Dance Anatomy & Kinesiology

62 Dance Anatomy and Kinesiology

Latin and Greek roots provide the fol-

lowing clues about a muscle:

• Action: adductor longus (adductor
  = to adduct or bring toward the
  midline), levator scapulae (levator
  = to lift)


• Direction of fibers: rectus abdomi-
  nis (rectus = straight), obliquus
  internus abdominis (obliquus =
  slanting or oblique)


• Location: triceps brachii (brachium
  = arm), pectoralis major (pectoris
  = chest)


• Number of divisions/proximal
  attachments (heads): quadriceps
  femoris (quadriceps = having four
  heads), triceps brachii (triceps =
  having three heads), biceps brachii
  (biceps = having two heads)


• Shape: deltoid (delta = shaped like
  the letter delta, triangular)


• Size/relative size: gluteus maximus
  (maximus = largest), adductor
  brevis (brevis = short)

2. Learn the muscle name and location.
   While keeping the meaning of useful word
   roots in mind, learn the name and location
   of the specific muscle.


3. Estimate the muscle’s line of pull,
   and deduce its action(s). From knowing
   the muscle’s location and approximate
   attachments, estimate its line of pull. Then,
   note where this line of pull is relative to
   the axis of the joint to deduce what type of
   movement would be produced at that joint
   when the muscle shortens (e.g., concentric
   contraction). Try to understand the logic,
   rather than just memorize the actions. For
   example, in many cases, muscles located
   anterior to the joint produce flexion;
   muscles located posterior to the joint pro-
   duce extension; muscles lateral to biaxial or triaxial
   joints produce abduction; and muscles medial to
   these types of joints produce adduction (exceptions
   include muscles at the knee joint and scapulae). Mus-
   cles producing external rotation are often located
   posteriorly, and those producing internal rotation
   are often located anteriorly; but this relationship is
   less consistent.
   Initially it is helpful to try to deduce just the pri-
   mary one or two actions some of the more commonly
   known muscles would have and cross-check these

deductions with the actions listed in figures 2.19 and

2.20. However, a more in-depth understanding of

muscles requires an appreciation of their secondary

actions and use in functional movements. Knowledge

regarding many of these more complex actions of

muscles has been derived from various methods

of research including electromyography (EMG).

Electromyography (G. electron, amber [electricity]

+ mys, muscle + grapho, to write) utilizes electrodes

inserted into the muscle (e.g., needle electrodes) or

applied to the skin over a given muscle (e.g., surface

TABLE 2.4 Word Roots and Muscle Names

Word root Meaning Sample muscle

abducens leading away from abductor hallucis

biceps two-headed biceps femoris

brachium upper arm brachialis

brevis short adductor brevis

delta triangle deltoid

gracilio slender gracilis

latissimus the broadest latissimus dorsi

levator lifter levator scapulae

longissimus the longest longissimus of erector spinae

longus long adductor longus

magnus larger adductor magnus

major the larger teres major

maximus the largest gluteus maximus

minimus the smallest gluteus minimus

minor the smaller pectoralis minor

obliquus oblique, slanting obliquus internus abdominis

pectoris chest pectoralis major

peroneus belonging to fibula peroneus longus

piriformis pear-shaped piriformis

quadriceps having four heads quadriceps femoris

rectus straight rectus abdominis

rhomboids rhomboid rhomboideus major

serratus serrated serratus anterior

sterno sternum sternocleidomastoid

tensor stretcher tensor fasciae latae

teres round teres minor

triceps three-headed triceps brachii

vastus large vastus medialis