FINE

ANATOMY
BY CATHERINE FISCELLA, MSPT

The Ankle Joint
Anatomy, common injuries and postrehab strategies.
ANATOMY REVIEW

from the floor surface. Pronation involves abduction, eversion and some dorsiflexion, whereas supination involves adduction, inversion and plantar flexion (Moore 1992).
ANKLE INSTABILITY

The bones involved in ankle articulation include the tibia, fibula and talus. The tibia and fibula are the long bones of the lower leg; the fibula, a relatively thinner bone, is lateral to the tibia. These two bones are bound together by the ligaments and the interosseous membrane. The talus is a wedge-shaped bone that fits into the mortise formed by the bound tibia and fibula (Moore 1992). Multiple ligamentous attachments, muscular attachments and a fibrous capsule maintain the articulation of all three bones. Three separate ligaments stabilize the lateral aspect of the ankle joint: the anterior talofibular, calcaneofibular and posterior talofibular ligaments. Medially, support comes from a collective group of ligaments known as the deltoid ligament.
MAJOR MOTIONS OF THE ANKLE JOINT Inversion/Eversion. These horizontal

movements in the sagittal plane most often occur in combination with supination and pronation. The tibialis anterior and gastrocnemius are the primary muscles working during inversion; and the fibularis (peroneus) brevis and longus are primarily responsible for eversion (Moore 1992). Plantar Flexion/Dorsiflexion. Plantar flexion and dorsiflexion are the movements involved when pointing the foot down and flexing it up, respectively. The gastrocnemius, soleus, tibialis posterior, fibularis brevis and longus, flexor hallucis longus, flexor digitorum longus and plantaris are the primary muscles acting in plantar flexion; and the tibialis anterior, extensor digitorum longus, extensor hallucis longus and peroneus tertius are primarily responsible for dorsiflexion (Moore 1992). Pronation/Supination. In simple terms, pronation occurs when the plantar side of the foot moves toward the floor surface in weight bearing, and supination occurs when the plantar side moves away

Individuals who suffer from ankle instability may complain of frequent sprains and difficulty with cutting and pivoting movements. Ankle instability is usually a sequel to chronic ankle sprains or poorly treated acute ankle sprains. Instability occurs when the ligamentous and muscular constraints are unable to support the ankle during athletic or complex movement demands (Kibler et al. 1998). Repeated episodes of instability will result in diffuse pain, decreased performance and, sometimes, swelling. Inversion ankle sprains, caused when the foot rolls inward and under the ankle, are suffered more commonly than eversion sprains. Inversion sprains result in damage to the lateral ligaments of the ankle (the anterior talofibular, calcaneofibular and posterior talofibular ligaments). In many cases, a client with ankle instability will experience weakness during eversion and plantar flexion. In planning a treatment program, a physical therapist or an athletic trainer will focus primarily on increasing the stability of the ankle joint through appropriate muscle strengthening, proprioceptive exercises, agility workouts and, at times, a brace (Kibler et al. 1998).
Postrehab Strategies

the ball of the foot. Hold the end of the tubing with tension, pulling medially away from the client’s foot (away from the big toe).