11-CS-2 Engineering Communications · December 2017
Question 2 of 7: Cumulative Trauma Disorders and Machine Guarding
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Notes on this paper
National Exams — December 2017 — 11-CS-2 Engineering in Society: Health and Safety. Closed book; approved calculator permitted. Any five of the seven questions constitute a complete paper; all questions are of equal value. Answers are written in point form but fully, as instructed. Complete answers to all seven questions follow.
Gradual injuries to muscles, tendons, nerves and joints from repeated micro-trauma (no single event). Risk factors: high repetition, force, awkward/static postures, contact stress, vibration, cold—combined over long durations. Symptoms progress from discomfort to pain, numbness, weakness and loss of function.
(ii) Typical Disorders
(a) Trigger finger — flexor tendon/sheath inflammation so the finger catches/snaps; from repeated gripping.
(b) Carpal tunnel syndrome — median-nerve compression at the wrist; numbness, tingling, pain, weakness in thumb/first fingers.
(c) Tenosynovitis — inflammation of a tendon and its sheath (pain, swelling, restricted movement).
(iii) Basic Principles of Machine Guarding
Prevent contact; secure and durable; create no new hazard; not interfere with the work; allow maintenance without full removal; interlock where appropriate (machine stops if guard opened), backed by lockout/tagout.
