Plantar Fasciitis is a common athletic foot injury. While runners are most likely
to suffer from Plantar Fasciitis, any athlete whose sport involves intensive use
of the feet may be vulnerable. The risk of this injury increases in athletes who
have a particularly high arch, or uneven leg length, though improper biomechanics
of the athlete's gait and simple overuse tend to be the primary culprits.
What is Plantar Fasciitis?
Plantar fasciitis refers to a type of foot injury which is an inflammation of the
plantar fascia, a thick, fibrous band running along the sole of the foot. Such inflammation
results from direct injury to the plantar fascia, usually, repeated trauma to the
tissue where the fascia attaches to the calcaneus or heel bone. The plantar fascia
is critical in maintaining the foot's complex arch system, also playing a
role in balance and fine control of certain phases of the athlete's gait.
Injury to the plantar fascia is particularly painful and disabling for runners and
can often prove stubbornly resistant to treatment. Rehabilitation is frequently
a lengthy and frustrating process. For these reasons, care should be taken where
possible to avoid such injury by means of preventative exercises and sensitivity
to early warning signs.
Anatomy involved
A non-elastic band of fibrous tissue—the plantar fascia—runs along the
bottom or plantar surface of the foot. It attaches to the calcaneus or heel bone,
(the largest bone in the foot), fanning out and attaching to the metatarsal bones
around the ball of the foot, at the base of the toes. Tension in the plantar fascia
acts to maintain the arch of the foot.
Most commonly, the plantar fascia is injured at its attachment point on the medial
tubercle of the calcaneus. During running, the arch of the foot flattens during
the pronation phase, allowing the foot to absorb shock as it makes contact with
the ground. Repetitive trauma to this tissue can produce micro tears, the signature
of plantar fasciitis. Pain usually develops on the calcaneus of the foot.
What causes Plantar Fasciitis?
Plantar fasciitis foot injury generally occurs over time, rather than being
the result of a single event. Micro trauma from repetitive stress to the tissue
often combines with a biomechanical deficiency of the foot to produce the condition.
In addition, arthritic and metabolic factors may contribute to the development of
this injury, (though they are unlikely to affect young athletes). A variety of training
errors commonly lead to plantar fasciitis, particularly a rapid increase in either
volume or intensity of athletic activity. Volume refers to the distance or time
an athlete performs, while intensity refers to the pace of activity and/or the recovery
time allowed following performance.
Training on improper, hard and/or irregular surfaces as well as excessive track
work in spiked shoes, or steep hill running, can stress the plantar fascia past
its limits of elasticity, leading to foot injury. Finally, failure in the early
season to warm up gradually gives the athlete insufficient time for the structures
of the foot to re-acclimate and return to a proper fitness level for intensive exercise.
Such unprepared and repeated trauma causes microscopic tearing, which may only be
detected once full-blown plantar fasciitis and accompanying pain and debilitation
have resulted.
If the level of damage to the plantar fascia is significant, an inflammatory reaction
of the heel bone can produce spike-like projections of new bone, known as heel spurs.
Indeed, plantar fasciitis has occasionally been refereed to as heel spur syndrome,
though such spurs are not the cause of the initial pain but are instead a further
symptom of the problem. While such spurs are sometimes painless, in other cases
they cause pain or disability in the athlete, and surgical intervention to remove
them may be required. A dull, intermittent pain in the heel is typical, sometimes
progressing to a sharp, sustained discomfort. Commonly, pain is worse in the morning
or after sitting, later decreasing as the patient begins walking, though standing
or walking for long periods usually brings renewal of the pain.
Certain preconditions favor the development of the foot injury plantar fasciitis.
These include genetic predisposition, excessive rigidity in the feet, overly high
arches, (or by contrast, flat feet), and running on the toes or in very soft surfaces
such as sand. Finally, improper footwear, particularly with insufficient arch support,
is a recipe for injury.