Soccer PlayersNCT07894250
Q-Angle, Segment Length, Quadriceps, and Knee Alignment in Soccer Players
An observational study of Soccer Players, run by Suleyman Demirel University at 1 site in Turkey (Türkiye).
Trial summary
The aim of this study is to investigate the relationship of Q-angle, lower extremity segment lengths, and quadriceps muscle activation with dynamic knee alignment during a single-leg squat in active soccer players. Read more about this study
- Who is it for?
- Ages 18 to 35 years, men only
- Conditions the study is for
- Soccer Players
- What is being tested?
- Group 1
- How many people
- 29 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 20 Oct 2026to 20 Jan 2027
- How long will I take part?
- 1 Day
- 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 35 years
- Men only
- No healthy volunteers
- Adult
Study population: 29
Who may be able to join
- Individuals who are actively playing football and have agreed to participate in the study voluntarily,
- Who have engaged in regular football training over the past six months,
- Who are able to perform a single-leg squat independently during the assessment,
- Who do not have any acute musculoskeletal issues that could affect the measurements.
Who cannot join
- Individuals who have undergone lower extremity surgery within the last 6 months,
- Sustained a severe lower extremity injury within the last 3 months,
- Experience acute pain during the assessment,
- Have a neurological or orthopedic condition,
- Have any condition that prevents the tests from being performed safely.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site
Nur ALP
Isparta
Nur ALP, Dr, +90 533 973 88 32, nuralp@sdu.edu.tr
About this study
Official title: Investigation of the Relationship of Q-Angle, Lower Extremity Segment Lengths, and Quadriceps Muscle Activation With Dynamic Knee Alignment During Single-Leg Squats in Soccer Players
The aim of this study is to investigate the relationship of Q-angle, lower extremity segment lengths, and quadriceps muscle activation with dynamic knee alignment during a single-leg squat in active soccer players.
Study hypotheses:
Read more
H1: There is a significant relationship between Q-angle and dynamic knee alignment during a single-leg squat in active soccer players.
H2: There is a significant relationship between femur length and dynamic knee alignment during a single-leg squat in active soccer players.
H3: There is a significant relationship between tibia length and dynamic knee alignment during a single-leg squat in active soccer players.
H4: There is a significant relationship between the ratio of lower extremity segment lengths and dynamic knee alignment during a single-leg squat in active soccer players.
H5: There is a significant relationship between the level of quadriceps muscle activation and dynamic knee alignment during a single-leg squat in active soccer players.
H6: When Q-angle, lower extremity segment lengths, and quadriceps muscle activation are evaluated together, they are significantly associated with dynamic knee alignment during a single-leg squat in active soccer players.
Read the detailed description
The study will be conducted with active football players from the Department of Physical Education and Coaching at Isparta Süleyman Demirel University. It has been designed as a cross-sectional and prospective study. The parameters to be evaluated in a total of 29 participants (n=29) are: Q-angle, lower extremity segment lengths, surface electromyography assessment, and dynamic knee alignment during a single-leg squat.
- Conditions
- Soccer Players
- Being tested
- Group 1
- Keywords
- Soccer, Anthropometry, Electromyography, Quadriceps Muscle, Biomechanical Phenomena
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Group 1Other
The study was designed to include individuals aged 18-35 who actively play football, voluntarily agreed to participate, had engaged in regular football training over the past six months, were able to perform a single-leg squat independently during the assessment, and had no acute musculoskeletal issues that could affect the measurements. All assessments for this group will be conducted by a doctor of physiotherapy. Plans were made to regularly record participation rates and measurements. For each player, measurements of the Q-angle, lower extremity segment lengths, surface electromyography, and dynamic knee alignment during a single-leg squat were planned for the dominant lower extremity.
| Study group | Role | What they receive |
|---|---|---|
| Group of footballers | Football player group: One-time measurements were planned. For each player, measurements of the Q-angle, lower extremity segment lengths, surface electromyography, and dynamic knee alignment during a single-leg squat were planned for the dominant lower extremity. Receives: Other: Group 1 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Q angle
Q-angle: With the subject in a supine position and the lower extremities in a neutral position, the angle formed by the lines connecting the anterior superior iliac spine (ASIS) to the center of the patella and the center of the patella to the tibial tuberosity will be recorded as the Q-angle using a universal goniometer. Three consecutive measurements will be performed on both extremities, and the mean of these measurements will be used in the analyses.
