ClinicalTrials.gg
RecruitingNCT07275164Updated Feb 13, 2026

HIIT for Inflammatory-driven Shoulder Pain.

An interventional study of High intensity interval training (HIIT) in Chronic Shoulder Pain, Rotator Cuff Related Shoulder Pain and Frozen Shoulder, sponsored by Universiteit Antwerpen. Recruiting at 1 site in Belgium. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-02-13.

Sponsored by Universiteit Antwerpen · Not applicable, Interventional, and Other

From the registry’s dates

  • Primary completion was expected by Apr 2026, 7 months ago, but the record still lists the study as recruiting.
  • Started Dec 2025; still recruiting 11 months later.
Phase
Not applicable
Study type
Interventional
Enrollment
30
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

This feasibility study investigates whether high-intensity interval training (HIIT) is feasible and acceptable for individuals with long-term shoulder pain where low-grade inflammation is suspected. Many patients do not recover fully with current local treatments, and systemic factors such as inflammation, and metabolic changes, additionally disturbances in the functioning of the nervous system often seem to play a role. HIIT is a time-efficient form of exercise that has been shown to improve inflammation and metabolic values and positively influence the balance of the nervous system. In this feasibility study, the investigators are enrolling 15 individuals with persistent shoulder pain (diagnosed with rotator cuff-related shoulder pain or frozen shoulder) with >3 months of symptoms, and 15 individuals without shoulder complaints. All participants will undergo measurements of inflammatory levels, glycosylated hemoglobin (HbA1c), blood pressure, body composition, pain sensitivity tests, and complete questionnaires about autonomic complaints and quality of life. Participants with shoulder pain will also perform one personalized HIIT session on a cycle ergometer. The investigators will assess whether participants accept a systemic intervention for their shoulder pain, if they are cooperative, and how they feel about the session; additionally, any side effects will be recorded. The aim is to determine whether HIIT is practically feasible and safe for this group and whether there are indications that systemic factors such as inflammation and nervous system function are associated with persistent shoulder pain. The outcome will determine whether follow-up research with a larger study is worthwhile.

Read the detailed description

Persistent musculoskeletal shoulder pain, such as rotator cuff-related complaints and frozen shoulder, is common and often leads to long-term limitations and reduced quality of life. Despite available treatment options, including exercise therapy, manual techniques and infiltrations, a significant group of patients do not experience full recovery. Growing scientific evidence suggests that chronic low-grade inflammation, metabolic disorders, such as insulin resistance or obesity, autonomic dysfunction, and changes in somatosensory processing contribute to the persistence of complaints. Within this framework, physical activity is receiving more attention as a systemic intervention. High-intensity interval training (HIIT) in particular appears to have a pronounced effect on inflammatory levels, metabolic parameters, cardiovascular function, and pain modulation in various populations. HIIT also offers practical advantages due to its short duration and higher efficiency compared to traditional endurance training. Therefore, the primary aim of the current study is to investigate the feasibility of a HIIT protocol in individuals with chronic inflammatory-driven shoulder pain. This investigation includes recruitment rate, adherence, acceptance, satisfaction, motivation, safety, and practical feasibility. A secondary aim of the current study is to explore differences between individuals with shoulder pain and asymptomatic controls in terms of inflammatory markers (C-Reactive Protein), metabolic parameters (HbA1c, blood pressure, body composition), autonomic functions (self-reported symptoms, heart rate variability) and somatosensory functions (pressure pain thresholds, temporal summation and conditioned pain modulation). This is a cross-sectional feasibility study with 30 participants (15 individuals with chronic shoulder pain and 15 asymptomatic controls). The individuals with shoulder pain participate in two sessions: a maximal exercise test on a cycle ergometer (to determine VO₂max and Wmax) and a combined assessment and HIIT session. Asymptomatic controls undergo a single assessment session. The HIIT protocol consists of five one-minute intervals of cycling at 100% of the individually determined VO₂max capacity, alternating with one minute of active rest at 50% of this capacity. The total exercise time is approximately 20 minutes. The session is supervised by an experienced physiotherapist in a research setting (MOVANT, University of Antwerp). Clinical parameters that will be assessed and stored in REDCap include demographics, shoulder pain and disability (SPADI), pain intensity (VAS), quality of life (EQ-5D), inflammation (c-reactive protein), nutrition-related inflammatory index, metabolic markers (glycosylated hemoglobin, blood pressure and body composition through bioelectrical impedance), autonomic functions (self-reported autonomic symptoms and Heart Rate Variability), and somatosensory processing (pressure pain thresholds, temporal summation, and conditioned pain modulation). Results are mainly reported descriptively, with confidence intervals to estimate effect sizes. As this is a pilot study, the design is not powered for formal hypothesis testing.The study aims to investigate whether HIIT is feasible and safe in this population and to provide initial indications of the role of systemic processes in the persistence of shoulder complaints. The results may form the basis for larger randomized studies and may contribute to a paradigm shift towards systemic approaches in the treatment of musculoskeletal pain.

