Isokinetic Knee StrengthISOK-WAnTNCT07921498
Isokinetic Knee Strength, Bilateral Muscle Balance, and Anaerobic Performance in Adolescent Athletes
An observational study of Isokinetic Knee Strength and Hamstring-to-Quadriceps Strength Ratio, run by Inonu University at 1 site in Turkey (Türkiye).
Trial summary
This study looks at how strong the knee muscles are in adolescent athletes and how this strength relates to short-term, high-intensity (anaerobic) performance. Strong, well-balanced thigh muscles may help athletes produce more power during sport movements, but this has not been studied well in teenagers. Read more about this study
- Who is it for?
- Ages 15 to 16 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Isokinetic Knee Strength, Hamstring-to-Quadriceps Strength Ratio, Anaerobic Performance
- What is being tested?
- Isokinetic Knee Strength Testing and Wingate Anaerobic Test
- How many people
- 21 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 28 Dec 2026to 28 Jan 2027
- 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 15 to 16 years
- Men only
- Healthy volunteers accepted
- Child
Study population: Male adolescent athletes aged 15-16 years who actively wrestle and train regularly in Malatya, Turkey. Participants are healthy athletes recruited from local clubs on a voluntary basis.
Who may be able to join
- Actively practicing wrestling in Malatya, Turkey
- Male, aged 15-16 years
- At least 2 years of regular training (at least 2 days per week)
- No lower-extremity injury or surgery in the last 6 months
- No musculoskeletal, cardiometabolic, or neurological condition that could prevent testing
- Willing to participate in all planned tests
Show all 15Show fewer
- Written informed consent signed by parent or legal guardian, and assent from the participant
- Exclusion Criteria: Younger than 15 or older than 16 years
- Lower-extremity injury or surgery within the last 6 months
- Musculoskeletal, cardiometabolic, or neurological condition that could prevent testing
- Open wound, varicose veins, acute inflammation, or history of thrombosis
- Regular use of analgesic or anti-inflammatory medication or ergogenic supplements in the last 3 months
- Unable to attend all planned testing sessions
- Unwilling to follow the pre-test rules (no heavy exercise for 48 hours, no caffeine for 12 hours, usual training and diet)
- Withdrawal during the study due to non-compliance, incomplete sessions, serious injury or illness, or participant request
Who cannot join
None listed.
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
Department of Physical Education and Sport Teaching, Faculty of Sports Sciences, Inonu University,
Malatya, Malatya, 44280
Özgür Eken, PhD, Assoc. Prof., +90 553 213 27 95, ozgur.eken@ınonu.edu.tr
Çalışkan, Dr., denizhancaliskann@gmail.com
About this study
Official title: Relationship of Isokinetic Knee Strength and Bilateral Muscle Balance With Anaerobic Performance in Adolescent Athletes
This study looks at how strong the knee muscles are in adolescent athletes and how this strength relates to short-term, high-intensity (anaerobic) performance. Strong, well-balanced thigh muscles may help athletes produce more power during sport movements, but this has not been studied well in teenagers. Male athletes aged 15-16 years will be measured on two separate days. On the first day, their height and body weight will be measured and the strength of the muscles at the front (quadriceps) and back (hamstrings) of both thighs will be tested on a special strength-testing machine. On the second day, they will do a 30-second all-out cycling test to measure anaerobic power. The study will compare the right and left legs and will examine whether knee muscle strength and the balance between the front and back thigh muscles are linked to power output during the cycling test. No treatment or intervention will be given. The results may help coaches and sports scientists understand the physical development of adolescent athletes.
Read the detailed description
Lower-limb strength and anaerobic power are important parts of the physical profile of adolescent athletes in high-intensity sports such as wrestling. Isokinetic dynamometry allows knee extensor (quadriceps) and flexor (hamstring) strength and the balance between these muscle groups to be measured objectively, while the 30-second Wingate Anaerobic Test (WAnT) is a widely used laboratory test of anaerobic performance. Evidence on how these measures relate to each other in adolescent athletes is limited.
This is a cross-sectional, correlational observational study. Twenty-one male adolescent athletes aged 15-16 years will be recruited in Malatya, Turkey. Written informed consent will be obtained from parents or legal guardians, and assent from participants. Testing will take place on two separate days to limit fatigue. Participants will avoid heavy exercise for 48 hours and caffeine for 12 hours before testing.