Measured: Baseline (Day 0)
Secondary outcomes (3)
Lower extremity segment lengths
Measurement of lower extremity segment lengths: The distance between the anterior superior iliac spine (ASIS) and the medial malleolus will be measured in centimeters with the subject in the supine position. Femur length will be measured in centimeters as the distance between the greater trochanter and the lateral condyle of the femur. Tibia length will be measured in centimeters as the distance between the lateral condyle of the femur and the lateral malleolus. A non-stretchable tape measure will be used for the measurements. Measurements for both extremities will be recorded separately, and right-left differences will be calculated. The femur/tibia ratio will be calculated by dividing the femur length by the tibia length. All measurements will be repeated once.
Measured: Baseline (Day 0)
Surface Electromyography Assessment:
A 'Noraxon' device will be used for surface electromyography to assess quadriceps muscle activity. EMG activity will be recorded from the *m. rectus femoris* (RF), *m. vastus medialis* (VM), and *m. vastus lateralis* (VL) muscles on the dominant side. Electrode placement will adhere to the standards of the "Surface EMG for Non-Invasive Assessment of Muscles" (SENIAM) project. Electrodes will be positioned parallel to the direction of the muscle fibers: for the RF, at approximately 50% of the line between the ASIS and the patella; for the VM, at approximately 80% of the line between the ASIS and the reference point on the medial aspect of the knee joint space; and for the VL, at approximately two-thirds of the line between the ASIS and the lateral edge of the patella. Prior to electrode placement, body hair and dead skin will be removed using a razor and alcohol, and electrodes will be placed with a center-to-center distance of 20 mm.
A BIOPAC MP150 system will be used for surface elec
Measured: Baseline (Day 0)
Dynamic Knee Alignment During Single-Leg Squat
Participants will be instructed on the correct squatting and descent technique from a lateral view using an instructional video and verbal explanations. Before the test begins, participants will perform the movement approximately four times. For the test, kinesiology tape markers will be placed at the following reference points: the anterior superior iliac spine (ASIS), the midpoint of the patella, and the midpoint of the ankle (between the medial and lateral malleoli). Three trials will be performed for each lower extremity, with a two-minute rest period between trials. Participants will be asked to perform a single-leg squat, flexing the knee to approximately 60°. During the test, participants will be required to stand barefoot on a marked line, keep the non-tested knee flexed at approximately 90°, cross their arms over their chest, and maintain a forward gaze. A maximum of 5 seconds will be allowed to complete the test, which will commence upon the researcher's command. A trial wil
Measured: Baseline (Day 0)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Oct 2026
- Study start20 Oct 2026 (estimated)
- Primary completion20 Dec 2026 (estimated)
- Study completion20 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Soccer PlayersStudies 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
- Observational
- Observational model
- Other
- Time perspective
- Cross-sectional
- Enrolment
- 29 participants (estimated)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- Suleyman Demirel University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mine ARGALI DENIZ, Suleyman Demirel University
- Investigators
- Mine ARĞALI DENİZ, Dr, Study director, Suleyman Demirel University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07894250
- Sponsor's protocol ID
- SuleymanDU-132/28
- Status last verified
- Oct 2026
- First submitted
- 14 Oct 2026
- Last updated
- 26 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The data for objectives of the research will be compared after they are received.
Study at a glance
From the registry record, last updated by the sponsor on 26 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigation of the Relationship of Q-Angle, Lower Extremity Segment Lengths, and Quadriceps Muscle Activation With Dynamic Knee Alignment During Single-Leg Squats in Soccer Players
- ClinicalTrials.gov ID
- NCT07894250
- Acronym / sponsor ID
- SuleymanDU-132/28
- Conditions
- Soccer Players
- Keywords
- Soccer, Anthropometry, Electromyography, Quadriceps Muscle, Biomechanical Phenomena
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 29 participants (estimated)
- Lead sponsor
- Suleyman Demirel UniversityUniversity, hospital or other
- Study start
- 20 Oct 2026 (estimated)
- Primary completion
- 20 Dec 2026 (estimated)
- Study completion
- 20 Jan 2027 (estimated)
- First posted
- 26 Oct 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 aim of this study is to investigate the relationship of Q-angle, lower extremity segment lengths, and quadriceps muscle activation with dynamic knee alignment during a single-leg squat in active soccer players.
