Athletic PerformanceNCT07447765
Trunk Muscle Endurance and Flexibility as Determinants of Athletic Performance in Elite Adolescent Tennis Players
An observational study of Athletic Performance and Physical Fitness, run by Hacettepe University at 1 site in Turkey (Türkiye).
Trial summary
This study aims to examine how trunk (core) muscle endurance and flexibility relate to athletic performance in elite adolescent tennis players aged 11-18 years. Tennis requires speed, balance, strength, coordination, and repeated high-intensity movements. Read more about this study
- Who is it for?
- Ages 11 to 18 yearsHealthy volunteers can take part
- Conditions the study is for
- Athletic Performance, Physical Fitness, Sports Performance
- What is being tested?
- Physical Performance Assessment
- How many people
- 38 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Apr 2025to 1 Jun 2025
- Phase
- Observational
- 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 11 to 18 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Study population: Elite adolescent tennis players who are licensed athletes, actively training and competing in tennis clubs. Participants represent trained youth athletes with regular high-frequency training exposure and competitive experience.
Who may be able to join
- Aged between 11 and 18 years
- Elite tennis players actively competing in official tournaments
- Minimum of 3 years of regular tennis training experience
- Participating in tennis training at least 4 days per week
- Ability to understand and follow instructions
- Written informed consent provided by participant and parent/guardian (if under 18)
Who cannot join
- History of musculoskeletal injury within the past 6 months affecting performance
- Presence of neurological, orthopedic, sensory, or motor disorders
- Any medical condition limiting physical activity
- Current pain that may affect test performance
- Pregnancy
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Ondokuz Mayis University
Samsun, Atakum, 55270
About this study
Official title: Investigation of the Relationship Between Trunk Muscle Endurance and Flexibility and Athletic Performance in Elite Adolescent Tennis Players
This study aims to examine how trunk (core) muscle endurance and flexibility relate to athletic performance in elite adolescent tennis players aged 11-18 years. Tennis requires speed, balance, strength, coordination, and repeated high-intensity movements. The trunk region plays an important role in transferring force between the upper and lower body and in maintaining posture and stability during sports activities. However, there is limited research on how trunk physical characteristics influence performance in young elite tennis players.
Participants who actively compete in tennis tournaments and train regularly will complete a set of standardized tests assessing flexibility, trunk muscle endurance, balance, sprint speed, agility, and strength. The results will help researchers understand whether trunk flexibility and endurance are associated with better athletic performance. Findings may guide coaches and health professionals in designing training programs that improve performance and potentially reduce injury risk in young athletes.
Read the detailed description
This cross-sectional descriptive study investigates the relationship between trunk muscle endurance, trunk flexibility, and athletic performance parameters in elite adolescent tennis players. Tennis is a high-intensity intermittent sport requiring rapid acceleration, deceleration, directional changes, and explosive movements. Physical performance depends on multiple components, including strength, flexibility, endurance, and neuromuscular coordination. The trunk region is biomechanically important because it provides proximal stability, supports postural control, and facilitates force transmission between upper and lower extremities during sport-specific movements.
Despite evidence suggesting that trunk function contributes to athletic performance and injury prevention, limited research has focused specifically on elite adolescent tennis players, whose neuromuscular characteristics may differ due to growth and maturation. Therefore, this study aims to clarify associations between trunk physical characteristics and performance outcomes in this population.
Elite tennis players aged 11-18 years who train regularly and compete in official tournaments will be recruited. After informed consent procedures, participants will undergo standardized testing on regular training days following a supervised warm-up protocol.
Assessments include:
Demographic measures: age, sex, height, body weight, body mass index, training frequency, and years of tennis experience.
Flexibility tests: sit-and-reach, trunk lateral flexion, trunk rotation, and trunk extension.
Trunk muscle endurance tests: Biering-Sorensen test, plank test, and side plank test.
Athletic performance tests: Y Balance Test for dynamic balance, 20-meter sprint test for speed, T-drill test for agility, push-up test for upper-extremity endurance, medicine ball throw for upper-body power, and vertical jump for lower-extremity explosive strength.
All measurements will be conducted in the same environment by an experienced assessor using standardized procedures. Statistical analyses will evaluate correlations and predictive relationships between trunk endurance/flexibility variables and performance outcomes.
