Hamstring Shortening, Short Hamstring SyndromeNCT07167602
Effect of Active and Positional Release on Hamstring Flexibility in Athletes
A study testing Positional Release Therapy, Active Release Therapy and Conventional Physiotherapy in people with Hamstring Shortening, Short Hamstring Syndrome, run by University of Lahore at 1 site in Pakistan.
Trial summary
Hamstring shortening is common in athletes and often causes pain, limited flexibility, and reduced function, which negatively impact performance. Manual therapy techniques such as Active Release Therapy (ART) and Positional Release Therapy (PRT) are frequently used, but their comparative effectiveness remains unclear. Read more about this study
- Who is it for?
- Ages 18 to 35 years
- Conditions the study is for
- Hamstring Shortening, Short Hamstring Syndrome
- What is being tested?
- Positional Release Therapy, Active Release Therapy and Conventional Physiotherapy
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 74 participants
- Where
- 1 sitePakistan
- Study dates
- 1 Jul 2025to 29 Aug 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 35 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Participants with age between 18 to 35
- Both genders
- Athletes with BMI between 18.5 kg/m² and 29.9 kg/m².
- Basketball, Football And Badminton Players.
- Athletes who practices atleast 3 days per week.
- Participants with Numeric pain rating scale values > 4.
- Participants with unilateral tightness of hamstring muscle with SLR < 80° and AKE < 125°
Who cannot join
- Participants with any acute chronic hamstring strain or lower back pain.
- Participants with leg length discrepancy.
- Participants with a sedentary lifestyle.
- Participants with upper motor neuron or lower motor neuron lesion.
- Participants with any previous history of lower extremity injury in the past three months
- Participants who are not willing to sign the consent
Trial locations and contacts
1 site in 1 country.
Pakistan1 site
University of Lahore - Teaching Hospital, University Institute of Physical Therapy
Lahore, Punjab Province
About this study
Official title: Active Versus Positional Release Therapy in Athletes With Hamstring Shortening
Hamstring shortening is common in athletes and often causes pain, limited flexibility, and reduced function, which negatively impact performance. Manual therapy techniques such as Active Release Therapy (ART) and Positional Release Therapy (PRT) are frequently used, but their comparative effectiveness remains unclear.
This randomized, single-blinded clinical trial enrolled 74 athletes aged 18-35 years with hamstring shortening at the University of Lahore. Participants were randomly assigned to receive either PRT with conventional physiotherapy (hot pack, TENS, stretching, ankle pumps) or ART with the same physiotherapy protocol. Each group received two supervised sessions per week for four weeks.
Read more
The primary outcomes were pain (Numeric Pain Rating Scale), range of motion (Popliteal Angle), and functional ability (Lower Extremity Functional Scale). The Active Knee Extension test was used as a secondary outcome.
This study seeks to determine which manual therapy approach provides greater improvements in pain, flexibility, and function, with the goal of guiding evidence-based rehabilitation for athletes.
Read the detailed description
Hamstring shortening, also referred to as short hamstring syndrome, is a frequent condition in athletes and has been linked to pain, reduced range of motion, and functional limitations that affect both sports performance and quality of life. Studies suggest that up to two-thirds of athletes may experience hamstring tightness, often as a result of repetitive strain, muscle imbalance, or inadequate recovery. Addressing this condition is therefore a priority in sports rehabilitation to minimize risk of injury and optimize performance.
Manual therapy is widely used in clinical practice to manage hamstring-related impairments. Among the commonly applied methods, Active Release Therapy (ART) aims to release adhesions and improve soft tissue mobility through tension and guided movements, while Positional Release Therapy (PRT) works by placing the muscle in a position of comfort to promote relaxation and reduce neuromuscular tension. Although both techniques have shown promise individually, limited evidence exists directly comparing their effectiveness in athletes with hamstring shortening.