Day 1: Height and body mass are measured and body mass index is calculated. Concentric knee extension and flexion are then tested bilaterally on a HUMAC NORM isokinetic dynamometer at 60, 120 and 180 degrees per second (three practice repetitions followed by five maximal repetitions at each speed; 45 seconds of rest between speeds and 10 minutes between limbs). Peak torque is recorded for the quadriceps and hamstrings of each limb, and the conventional hamstring-to-quadriceps (H/Q) ratio is calculated.
Day 2: Participants complete a 30-second WAnT on a mechanically braked cycle ergometer (Monark 874E) with a braking load of 0.075 kg per kg of body mass, after a standardized warm-up. Peak power, mean power and fatigue index are recorded.
Differences between the right and left limbs will be examined with paired-samples t-tests (with 95% confidence intervals and Cohen's dz). Associations between isokinetic variables and WAnT outcomes will be examined with Pearson correlation. The sample size (minimum 19) was calculated with G*Power for a correlation of r = 0.60 (alpha = 0.05, power = 0.80); 21 participants are planned to allow for possible data loss.
- Being tested
- Isokinetic Knee Strength Testing, Wingate Anaerobic Test
- Keywords
- adolescent athletes, isokinetic dynamometry, knee strength, hamstring-to-quadriceps ratio, muscle balance, Wingate Anaerobic Test, anaerobic power
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Isokinetic Knee Strength TestingDiagnostic test
Bilateral concentric knee extension and flexion tested on an isokinetic dynamometer at 60, 120, and 180 degrees per second. Peak torque and the conventional hamstring-to-quadriceps ratio are recorded.
Wingate Anaerobic TestDiagnostic test
Also called WAnT
A 30-second all-out cycling test on a mechanically braked cycle ergometer with a braking load of 0.075 kg per kg of body mass. Peak power, mean power, and fatigue index are recorded.
| Study group | Role | What they receive |
|---|---|---|
| Adolescent Athletes | Male adolescent athletes aged 15-16 years who regularly train and compete. All participants complete anthropometric measurements, bilateral isokinetic knee strength testing, and the Wingate Anaerobic Test on separate days. Receives: Diagnostic Test: Isokinetic Knee Strength Testing; Diagnostic Test: Wingate Anaerobic Test |
What is being measured
The primary outcome is the main question the study is designed to answer.
Isokinetic Peak Torque of the Knee Extensors and Flexors
Peak torque (N·m) of the quadriceps and hamstrings, measured separately for the right and left limbs at 60, 120, and 180 degrees per second on an isokinetic dynamometer (highest value across five maximal concentric repetitions). Right-to-left differences and associations with Wingate Anaerobic Test outcomes are analyzed.
Measured: Day 1 of testing (single measurement session)
Wingate Anaerobic Test Peak Power
Highest power output (W) achieved during the 30-second Wingate Anaerobic Test performed on a mechanically braked cycle ergometer with a braking load of 0.075 kg per kg of body mass.
Measured: Day 2 of testing (single measurement session)
Secondary outcomes (3)
Conventional Hamstring-to-Quadriceps (H/Q) Strength Ratio
Concentric hamstring peak torque divided by quadriceps peak torque, multiplied by 100 (%), calculated for each limb at 60, 120, and 180 degrees per second.
Measured: Day 1 of testing
Wingate Anaerobic Test Mean Power
Average power output (W) maintained across the 30-second Wingate Anaerobic Test.
Measured: Day 2 of testing
Wingate Anaerobic Test Fatigue Index
Percentage decline from peak power to the lowest power output during the test: [(peak power - minimum power) / peak power] × 100.
Measured: Day 2 of testing
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Nov 2026
- Study start28 Dec 2026 (estimated)
- Primary completion28 Jan 2027 (estimated)
- Study completion28 Jan 2027 (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 Isokinetic Knee StrengthStudies of the same condition, open and under way.
- More trials run by Inonu 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
- 21 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Inonu University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Assoc. Prof. Dr. Özgür EKEN, Inonu University
- Investigators
- Özgür Eken, PhD, Assoc. Prof., Principal investigator, Inonu University, Faculty of Sport SciencesDenizhan Çalışkan, Dr., Study director, Eskisehir Provincial Directorate of Youth and Sports, Eskisehir, Türkiye
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07921498
- Sponsor's protocol ID
- INONU-ISOKINETIC-2026-01
- Other IDs
- IKINETIK-WAnT-2026
- Acronym
- ISOK-WAnT
- Status last verified
- Nov 2026
- First submitted
- 2 Nov 2026
- Last updated
- 6 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared, because participants are minors and the consent forms state that data will be used only for the purposes of this research and kept confidential. Aggregate results will be published.
