Plantar fasciitis is a common overuse injury, often characterized by heel pain that is usually more severe when the patient first begins ambulation after prolonged periods of non-weight-bearing.
Plantar fasciitis is a common overuse injury, often characterized by heel pain that is usually more severe when the patient first begins ambulation after prolonged periods of non-weight-bearing. Frequent precipitating factors include adverse foot mechanics, training errors, and degenerative changes.2 Plantar fasciitis can be present in all levels of athletics as well as in a non-athletic population. As with most overuse injuries plantar fasciitis may present as an acute problem or develop into a chronic protracted lesion.1 Management of plantar fasciitis is a three-part process that involves treating the inflammatory lesion, correcting precipitating factors and instituting a graded rehabilitation program.
The plantar fascia or plantar aponeurosis is a thick white band of fibrous tissue originating from the medial tuberosity of the calcaneus and ending at the proximal heads of the metatarsals. This inert structure consists of three bands located between the deep and superficial muscles on the plantar surface of the foot. The central band is the largest and most significant. Working in conjunction with the longitudinal arches, ligaments, and bony arched anatomy of the metatarsals, the plantar fascia supports the foot against downward forces.1
The majority of forces that act on the plantar fascia causing problems take place while weight bearing. Despite a lack of significant movement from the plantar fascia itself other structures related to both walking and running must be examined to fully understand the kinematics. The dynamic functions of the foot during walking include a flexible foot to accommodate the variations in the external environment, a semi-rigid foot which can act as a spring and lever arm for the push-off during gait and a rigid foot to enable body weight to be carried with adequate stability.4,7 To understand the basic gait pattern the whole kinetic chain needs to be examined, by starting at the pelvis and progressing down the leg, these kinematics can be described as follows. During walking, pelvic rotation causes the femur, fibula, and tibia to rotate about the long axis of the limb. The lower limb generally rotates internally during the swing phase and early stance phase then externally until the stance phase is complete and toe-off has occurred.8 The knee will go through two cycles of flexion and extension from a period of heel strike through toe off. At the foot the heel strike takes place first and absorbs the initial force; followed by the tri-planer movement of pronation where an eccentric force is absorbed. Movements that occur at this time are internal rotation of the tibia, eversion of the subtalar joint and dorsiflexion of the talocrural joint. The point at which the weight is centered over the foot is called the midstance. Before the final stage of toe off the foot goes through a period of supination. This supination is opposite of pronation both with direction of movement as well as being a concentric contraction. The following chart is a comprehensive list of muscles that provide dynamic stabilization specifically at the foot and ankle.6
