Repeatedly raising arms upward in a task may be linked with which strain?

Correct answer: Shoulder strain

The direct answer is B: shoulder strain. Ergonomics studies how body movement and workplace design affect comfort and safety. When a worker repeatedly raises the arms above a comfortable level, the shoulder muscles must work again and again. Holding the arms up or reaching too high can cause muscle fatigue, pain, stiffness, and strain in the shoulders and nearby upper back. Option B is correct because the repeated movement directly loads the shoulder area. Option A is wrong because repeated overhead movement does not provide waist comfort; it may even cause other discomfort. Option C is wrong because eye comfort is mainly related to lighting, screens, and visual breaks, not arm height. Option D is wrong because foot safety is not the main body area affected by raising the arms. Remember: repeated overhead reaching points first to shoulder strain.