The results are expected to clarify whether trunk flexibility and endurance are key determinants of athletic performance in adolescent tennis players. Understanding these relationships may support evidence-based training strategies targeting trunk function to enhance performance and reduce injury risk.
- Being tested
- Physical Performance Assessment
- Keywords
- Endurance, Flexibility, Trunk, Sports performance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Physical Performance AssessmentOther
Participants undergo a standardized assessment protocol including trunk muscle endurance tests, flexibility measurements, balance, sprint, agility, strength, and power performance tests. No therapeutic or training intervention is applied. All procedures are observational and conducted under standardized testing conditions.
| Study group | Role | What they receive |
|---|---|---|
| Elite Adolescent Tennis Players | Elite tennis players aged 11 to 18 years who actively compete and train regularly. Participants undergo standardized assessments of trunk muscle endurance, flexibility, and athletic performance. No intervention is applied; all measurements are observational and conducted under standardized conditions. Receives: Other: Physical Performance Assessment |
What is being measured
The primary outcome is the main question the study is designed to answer.
20-Meter Sprint Time
Sprint performance is assessed using a 20-meter sprint test. Participants perform a maximal sprint over a 20-meter distance, and time is recorded in seconds using a stopwatch. Lower time values indicate better sprint performance.
Measured: Baseline
T-Drill Agility Test Time
Agility performance is measured using the T-drill test. Participants complete a standardized agility course involving forward sprinting, lateral shuffling, and backward running. Completion time is recorded in seconds. Lower time values indicate better agility performance.
Measured: Baseline
Vertical Jump Height
Lower extremity explosive power is assessed using a vertical jump test. Jump height is measured in centimeters. Higher jump height values indicate better explosive strength performance.
Measured: Baseline
Medicine Ball Throw Distance
Upper extremity explosive power is evaluated using a medicine ball throw test. The distance the ball is thrown is measured in centimeters. Greater distances indicate better upper body explosive strength performance.
Measured: Baseline
Dynamic Balance Performance (Y Balance Test)
Dynamic balance is assessed using the Y Balance Test. Reach distances in the anterior, posteromedial, and posterolateral directions are measured and normalized to leg length (expressed as percentages). Higher percentage values indicate better dynamic balance performance.
Measured: Baseline
Secondary outcomes (7)
Sit-and-Reach Test Distance (cm)
The Sit-and-Reach Test will be used to assess hamstring and lower back flexibility. Participants will sit barefoot with their feet flat against a standardized testing box and reach forward without bending their knees. The final position will be held for 2 seconds. Two trials will be performed, and the best value will be recorded in centimeters.
Measured: Baseline
Biering-Sørensen Test Duration
The Biering-Sørensen Test will be used to assess trunk extensor muscle endurance. Participants will be positioned prone on a treatment table with the lower extremities stabilized using straps or manual fixation. The upper body will be positioned beyond the edge of the table at the level of the anterior superior iliac spines. Participants will cross their arms over the chest and maintain the horizontal trunk position as long as possible. The test will be terminated when the trunk position can no longer be maintained. Duration will be recorded in seconds.
Measured: Baseline
Trunk Lateral Flexion Distance
Trunk lateral flexion flexibility will be assessed in standing position with feet shoulder-width apart and arms alongside the body. The participant will slide the hand down the thigh while bending laterally without trunk rotation. The distance between the initial and final positions of the third fingertip will be measured in centimeters. Three trials will be performed for each side, and the best value for each side will be recorded in centimeters.
Measured: Baseline
Trunk Extension Distance
Trunk extension flexibility will be assessed in standing position facing a wall with the pelvis stabilized. The distance between the suprasternal notch and the wall will be measured at rest and during maximal trunk extension. The difference between the two measurements will be recorded in centimeters. Three trials will be performed, and the highest value will be recorded.
Measured: Baseline
Trunk Rotation Distance
Trunk rotation flexibility will be assessed in standing position with feet shoulder-width apart and arms extended at shoulder level. Participants will rotate the trunk maximally to the right and left without moving the pelvis or feet. The distance reached by the fingertips will be recorded using a wall-mounted scale in centimeters. At least two trials will be performed for each direction, and the highest value will be recorded.
