Hamstring Tightness and Lumbar Lordosis Angel Across Functional Sitting Posture.

NCT07682142 | Not Yet Recruiting

• 1 other identifier: P.T.REC/012/006548
• Study Type: observational
• Target: 110
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Hamstring Tightness; Lumbar Lordosis; Sedentary Behavior; Posture Sitting Position

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

Outcome Measures

Primary Outcomes (1)

• 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.

  At a single assessment session (cross-sectional; Day 1).

Secondary Outcomes (3)

• Difference in hamstring tightness between males and females

  At a single assessment session (cross-sectional; Day 1).

• Difference in hamstring tightness between the dominant and non-dominant lower limb

  At a single assessment session (cross-sectional; Day 1).

• Difference in lumbar lordosis angle between males and females across the three sitting postures

  At a single assessment session (cross-sectional; Day 1).

Study Arms (1)

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).

Other: Hamstring tightness and lumbar lordosis assessment

Interventions

Hamstring tightness and lumbar lordosis assessment OTHER

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.

Sedentary adults

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

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

You may qualify if:

• 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.

You may not qualify if:

• 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

Sponsors & Collaborators

• Cairo University: lead

Study Sites (1)

Nasser institute hospital

Cairo, Shubra Misr, 12616, Egypt

Location

MeSH Terms

Conditions

Lordosis; Sedentary Behavior

Condition Hierarchy (Ancestors)

Spinal Curvatures; Spinal Diseases; Bone Diseases; Musculoskeletal Diseases; Behavior

Central Study Contacts

Ahmed youssef, physiotherapist

CONTACT

+201008650006; ahmedshamebella@gmail.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: physiotherapist

Study Record Dates

• First Submitted: June 27, 2026
• First Posted: July 2, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): October 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: July 6, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

EG (1)