Can radio waves ease muscle pain? new trial seeks answers

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Individuals with Muscle Injury Inclusion Criteria: * Age over 18 years. * Athletes: amateur soccer players or sprinters with regular, systematic training. * Suspected Grade I or II hamstring strain. * Cessation of training due to injury. * No surgical intervention in the previous year (for initial assessment as potential participants). Exclusion Criteria: * History of injury to the same muscle (ipsilateral side) within the last 6 months. * Other injury to the posterior aspect of the thigh. * Other injuries or chronic pain in the trunk or lower limbs. * Use of non-steroidal anti-inflammatory drugs (NSAIDs) in the 3 months prior to the injury. Individuals with Acute Low Back Pain Inclusion Criteria: * Age over 18 years. * Pain located between the lower ribs and the gluteal folds (top of the buttocks). * Pain occurred on fewer than half of the days over the preceding six months. * Pain intensity $\\ge$ 6/10 on the Visual Analogue Scale (VAS). * Pain related to one or more of the following: * Lumbar facet joints * Sacroiliac joints * Lumbar intervertebral discs * Muscles, tendons, or ligaments of the lumbar and sacral region * Other bony structures of the lumbar spine * Discontinuation of non-steroidal anti-inflammatory drugs (NSAIDs) or analgesics: * 1 day prior to measurement * 48 hours after measurement Exclusion Criteria: * Radiographic evidence of inflammatory disease affecting the spine. * Spinal fracture. * Significant genetic structural abnormality of the spine. * Pregnancy. * Psychiatric disorders. * Receipt of systemic medication or treatment in the last 3 months. * Presence of neurological deficits (sensory, motor, or reflexes). * Receipt of TENS or TECAR therapy within the last year. Individuals with Chronic Low Back Pain Inclusion Criteria: * Episodes of low back pain (between the lower rib margin and the gluteal fold) for at least half of the days during the last 6 months. * Pain intensity $\\ge$ 20% on the Visual Analogue Scale (VAS). Exclusion Criteria: * Spinal stenosis. * Radiographic evidence of inflammatory disease affecting the spine. * Vertebral fracture. * Presence of spondylolisthesis or spondylolytic lesion (spondylolysis). * Significant genetic structural abnormality of the spine. * Daily, severe low back pain. * Pregnancy. * Use of medications that might influence heart rate or blood pressure. * Psychiatric disorders.