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Volleyball PlayersNCT07784517

Diaphragmatic Facilitation and Upper Extremity Performance in Volleyball Players

A study testing Diaphragmatic Facilitation in people with Volleyball Players, run by Istinye University at 1 site in Turkey (Türkiye).

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The diaphragm contributes to both respiration and trunk stabilization. Effective diaphragmatic function may support postural control, force transfer, and upper extremity performance during dynamic activities. Read more about this study

Who is it for?
Ages 18 to 30 yearsHealthy volunteers can take part
Conditions the study is for
Volleyball Players
What is being tested?
Diaphragmatic Facilitation
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
50 participants
Where
1 siteTurkey (Türkiye)
Study dates
30 Aug 2026to 30 Nov 2026
Phase
Interventional
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 30 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Aged between 18 and 30 years.
  • Regularly participating in volleyball for at least one year.
  • Training at least twice per week or actively participating in volleyball at the league or tournament level.
  • No history of a serious upper extremity or trunk injury within the previous six months, i-including injuries affecting the shoulder, scapular region, or spine.
  • No diagnosed chronic respiratory disease, including asthma, chronic obstructive pulmonary disease, or allergic bronchitis.
  • Willing and able to provide written informed consent.

Who cannot join

  • History of surgery involving the upper extremity, spine, or trunk within the previous six months, including shoulder arthroscopy or spinal disc surgery.
  • Presence of an active musculoskeletal injury, including tendinopathy, bursitis, or ligament injury.
  • Presence of a diagnosed respiratory disease, including asthma, chronic obstructive pulmonary disease, or bronchiectasis.
  • Presence of a diagnosed postural or spinal deformity that may affect study assessments, including scoliosis, clinically significant kyphosis, or clinically significant lordosis.
  • History of a neurological or cardiovascular disease.

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, 1 recruiting
  • Istinye University

    Istanbul, 34010

    Kubra Kardes, Asst.Prof, 05387115631, kubrakoce@gmail.com

    Recruiting

Other trials in Turkey (Türkiye)

About this study

Official title: Immediate Effects of Diaphragmatic Facilitation on Upper Extremity Performance in Volleyball Players

The diaphragm contributes to both respiration and trunk stabilization. Effective diaphragmatic function may support postural control, force transfer, and upper extremity performance during dynamic activities. However, evidence regarding the immediate effects of manual diaphragmatic facilitation on upper extremity performance in athletes remains limited.

This study aims to investigate the immediate effects of manual diaphragmatic facilitation on upper extremity performance and respiratory function in actively participating volleyball players. Participants will receive an approximately 15-minute session of manual diaphragmatic facilitation. Pulmonary function, respiratory muscle strength, and upper extremity strength, stability, and endurance will be assessed immediately before and after the intervention. Assessments will include spirometry, maximal inspiratory and expiratory pressures, the Medicine Ball Throw Test, the Closed Kinetic Chain Upper Extremity Stability Test, and the Scapular Endurance Test.

Being tested
Diaphragmatic Facilitation, Sham Facilitation
Keywords
Diaphragm, Diaphragmatic Facilitation, Volleyball Players, Upper Extremity Performance, Respiratory Function, Respiratory Muscle Strength, Manual Therapy, Sports Physiotherapy
Medical subject headings
Respiratory Aspiration

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Diaphragmatic FacilitationOther

    Following a standardized dynamic warm-up, participants in the intervention group will receive a single session of manual resisted diaphragmatic facilitation.

  • Sham FacilitationOther

    Participants in the control group will complete the same dynamic warm-up protocol, followed by a sham intervention consisting of superficial, non-facilitatory palpation and general breathing instructions.

Study groups in NCT07784517
Study groupRoleWhat they receive
Intervention GroupExperimentalDiaphragmatic Facilitation Group
Receives: Other: Diaphragmatic Facilitation
Control GroupExperimentalSham Control Group
Receives: Other: Sham Facilitation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Forced Vital Capacity

    Forced vital capacity is the maximum volume of air that a participant can forcibly exhale after taking the deepest possible breath. It will be measured by spirometry and recorded in liters. Higher values generally indicate greater ventilatory capacity, whereas lower values may indicate reduced pulmonary capacity or expiratory limitation.

