Hamstring TightnessLLA-HTNCT07682142
Hamstring Tightness and Lumbar Lordosis Angel Across Functional Sitting Posture.
An observational study of Hamstring Tightness and Lumbar Lordosis, run by Cairo University at 1 site in Egypt.
Trial summary
The goal of this observational study is to learn about the relationship between hamstring tightness and the lumbar lordosis angle in sedentary adults across different sitting postures. Read more about this study
- Who is it for?
- Ages 18 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Hamstring Tightness, Lumbar Lordosis, Sedentary Behavior
- What is being tested?
- Hamstring tightness and lumbar lordosis assessment
- How many people
- 110 participants
- Where
- 1 siteEgypt
- Study dates
- 1 Aug 2026to 1 Dec 2026
- Phase
- Observational
- 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 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Sedentary adults of both sexes, aged 18 to 45 years, recruited from the Nasser institute hospital, and the surrounding community. Eligible participants are healthy individuals with a sedentary lifestyle (more than six hours of sitting per day and a physical-activity level below 600 MET-minutes per week on the International Physical Activity Questionnaire), a body mass index below 30 kg/m², and bilateral hamstring tightness, with no current low back pain or other excluding musculoskeletal, neurological, or spinal conditions
Who may be able to join
- Healthy adults aged 18-45 years.
- Sedentary occupation requiring > 6 hours of sitting per day.
- Active Knee Extension (AKE) angle >15°.
- Bilateral hamstring tightness.
- Sedentary individual as determined by IPAQ (MET≤ 600 min/week).
- Asymptomatic for low back pain at the time of testing.
Who cannot join
- History of significant low back pain requiring medical treatment in the past 12 months.
- Previous spinal surgery or structural spinal deformities.
- Lower extremity injury or surgery within the past 6 months.
- Neurological disorders affecting sensation or movement.
- Pregnant female or get birth in the last year.
- Body mass index (BMI) ≥ 30 kg/m².
- postural deviations resulting from shortening of the iliopsoas and erector spinae or insufficiency of the core stabilizers and hip extensors
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Egypt1 site
Nasser institute hospital
Cairo, Shubra Misr, 12616
nasser institute, 22039356, Info@nasserinstitute.com
About this study
Official title: Correlation Between Hamstring Tightness and Lumbar Lordosis Angel Across Functional Sitting Posture in Sedentary Adults.
The goal of this observational study is to learn about the relationship between hamstring tightness and the lumbar lordosis angle in sedentary adults across different sitting postures. The main question it aims to answer is:
Is hamstring tightness related to the lumbar lordosis angle across three functional sitting postures (upright, slumped, and forward-leaning)? It also asks whether hamstring tightness differs between men and women, whether it differs between the dominant and non-dominant leg, and whether the lumbar lordosis angle differs between men and women across the three postures.
Participants will have their hamstring tightness measured with the Active Knee Extension test and their lumbar lordosis angle measured with a bubble inclinometer while sitting in each of the three postures.
Read the detailed description
Prolonged sitting is a defining feature of contemporary sedentary lifestyles and an established risk factor for musculoskeletal disorders of the lumbar spine. During sustained sitting, the hip is held in flexion and the hamstring muscle-tendon unit is maintained in a shortened position, which over time is associated with reduced hamstring extensibility (hamstring tightness). Because the hamstrings originate from the ischial tuberosity, a loss of hamstring extensibility exerts a posteriorly directed pull on the pelvis, promoting posterior pelvic tilt. Through regional spinopelvic coupling, this change in pelvic orientation alters the sacral slope and, consequently, the lumbar lordosis angle.
Although the relationship between hamstring tightness and lumbar lordosis has been described previously, most existing studies have evaluated it in the standing position. Sedentary individuals, however, spend the majority of their day seated, where the line of gravity, baseline muscle activity, and passive tissue demands placed on the spine differ substantially from those in standing. Evidence is therefore limited regarding how hamstring tightness relates to the lumbar lordosis angle across the functional sitting postures encountered in daily life, and regarding how this relationship may vary by sex and between the dominant and non-dominant lower limb.
