Objectives: To determine whether patients with AC, stratified by phase, who receive high-volume HD therapy achieve better outcomes in the Shoulder Pain and Disability Index (SPADI), Analgesic Analogue Scale (VAS), and ROM at the first, third, and sixth months of therapy compared to patients who receive low-volume HD. To determine whether there are differences in FST times and to determine mean axilar recess (AR) values.

Methods: A randomized, triple-blind, parallel-block clinical trial will be conducted in 64 patients with AC in phases 1 and 2, aged 30 to 70 years, with limited active and passive ROM in two planes, and shoulder pain lasting more than 3 months. HD will be administered with volumes of 20 ml or 40 ml, followed by a physical therapy program. Outcomes will be reviewed at the first, third, and sixth months of HD. Variables collected will include SPADI, VAS, ROM, Lattinen assessment, AR size, and time to completion of PT