The pectoralis major is classifies as a

Pectoralis major muscle is typically classified as a spiral Muscle. Muscles with spiral or twisted fasciculi are found in Trapezius, Pectoralis major, Latissimus dorsi, and supinator. Spiral or Twisted: The muscle fibers undergo a twist of approximately 180 degrees between their medial and lateral attachement. Spiral or Twisted Muscle: Pectoralis major Latissimus dorsi Trapezius Supinator Some skeletal muscles may be classified into more than one category. Pectoralis Major muscle has been classified both as convergent (or Triangular muscle) and Spiral Muscle in different textbooks. Note that Pectoralis major has been classified as &;Spiral &; in Gray&;s text and hence this has been selected as the single best answer of choice for this question. Convergent may be selected as the correct answer if spiral is not provided amongst the options. Ref: Gray&;s anatomy 41st edition Pgno: 113