This cross-sectional observational study will be conducted on 110 sedentary adults (55 male and 55 female), aged 18 to 45 years, recruited according to predefined eligibility criteria. The sample size was determined using G*Power based on a bivariate-normal correlation model. Eligible participants will be sedentary (more than six hours of sitting per day and a physical-activity level below 600 MET-minutes/week on the International Physical Activity Questionnaire), with a body mass index below 30 kg/m², bilateral hamstring tightness, and no current low back pain or other exclusionary conditions.
Following screening and informed consent, each participant's demographic and anthropometric data will be recorded, and lower-limb dominance will be determined using a three-task behavioral battery. Hamstring tightness will be assessed bilaterally using the Active Knee Extension (AKE) test, recorded with a digital goniometer, with the mean of three trials used for analysis. The lumbar lordosis angle (T12-S2) will be measured using a double bubble inclinometer in three randomized functional sitting postures-upright, slumped, and forward-leaning-with the mean of three trials per posture used for analysis.
The primary aim is to examine the correlation between hamstring tightness and the lumbar lordosis angle in each of the three sitting postures. The secondary aims are to compare hamstring tightness between male and female participants, to compare hamstring tightness between the dominant and non-dominant lower limb, and to compare the lumbar lordosis angle between male and female participants across the three postures. Data will be analyzed using Pearson correlation coefficients, independent- and paired-samples t-tests, and a mixed-design analysis of variance, with the significance level set at p < 0.05.
- Being tested
- Hamstring tightness and lumbar lordosis assessment
- Keywords
- Hamstring tightness, Lumbar lordosis, Sitting posture, Functional sitting postures, Sedentary adults, Active Knee Extension test, AKE test, bubble inclinometer, Pelvic tilt, Lumbopelvic rhythm, Limb dominance, Posterior pelvic tilt, Spinopelvic alignment
- Medical subject headings
- Lordosis, Sedentary Behavior
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hamstring tightness and lumbar lordosis assessmentOther
Hamstring tightness measured bilaterally with the Active Knee Extension test (digital goniometer) and lumbar lordosis angle (T12-S2) measured with a bubble inclinometer across three functional sitting postures. No therapeutic intervention is administered; these are observational measurements only.
| Study group | Role | What they receive |
|---|---|---|
| Sedentary adults | Sedentary adults aged 18-45 years (55 male, 55 female) with bilateral hamstring tightness and no current low back pain, assessed for hamstring tightness (Active Knee Extension test) and lumbar lordosis angle (bubble inclinometer) across three functional sitting postures (upright, slumped, and forward-leaning). Receives: Other: Hamstring tightness and lumbar lordosis assessment |
What is being measured
The primary outcome is the main question the study is designed to answer.
Correlation between hamstring tightness and lumbar lordosis angle across three functional sitting postures
Hamstring tightness is measured as the Active Knee Extension (AKE) deficit in degrees (mean of three trials per limb, using a digital goniometer). The lumbar lordosis angle is measured in degrees using a bubble inclinometer (T12-S2, mean of three trials per posture) in three functional sitting postures: upright, slumped, and forward-leaning. The association between hamstring tightness and the lumbar lordosis angle is assessed for each posture using the Pearson correlation coefficient.
Measured: At a single assessment session (cross-sectional; Day 1).
Secondary outcomes (3)
Difference in hamstring tightness between males and females
Hamstring tightness (bilateral mean Active Knee Extension deficit, in degrees) compared between male and female participants.
Measured: At a single assessment session (cross-sectional; Day 1).
Difference in hamstring tightness between the dominant and non-dominant lower limb
Hamstring tightness (Active Knee Extension deficit, in degrees) compared between the dominant and non-dominant limb. Limb dominance is determined using a three-task behavioral battery.
Measured: At a single assessment session (cross-sectional; Day 1).
