This observational study aims to evaluate pain and upper extremity function in adults with obstetric brachial plexus palsy who underwent shoulder tendon transfer surgery using the Modified Hoffer technique during childhood. Data on the long-term clinical outcomes of this surgical procedure in adulthood are limited. Participants with obstetric brachial plexus palsy and healthy age-matched individuals will be assessed in a single session. The evaluations will include pain, range of motion, muscle strength, upper extremity functional status, social appearance anxiety, and role performance. The study aims to describe the clinical profile of adults with obstetric brachial plexus palsy after Modified Hoffer tendon transfer and compare their outcomes with healthy peers.