other | Post-Isometric Relaxation |
| Active Static StretchingParticipants will perform Active Static Stretching exercises for the hamstrings, where the stretch is held actively without assistance.Seated long sitting position. Participant actively stretches hamstrings for 30 seconds. 10 repetitions, 3 times/week for 4 week | Other | Active Static Stretching |
Primary outcome
Hamstring flexibility
Time frame: 4 weeks
Hamstring flexibility, assessed by the Active Knee Extension (AKE) test using a universal goniometer. Assessment Timeline: Baseline (Day 0) Post-intervention (End of Week 4)
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 4 Sep 2025.
- Derived from this study: PubMed 42092043Arif T, Mehmood W, Arif T. Comparison of post-isometric relaxation and active static stretching in improving hamstring flexibility among allied health sciences students: a randomized controlled trial. Sci Rep. 2026 May 6;16(1):21489. doi: 10.1038/s41598-026-52130-5.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Post-Isometric Relaxation and Active Static Stretching in people with Hamstring Tightness and Hamstring Flexibility, run by University of Health Sciences Lahore at 1 site in Pakistan.
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 1 inclusion and 1 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: under way, not looking for participants, as of the sponsor's last update on 4 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Pakistan. Whether a site is taking part right now should be confirmed with that site. See every site.
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?
Hamstring flexibility (time frame: 4 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07153510, which also lists 1 linked publication.
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 4 Sep 2025.