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qid 6729 · health

Question: Which of the following is true of the assessment of power in the arms?

  1. Extension at the elbow is produced by the biceps muscle
  2. Grade 3/5 (MRC scale) represents movement of the arm only when gravity is eliminated
  3. Grade 2/5 power represents movement of the arm only against gravity.
  4. The brachioradialis muscle is responsible for shoulder abduction
  5. Grade 0/5 power represents full range of motion with resistance
  6. The root value of shoulder abduction is C5
  7. Flexion at the elbow is produced by the triceps muscle
  8. Grade 5/5 (MRC scale) represents movement of the arm only when gravity is eliminated
  9. The root value of shoulder abduction is C7
  10. Grade 1/5 power represents no movement or muscle contraction

Our answer: F. The root value of shoulder abduction is C5 Source quote machine-checked (exact quote)

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How it was answered

Stored method, replayed by code (kind: formula)

card: formula · card sha256 973dd3f9dc20810f…

Current source

GetOnCourse.ai, "Motor testing of myotomes" (medical anatomy revision page)

https://getoncourse.ai/revision/us-medical-pg/anatomy/dermatomes-and-myotomes/motor-testing-of-myotomes/

“C5 (deltoid) is key for shoulder abduction; test by resisting downward arm pressure.”

Source quote machine-checked (exact quote)

retrieved 2026-09-18T00:09:47.392Z

page text sha256 2b7b9ecb7bbdee8c… · content sha256 394f8472d4ecdebe…

addendum formula_qid6729.formula_ADDENDUM_source_rs20260918T000947Z · sha256 5de9bcc7f658e607… · replaces the version below, addendum sha256 01a6b6620d94f263…

Earlier version (superseded)

No public source has been found for this card yet (2 places checked internally).

addendum formula_qid6729.formula_ADDENDUM_source · sha256 01a6b6620d94f263…

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