An ergonomic assessment of the airline baggage handler

13Figure 2.3 Herniated disk and pinched spinal nerve.2.2.1 Common Causes of Low Back PainThe lower back contains a team of muscles and ligaments allowing strength and stabilityfor walking, lifting, standing, bending, etc. A strain is injury to the muscle. When itcomes to the back, a sprain is typically an injury to the lower back musculature, which isoften caused when a muscle is overworked, overstretched, or used in a poorlyconditioned state. As a result pain most commonly occurs during activity. Thiscondition is usually worsened with back flexion and prolonged standing, as the pain fromsprain might not immediately occur. As a natural response to the injury and subsequentdiscomfort from back sprain, the affected area's muscles spasm or stiffen as the bodyattempts to immobilize the painful area to prevent it from further damage.A sprain is an injury to the ligaments. These injuries commonly occur when asudden or forceful movement damages a ligament. Once damaged or injured theligament may become stiff or weak. Injury may have resulted from overuse due toexcessive or repetitious motion generally associated with material handling.Lumbosacral sprains and strains are the most common causes of lower back pain, of