02

Conditions studied

  • Chronic Shoulder Pain
  • Rotator Cuff Related Shoulder Pain
  • Frozen Shoulder
  • Shoulder Adhesive Capsulitis
  • Shoulder Pain

Keywords

  • low-grade inflammation
  • chronic shoulder pain
  • autonomic dysfunction
  • metabolic syndrome
  • frozen shoulder
  • rotator cuff related shoulder pain
  • high intensity interval training
03

In context

Bursitis

383 studies on the registry are indexed under Bursitis; 111 are open to participants now.

This study's planned enrollment of 30 is below the median of 44 across 346 interventional studies indexed under Bursitis.

Browse Bursitis studies →

Lead sponsor

Universiteit Antwerpen is the lead sponsor of 135 studies on the registry; 32 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

Shoulder pain group

  • Shoulder pain > 3 months
  • Diagnosis of rotator cuff related shoulder pain or frozen shoulder
  • Understanding Dutch in speaking and writing.

Control group

o Understanding Dutch in speaking and writing

Exclusion criteria

Exclusion Criteria:

Shoulder pain group

  • \<18 years
  • Shoulder surgery or trauma in past year
  • Neurological, cancer, or neuromuscular disease
  • Osteoarthritis, cervical or AC joint pathology
  • Heavy physical exertion \<48h before testing

Control group

  • \<18 years
  • recent or recurrent neck/shoulder pain
  • systemic or neurological disease
  • psychiatric disorders
  • pregnancy/breastfeeding
  • pain medication \<48h before test
05

Study design

Phase
Not applicable
Primary purpose
Other
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
30 participants (estimated)

Study arms

  • Experimental
    High intensity interval training (HIIT)

    One 20-minute HIIT session (5x1 min at VO₂max with 1 min recovery at 50% VO₂max) on cycle ergometer

    Other: High intensity interval training (HIIT)

Interventions

  • OtherHigh intensity interval training (HIIT)

    One 20-minute HIIT session (5x1 min at VO₂max with 1 min recovery at 50% VO₂max) on cycle ergometer.

06

What researchers measure

Primary outcomes

  1. Participant acceptance and satisfaction

    Participant acceptance and satisfaction of the HIIT-session will be assessed with an adapted short questionnaire based on the total shoulder arthroplasty postoperative satisfaction questionnaire.

    Time frame: Immediately after the HIIT training session

  2. HIIT protocol adherence

    HIIT protocol adherence will be assessed by determining the percentage of HIIT-protocol completers and registration of protocol adjustments.

    Time frame: During the training session

  3. Intrinsic motivation

    Intrinsic motivation of the participants with shoulder pain will be assessed using the intrinsic motivation inventory (IMI). From this questionnaire only the following domains will be questioned: interest/enjoyment, effort, and value/usefulness. The questions will be adapted specific to the current study, as recommended.

    Time frame: Immediately after the training session

  4. Study recruitment rate

    Study recruitment rate will be determined by dividing the number of participants by the number of contacted individuals. Reasons for non-participation will be assessed with preset response options.

    Time frame: During the study period

  5. Full protocol conduction

    Assessment of full protocol conduction will be assessed by registering preparation time, protocol duration, and issues with equipment and location.

    Time frame: Immediately after the assessment and training session

  6. Adverse events

    The severity of the adverse event will be determine based on the Common Terminology Criteria for Adverse Events (CTCAE).