    Measured: 4 weeks

  2. Forced Expiratory Volume in One Second

    Forced expiratory volume in one second is the volume of air that a participant can forcibly exhale during the first second of a forced expiratory maneuver. It will be measured by spirometry and recorded in liters. Higher values generally indicate better expiratory airflow, whereas lower values may indicate reduced expiratory airflow.

    Measured: 4 weeks

  3. Ratio of Forced Expiratory Volume in One Second to Forced Vital Capacity

    The ratio of forced expiratory volume in one second to forced vital capacity represents the proportion of the forced vital capacity exhaled during the first second of a forced expiratory maneuver. It will be calculated from spirometric measurements and reported as a percentage. Higher values generally indicate a greater proportion of air expelled during the first second, whereas lower values may indicate expiratory airflow limitation. The results will be interpreted with consideration of age- and sex-appropriate reference values.

    Measured: 4 weeks

  4. Maximal Inspiratory Pressure

    Maximal inspiratory pressure will be used to assess inspiratory muscle strength, primarily reflecting the function of the diaphragm and other inspiratory muscles. The measurement will be repeated three times, and the highest valid value will be recorded in centimeters of water. A higher absolute pressure value indicates greater inspiratory muscle strength, whereas a lower absolute pressure value indicates weaker inspiratory muscle strength.

    Measured: 4 weeks

  5. Maximal Expiratory Pressure

    Maximal expiratory pressure will be used to assess expiratory muscle strength, particularly the strength of the abdominal and other expiratory muscles. The measurement will be repeated three times, and the highest valid value will be recorded in centimeters of water. A higher pressure value indicates greater expiratory muscle strength, whereas a lower pressure value indicates weaker expiratory muscle strength.

    Measured: 4 weeks

  6. Medicine Ball Throw Distance

    Upper extremity explosive power will be assessed using the Medicine Ball Throw Test. The participant will sit with the back supported against a wall and the legs extended and will be instructed to throw the medicine ball as far as possible. Throwing distance will be measured in meters. A longer distance indicates greater upper extremity explosive power, whereas a shorter distance indicates lower explosive power.

    Measured: 4 weeks

  7. Closed Kinetic Chain Upper Extremity Stability Test Score

    Upper extremity stability, strength, power, and endurance will be assessed using the Closed Kinetic Chain Upper Extremity Stability Test. The participant will assume a push-up position with the hands placed on two markers positioned 90 centimeters apart. The participant will alternately move each hand across the body to touch the opposite marker during the specified test period. The total number of valid touches will be recorded. A higher number of touches indicates better upper extremity functional performance and stability, whereas a lower number indicates poorer performance.

    Measured: 4 weeks

  8. Scapular Muscular Endurance Time

    The functional endurance of the scapular stabilizing muscles will be assessed using the Scapular Muscular Endurance Test. An appropriately sized wooden rod will be positioned between the participant's elbows while both scapulae are maintained in a neutral position. The length of time for which the participant can maintain the standardized test position will be recorded in seconds. A longer duration indicates greater scapular muscular endurance, whereas a shorter duration indicates lower scapular muscular endurance.

    Measured: 4 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted25 Aug 2026
  2. Study start30 Aug 2026
  3. Primary completion15 Nov 2026 (estimated)
  4. Study completion30 Nov 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
This study is designed as a two-arm, randomized, sham-controlled trial using stratified randomization. Thirty volleyball players who provide informed consent will be allocated to either the Diaphragmatic Facilitation Group or the Sham Control Group.
Masking
Double blind
Who is masked
Participant, Outcomes assessor
Enrolment
50 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07784517
Sponsor's protocol ID
2025/07
Status last verified
Sep 2026
First submitted
21 Aug 2026
Last updated
1 Oct 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A study testing Diaphragmatic Facilitation in people with Volleyball Players, run by Istinye 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: looking for participants now, as of the sponsor's last update on 1 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?

Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Forced Vital Capacity (time frame: 4 weeks). The study lists 8 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 1 Oct 2026.

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