Measured: Baseline
Plank Test Duration
The plank test will be used to assess anterior trunk muscle endurance. Participants will assume a prone bridge position supported on the forearms and toes, maintaining a straight line from head to heels. The position must be held without hip elevation or sagging. The test will be terminated when proper alignment is lost. Duration will be recorded in seconds.
Measured: Baseline
Side Plank Test Duration
The side plank test will be used to assess lateral trunk muscle endurance. Participants will lie on one side with the forearm perpendicular to the body and feet together. When ready, participants will lift the hips off the surface, supporting their body weight on the forearm and feet, maintaining a straight body alignment. The test will be terminated when alignment is lost. The test will be performed on both sides, and duration will be recorded in seconds.
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Mar 2026
- Study start1 Apr 2025
- Primary completion1 Jun 2025
- Study completion1 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Athletic PerformanceStudies of the same condition, open and under way.
- More trials run by Hacettepe 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
- 38 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hacettepe University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Sumeyye Zehra Guler, Ondokuz Mayıs University
- Investigators
- SÜMEYYE ZEHRA Z GÜLER, MSc, Principal investigator, Ondokuz Mayıs University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07447765
- Sponsor's protocol ID
- OMÜKAEK2024/172
- Status last verified
- Feb 2026
- First submitted
- 26 Feb 2026
- Last updated
- 5 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The individual participant data will not be shared because of participant privacy considerations and institutional policy
Study at a glance
From the registry record, last updated by the sponsor on 5 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigation of the Relationship Between Trunk Muscle Endurance and Flexibility and Athletic Performance in Elite Adolescent Tennis Players
- ClinicalTrials.gov ID
- NCT07447765
- Acronym / sponsor ID
- OMÜKAEK2024/172
- Keywords
- Endurance, Flexibility, Trunk, Sports performance
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 38 participants (actual)
- Lead sponsor
- Hacettepe UniversityUniversity, hospital or other
- Study start
- 1 Apr 2025 (actual)
- Primary completion
- 1 Jun 2025 (actual)
- Study completion
- 1 Jun 2025 (actual)
- First posted
- 3 Mar 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 aims to examine how trunk (core) muscle endurance and flexibility relate to athletic performance in elite adolescent tennis players aged 11-18 years. Tennis requires speed, balance, strength, coordination, and repeated high-intensity movements. The trunk region plays an important role in transferring force between the upper and lower body and in maintaining posture and stability during sports activities. However, there is limited research on how trunk physical characteristics influence performance in young elite tennis players.
Participants who actively compete in tennis tournaments and train regularly will complete a set of standardized tests assessing flexibility, trunk muscle endurance, balance, sprint speed, agility, and strength. The results will help researchers understand whether trunk flexibility and endurance are associated with better athletic performance. Findings may guide coaches and health professionals in designing training programs that improve performance and potentially reduce injury risk in young athletes.
Detailed description
This cross-sectional descriptive study investigates the relationship between trunk muscle endurance, trunk flexibility, and athletic performance parameters in elite adolescent tennis players. Tennis is a high-intensity intermittent sport requiring rapid acceleration, deceleration, directional changes, and explosive movements. Physical performance depends on multiple components, including strength, flexibility, endurance, and neuromuscular coordination. The trunk region is biomechanically important because it provides proximal stability, supports postural control, and facilitates force transmission between upper and lower extremities during sport-specific movements.
Despite evidence suggesting that trunk function contributes to athletic performance and injury prevention, limited research has focused specifically on elite adolescent tennis players, whose neuromuscular characteristics may differ due to growth and maturation. Therefore, this study aims to clarify associations between trunk physical characteristics and performance outcomes in this population.
Elite tennis players aged 11-18 years who train regularly and compete in official tournaments will be recruited. After informed consent procedures, participants will undergo standardized testing on regular training days following a supervised warm-up protocol.
Assessments include:
Demographic measures: age, sex, height, body weight, body mass index, training frequency, and years of tennis experience.
Flexibility tests: sit-and-reach, trunk lateral flexion, trunk rotation, and trunk extension.
Trunk muscle endurance tests: Biering-Sorensen test, plank test, and side plank test.
