Plantar fasciitis is a fairly common affliction of the runner. It typically presents as a pain on weight bearing where the arch of the foot meets the heel. Often it is worse in the morning and improves with exercise. In many cases it is a repetitive strain injury related to the ‘too much, too soon’ phenomenon of overuse of soft tissues not adapted to the training loads. Plantar fasciitis can also occur as an acute injury related to a sudden connective tissue tearing of the plantar fascia itself. Often this is associated with a history of low grade chronic plantar fasciitis and rarely occurs spontaneously. An ultrasound diagnostic imaging test is the best tool to confirm a tear of the plantar fascia. In either case cessation of running is required to allow injured tissues to heal followed by a progressive strengthening program. One may be tempted to ‘run through’ the heel pain often decreases with exercise, but this unfortunately tends to make the problem worse and more difficult to heal in the long term.
The plantar fascia is a connective tissue structure on the undersurface of the foot that connects the heel to the forefoot. Its function is primarily as a support structure but the plantar fascia also has muscle attachments into it. During the gait cycle when the foot rolls from heel strike to push off, the plantar fascia is put on tension which helps to stiffen the foot thus enhancing propulsion.
Foot mechanics are thought to play a role in plantar fascia stress. On one hand, the stiffer higher arched foot generally has more tension within the fascia so increased running distance and/or speed may overstress the already tight structure. Conversely, the plantar fascia of the flatter arched, floppier foot has less tension and so excessive forces may cause irritation because of decreased support to the foot. In either case, flexibility of the calf, mobility of the foot and ankle as well as strength of the calf and foot muscles are important factors to evaluate. As with any lower body injury, good strength of the trunk and hip muscles will help dissipate loads into the extremity. Taping and shoe inserts can also help with relief of pain in the early stages. Anti-inflammatory medication, icing and heating can also help with pain control, but ultimately there needs to be a protective phase for tissue healing followed by strengthening and gradual return to activity.
In some cases heel pain can be caused by nerve entrapment from the lower back. Although often associated with back pain, the nerve pain can just be isolated to the heel and be confused with plantar fasciitis. Clinical tests assessing location of the pain and tension of the nerves of the leg can help rule this out.
Interesting to note in this era of the minimalist running, the calf muscles, Achilles tendon and plantar fascia are all put under more stress when using less supportive shoes. This is not necessarily a negative effect as it can lead to improved strength overall, but one needs to be careful with an aggressive switch from a stiff supportive shoe to a lightweight flexible one. The body always needs time to adapt so gradual changes are always safer than abrupt ones.
(Originally published in No Limits Blog, 2012)