Over the past month I have seen two runners referred with a diagnosis of plantar fasciitis. Not an unreasonable assumption, given their symptoms: pain under the arch of the foot, apparently as a result of running; symptoms worse with prolonged standing, walking, and running; intensity of pain increased with speedwork and hills.
Plantar fasciitis is indeed one of the most common running injuries, certainly the most frequently seen ailment in the foot and ankle. As we have previously seen [Article #13], the plantar fascia is a thick, tendinous band of connective tissue that originates on the bottom of the heel (calcaneus) and runs forward to the base of the toes, broadening out as it traverses the arch of the foot. Its primary function is to assist in supporting the arch during the mid-stance phase of gait. Too much stress on this band of tissue, such as from an overpronating foot, may cause tearing of the tissue that results in pain and inflammation.
The site of this injury and pain of plantar fasciitis, however, is virtually always at the attachment site on the calcaneus. A severe case will radiate pain into the arch, but this discomfort will never be exclusive of heel pain. The two runners described above had no heel pain, nor tenderness to pressure in that area. They also failed to describe one of the hallmark symptoms of plantar fasciitis: pain at its worst the first few steps after getting out of bed in the morning or after sitting for a long period. Both patients reported pain primarily with running or climbing stairs. They were most tender at the mid-arch, and only along the inner portion, not down the center of the foot where the plantar fascia runs. Most significantly, when they attempted to use orthotics or generic arch supports, their pain was exacerbated.
What then did these runners suffer from if not plantar fasciitis? The answer could be found with two simple tests, both involving the great toe. As the toe was extended (pushed upward) passively, pain was reproduced in the arch. Most significantly, both subjects were exquisitely tender directly on the tendon that becomes easily palpable as this test is performed. (Go ahead – try it.) This tendon is the flexor hallicus longus (FHL). Its function is to flex the great toe in a downward direction. The second test, manual resistance to this movement, also provoked pain in these two patients as the tendon was stressed during muscle contraction.
FHL tendinitis is not the most common injury in runners. It is most prevalent in dancers (especially ballet) and figure skaters and is a classic overuse syndrome that is a result of repetitive flexion of the toe. Imagine the movements of these artist-athletes and it is easy to see how this occurs.
Runners can sustain this injury in number of ways, the most common in my experience being the result of too much extension of the great toe during the latter phases of stance. Sometimes, a shoe too flexible in the forefoot allows excessive motion that stresses the tendon trying to control or decelerate that movement. Runners who overstride will also stress this particular muscle/tendon as they produce a more forceful push-off. This helps explain why speedwork and hills increase the risk for acquiring this ailment.
And sometimes, runners come down with this problem as a result of attempts to cross-train, as one of the above patients demonstrated. After many questions focusing on his running schedule failed to offer any clues as to the precipitating factor for his tendinitis, he was kind enough to casually offer as an afterthought the information that he had – just prior to the onset of his injury, naturally – commenced a routine that included a stairmaster machine. Further investigation made it clear that his rising up on his toes as he worked this piece of equipment was the definitive explanation for his problem.
FHL tendinitis should be treated at first sign with ice and a few days rest – at least until the tendon is no longer tender to touch. Another couple of weeks of easy running, avoiding track and hill work, should suffice to allow proper healing before ramping up again to hard training. Stretching, if done at all in the initial acute phase, should be done very gently. Most importantly, don’t let anyone talk you into orthotics if even a simple arch support worsens your symptoms.