Plantar fasciitis is the most frequently encountered cause of plantar heel pain (I suffered with it for 6 weeks!).
For many years pain in this region has been incorrectly termed the "heel spur syndrome". It would be better termed a "plantar heel pain syndrome". While heel spurs sound ominous, they can be present (50% percent of the population has one) and not cause any pain.
The most frequent cause is an abnormal motion of the foot called excessive pronation. Normally, while walking or during long distance running, your foot will strike the ground on the heel, then roll forward toward your toes and inward to the arch. Your arch should only dip slightly during this motion. If it lowers too much, you have what is known as excessive pronation placing increased tension on the fascia. For this reason certain shoes MUST be avoided such as Flip-Flops, flat sandals and loafers.
Other factors which may contribute to plantar fasciitis include a sudden increase in daily activities, increase in weight (not usually a problem with runners), or a change of shoes.
Dramatic increase in training intensity or duration may cause plantar fasciitis. Shoes that are too flexible in the middle of the arch or shoes that bend before the toe joints will cause an increase in tension in the plantar fascia. Make sure your shoes are not excessively worn. These shoes and other shoes that are not sufficiently controlling of pronation combined with an increase in training can lead to this condition. A change in running style, such as starting speed work, running on the ball of your foot or sudden increase in hill workouts up and/or down may also lead to this condition.
The lesson I have learned, over the 35 years in practice, is the fact that when patients wait more than six months to seek professional treatment for plantar fasciitis, they jeopardize the prognosis for successful conservative treatment. The patients who eventually did become pain free with conservative treatment had their symptoms for less than six months before seeking treatment while those who remained symptomatic for years had their symptoms for 365 days, or more, before obtaining professional care.
The inflamed fascia over time will become thick (over 4 millimeters) and can impinge on one of the nerves to the bottom of the heel or the inflamed fascia can turn into degenerative tissue (scar tissue) that will fail most conservative treatment. At this point treatment changes from the standard conservative approach to a more aggressive treatment with one of the following procedures.