The Ankle and Foot 371plantar flexion and dorsiflexion to that of the ankle,
and also provide inversion, eversion, abduction,
and adduction of the foot. Together, these joints
give rise to the combined motions of pronation and
supination. The MTP joints are condyloid joints that
allow for flexion, extension, slight abduction, and
slight adduction of the toes on the metatarsals. The
IP joints are hinge joints that allow for flexion and
extension of the digits themselves. These additional
joints have capsules and ligaments that provide
additional stability to the ankle-foot complex. Twelve
extrinsic and 12 intrinsic muscles function to move
the ankle and foot. The extrinsic muscles have a
logical arrangement in which the anterior muscles
cause dorsiflexion, the lateral muscles eversion, the
posterior muscles plantar flexion, and the medial
muscles inversion of the ankle or foot. Many of these
muscles also have additional actions, important for
movement, placement of body weight, and support
of the arches of the foot.
The arrangement of the arches in the foot is
important for meeting the diverse challenges of
stability and mobility. When the foot is supinated,
the foot becomes stable with a formed medial lon-
gitudinal arch, allowing effective initial contact of
the foot with the ground or propulsion of the body.
In contrast, pronation unlocks the foot, making it
more flexible and allowing it to function to accom-
modate uneven surfaces and absorb the large forces
associated with movement. Individual differences in
arch formation will influence the ability of the foot
to meet these opposite demands, with the rigid pes
cavus foot type being stable but less able to absorb
shock, and the flexible pes planus foot type being
able to easily accommodate but less stable.
While pronation and supination are normal foot
movements, excessive amounts of either can easily
lead to foot problems. Learning to use optimal place-
ment of the foot when standing, desired knee-foot
alignment, and coordinated use of the stirrup muscles
can aid with the development of desired dance skill.
Similarly, strengthening of the stirrup and other key
muscles and stretching to achieve both adequate dor-
siflexion and plantar flexion can help enhance ankle
and foot function and prevent injuries. If an injury
does occur, effective treatment and aggressive reha-
bilitation are vital to prevent recurrence or instability
and to allow successful return to dance.Study Questions and Applications
- Locate the following bones and bony landmarks on a skeleton or drawing of a skeleton and
then on your own body: (a) tibia and medial malleolus, (b) fibula and lateral malleolus, (c)
talus, (d) calcaneus, (e) cuboid, (f) navicular and tubercle of the navicular, (g) cuneiforms,
(h) metatarsals and their base and head, (i) phalanges (proximal, middle, and distal), (j)
sesamoids. - Draw the following muscles on a skeletal chart, and use an arrow to indicate the line of pull
of each muscle. Then, next to each muscle, list its actions: (a) gastrocnemius, (b) soleus, (c)
tibialis anterior, (d) tibialis posterior, (e) peroneus longus, (f) peroneus brevis. - Locate the following muscles on your partner or your own body, perform or have your part-
ner perform actions that these muscles produce, and palpate their contraction during these
movements: (a) gastrocnemius, (b) soleus, (c) tibialis anterior, (d) extensor hallucis longus,
(e) extensor digitorum longus, (f) tibialis posterior, (g) flexor hallucis longus, (h) flexor
digitorum longus, (i) peroneus longus, (j) peroneus brevis. - Observe a partner while standing from behind, and note the position of his or her rearfoot.
How would the presence of rearfoot valgus or varus tend to influence foot pronation? - Explore the concept of coupling of the leg and the foot. Note what happens to the lower
leg when the foot inverts and when it everts. Now, note what happens to the foot when the
lower leg internally rotates and when it externally rotates. How could this coupling relate to
turnout and pronation in dance?
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