Tennis elbow, also known as lateral epicondylitis, is a pathology of the enthesis of tendons attaching near or directly on the lateral epicondyle of the humerus. Lateral epicondylitis is characterized by progressive pain localized on the outer edge of the elbow, reproduced by palpation, stretching, and/or isometric resistance contraction of the lateral epicondylar muscles. This pain may be accompanied by a deficit in muscle strength compared to the opposite side. The diagnosis is mainly clinical, although imaging tests may be considered in cases of doubt or if the pain persists despite appropriate therapeutic management. There is no specific treatment for tennis elbow that has been proven to be effective. However, starting treatment can speed up the return to sporting activities and prevent the condition from becoming chronic. This study aims to fill this gap by evaluating the effectiveness of a simple and natural treatment for the symptoms of tennis elbow: a roller equipped with a ball that facilitates self-massage with simultaneous diffusion of an essential oil-based emulsion.

Objective : To evaluate the analgesic and functional efficacy of a roller device that facilitates mechanical self-massage through the simultaneous diffusion of an emulsion composed mainly of essential oils in the treatment of chronic lateral epicondylitis.

Participants : Lateral epicondylitis lasting more than 3 months, isolated and confirmed by clinical examination and ultrasound, in subjects aged 18 years and older.

Procedures : Clinical examination to confirm the diagnosis of lateral epicondylitis (specific tests for pain on stretching and palpation, elimination of differential diagnoses), and ultrasound.

• Assessment using the PRTEE (Patient-Rated Tennis Elbow Evaluation) questionnaire (French version).
• Assessment using the numerical pain rating scale (0-10),
• Assessment of the location associated with the pain.
• Treatment instructions: 2 daily applications, morning and evening, involving mechanical friction of the epicondylar and muscular area for 2 minutes, i.e., a total of 2 x 70 roller rotations (70 roller rotations on the tendon and 70 roller rotations on the muscle) for 3 months. The same parameters will be assessed one month, two months, and three months after use of the device. Patients will be randomized to receive either an Articulations & Muscles (AM) roller or a Control (T) roller.
• Assessment of analgesic and anti-inflammatory consumption. Each participant will be given a daily monitoring diary to record their analgesic and anti-inflammatory intake.

6.1 Type of Study

International multicenter interventional, single-blind, randomized, controlled, parallel-group study in centers with practitioners trained in diagnosis.

Randomization is achieved by dedicated software.

6.2 Primary Endpoint

• Improvement in PRTEE questionnaire scores [10, 11, 12] before and after application of the Control roller (T) or the Joints & Muscles roller (AM) combined with simultaneous delivery of an emulsion composed notably of essential oils. An improvement of 20% [13] (minimum clinically significant threshold for epicondylitis) in the PRTEE score will be used as the success criterion.
• Improvement of the score at 1 month, 2 months, and 3 months.

6.3 Secondary Endpoints

• Reduction in pain assessed by a numerical rating scale (0-10).
• Reduction in analgesic and anti-inflammatory consumption.
• Assessment of device tolerability.

6.4 Calculation of the number of participants

The primary endpoint is clinical response, defined as a ≥ 20% reduction in the PRTEE score from baseline. For each patient, the month in which the first response is observed is assessed - month 1, month 2, or month 3. If there is no response at these three time points, the patient remains included in the analysis. The model then takes into account the fact that the patient did not respond at three months and that their clinical progression beyond that point remains unknown.

Sample size:

The power of the Cox model was evaluated based on a simulation of a response 2 times faster in the active group (10%, 15%, and 20% reduction in score at 1, 2, and 3 months versus 5%, 7%, and 10% in the control group). With 40 and 30 patients per group, we obtain a power of 0.83 and 0.72 at the 0.05 level, respectively.

The following will therefore be included:

80 patients, randomly divided into two groups: Group 1: 40 patients with Control roller (T) Group 2: 40 patients with Joints and Muscles roller (AM) and essential oil-based solution

Consultation C1 (Baseline):

• Provision of information and signing of informed consent (see Appendix 1 and 2).
• Verification of inclusion and exclusion criteria.
• Assessment via PRTEE questionnaire.
• Assessment via numerical pain rating scale (0-10).
• Assessment of pain location.
• Provision of treatment instructions: 2 daily applications morning and evening by mechanical self-massage of the epicondylar and muscular area for 2 minutes, i.e. 2 × 70 roller passes in total (70 on the tendon and 70 on the muscle), for 3 months (an explanatory video provided via QR code in an appendix given to patients and assessors).
• Assessment of analgesic and anti-inflammatory consumption. A daily monitoring diary will be given to each participant to record intake.
• Provision of 3 Rollers.

Consultation C2 (1 month):

• Assessment via PRTEE questionnaire.
• Assessment via numerical pain rating scale (0-10).
• Assessment of analgesic and anti-inflammatory consumption.
• Provision of 3 Rollers.

Consultation C3 (2 months):

• Assessment via PRTEE questionnaire.
• Assessment via numerical pain rating scale (0-10).
• Assessment of analgesic and anti-inflammatory consumption.
• Provision of 3 Rollers.

Consultation C4 (3 months):

• Assessment via PRTEE questionnaire.
• Assessment via numerical pain rating scale (0-10).
• Assessment of analgesic and anti-inflammatory consumption.
• Provision of the numerical pain rating scale, in preparation for the telephone consultation.

Optional Telephone Consultation C5 (6 months):

• Assessment via PRTEE questionnaire.
• Assessment via numerical pain rating scale (0-10).

Inclusion Criteria:• Lateral epicondylitis of more than 3 months' duration, isolated and confirmed by clinical and ultrasonographic examination.

• Failure of at least one prior rehabilitation treatment.
• No ongoing physical treatment (shockwave therapy, physiotherapy) for at least 6 weeks, including a well-conducted rehabilitation.
• Adults aged over 18 years.

Exclusion Criteria:• Manual workers in active employment conducive to lateral epicondylitis.

• Occupational injury.
• Patients who have received at least one treatment with PRP (platelet-rich plasma) or any other regenerative treatment.
• Uncontrolled inflammatory or metabolic diseases.
• Neuropsychological disorders preventing proper completion of the protocol.
• Age under 18 years.
• Person unable to understand French.
• Associated osteoarticular and neurological pathologies of the upper limb.
• Known allergy to any component of the essential oils used.