Home-Based Corrective Exercise With Remote Reinforcement for Upper Crossed Syndrome

Upper Crossed Syndrome (UCS) is a musculoskeletal condition defined by simultaneous forward head posture (craniovertebral angle, CVA \< 52°), rounded shoulders (RSP \> 52°), and thoracic hyperkyphosis (\> 42°). It is highly prevalent in sedentary workers and musicians and is associated with neck pain, shoulder pain, and reduced pulmonary function. This two-arm parallel randomized controlled trial will compare two home-based corrective exercise programs over 12 weeks in adults with confirmed UCS. Both groups (Experimental, EG; Control, CG) perform the same 20-minute program three times per week: diaphragmatic breathing re-education and targeted muscle strengthening and stretching. The EG additionally uses a volumetric incentive spirometer (Coach2, 4000 mL) as respiratory biofeedback and receives active remote reinforcement (biweekly video calls + asynchronous educational material from a physiotherapist); the CG performs the same exercises without the spirometer and receives only minimal adherence monitoring. Outcomes are assessed at baseline (week 0) and at weeks 4, 8, and 12. Primary outcome: craniovertebral angle (CVA) measured by lateral photogrammetry. Secondary outcomes: rounded shoulder angle (RSP), thoracic kyphosis (bubble inclinometer and smartphone inclinometer), pain (Visual Analogue Scale), cervical disability (Neck Disability Index), shoulder pain and disability (SPADI), exercise adherence, and pulmonary function (spirometry: FVC, FEV₁/FVC, MVV) at weeks 0 and 12. Recruitment will take place at the Associació Amics de la Música de Meliana, Fisioterapia A Punto, and Universidad Cardenal Herrera CEU (Valencia, Spain). A total of 96 participants (48 per arm) will be enrolled over a 2-year recruitment window.

Inclusion Criteria: * • Confirmed UCS diagnosis, defined by the simultaneous presence of: (a) craniovertebral angle (CVA) \< 52°; (b) rounded shoulder posture angle (RSP) \> 52°; and (c) thoracic kyphosis angle \> 42°. * Age between 18 and 65 years. * Available and willing to perform the home exercise program and to attend all four face-to-face assessment sessions (weeks 0, 4, 8, and 12). * Access to a camera-equipped device (smartphone or tablet) for remote monitoring and reinforcement. * Ability to understand the study procedures and to sign informed consent. Exclusion Criteria: * Severe cervical or thoracic pathology: vertebral fracture, neoplasm, infection, or active systemic inflammatory disease. * Spinal surgery within the preceding 12 months. * Respiratory pathology contraindicating use of a volumetric incentive spirometer: recent pneumothorax (\< 6 weeks), COPD GOLD grade III-IV, or unstable bronchial asthma. * Active physiotherapy treatment specifically targeting UCS within the preceding 3 months. * Pregnancy or breastfeeding. * Cognitive impairment or language barrier preventing comprehension of the exercise program. * Simultaneous participation in another clinical trial.