This single-site, single-blinded randomized controlled trial was conducted at the University of Lahore Teaching Hospital to address this gap. Seventy-four athletes between 18 and 35 years of age were recruited using convenience sampling and randomized to one of two groups. Group A received Positional Release Therapy in addition to conventional physiotherapy, while Group B received Active Release Therapy with the same physiotherapy protocol. Conventional care included hot pack application, transcutaneous electrical nerve stimulation, hamstring stretching, and ankle pumps. Both groups received two sessions per week for four weeks, with outcome measures collected at baseline and post-intervention. The primary outcome measures were pain intensity, hamstring flexibility, and lower limb function, assessed respectively using the Numeric Pain Rating Scale (NPRS), Popliteal Angle test, and Lower Extremity Functional Scale (LEFS). The Active Knee Extension (AKE) test was included as a secondary outcome. The study design incorporated allocation concealment with sealed envelopes, blinding of assessors, and standardized protocols to minimize bias.
By directly comparing PRT and ART, this trial aims to provide evidence to guide clinical decision-making for the management of hamstring shortening in athletes. The results may inform physiotherapists, sports medicine professionals, and rehabilitation specialists about the relative benefits of each technique and support the use of effective, evidence-based interventions to improve pain, flexibility, and function in athletic populations.
- Being tested
- Positional Release Therapy, Active Release Therapy, Conventional Physiotherapy
- Keywords
- hamstring shortening, short hamstring syndrome, athlete, physiotherapy, manual therapy, active release therapy, positional release therapy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Positional Release TherapyBehavioural
Also called PRT, positional release technique
A manual therapy technique applied to the medial and lateral hamstrings after conventional physiotherapy. In PRT, the affected muscle is placed in a position of maximal comfort and relative shortening, while gentle pressure and controlled joint movements are applied. This position is held for approximately 30 seconds and repeated three times per session. The method aims to decrease neuromuscular tension, reduce pain, and promote muscle relaxation through a reflexive response. Distinct from Active Release Therapy, PRT does not involve active contractions or longitudinal tension but instead relies on positioning and relaxation to achieve therapeutic effects.
Active Release TherapyBehavioural
Also called ART, active release technique
A manual therapy technique applied to the hamstrings after conventional physiotherapy. ART combines therapist-applied longitudinal tension with patient movement and brief isometric contractions of both hamstrings and quadriceps. The limb is guided through specific ranges of motion to break down adhesions, restore tissue mobility, and improve flexibility. Unlike Positional Release Therapy, ART is an active technique requiring patient engagement through contractions and controlled movement against resistance, targeting scar tissue and myofascial restrictions.
Conventional PhysiotherapyOther
Hot pack, TENS, hamstring stretching, ankle pumps (common to both groups).
| Study group | Role | What they receive |
|---|---|---|
| Positional Release Therapy plus Conventional Physiotherapy | Experimental | Participants in this group first received conventional physiotherapy consisting of hot pack application (10 minutes), transcutaneous electrical nerve stimulation (15 minutes), passive hamstring stretching, and ankle pumps. After conventional therapy, Positional Release Therapy (PRT) was administered for the medial and lateral hamstrings. PRT involved positioning the muscle in shortened positions of comfort and applying gentle pressure with specific limb movements to facilitate relaxation, reduce neuromuscular tension, and relieve discomfort. Each session lasted approximately 50 minutes (35 minutes conventional therapy + 15 minutes PRT) and was delivered twice weekly for 4 weeks. Receives: Behavioral: Positional Release Therapy; Other: Conventional Physiotherapy |
| Active Release Therapy plus Conventional Physiotherapy | Active comparator | Participants in this group also received conventional physiotherapy consisting of hot pack application (10 minutes), transcutaneous electrical nerve stimulation (15 minutes), passive hamstring stretching, and ankle pumps. Following conventional care, Active Release Therapy (ART) was administered. ART involved applying longitudinal tension to the hamstring muscles while guiding the limb through specific ranges of motion, combined with brief isometric contractions of the hamstrings and quadriceps. This technique aimed to release adhesions, restore soft tissue mobility, and improve flexibility. Each session lasted approximately 50 minutes (35 minutes conventional therapy + 15 minutes ART) and was delivered twice weekly for 4 weeks. Receives: Behavioral: Active Release Therapy; Other: Conventional Physiotherapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Hamstring flexibility (Popliteal Angle test)
Hamstring flexibility was assessed with a universal goniometer during the Popliteal Angle test. Participants lay supine with the hip flexed to 90°, and the knee was extended until a stretch was felt. The angle between the thigh and lower leg was recorded; larger angles reflect greater hamstring tightness. This test is widely used to quantify hamstring shortening.