Study hypotheses:
H1: There is a significant relationship between Q-angle and dynamic knee alignment during a single-leg squat in active soccer players.
H2: There is a significant relationship between femur length and dynamic knee alignment during a single-leg squat in active soccer players.
H3: There is a significant relationship between tibia length and dynamic knee alignment during a single-leg squat in active soccer players.
H4: There is a significant relationship between the ratio of lower extremity segment lengths and dynamic knee alignment during a single-leg squat in active soccer players.
H5: There is a significant relationship between the level of quadriceps muscle activation and dynamic knee alignment during a single-leg squat in active soccer players.
H6: When Q-angle, lower extremity segment lengths, and quadriceps muscle activation are evaluated together, they are significantly associated with dynamic knee alignment during a single-leg squat in active soccer players.
Detailed description
The study will be conducted with active football players from the Department of Physical Education and Coaching at Isparta Süleyman Demirel University. It has been designed as a cross-sectional and prospective study. The parameters to be evaluated in a total of 29 participants (n=29) are: Q-angle, lower extremity segment lengths, surface electromyography assessment, and dynamic knee alignment during a single-leg squat.
Study design
- Observational model
- Other
- Time perspective
- Cross-sectional
- Target follow-up
- 1 Day
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Group of footballers | – | Other: Group 1Football player group: One-time measurements were planned. For each player, measurements of the Q-angle, lower extremity segment lengths, surface electromyography, and dynamic knee alignment during a single-leg squat were planned for the dominant lower extremity. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- 29
Key inclusion criteria (4 listed)
- Individuals who are actively playing football and have agreed to participate in the study voluntarily,
- Who have engaged in regular football training over the past six months,
- Who are able to perform a single-leg squat independently during the assessment,
- Who do not have any acute musculoskeletal issues that could affect the measurements.
Key exclusion criteria (5 listed)
- Individuals who have undergone lower extremity surgery within the last 6 months,
- Sustained a severe lower extremity injury within the last 3 months,
- Experience acute pain during the assessment,
- Have a neurological or orthopedic condition,
- Have any condition that prevents the tests from being performed safely.
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 |
|---|---|---|
| Group 1The study was designed to include individuals aged 18-35 who actively play football, voluntarily agreed to participate, had engaged in regular football training over the past six months, were able to perform a single-leg squat independently during the assessment, and had no acute musculoskeletal issues that could affect the measurements. All assessments for this group will be conducted by a doctor of physiotherapy. Plans were made to regularly record participation rates and measurements. For each player, measurements of the Q-angle, lower extremity segment lengths, surface electromyography, and dynamic knee alignment during a single-leg squat were planned for the dominant lower extremity. | Other | Group of footballers |
Primary outcome
Q angle
Time frame: Baseline (Day 0)
Q-angle: With the subject in a supine position and the lower extremities in a neutral position, the angle formed by the lines connecting the anterior superior iliac spine (ASIS) to the center of the patella and the center of the patella to the tibial tuberosity will be recorded as the Q-angle using a universal goniometer. Three consecutive measurements will be performed on both extremities, and the mean of these measurements will be used in the analyses.
3 secondary outcomes
Lower extremity segment lengths
Time frame: Baseline (Day 0)
Surface Electromyography Assessment:
Time frame: Baseline (Day 0)
Dynamic Knee Alignment During Single-Leg Squat
Time frame: Baseline (Day 0)
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 26 Oct 2026.
- Individual participant dataSharing planned: No. The data for objectives of the research will be compared after they are received.
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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.
Mine ARĞALI DENİZ, Dr study director
Suleyman Demirel University
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 Soccer Players, run by Suleyman Demirel University at 1 site in Turkey (Türkiye).
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 5 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 26 Oct 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 Turkey (Türkiye). 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 NUR ALP, Dr (+90 533 973 88 32, nuralp@sdu.edu.tr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Q angle (time frame: Baseline (Day 0)). 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 26 Oct 2026.