DEgenerative ROtator Cuff Disease and Botulinum TOXin

Inclusion Criteria: * age \> 40 years; * pain duration \> 1 month; * pain intensity ≥ 40/100 on visual analog scale; * SPADI ≥ 30/100; * medication against pain stable at least 30 days before enrolment; * pain with or without weakness during the Jobe manoeuver; * ultrasonography within the 30 days, showing tendinopathy of the supra-spinatus, with or without tear; * affiliation to health insurance Sécurité Sociale; * ability to give consent, complete the weekly notebook (collection of drug treatments taken against pain); * availability for the visits planned by the protocol; * use of an effective method of contraception in women of childbearing potential, started at least 1 month before and lasting for at least 1 month after receiving study treatment. * Negative urine test for women of childbearing age Exclusion Criteria: * reduced passive range of motion; * antero-posterior instability; * tendinous calcification; * ultrasonography showing concomitant tear of the infra-spinatus or the subscapularis; * corticosteroid injection within the previous 30 days; * previous surgery of the shoulder; * humeral fracture, inflammatory joint disease and neoplastic disorders; * contraindication to XEOMIN® (allergy to XEOMIN® or any other botulinum toxin product); * skin infection at the planned injection site; * participation in another interventional research involving the human person (RIPH) during the 3 months of follow-up of the DEROTOX Research; participation in another RIPH will be possible beyond these 3 months; * concomitant use of aminoglycosides, cyclosporine, aminoquinolines and spectinomycine; * patients with a history of aspiration pneumonia and dysphagia; * patients on anticoagulant therapy or on therapy that may have an anticoagulant effect; * Patients with bleeding disorders; * Patients with amyotrophic lateral sclerosis, myasthenia gravis or, Lambert-Eaton syndrome; * Patients with other conditions causing peripheral neuromuscular dysfunction; * In target muscles that show pronounced weakness or atrophy; * Women of childbearing age who have not performed a urine pregnancy test and or who have a positive urine pregnancy test; * in case of pregnancy, breastfeeding * injection of botulinum toxin in the last 6 months * vulnerable people (under legal protection, guardianship or curatorship)