Chapter 19: The Ankle and Lower Leg

William E. Prentice

OBJECTIVES

When you finish this chapter you should be able to

• Identify the major anatomical components of the ankle and lower leg that are commonly injured.

• Accurately assess ankle and lower leg injuries.

• Discuss the etiology, symptoms and signs, and management of injuries occurring to the ankle and lower leg.

• Develop a rehabilitation plan for various injuries to the ankle and lower leg.

INTRODUCTION

Like the foot, the ankle and lower leg are common sites of injury in the physically active population.⁵⁰ Ankle injuries, especially to the stabilizing ligaments, are the most frequent injuries in athletes at all levels, the military, and the performing arts. This chapter focuses on traumatic and overuse injuries in the ankle and lower leg.

ANATOMY OF THE ANKLE AND LOWER LEG

Bones

The portion of the lower extremity that lies between the knee and the ankle is defined as the lower leg and contains two bones, the tibia and the fibula. The bones that form the ankle joint (talocrural joint) are the distal portion of the tibia, the distal portion of the fibula, and the talus. The calcaneus also plays a critical role in the function of the ankle joint.

Tibia With the exception of the femur, the tibia is the longest bone in the body. It serves as the principal weight-bearing bone of the leg. It is located on the medial side of the lower leg. The tibia is triangular in its upper two-thirds but is rounded and more constricted in the lower third. The most pronounced change occurs in the lower third of the shaft and produces an anatomical weakness that establishes this area as the site of most fractures occurring to the leg. The shaft of the tibia has three surfaces: posterior, medial, and lateral. The posterior and lateral surfaces are covered by muscle; the medial surface is subcutaneous and, as a result, is vulnerable to outside trauma (Figure 19–1).

Fibula The fibula is long and slender and is located along the lateral aspect of the tibia, joining it in an arthrodial articulation at the upper end, just below the knee joint, and as a syndesmotic joint at the lower end. Both the upper and the lower tibiofibular joints are held in position by strong anterior and posterior ligaments. The main function of the fibula is to provide for the attachment of muscles.

Tibial and Fibular Malleoli The thickened distal ends of both the tibia and the fibula are referred to as the medial malleolus and lateral malleolus, respectively. The lateral malleolus ...