Measured: Baseline and 4 weeks after intervention
Pain intensity (Numeric Pain Rating Scale, NPRS)
Pain severity in the posterior thigh was measured using the Numeric Pain Rating Scale (NPRS), an 11-point scale ranging from 0 ("no pain") to 10 ("worst imaginable pain"). Participants reported their average pain over the preceding 24 hours. This outcome captures the degree of symptom relief experienced after either Positional Release Therapy or Active Release Therapy.
Measured: Baseline and 4 weeks (end of intervention)
Lower extremity function (Lower Extremity Functional Scale, LEFS)
Functional ability was measured using the LEFS, a 20-item patient-reported questionnaire assessing difficulty with daily and sports-related lower limb activities. Each item is scored from 0 ("extreme difficulty or unable to perform") to 4 ("no difficulty"), for a total score range of 0-80. Higher scores indicate better function. The LEFS has high reliability (0.85-0.99) and validity for musculoskeletal conditions.
Measured: Baseline and 4 weeks after intervention
Secondary outcomes (1)
Hamstring tightness (Active Knee Extension test, AKE)
Hamstring tightness was measured with the Active Knee Extension (AKE) test using a universal goniometer. Participants lay supine with the hip flexed to 90° and the knee initially flexed to 90°. They were instructed to actively extend the knee until a stretch or mild pain was felt, and the angle was recorded. An angle >20° was classified as hamstring tightness. This test provides an active, participant-driven measure of flexibility, complementing the passive Popliteal Angle test.
Measured: Baseline and 4 weeks after intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Sep 2025
- Study start1 Jul 2025
- Primary completion29 Aug 2025
- Study completion29 Aug 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hamstring Shortening, Short Hamstring SyndromeStudies 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
- This study used a parallel assignment design in which 74 athletes with hamstring shortening were randomized into two equal groups. Group A received Positional Release Therapy combined with conventional physiotherapy, while Group B received Active Release Therapy combined with the same physiotherapy protocol.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 74 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Lahore
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Muhammad Asim Arif, Principal investigator, University Institute of Physical Therapy, University of Lahore
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07167602
- Sponsor's protocol ID
- UOL/I/REB/25/09/0060
- Status last verified
- Sep 2025
- First submitted
- 4 Sep 2025
- Last updated
- 11 Sep 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Can only be requested from principal investigator
Study at a glance
From the registry record, last updated by the sponsor on 11 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Active Versus Positional Release Therapy in Athletes With Hamstring Shortening
- ClinicalTrials.gov ID
- NCT07167602
- Acronym / sponsor ID
- UOL/I/REB/25/09/0060
- Keywords
- hamstring shortening, short hamstring syndrome, athlete, physiotherapy, manual therapy, active release therapy, positional release therapy
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 74 participants (actual)
- Lead sponsor
- University of LahoreUniversity, hospital or other
- Study start
- 1 Jul 2025 (actual)
- Primary completion
- 29 Aug 2025 (actual)
- Study completion
- 29 Aug 2025 (actual)
- First posted
- 11 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 shortening is common in athletes and often causes pain, limited flexibility, and reduced function, which negatively impact performance. Manual therapy techniques such as Active Release Therapy (ART) and Positional Release Therapy (PRT) are frequently used, but their comparative effectiveness remains unclear.
This randomized, single-blinded clinical trial enrolled 74 athletes aged 18-35 years with hamstring shortening at the University of Lahore. Participants were randomly assigned to receive either PRT with conventional physiotherapy (hot pack, TENS, stretching, ankle pumps) or ART with the same physiotherapy protocol. Each group received two supervised sessions per week for four weeks.
The primary outcomes were pain (Numeric Pain Rating Scale), range of motion (Popliteal Angle), and functional ability (Lower Extremity Functional Scale). The Active Knee Extension test was used as a secondary outcome.
