The Ankle and Foot 305rotate, and an ankle sprain can readily occur unless
muscles (the evertors of the foot) act quickly to
counter this undesired extreme inversion.
Classification and Movements
of Other Joints of the Midfoot and Forefoot
The remaining joints between the tarsal bones
(intertarsal joints), as well as the joints between the
tarsal bones and the proximal ends of metatarsals 2
through 5 (tarsometatarsal [TMT] joints), are glid-
ing joints. These joints permit small motions that
continue the function of the transverse tarsal joint,
acting to continue or counter the motions of the
hindfoot in accordance with the goal of the move-
ment. The tarsometatarsal joints also contribute to
“cupping” or “flattening” of the foot when it is weight
bearing, similar to that which occurs in the hand to
facilitate grasping objects.
The joints between the heads of the metatarsal
bones and the adjacent proximal phalanges—the
metatarsophalangeal joints (MTP)—are condyloid
joints. These joints allow a considerable amount of
motion in flexion (30-45°) and extension (90°), with
greater motion allowed in extension (Smith, Weiss, and
Lehmkuhl, 1996). This extension motion (sometimes
termed hyperextension) is important in weight-bear-
ing functions such as in walking or rising onto the toes
in demi-pointe, allowing the toes to maintain contact
with the ground while the heel rises. The motion of
abduction-adduction is more limited and is oriented
relative to a line through the second toe. So, abductionSelected Orthopedic Stress Tests for the Ankle
Two tests are shown that are commonly performed by physicians to test the stability of the ankle
and evaluate lateral ligamental injury. Consider each test in terms of both the restraints offered by a
normal intact ligament and the excessive motion allowed when injury occurs.
Anterior Drawer Test
When one hand is used to push backward on the lower tibia while the other hand is used to pull the
calcaneus (and talus) forward, the ATFL resists this motion. When the ATFL is torn, the talus will slide
anteriorly from under the tibia. This is termed a positive anterior drawer sign as shown in A.
Talar Tilt Test
When the foot is inverted, the calcaneofibular ligament resists this varus stress. When the calcaneo-
fibular and anterior talofibular ligament are torn, excessive calcaneal varus is permitted, and the talus
will gap and rock in the ankle mortise. This is termed a positive talar tilt sign as seen in B.