Inclusion Criteria:  Over 18 years; Diagnosis of grade I, II or II thumb CMC joint OA in their dominant hand according to the Eaton Classification Stage; A minimum pain rating of 4/10 on the Visual Analogue Scale (VAS) during activities of daily living (ADLs) at the time of the initial evaluation; Ability to read and understand the patient information sheets and exercises  Exclusion Criteria:  Neurological disorder affecting the upper limb; Treatment for hand or thumb pain in the same limb in the last 6 months (including injections to the wrist, fingers, or thumb); Fracture or significant hand injury; Previous surgery to the wrist or hand; Hand/finger tenosynovitis; Dupuytren disease; Cognitive impairment that inhibited an understanding of the informed consent and exercise program; Fixed thumb adduction contracture or blindness.