This study seeks to determine which manual therapy approach provides greater improvements in pain, flexibility, and function, with the goal of guiding evidence-based rehabilitation for athletes.
Detailed description
Hamstring shortening, also referred to as short hamstring syndrome, is a frequent condition in athletes and has been linked to pain, reduced range of motion, and functional limitations that affect both sports performance and quality of life. Studies suggest that up to two-thirds of athletes may experience hamstring tightness, often as a result of repetitive strain, muscle imbalance, or inadequate recovery. Addressing this condition is therefore a priority in sports rehabilitation to minimize risk of injury and optimize performance.
Manual therapy is widely used in clinical practice to manage hamstring-related impairments. Among the commonly applied methods, Active Release Therapy (ART) aims to release adhesions and improve soft tissue mobility through tension and guided movements, while Positional Release Therapy (PRT) works by placing the muscle in a position of comfort to promote relaxation and reduce neuromuscular tension. Although both techniques have shown promise individually, limited evidence exists directly comparing their effectiveness in athletes with hamstring shortening.
This single-site, single-blinded randomized controlled trial was conducted at the University of Lahore Teaching Hospital to address this gap. Seventy-four athletes between 18 and 35 years of age were recruited using convenience sampling and randomized to one of two groups. Group A received Positional Release Therapy in addition to conventional physiotherapy, while Group B received Active Release Therapy with the same physiotherapy protocol. Conventional care included hot pack application, transcutaneous electrical nerve stimulation, hamstring stretching, and ankle pumps. Both groups received two sessions per week for four weeks, with outcome measures collected at baseline and post-intervention. The primary outcome measures were pain intensity, hamstring flexibility, and lower limb function, assessed respectively using the Numeric Pain Rating Scale (NPRS), Popliteal Angle test, and Lower Extremity Functional Scale (LEFS). The Active Knee Extension (AKE) test was included as a secondary outcome. The study design incorporated allocation concealment with sealed envelopes, blinding of assessors, and standardized protocols to minimize bias.
By directly comparing PRT and ART, this trial aims to provide evidence to guide clinical decision-making for the management of hamstring shortening in athletes. The results may inform physiotherapists, sports medicine professionals, and rehabilitation specialists about the relative benefits of each technique and support the use of effective, evidence-based interventions to improve pain, flexibility, and function in athletic populations.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- This study used a parallel assignment design in which 74 athletes with hamstring shortening were randomized into two equal groups. Group A received Positional Release Therapy combined with conventional physiotherapy, while Group B received Active Release Therapy combined with the same physiotherapy protocol.
| Arm | Type | Receives |
|---|---|---|
| Positional Release Therapy plus Conventional Physiotherapy | Experimental | Behavioral: Positional Release Therapy, Other: Conventional PhysiotherapyParticipants in this group first received conventional physiotherapy consisting of hot pack application (10 minutes), transcutaneous electrical nerve stimulation (15 minutes), passive hamstring stretching, and ankle pumps. After conventional therapy, Positional Release Therapy (PRT) was administered for the medial and lateral hamstrings. PRT involved positioning the muscle in shortened positions of comfort and applying gentle pressure with specific limb movements to facilitate relaxation, reduce neuromuscular tension, and relieve discomfort. Each session lasted approximately 50 minutes (35 minutes conventional therapy + 15 minutes PRT) and was delivered twice weekly for 4 weeks. |
| Active Release Therapy plus Conventional Physiotherapy | Active comparator | Behavioral: Active Release Therapy, Other: Conventional PhysiotherapyParticipants in this group also received conventional physiotherapy consisting of hot pack application (10 minutes), transcutaneous electrical nerve stimulation (15 minutes), passive hamstring stretching, and ankle pumps. Following conventional care, Active Release Therapy (ART) was administered. ART involved applying longitudinal tension to the hamstring muscles while guiding the limb through specific ranges of motion, combined with brief isometric contractions of the hamstrings and quadriceps. This technique aimed to release adhesions, restore soft tissue mobility, and improve flexibility. Each session lasted approximately 50 minutes (35 minutes conventional therapy + 15 minutes ART) and was delivered twice weekly for 4 weeks. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Participants with age between 18 to 35
- Both genders
- Athletes with BMI between 18.5 kg/m² and 29.9 kg/m².
