Biology 122 Spring, 2008

Laboratory 10

Foot

OBJECTIVES

At the end of this laboratory you should:

1. Know and be able to palpate the bones, bony landmarks and soft tissues on the dorsal, medial, lateral and plantar surfaces of the foot. Be able to identify all of the bones of the foot and ankle on an articulated skeleton and in radiographs. Be able to distinguish the ankle and subtalar joints and know the main movements that take place at the ankle and subtalar joints.

2. Understand the function of the muscles in the leg and the courses of their tendons to attachments to the bones of the foot.

3. Be able to outline the course and distribution of the branches of the anterior and posterior tibial arteries to the foot. Special attention should be given to the position of the dorsalis pedis artery; you should know where to palpate its pulsations in a living subject.

4. Understand the transverse and longitudinal arches of the foot and the structures that contribute to and support them (shapes of bones; the long and short plantar ligaments and the spring (calcaneonavicular) ligament).

5. Know the arrangement and layering of the intrinsic muscles of the foot, blood vessels and nerves in the plantar region of the foot. Be able to compare the organization in the hand vs. the foot.

6. Know the position, orientation and attachments of the ligaments associated with the ankle joint.

PRELAB PREPARATION

1. Read those portions of your textbook that deal with the foot (pp. 570-578, 658-672) and joints of the foot (pp. 702-716). Review the section on gait (pp. 588- 591).

2. Review the structure of the hand and be able to compare common structural features. Concentrate on the following, in both the hand and foot:

a) The skin on the flexor surfaces are adherent to a thick layer of fascia or aponeurosis; plantar in the foot and palmar in the hand.

b) The distribution of the medial and lateral nerves are basically similar in their distribution; medial plantar = median nerve; lateral plantar = ulnar nerve.

c) The majority of the intrinsic muscles are basically equivalent, i.e. the interossei, lumbricals, and positioning muscles (abductors and adductors) of the first and 5th digits.

d) The bones are organized into a proximal series of irregular bones (carpals vs. tarsals), five distal rays with “meta” elements, and proximal, middle and distal phalanges.

e) Differences in symmetry that are reflected in the patterns of intrinsic muscle attachment (particularly the interossei).

3. Give special attention to the specialized features of the foot related to weight-bearing, arch formation and arch support.