    Time frame: Up to 3 days after training and assessment

Secondary outcomes

  1. Shoulder pain and disability

    The shoulder pain and disability index (SPADI) will be used, this is a self-reported index that consists of 13 items in two domains (pain (5 items) and disability (8 items)). A percentage ranging from 0 (no pain or disability) to 100 (worst pain or disability) will be used to present the pain and disability experienced by the participants. The SPADI has been found valid and reliable in evaluating pain and disability in shoulder disorders.

    Time frame: Baseline

  2. Pain intensity

    Pain intensity will be measured by a visual analogue scale. Participants will be asked to rate their pain on a 10 cm line by drawing a vertical mark on that line. The left end of the line represents 'No pain' (0 cm) and the right end 'Most severe pain' (10 cm). The scoring is the distance (in millimeter) from the left end of the line to the vertical mark of the participant. Participants must rate their shoulder pain for three moments: current and minimal and maximal pain during the last week. The VAS has been found valid and reliable.

    Time frame: Baseline

  3. Health-related quality of life

    Health-related quality of life will be assessed with the EQ-5D. The EQ-5D is a standardized, validated measure comprising five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension is rated on a five-level ordinal scale (from 'no problems' to 'extreme problems'), offering improved sensitivity and reduced ceiling effects compared to the earlier 3-level version. Additionally, the EQ-5D includes a visual analogue scale (EQ-VAS), on which participants rate their overall health on a scale ranging from 0 ("the worst health you can imagine") to 100 ("the best health you can imagine"). The psychometric properties of the EQ-5D are excellent in a broad range of populations, conditions and settings. Utility scores will be calculated using the Dutch EQ-5D value set.

    Time frame: Baseline

  4. C-reactive protein level

    C-reactive protein (CRP) level will be measured by the QuikRead go easy CRP, a highly sensitive tool. With 10 μL blood (fingerprick) the level of CRP between 1 and 120 mg/L can be determined within 5 minutes. This tool has been found reliable.

    Time frame: Baseline

  5. Adapted dietary inflammatory index

    The adapted dietary inflammatory index (ADII) will be based on data acquired through the food frequency questionnaire (FFQ), as conducted previously. The ADII is a literature-derived index that summarizes an individual's diet on the continuum from maximally anti-inflammatory to maximally pro-inflammatory. ADII was calculated by multiplying the dietary inflammatory weights of the dietary components by the daily intake.

    Time frame: Baseline

  6. Glycosylated hemoglobin

    Glycosylated hemoglobin (HbA1c) will be measured with the A1CNOW+ tool. The A1CNOW+ is a tool that measures the A1c and total hemoglobin and determines the percentage HbA1c over the last 90 days, which is valid and reliable.

    Time frame: Baseline

  7. Blood pressure

    Blood pressure will be measured using an automated office blood pressure monitor in a seated position in a quit examination room. Both diastolic and systolic pressure will be recorded.

    Time frame: Baseline

  8. Body composition

    Body composition will be determined by the InBody 770® (InBodyUSA, Cerritos, CA), more specifically %body fat and fat free mass of the participants will be determined.

    Time frame: Baseline

  9. Self-reported autonomic symptoms

    Self-reported autonomic symptoms will be assessed by the composite autonomic symptom score 31 (COMPASS-31), which has 31 questions in six domains (orthostatic intolerance, vasomotor, secretomotor, gastrointestinal, constipation, bladder, and pupillomotor). Total score ranges from 0 to 100 because of summation of the six subdomains.

    Time frame: Baseline

  10. Vasomotor function

    Vasomotor function of the autonomic nervous system (parasympathetic branch) will be measured with the help of resting heart rate variability (HRV), which will be measured using a chest strap (polar H10). The root mean square of successive RR-interval differences (RRSMD), mean RR interval, standard deviation of all normal RR intervals (SDNN), and percentage of successive RR intervals that differ by more than 50 ms (pNN50) will be determined.

    Time frame: Baseline

  11. Primary and secondary hyperalgesia

    Primary and secondary hyperalgesia (in kg/cm2) will be assessed by pressure pain thresholds (PPTs). The PPTs will be determined at both affected and unaffected (shoulder pain group) and dominant and non-dominant (control group) shoulders and affected side (shoulder pain group) or dominant (control group) quadriceps muscle.

