This prospective, randomized, double blind study aims to determine the optimal volume for adequate sensorial and motor blockade following an infraclavicular block. Patients will be randomized into three groups. Using a constant dose of local anesthetics (45mg bupivacaine 180mg prilocaine), different volumes will be used in each of the groups (First group; 18mL, second group; 27mL, third group; 36mL). Onset, duration and quality of sensory and motor block will be compared for patients between groups