Publications
Aagaard, P., Simonsen, E. B., Magnusson, S. P., Larsson, B., & Dyhre-Poulsen, P. (1998). A new concept for isokinetic hamstring:quadriceps muscle strength ratio. The American Journal of Sports Medicine, 26(2), 231-237. Alemdaroğlu, U. (2012). The relationship between muscle strength, anaerobic performance, agility, sprint ability and vertical jump performance in professional basketball players. Journal of Human Kinetics, 31, 149-158. Chaabene, H., Negra, Y., Bouguezzi, R., Capranica, L., Franchini, E., Prieske, O., Hbacha, H., & Granacher, U. (2017). Physical and physiological attributes of wrestlers: An update. Journal of Strength and Conditioning Research, 31(5), 1411-1442. Iossifidou, A., Baltzopoulos, V., & Giakas, G. (2005). Isokinetic knee extension and vertical jumping: Are they related? Journal of Sports Sciences, 23(9), 1121-1127.
Study at a glance
From the registry record, last updated by the sponsor on 6 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Relationship of Isokinetic Knee Strength and Bilateral Muscle Balance With Anaerobic Performance in Adolescent Athletes
- ClinicalTrials.gov ID
- NCT07921498
- Acronym / sponsor ID
- ISOK-WAnT / INONU-ISOKINETIC-2026-01
- Keywords
- adolescent athletes, isokinetic dynamometry, knee strength, hamstring-to-quadriceps ratio, muscle balance, Wingate Anaerobic Test, anaerobic power
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 21 participants (estimated)
- Lead sponsor
- Inonu UniversityUniversity, hospital or other
- Study start
- 28 Dec 2026 (estimated)
- Primary completion
- 28 Jan 2027 (estimated)
- Study completion
- 28 Jan 2027 (estimated)
- First posted
- 6 Nov 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.
This study looks at how strong the knee muscles are in adolescent athletes and how this strength relates to short-term, high-intensity (anaerobic) performance. Strong, well-balanced thigh muscles may help athletes produce more power during sport movements, but this has not been studied well in teenagers. Male athletes aged 15-16 years will be measured on two separate days. On the first day, their height and body weight will be measured and the strength of the muscles at the front (quadriceps) and back (hamstrings) of both thighs will be tested on a special strength-testing machine. On the second day, they will do a 30-second all-out cycling test to measure anaerobic power. The study will compare the right and left legs and will examine whether knee muscle strength and the balance between the front and back thigh muscles are linked to power output during the cycling test. No treatment or intervention will be given. The results may help coaches and sports scientists understand the physical development of adolescent athletes.
Detailed description
Lower-limb strength and anaerobic power are important parts of the physical profile of adolescent athletes in high-intensity sports such as wrestling. Isokinetic dynamometry allows knee extensor (quadriceps) and flexor (hamstring) strength and the balance between these muscle groups to be measured objectively, while the 30-second Wingate Anaerobic Test (WAnT) is a widely used laboratory test of anaerobic performance. Evidence on how these measures relate to each other in adolescent athletes is limited.
This is a cross-sectional, correlational observational study. Twenty-one male adolescent athletes aged 15-16 years will be recruited in Malatya, Turkey. Written informed consent will be obtained from parents or legal guardians, and assent from participants. Testing will take place on two separate days to limit fatigue. Participants will avoid heavy exercise for 48 hours and caffeine for 12 hours before testing.
Day 1: Height and body mass are measured and body mass index is calculated. Concentric knee extension and flexion are then tested bilaterally on a HUMAC NORM isokinetic dynamometer at 60, 120 and 180 degrees per second (three practice repetitions followed by five maximal repetitions at each speed; 45 seconds of rest between speeds and 10 minutes between limbs). Peak torque is recorded for the quadriceps and hamstrings of each limb, and the conventional hamstring-to-quadriceps (H/Q) ratio is calculated.
Day 2: Participants complete a 30-second WAnT on a mechanically braked cycle ergometer (Monark 874E) with a braking load of 0.075 kg per kg of body mass, after a standardized warm-up. Peak power, mean power and fatigue index are recorded.