    Time frame: Baseline

  12. Temporal summation

    Temporal summation will be induced with a train of 10 repeated pressure stimuli at the quadriceps muscle at the affected (shoulder pain group) or dominant (control group) side using a digital algometer. Pressure will be applied with 2 kg/s with 1-second interstimulus intervals. The pressure for temporal summation will be the mean PPT previously determined for the quadriceps. Participants rate their pain intensity on a NRS (0-10) after the first, fifth, and tenth repetition of the train stimuli. Temporal summation is calculated as the difference in pain intensity between the tenth and the first pulse

    Time frame: Baseline

  13. Conditioned pain modulation

    The test stimulus consists of mechanical pressure pain elicited (PPT). The conditioning stimulus consists of ischemic occlusion and will be applied to the unaffected (shoulder pain group) or non-dominant (control group) arm with an inflatable air cuff (Boso Profitest). The absolute conditioned pain modulation effect will be calculated as the difference between the PPT at baseline and the PPT with conditioning stimulus, while the relative effect will be calculated as follows: (PPT at baseline - PPT with conditioning stimulus) / PPT at baseline.

    Time frame: Baseline

Other outcomes

  1. Gender

    The gender of the participant

    Time frame: Baseline

  2. Age

    The age of the participant

    Time frame: Baseline

  3. Job status

    The job status of the participant

    Time frame: Baseline

  4. Alcohol abuse

    The alcohol abuse status of the participant

    Time frame: Baseline

  5. Smoking status

    Smoking status of the participant

    Time frame: Baseline

  6. Comorbidities

    Presence and type(s) of comorbidities of the participant

    Time frame: Baseline

  7. Disorder characteristics

    Characteristics of the disorder the participant presents with

    Time frame: Baseline

07

Study locations

1 of 1 sites recruiting
  • Universiteit Antwerpen
    Wilrijk, 2610, Belgium
    Recruiting
    • Michel Mertens, PhD · Contactmichel.mertens@uantwerpen.be · +32 3 265 89 76
    • Mira Meeus, PhD · Sub investigator
    • An De Groef, PhD · Sub investigator
    • Jonas Verbrugghe, PhD · Sub investigator
    • Sebastiaan Dalle, PhD · Sub investigator
    • Lisa Van Hecke · Sub investigator
    • Niels Polfliet · Sub investigator
    • Chloe Van Der Auwera · Sub investigator
    • Lennert Moons · Sub investigator
    • Tom Philips · Sub investigator
    • Levi Peeters · Sub investigator
08

References and documents

Individual participant data

Plan to share: Yes — The results of the food frequency questionnaire, which is part of the nutritional inflammatory index, will be shared with the developers of the questionnaire for optimization of the questionnaire. Furthermore, all data can be shared with other researchers upon reasonable request. Data will not be publicly available.

Time frame: It will only be available upon reasonable request.

Access criteria: The requested data will be send to the requester by the PI of the study and a data sharing agreement will be signed by both parties.

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Dec 2025 (actual). Primary completion is estimated for Apr 2026, 3 months after the start.

Of 217 non-industry interventional studies with no phase under Bursitis, half reached primary completion within 10 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 17. This study's planned 3 months is below that.

Counting every sponsor, half of 217 studies reached it within 10 months; a quarter within 5 and three quarters within 17.

How these figures are worked out, and which studies are left out of them.

Registered
Nov 17, 2025
First posted
Dec 10, 2025
StartActual
Dec 10, 2025
Primary completionEst.
Apr 1, 2026
CompletionEst.
Oct 2026
Last update
Feb 13, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Feb 13, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07275164
Responsible party
Michel GCAM Mertens (Dr., Universiteit Antwerpen) — Principal investigator
First posted
Dec 10, 2025
Start date
Dec 10, 2025
Primary completion
Apr 1, 2026 (estimated)
Completion
Oct 2026 (estimated)
Last update
Feb 13, 2026

Study contacts

Michel Mertens, PhD
Contact
michel.mertens@uantwerpen.be
+32 3 265 89 76
Mira Meeus, PhD
Contact
mira.meeus@uantwerpen.be
Michel Mertens, PhD
principal investigator · Universiteit Antwerpen

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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