Clinical Research Directory

ACUTE EFFECTS OF HIGH-INTENSITY LASER THERAPY ON PAIN, MUSCLE STIFFNESS, AND GRIP STRENGTH IN HEALTHY ADULTS

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.