Dance Anatomy & Kinesiology

320 Dance Anatomy and Kinesiology

Intrinsic Muscles of the Foot

Remember that by definition the intrinsic muscles have both their proximal and distal attachments within

the foot, but some of these intrinsic muscles have similar functions to the extrinsic muscles. To help

distinguish between extrinsic and intrinsic muscles with similar functions, the terms short (brevis) and

long (longus) are sometimes used. For example, the extrinsic extensor of the great toe is called exten-

sor hallucis longus while the intrinsic extensor is called extensor hallucis brevis. This short extensor

of the hallux (extensor hallucis brevis), as well as the short extensors of the digits (extensor digitorum

brevis), is located on the dorsum of the foot as seen in figure 6.25. The remaining 10 intrinsic muscles

are called the plantar muscles and can be grouped into four layers as seen in figure 6.26. While the

first three groups are located on the plantar aspect of the foot in progressively deeper layers, layer 4

is actually located between the metatarsals and phalanges.

The intrinsic muscles of the foot are responsible for abduction, adduction, flexion, and extension of

the toes. Some of these muscles are also important for dynamic maintenance of the arches, propulsion,

and fine adjustments of the feet. One of the important and often overlooked functions of the intrinsic

muscles is to maintain the IP joints in extension to aid the flexor hallucis longus and flexor digitorum

longus in producing a powerful push-off in locomotor movements. If the toes are not maintained in

FIGURE 6.23 Posterior view of primary muscles acting on the ankle and foot (right foot). (A) More superficial view of

muscles, (B) deeper view of muscles, (C) attachments, (D) lines of pull and actions.

Gastrocnemius

• A-F plantar flexion


• Knee flexion


• Foot inversion


• Foot inversion