An interventional study of High-Intensity Laser Therapy (HILT) and sham HILT in Exercise-Induced Muscle Fatigue, Fatigue Recovery and Health Adult Subjects, sponsored by University of Primorska. Not yet recruiting. Open to participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-05.
Sponsored by University of Primorska · Not applicable, Interventional, and Prevention
The goal of this clinical trial is to learn whether high-intensity laser therapy applied before exercise reduces the loss of handgrip strength, muscle stiffness, and pain after a tiring forearm exercise in healthy adults. This therapy delivers laser light through the skin to the underlying tissues.
The main questions this study aims to answer are:
Does laser therapy reduce the loss of handgrip strength after exercise compared with placebo treatment?
Does laser therapy reduce the increase in forearm muscle stiffness after exercise?
Does laser therapy reduce pain after exercise?
Researchers will compare active laser therapy with placebo laser treatment to assess whether the active treatment affects the muscles' response to exercise. Each participant will receive both treatments on separate visits. The order of treatments will be assigned by chance.
Participants will attend two laboratory visits at the Faculty of Health Sciences, University of Primorska, Slovenia. At one visit, they will receive active laser therapy over the muscles that bend the wrist in their dominant forearm. At the other visit, they will receive placebo treatment over the same area.
At each visit, participants will:
Rest before the initial measurements.
Have their handgrip strength, forearm muscle stiffness, and pain measured before treatment.
Receive active laser therapy or placebo treatment.
Wait five minutes before starting the exercise procedure.
Complete a wrist-strength test, then hold a muscle contraction at half of their maximum wrist-bending strength until they can no longer maintain the required force.
Have their handgrip strength, muscle stiffness, and pain measured again immediately after exercise and five and fifteen minutes later.
Handgrip strength will be measured by squeezing a handheld device. Muscle stiffness will be measured using a device that applies a brief, gentle mechanical tap to the skin over the muscle. Participants will rate their pain using a visual scale.
Participants will be asked to avoid strenuous physical activity for at least 24 hours before each visit and to keep their diet and regular supplement use similar before both visits.
The main outcome is the change in handgrip strength from before treatment to after exercise. Changes in muscle stiffness and pain will also be compared between the two treatments. Researchers expect active laser therapy to result in a smaller decrease in handgrip strength and smaller increases in muscle stiffness and pain than placebo treatment.
2,229 studies on the registry are indexed under Fatigue; 426 are open to participants now.
This study's planned enrollment of 30 is below the median of 54 across 1,757 interventional studies indexed under Fatigue.
Browse Fatigue studies →University of Primorska is the lead sponsor of 56 studies on the registry; 7 are open to participants now.
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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.
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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.
High-intensity laser therapy will be administered using the Platinum 4 device (Summus Medical Laser) over the wrist flexor muscles of the dominant forearm, from the medial epicondyle of the humerus toward the wrist. All four wavelengths available on the device will be used. Each participant will receive one active treatment session, followed by a five-minute interval before the muscle-fatiguing exercise procedure. Both the participant and the therapist will wear appropriate protective eyewear.
Device: High-Intensity Laser Therapy (HILT) and sham HILT
Sham high-intensity laser therapy will be administered over the wrist flexor muscles of the dominant forearm before the same muscle-fatiguing exercise procedure used in the active treatment condition. Each participant will receive one placebo treatment session, followed by a five-minute interval before the exercise procedure.
Device: High-Intensity Laser Therapy (HILT) and sham HILT
High-intensity laser therapy will be administered using the Platinum 4 device (Summus Medical Laser) over the wrist flexor muscles of the dominant forearm, from the medial epicondyle of the humerus toward the wrist. All four wavelengths available on the device will be used. Each participant will receive one active treatment session, followed by a five-minute interval before the muscle-fatiguing exercise procedure. Both the participant and the therapist will wear appropriate protective eyewear. Placebo high-intensity laser therapy will be administered over the wrist flexor muscles of the dominant forearm before the same muscle-fatiguing exercise procedure used in the active treatment condition. Each participant will receive one placebo treatment session, followed by a five-minute interval before the exercise procedure.
Handgrip Strength
Handgrip strength will be measured using a Baseline Lite handheld dynamometer on the dominant hand. Participants will be seated with the upper arm alongside the trunk, the elbow flexed to 90 degrees, the forearm in a neutral position, and the wrist in slight extension and ulnar deviation. Three maximal grip attempts will be performed at each assessment, and the highest value will be used for analysis. Changes from the pre-intervention baseline will be compared between active and placebo high-intensity laser therapy.
Time frame: At each of the two study visits: before the intervention (baseline), immediately after the fatiguing exercise, and 5 and 15 minutes after the fatiguing exercise. Visits will be separated by at least one week.
Wrist Flexor Muscle Stiffness
Muscle stiffness will be assessed using the MyotonPRO device at a predefined and marked anatomical measurement site over the wrist flexor muscles of the dominant forearm. The device applies a brief mechanical impulse to the skin and measures the tissue response to calculate muscle stiffness in newtons per meter (N/m). Higher values indicate greater stiffness. Changes from the pre-intervention baseline will be compared between active and placebo high-intensity laser therapy.
Time frame: At each of the two study visits: before the intervention (baseline), immediately after the fatiguing exercise, and 5 and 15 minutes after the fatiguing exercise. Visits will be separated by at least one week.
No study locations are listed for this record.
Plan to share: Undecided
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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