Final answer:
Putting excess force on the spine is the most common factor contributing to ergonomic injury in healthcare, often due to musculoskeletal disorders caused by poor posture and repetitive motions leading to back pain.
Step-by-step explanation:
The most common factor contributing to ergonomic injury in healthcare is putting excess force on the spine. Musculoskeletal disorders are commonly caused by biomechanical stresses, such as sudden exertion, over-exertion, and repetitive motions. These stresses can lead to injuries in muscles or associated tissues, such as the spine, due to poor ergonomic practices like bad posture or heavy lifting. Poor posture, for instance, can create significant strains on lower back muscles to maintain balance when the center of gravity of the upper body shifts forward, causing muscle strain and back pain. Therefore, option b) is the answer: Putting excess force on the spine is the most common factor.