Difference in lumbar lordosis angle between males and females across the three sitting postures
Lumbar lordosis angle (degrees, bubble inclinometer, T12-S2) compared between male and female participants in each of the three functional sitting postures (upright, slumped, forward-leaning).
Measured: At a single assessment session (cross-sectional; Day 1).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jul 2026
- Study start1 Aug 2026 (estimated)
- Primary completion1 Oct 2026 (estimated)
- Study completion1 Dec 2026 (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.
- More trials run by Cairo UniversityThe sponsor's other registered studies.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 110 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Cairo University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ahmed youssef saleh saeed, Nasser Institute For Research and Treatment
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07682142
- Sponsor's protocol ID
- P.T.REC/012/006548
- Acronym
- LLA-HT
- Status last verified
- Jul 2026
- First submitted
- 27 Jun 2026
- Last updated
- 6 Jul 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Correlation Between Hamstring Tightness and Lumbar Lordosis Angel Across Functional Sitting Posture in Sedentary Adults.
- ClinicalTrials.gov ID
- NCT07682142
- Acronym / sponsor ID
- LLA-HT / P.T.REC/012/006548
- Keywords
- Hamstring tightness, Lumbar lordosis, Sitting posture, Functional sitting postures, Sedentary adults, Active Knee Extension test, AKE test, bubble inclinometer
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 110 participants (estimated)
- Lead sponsor
- Cairo UniversityUniversity, hospital or other
- Study start
- 1 Aug 2026 (estimated)
- Primary completion
- 1 Oct 2026 (estimated)
- Study completion
- 1 Dec 2026 (estimated)
- First posted
- 2 Jul 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.
The goal of this observational study is to learn about the relationship between hamstring tightness and the lumbar lordosis angle in sedentary adults across different sitting postures. The main question it aims to answer is:
Is hamstring tightness related to the lumbar lordosis angle across three functional sitting postures (upright, slumped, and forward-leaning)? It also asks whether hamstring tightness differs between men and women, whether it differs between the dominant and non-dominant leg, and whether the lumbar lordosis angle differs between men and women across the three postures.
Participants will have their hamstring tightness measured with the Active Knee Extension test and their lumbar lordosis angle measured with a bubble inclinometer while sitting in each of the three postures.
Detailed description
Prolonged sitting is a defining feature of contemporary sedentary lifestyles and an established risk factor for musculoskeletal disorders of the lumbar spine. During sustained sitting, the hip is held in flexion and the hamstring muscle-tendon unit is maintained in a shortened position, which over time is associated with reduced hamstring extensibility (hamstring tightness). Because the hamstrings originate from the ischial tuberosity, a loss of hamstring extensibility exerts a posteriorly directed pull on the pelvis, promoting posterior pelvic tilt. Through regional spinopelvic coupling, this change in pelvic orientation alters the sacral slope and, consequently, the lumbar lordosis angle.
Although the relationship between hamstring tightness and lumbar lordosis has been described previously, most existing studies have evaluated it in the standing position. Sedentary individuals, however, spend the majority of their day seated, where the line of gravity, baseline muscle activity, and passive tissue demands placed on the spine differ substantially from those in standing. Evidence is therefore limited regarding how hamstring tightness relates to the lumbar lordosis angle across the functional sitting postures encountered in daily life, and regarding how this relationship may vary by sex and between the dominant and non-dominant lower limb.
This cross-sectional observational study will be conducted on 110 sedentary adults (55 male and 55 female), aged 18 to 45 years, recruited according to predefined eligibility criteria. The sample size was determined using G*Power based on a bivariate-normal correlation model. Eligible participants will be sedentary (more than six hours of sitting per day and a physical-activity level below 600 MET-minutes/week on the International Physical Activity Questionnaire), with a body mass index below 30 kg/m², bilateral hamstring tightness, and no current low back pain or other exclusionary conditions.
Following screening and informed consent, each participant's demographic and anthropometric data will be recorded, and lower-limb dominance will be determined using a three-task behavioral battery. Hamstring tightness will be assessed bilaterally using the Active Knee Extension (AKE) test, recorded with a digital goniometer, with the mean of three trials used for analysis. The lumbar lordosis angle (T12-S2) will be measured using a double bubble inclinometer in three randomized functional sitting postures-upright, slumped, and forward-leaning-with the mean of three trials per posture used for analysis.