Differences between the right and left limbs will be examined with paired-samples t-tests (with 95% confidence intervals and Cohen's dz). Associations between isokinetic variables and WAnT outcomes will be examined with Pearson correlation. The sample size (minimum 19) was calculated with G*Power for a correlation of r = 0.60 (alpha = 0.05, power = 0.80); 21 participants are planned to allow for possible data loss.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Adolescent Athletes | – | Diagnostic Test: Isokinetic Knee Strength Testing, Diagnostic Test: Wingate Anaerobic TestMale adolescent athletes aged 15-16 years who regularly train and compete. All participants complete anthropometric measurements, bilateral isokinetic knee strength testing, and the Wingate Anaerobic Test on separate days. |
Who may qualify
- Ages
- 15 to 16 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Child
- Study population
- Male adolescent athletes aged 15-16 years who actively wrestle and train regularly in Malatya, Turkey. Participants are healthy athletes recruited from local clubs on a voluntary basis.
Key inclusion criteria (15 listed)
- Actively practicing wrestling in Malatya, Turkey
- Male, aged 15-16 years
- At least 2 years of regular training (at least 2 days per week)
- No lower-extremity injury or surgery in the last 6 months
- No musculoskeletal, cardiometabolic, or neurological condition that could prevent testing
Key exclusion criteria (0 listed)
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 |
|---|---|---|
| Isokinetic Knee Strength TestingBilateral concentric knee extension and flexion tested on an isokinetic dynamometer at 60, 120, and 180 degrees per second. Peak torque and the conventional hamstring-to-quadriceps ratio are recorded. | Diagnostic test | Adolescent Athletes |
| Wingate Anaerobic TestAlso: WAnTA 30-second all-out cycling test on a mechanically braked cycle ergometer with a braking load of 0.075 kg per kg of body mass. Peak power, mean power, and fatigue index are recorded. | Diagnostic test | Adolescent Athletes |
Primary outcome
Isokinetic Peak Torque of the Knee Extensors and Flexors
Time frame: Day 1 of testing (single measurement session)
Peak torque (N·m) of the quadriceps and hamstrings, measured separately for the right and left limbs at 60, 120, and 180 degrees per second on an isokinetic dynamometer (highest value across five maximal concentric repetitions). Right-to-left differences and associations with Wingate Anaerobic Test outcomes are analyzed.
Wingate Anaerobic Test Peak Power
Time frame: Day 2 of testing (single measurement session)
Highest power output (W) achieved during the 30-second Wingate Anaerobic Test performed on a mechanically braked cycle ergometer with a braking load of 0.075 kg per kg of body mass.
3 secondary outcomes
Conventional Hamstring-to-Quadriceps (H/Q) Strength Ratio
Time frame: Day 1 of testing
Wingate Anaerobic Test Mean Power
Time frame: Day 2 of testing
Wingate Anaerobic Test Fatigue Index
Time frame: Day 2 of testing
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 Nov 2026.
- BackgroundAagaard, P., Simonsen, E. B., Magnusson, S. P., Larsson, B., & Dyhre-Poulsen, P. (1998). A new concept for isokinetic hamstring:quadriceps muscle strength ratio. The American Journal of Sports Medicine, 26(2), 231-237. Alemdaroğlu, U. (2012). The relationship between muscle strength, anaerobic performance, agility, sprint ability and vertical jump performance in professional basketball players. Journal of Human Kinetics, 31, 149-158. Chaabene, H., Negra, Y., Bouguezzi, R., Capranica, L., Franchini, E., Prieske, O., Hbacha, H., & Granacher, U. (2017). Physical and physiological attributes of wrestlers: An update. Journal of Strength and Conditioning Research, 31(5), 1411-1442. Iossifidou, A., Baltzopoulos, V., & Giakas, G. (2005). Isokinetic knee extension and vertical jumping: Are they related? Journal of Sports Sciences, 23(9), 1121-1127.
- Individual participant dataSharing planned: No. Individual participant data will not be shared, because participants are minors and the consent forms state that data will be used only for the purposes of this research and kept confidential. Aggregate results will be published.
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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.
Özgür Eken, PhD, Assoc. Prof. principal investigator
Inonu University, Faculty of Sport Sciences
Denizhan Çalışkan, Dr. study director
Eskisehir Provincial Directorate of Youth and Sports, Eskisehir, Türkiye
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 Isokinetic Knee Strength and Hamstring-to-Quadriceps Strength Ratio, run by Inonu 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 15 inclusion and 0 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 Nov 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 Ozgur Eken, PhD, Associate Professor (+90 553 213 27 95, ozgur.eken@inonu.edu.tr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Isokinetic Peak Torque of the Knee Extensors and Flexors (time frame: Day 1 of testing (single measurement session)). The study lists 2 primary outcomes in all. 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 NCT07921498, 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 6 Nov 2026.