- Basketball, Football And Badminton Players.
- Athletes who practices atleast 3 days per week.
Key exclusion criteria (6 listed)
- Participants with any acute chronic hamstring strain or lower back pain.
- Participants with leg length discrepancy.
- Participants with a sedentary lifestyle.
- Participants with upper motor neuron or lower motor neuron lesion.
- Participants with any previous history of lower extremity injury in the past three months
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 |
|---|---|---|
| Positional Release TherapyAlso: PRT, positional release techniqueA manual therapy technique applied to the medial and lateral hamstrings after conventional physiotherapy. In PRT, the affected muscle is placed in a position of maximal comfort and relative shortening, while gentle pressure and controlled joint movements are applied. This position is held for approximately 30 seconds and repeated three times per session. The method aims to decrease neuromuscular tension, reduce pain, and promote muscle relaxation through a reflexive response. Distinct from Active Release Therapy, PRT does not involve active contractions or longitudinal tension but instead relies on positioning and relaxation to achieve therapeutic effects. | Behavioural | Positional Release Therapy plus Conventional Physiotherapy |
| Active Release TherapyAlso: ART, active release techniqueA manual therapy technique applied to the hamstrings after conventional physiotherapy. ART combines therapist-applied longitudinal tension with patient movement and brief isometric contractions of both hamstrings and quadriceps. The limb is guided through specific ranges of motion to break down adhesions, restore tissue mobility, and improve flexibility. Unlike Positional Release Therapy, ART is an active technique requiring patient engagement through contractions and controlled movement against resistance, targeting scar tissue and myofascial restrictions. | Behavioural | Active Release Therapy plus Conventional Physiotherapy |
| Conventional PhysiotherapyHot pack, TENS, hamstring stretching, ankle pumps (common to both groups). | Other | Active Release Therapy plus Conventional Physiotherapy, Positional Release Therapy plus Conventional Physiotherapy |
Primary outcome
Hamstring flexibility (Popliteal Angle test)
Time frame: Baseline and 4 weeks after intervention
Hamstring flexibility was assessed with a universal goniometer during the Popliteal Angle test. Participants lay supine with the hip flexed to 90°, and the knee was extended until a stretch was felt. The angle between the thigh and lower leg was recorded; larger angles reflect greater hamstring tightness. This test is widely used to quantify hamstring shortening.
Pain intensity (Numeric Pain Rating Scale, NPRS)
Time frame: Baseline and 4 weeks (end of intervention)
Pain severity in the posterior thigh was measured using the Numeric Pain Rating Scale (NPRS), an 11-point scale ranging from 0 ("no pain") to 10 ("worst imaginable pain"). Participants reported their average pain over the preceding 24 hours. This outcome captures the degree of symptom relief experienced after either Positional Release Therapy or Active Release Therapy.
Lower extremity function (Lower Extremity Functional Scale, LEFS)
Time frame: Baseline and 4 weeks after intervention
Functional ability was measured using the LEFS, a 20-item patient-reported questionnaire assessing difficulty with daily and sports-related lower limb activities. Each item is scored from 0 ("extreme difficulty or unable to perform") to 4 ("no difficulty"), for a total score range of 0-80. Higher scores indicate better function. The LEFS has high reliability (0.85-0.99) and validity for musculoskeletal conditions.
1 secondary outcome
Hamstring tightness (Active Knee Extension test, AKE)
Time frame: Baseline and 4 weeks after intervention
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Sep 2025.
- Individual participant dataSharing planned: Undecided. Can only be requested from principal investigator
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.
Muhammad Asim Arif principal investigator
University Institute of Physical Therapy, University of Lahore
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Positional Release Therapy, Active Release Therapy and Conventional Physiotherapy in people with Hamstring Shortening, Short Hamstring Syndrome, run by University of 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 7 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: finished, as of the sponsor's last update on 11 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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 (Popliteal Angle test) (time frame: Baseline and 4 weeks after intervention). The study lists 3 primary outcomes in all. 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 11 Sep 2025.