This prospective, randomized, double-blind, sham-controlled clinical trial aims to evaluate the efficacy of Capacitive and Resistive Energy Transfer (TECAR) therapy in patients with lateral epicondylitis. Participants will be randomly assigned to either a TECAR plus exercise group or a sham TECAR plus exercise group.

Both groups will receive a standardized home exercise program including elbow and wrist range-of-motion, stretching, eccentric strengthening, and handgrip strengthening exercises. The TECAR group will additionally receive active TECAR therapy, while the control group will receive sham TECAR treatment using the same device and treatment protocol without therapeutic energy delivery.

Outcome assessments will be performed by a blinded evaluator at baseline, immediately after treatment, and at 1- and 2-month follow-up visits. The study aims to determine whether TECAR therapy provides additional benefits in pain relief, functional improvement, and clinical outcomes when combined with exercise therapy in patients with lateral epicondylitis.

This study is planned as a prospective, randomized, double-blind, sham-controlled clinical trial involving patients diagnosed with lateral epicondylitis who present to the Physical Medicine and Rehabilitation Outpatient Clinic of Gaziantep City Hospital.

Participants will be randomly allocated into two groups using a computer-generated randomization method:

• Group 1: TECAR therapy + exercise group
• Group 2: Sham TECAR therapy + exercise group

All participants in both groups will receive a home-based exercise program consisting of elbow and wrist range-of-motion exercises, stretching exercises, eccentric strengthening exercises, and handgrip strengthening exercises. The exercise program will be explained in detail by a physiotherapist, and participants will be instructed to perform each exercise 10 repetitions, three times daily, throughout the treatment period. Adherence to the exercise program will be monitored through weekly telephone follow-ups and daily exercise log sheets completed by the participants at home. Compliance with regular splint use will also be monitored.

Outcome assessments will be conducted by a blinded evaluator at baseline, immediately after completion of treatment, and at the 1st and 2nd months following treatment.

TECAR Group (Active Treatment Group):

In addition to the exercise program, participants in the TECAR group will receive TECAR therapy consisting of a capacitive mode application at a frequency of 500 kHz for 5 minutes and a resistive mode application at a frequency of 500 kHz for 10 minutes, for a total treatment duration of 15 minutes per session. Treatment will be administered five sessions per week for two weeks, resulting in a total of 10 sessions. The capacitive mode will be applied to target superficial soft tissues, whereas the resistive mode will be used to affect deeper and higher-impedance connective tissues, such as the common extensor tendon.

Sham TECAR Group (Control Group):

Participants in the sham TECAR group will be treated using the same device, electrode, application area, treatment duration, and procedural protocol as the active treatment group. However, the device will be configured to deliver no therapeutic energy, thereby serving as a sham intervention.

Inclusion Criteria:

• Patients with lateral epicondylitis who have experienced elbow pain for at least 6 weeks and have at least two positive provocative tests (Cozen's, Mill's, or Maudsley's test).
• Age between 18 and 65 years.
• Unilateral pain and tenderness over the lateral epicondyle lasting longer than 6 weeks.
• Clinically diagnosed lateral epicondylitis.
• No cognitive impairment.
• Willingness to participate and provide informed consent.

Exclusion Criteria:

• History of interventional injection to the affected elbow within the previous 3 months.
• Receipt of physical therapy for the affected elbow within the previous 3 months.
• Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) within the previous 2 weeks.
• History of fracture or surgery involving the affected elbow.
• Presence of a chronic inflammatory disease.
• History of malignancy.
• Active infection.
• Pregnancy.
• Presence of a cardiac pacemaker or other electronic implant.
• Coagulation disorders.
• Cervical radiculopathy, entrapment neuropathy, or peripheral nerve injury.
• Body mass index (BMI) ≥ 35 kg/m².

The individual participant data (IPD) generated and analyzed during the current study will not be publicly shared. However, de-identified data may be made available by the corresponding author upon reasonable request, subject to ethical approval and institutional data-sharing policies.

Data will be available after publication of the study results.

De-identified individual participant data and supporting documents will be available to qualified researchers upon reasonable request to the principal investigator. Access will be granted for scientific research purposes after approval of the research proposal. Data will be shared through secure electronic transfer.

This study employs a double-blind design in which both participants and outcome assessors are blinded to treatment allocation. Participants will receive either active TECAR therapy or sham TECAR therapy using the same device, applicator, treatment duration, and treatment procedures. The sham intervention will mimic the active treatment without delivering therapeutic energy. Outcome assessments will be performed by an independent evaluator who will remain unaware of group allocation throughout the study.