An interventional study of massage gun and heat treatment in Healthy Participants, sponsored by University of Zurich. Recruiting at 1 site in Switzerland. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-11-19.
Sponsored by University of Zurich · Not applicable, Interventional, and Treatment
The purpose of this study is to evaluate the changes in the stiffness of the masseter muscle (a jaw muscle) before and after two types of treatment: applying commercial heat pads or using a commercial massage gun.
We will measure the muscle stiffness on the surface of the muscle using a special ultrasound probe, with a method called shear wave elastography.
When this muscle is too stiff, it's often linked to jaw pain and problems with the jaw joint - a condition known as Temporomandibular Disorder (TMD).
The goal is to find better treatment options for people with TMD and to collect data using this imaging technique.
In our study, participants will be randomly assigned to one of two groups. This is important to ensure reliable results and is called randomization.
The two groups are as follows:
Group A:
First, the stiffness of the masseter muscle in the cheek is measured using ultrasound. Then, we will assess the mouth opening, the muscle's sensitivity to pressure, bite force, and chewing efficiency using several short tests. After that, the masseter muscle will be treated with a massage gun with a soft attachment for 2 minutes. All tests will be repeated after the treatment.
Group B:
First, the stiffness of the masseter muscle in the cheek is measured using ultrasound. Then, we will assess the mouth opening, the muscle's sensitivity to pressure, bite force, and chewing efficiency using several short tests. After that, the masseter muscle will be treated with a heat pad for 20 minutes. The heat pad will be held in place with a strap, and participants may sit and read or relax during the treatment. All tests will be repeated after the treatment.
Each participant will receive both treatments (massage gun and heat pad), but in a different order depending on group assignment. There will be a two-week washout phase between the two treatments to ensure that the effects of the first treatment do not influence the second.
438 studies on the registry are indexed under Fever; 55 are open to participants now.
This study's planned enrollment of 40 is below the median of 123 across 271 interventional studies indexed under Fever.
Browse Fever studies →University of Zurich is the lead sponsor of 1,049 studies on the registry; 133 are open to participants now.
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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.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The massage gun is the new treatment (experimental). Heat treatment is already commonly used for muscle stiffness and could be considered an active comparator. However, since its specific effects on the masseter muscle are not well established, it may also be classified as experimental.
Device: massage gun · Device: heat treatment
The massage gun is the new treatment (experimental). Heat treatment is already commonly used for muscle stiffness and could be considered an active comparator. However, since its specific effects on the masseter muscle are not well established, it may also be classified as experimental.
Device: massage gun · Device: heat treatment
The massage gun used in this study will be equipped with a soft attachment designed for use on the face, ensuring safe and comfortable application to the masseter muscle.
The heat treatment will be applied for 20min.
Also known as: heat pad, heating pad
Masseter muscle stiffness
Muscle stiffness will be assessed using shear wave elastography (SWE) via ultrasound. Results will be reported in kilopascals (kPa) and/or meters per second (m/s).
Time frame: The time from the first appointment to the second (final) appointment will be two weeks.
Algometry of the Masseter Muscle
Algometry is the quantitative assessment of pain sensitivity, performed using a pressure algometer to determine pressure pain thresholds (PPTs) at specific anatomical sites.
Time frame: The time from the first appointment to the second (final) appointment will be two weeks.
mouth opening
The mouth opening will be measured with a ruler.
Time frame: The time from the first appointment to the second (final) appointment will be two weeks.
maximum bite force
Maximum bite force can be measured with a bite sensor or an occlusal force-meter, that is placed between the patients' teeth. The patient is requested to bite on the bite sensor as hard as possible. Bite force is usually measured in Newton.
Time frame: The time from the first appointment to the second (final) appointment will be two weeks.
chewing efficiency
Chewing efficiency will be measured with a two-coloured chewing gum. The person tested will take two chewing gums simultaneously, both with different colour. The gums must be chewed 20 times and after that the mass is pressed on a glass plate and is analysed how much the colours have mixed.
Time frame: The time from the first appointment to the second (final) appointment will be two weeks.
Plan to share: Yes — Upon reasonable request from another research group, the raw IPD will be anonymized and shared.
Time frame: starting 6 months after publication
No publications or documents are linked to this record.
Start is estimated for Nov 2025; primary completion for Mar 2026, 4 months later.
Of 66 non-industry interventional studies with no phase under Fever, half reached primary completion within 17 months of starting (the median), counting those still running; a quarter within 7 and three quarters within 30. This study's planned 4 months is below that.
Counting every sponsor, half of 74 studies reached it within 16 months; a quarter within 6 and three quarters within 30.
How these figures are worked out, and which studies are left out of them.
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