Athletic performance tests: Y Balance Test for dynamic balance, 20-meter sprint test for speed, T-drill test for agility, push-up test for upper-extremity endurance, medicine ball throw for upper-body power, and vertical jump for lower-extremity explosive strength.
All measurements will be conducted in the same environment by an experienced assessor using standardized procedures. Statistical analyses will evaluate correlations and predictive relationships between trunk endurance/flexibility variables and performance outcomes.
The results are expected to clarify whether trunk flexibility and endurance are key determinants of athletic performance in adolescent tennis players. Understanding these relationships may support evidence-based training strategies targeting trunk function to enhance performance and reduce injury risk.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Elite Adolescent Tennis Players | – | Other: Physical Performance AssessmentElite tennis players aged 11 to 18 years who actively compete and train regularly. Participants undergo standardized assessments of trunk muscle endurance, flexibility, and athletic performance. No intervention is applied; all measurements are observational and conducted under standardized conditions. |
Who may qualify
- Ages
- 11 to 18 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
- Study population
- Elite adolescent tennis players who are licensed athletes, actively training and competing in tennis clubs. Participants represent trained youth athletes with regular high-frequency training exposure and competitive experience.
Key inclusion criteria (6 listed)
- Aged between 11 and 18 years
- Elite tennis players actively competing in official tournaments
- Minimum of 3 years of regular tennis training experience
- Participating in tennis training at least 4 days per week
- Ability to understand and follow instructions
Key exclusion criteria (5 listed)
- History of musculoskeletal injury within the past 6 months affecting performance
- Presence of neurological, orthopedic, sensory, or motor disorders
- Any medical condition limiting physical activity
- Current pain that may affect test performance
- Pregnancy
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 |
|---|---|---|
| Physical Performance AssessmentParticipants undergo a standardized assessment protocol including trunk muscle endurance tests, flexibility measurements, balance, sprint, agility, strength, and power performance tests. No therapeutic or training intervention is applied. All procedures are observational and conducted under standardized testing conditions. | Other | Elite Adolescent Tennis Players |
Primary outcome
20-Meter Sprint Time
Time frame: Baseline
Sprint performance is assessed using a 20-meter sprint test. Participants perform a maximal sprint over a 20-meter distance, and time is recorded in seconds using a stopwatch. Lower time values indicate better sprint performance.
T-Drill Agility Test Time
Time frame: Baseline
Agility performance is measured using the T-drill test. Participants complete a standardized agility course involving forward sprinting, lateral shuffling, and backward running. Completion time is recorded in seconds. Lower time values indicate better agility performance.
Vertical Jump Height
Time frame: Baseline
Lower extremity explosive power is assessed using a vertical jump test. Jump height is measured in centimeters. Higher jump height values indicate better explosive strength performance.
Medicine Ball Throw Distance
Time frame: Baseline
Upper extremity explosive power is evaluated using a medicine ball throw test. The distance the ball is thrown is measured in centimeters. Greater distances indicate better upper body explosive strength performance.
Dynamic Balance Performance (Y Balance Test)
Time frame: Baseline
Dynamic balance is assessed using the Y Balance Test. Reach distances in the anterior, posteromedial, and posterolateral directions are measured and normalized to leg length (expressed as percentages). Higher percentage values indicate better dynamic balance performance.
7 secondary outcomes
Sit-and-Reach Test Distance (cm)
Time frame: Baseline
Biering-Sørensen Test Duration
Time frame: Baseline
Trunk Lateral Flexion Distance
Time frame: Baseline
Trunk Extension Distance
Time frame: Baseline
Trunk Rotation Distance
Time frame: Baseline
Plank Test Duration
Time frame: Baseline
Side Plank Test Duration
Time frame: Baseline
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 5 Mar 2026.
- Individual participant dataSharing planned: No. The individual participant data will not be shared because of participant privacy considerations and institutional policy
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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. This study is not recruiting at the moment.
SÜMEYYE ZEHRA Z GÜLER, MSc principal investigator
Ondokuz Mayıs 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 Athletic Performance and Physical Fitness, run by Hacettepe 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 6 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: finished, as of the sponsor's last update on 5 Mar 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?
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?
20-Meter Sprint Time (time frame: Baseline). The study lists 5 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 5 Mar 2026.