An employee was checking the brakes on a cab crane while donned in a safety harness with a 6 ft. lanyard. The employee leaned over a gear box that controls the auxiliary hoist to the crane and his lanyard was caught in a shaft that was turning inside the gear box. When the lanyard was caught it pulled the employee quickly to the catwalk surface on top of the crane. During the fall the employee hit his head and suffered a scapula fracture due to being constricted by his harness. The employee was admitted to the hospital.