Chapter 18: The Foot

William E. Prentice

OBJECTIVES

When you finish this chapter you should be able to

• Identify the major anatomical and functional features of the foot.

• Discuss how foot injuries may be prevented.

• Explain the process for evaluating injuries to the foot.

• Identify specific injuries that occur in the foot, and discuss plans for management.

• Design rehabilitation techniques for the injured foot.

INTRODUCTION

Many activities involve some elements of walking, running, jumping, and changing direction. The foot is in direct contact with the ground, and the forces created by these athletic movements place a great deal of stress on the structures of the foot. Consequently, the foot has a high incidence of injury.¹⁰

The function of the foot is critical in walking, running, jumping, and changing direction. In one instant, the foot must act as a shock absorber to dissipate the ground reaction forces. In the next instant, it must become a rigid lever that propels the body forward, backward, or to the side.⁶²

The foot forms the base for the entire kinetic chain, and different structural foot types can affect movement, stability, and the biomechanics throughout the kinetic chain.³⁰ Because of the stress that these movements place on the foot and because of the complex nature of the anatomical structures of this body part, recognition and management of injuries to the foot present a major challenge to the athletic trainer.

FOOT ANATOMY

It has been proposed that a core system exists in the foot that is similar to the core system in the lumbo-pelvic-hip complex.⁶¹ When the core is not functioning properly, the foundation becomes unstable and malaligned and abnormal movement of the foot ensues eventually resulting in injury. The foot core system consists of passive, active, and neural subsystems interacting collectively to provide stability and flexibility to cope with changing foot demands.

All of the ligaments of the foot in combination with the bony congruency of the joints and the plantar fascia form the passive subsystem of the foot core system. Muscles are the active subsystem of the foot in which both extrinsic muscles originating in the lower leg and intrinsic muscles on the plantar surface of the foot combine to produce foot stability and adaptability. The neural subsystem consists of the sensory receptors on the plantar surface of the foot and in the plantar fascia, ligaments, joint capsules, muscles, and tendons involved in the active and passive subsystems.⁶¹

Bones

The foot consists of 26 bones: 14 phalangeal, 5 metatarsal, and 7 tarsal (Figure 18–1). Additionally, there are two sesamoid bones beneath the first metatarsal.