The primary aim is to examine the correlation between hamstring tightness and the lumbar lordosis angle in each of the three sitting postures. The secondary aims are to compare hamstring tightness between male and female participants, to compare hamstring tightness between the dominant and non-dominant lower limb, and to compare the lumbar lordosis angle between male and female participants across the three postures. Data will be analyzed using Pearson correlation coefficients, independent- and paired-samples t-tests, and a mixed-design analysis of variance, with the significance level set at p < 0.05.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Sedentary adults | – | Other: Hamstring tightness and lumbar lordosis assessmentSedentary adults aged 18-45 years (55 male, 55 female) with bilateral hamstring tightness and no current low back pain, assessed for hamstring tightness (Active Knee Extension test) and lumbar lordosis angle (bubble inclinometer) across three functional sitting postures (upright, slumped, and forward-leaning). |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Sedentary adults of both sexes, aged 18 to 45 years, recruited from the Nasser institute hospital, and the surrounding community. Eligible participants are healthy individuals with a sedentary lifestyle (more than six hours of sitting per day and a physical-activity level below 600 MET-minutes per week on the International Physical Activity Questionnaire), a body mass index below 30 kg/m², and bilateral hamstring tightness, with no current low back pain or other excluding musculoskeletal, neurological, or spinal conditions
Key inclusion criteria (6 listed)
- Healthy adults aged 18-45 years.
- Sedentary occupation requiring > 6 hours of sitting per day.
- Active Knee Extension (AKE) angle >15°.
- Bilateral hamstring tightness.
- Sedentary individual as determined by IPAQ (MET≤ 600 min/week).
Key exclusion criteria (7 listed)
- History of significant low back pain requiring medical treatment in the past 12 months.
- Previous spinal surgery or structural spinal deformities.
- Lower extremity injury or surgery within the past 6 months.
- Neurological disorders affecting sensation or movement.
- Pregnant female or get birth in the last year.
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 |
|---|---|---|
| Hamstring tightness and lumbar lordosis assessmentHamstring tightness measured bilaterally with the Active Knee Extension test (digital goniometer) and lumbar lordosis angle (T12-S2) measured with a bubble inclinometer across three functional sitting postures. No therapeutic intervention is administered; these are observational measurements only. | Other | Sedentary adults |
Primary outcome
Correlation between hamstring tightness and lumbar lordosis angle across three functional sitting postures
Time frame: At a single assessment session (cross-sectional; Day 1).
Hamstring tightness is measured as the Active Knee Extension (AKE) deficit in degrees (mean of three trials per limb, using a digital goniometer). The lumbar lordosis angle is measured in degrees using a bubble inclinometer (T12-S2, mean of three trials per posture) in three functional sitting postures: upright, slumped, and forward-leaning. The association between hamstring tightness and the lumbar lordosis angle is assessed for each posture using the Pearson correlation coefficient.
3 secondary outcomes
Difference in hamstring tightness between males and females
Time frame: At a single assessment session (cross-sectional; Day 1).
Difference in hamstring tightness between the dominant and non-dominant lower limb
Time frame: At a single assessment session (cross-sectional; Day 1).
Difference in lumbar lordosis angle between males and females across the three sitting postures
Time frame: At a single assessment session (cross-sectional; Day 1).
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 6 Jul 2026.
- Individual participant dataSharing planned: No
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Hamstring Tightness and Lumbar Lordosis, run by Cairo University at 1 site in Egypt.
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 6 inclusion and 7 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 6 Jul 2026. 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 Egypt. 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?
Contact Ahmed youssef, physiotherapist (+201008650006, ahmedshamebella@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Correlation between hamstring tightness and lumbar lordosis angle across three functional sitting postures (time frame: At a single assessment session (cross-sectional; Day 1).). 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 6 Jul 2026.