Inspiratory Muscle Strength and Diaphragm Thickness in People With Shoulder Pain in Tennis Players (SHOULDER-DIAPH)

Inspiratory Muscle Strength and Diaphragm Thickness in Tennis Players With and Without Shoulder Pain: A Case-Control Study

This observational case-control study will compare inspiratory muscle function and diaphragm morphology between individuals with shoulder pain and asymptomatic controls. Participants will be allocated into two groups according to the presence or absence of shoulder pain.

Inspiratory muscle strength will be assessed by measuring maximal inspiratory pressure (MIP) using standardized procedures. Diaphragm thickness will be evaluated bilaterally using ultrasound imaging at the end of inspiration (Tins) and at the end of expiration (Texp).

Pain intensity will be assessed using the Visual Analog Scale (VAS). Upper limb disability will be evaluated using the QuickDASH questionnaire, including the activities of daily living module and the optional sports module.

All outcomes will be assessed in a single evaluation session. Between-group comparisons will be performed to analyze differences in inspiratory muscle strength, diaphragm thickness, pain intensity, and upper limb disability between participants with and without shoulder pain.

Study Overview

• Status: Completed
• Conditions: Shoulder Pain

• Study Type: Observational
• Enrollment (Actual): 64

Contacts and Locations

Study Locations

• Spain
  • Madrid
    • Pozuelo de Alarcón, Madrid, Spain, 28223
      • Universidad Francisco de Vitoria

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Adult racket sport players aged 18 to 60 years, both with and without non-specific shoulder pain, recruited from local sports clubs and university-related facilities.

Description

Inclusion Criteria:

• Tennis player who suffered from non-specific shoulder pain
• Training at least two times per week
• Have experienced at least 1 episode of non-specific shoulder pain in the last month
• A positive result on the following diagnostic tests: Neer Test and Jobe Test

Exclusion Criteria:

• Having taken anti-inflammatories or muscle relaxants within the last 72 hours before the study
• Pregnancy
• Previous diagnosis of respiratory or neurological diseases
• Previous surgeries, fractures, and dislocations in the dominant shoulder
• Inability to follow instructions during the study
• All those for whom measuring maximum inspiratory pressure is contraindicated: unstable angina, recent myocardial infarction (within 4 weeks of the even or myocarditis, uncontrolled systemic hypertension, recent pneumothorax, post-lung biopsy surgery of less than one week, postoperative abdominal or genitourinary surgery of less than 6 months, and urinary incontinence

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Shoulder Pain Group; Participants with shoulder pain
Healthy Control Group; Participants without shoulder pain

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximal Inspiratory Pressure (MIP)	Maximal inspiratory pressure measured in cmH₂O using a respiratory pressure meter as an indicator of inspiratory muscle strength.	Single assessment at baseline visit
Diaphragm thickness at inspiration	Bilateral diaphragm muscle thickness measured by ultrasound imaging at the end of maximal inspiration (Tins)	Single assessment at baseline visit
Diaphragm thickness at expiration	Bilateral diaphragm muscle thickness measured by ultrasound imaging at the end of maximal expiration (Texp).	Single assessment at baseline visit

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain intensity (VAS)	Shoulder pain intensity assessed using the Visual Analog Scale (VAS) ranging from 0 to 10, where 0 = no pain and 10 = worst imaginable pain; higher scores indicate worse pain	Single assessment at baseline visit
Upper limb disability - activities of daily living	Upper limb disability in activities of daily living assessed using the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH-Core) questionnaire (11 items). Scores range from 0 to 100, where 0 = no disability and 100 = most severe disability; higher scores indicate worse disability.	Single assessment at baseline visit
Upper limb disability - sport	Upper limb disability in sport activities assessed using the Quick Disabilities of the Arm, Shoulder and Hand Sport module (4 ítems). Scores range from 0 to 100, where 0 = no disability and 100 = most severe disability; higher scores indicate worse disability.	Single assessment at baseline visit

Collaborators and Investigators

• Sponsor: Universidad Francisco de Vitoria

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2026
• Primary Completion (Actual): March 1, 2026
• Study Completion (Actual): March 20, 2026

Study Registration Dates

• First Submitted: January 3, 2026
• First Submitted That Met QC Criteria: January 3, 2026
• First Posted (Actual): January 12, 2026

Study Record Updates

• Last Update Posted (Actual): April 28, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Ultrasound imaging; Shoulder pain; diaphragm; Maximal inspiratory pressure
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Musculoskeletal Diseases; Joint Diseases; Arthralgia; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Shoulder Pain
• Other Study ID Numbers: SHOULDER-DIAPH-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: At this time, it is unclear whether individual participant data (IPD) will be shared. Data sharing will depend on institutional policies, ethical approvals, participant privacy considerations, and the feasibility of preparing de-identified datasets. A final decision will be made once data collection and analysis are completed.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No