Plantar fasciitis is the most common cause of localized heel pain. In a study of 232 injured runners, 7% had plantar fasciitis. The plantar fascia is a long band of fibrous tissue on the bottom of the foot that extends from the heel to the bases of the toes. It supports the joints, bones, and muscles under the foot during midstep and creates a rigid lever for push-off. It maintains the longitudinal arch of the foot.
Plantar fasciitis is an inflammation of the plantar fascia. It is usually chronic with an insidious beginning, although occasionally a runner might develop sudden onset. Repetitive trauma produces microtears in the plantar fascia near its attachment to the heel. The body's attempt to repair these tears leads to chronic inflammation and resulting pain.
Runners alter how they run in order to run through plantar fascial pain: shortening stride length, foot striking with toes first rather than heel first, and running on the outside border of the foot are among the alterations. These adaptations may lead to other problems, however, including knee pain, hip pain, back pain, or other foot pain.
Another muscle group of primary importance to foot function is the small (intrinsic) muscles in the foot. This is an often overlooked group of muscles, as they do not function when the foot is standing. The foot intrinsic muscles stabilize the foot during propulsion. If you pronate, there is greater intrinsic muscle activity needed to stabilize the arch that runs from side to side underneath your foot and the joint where your ankle connects to your foot. Strong intrinsic muscles can reduce heel and arch pain.
Biomechanical factors that contribute to plantar fasciitis include flat feet and high arches. A runner with heel pain is more likely to have flat feet and pronate. If you pronate excessively, the hind foot will have decreased stability, and this adds more strain on the plantar fascia at its heel attachment during the stance and push-off phase of running. In the runner with high arched feet, there will be decreased motion where the ankle attaches to the foot, and this results in decreased ability of the foot to absorb the force of ground contact. At foot strike, the heel remains rolled outward, and the longitudinal arch remains rigid throughout the midstance phase of running. Stress is passed through the outer border of the foot and knee.
Other biomechanical factors that could contribute to plantar fasciitis include bowlegs, knock knees, tibial torsion (twisting of the tibial bone in the lower leg), leg length differences, and rotation of the hip socket.
Deficiencies in running shoes may also contribute to plantar fasciitis too loose a heel counter or too flat a shoe resulting in excessive rolling in; too flexible a shoe allowing excessive toe flexion and increased plantar fascial tension; too tight a toe box or too rigid a sole restricting movement at the metatarsal toe joint; worn-out shoes lacking shock absorption or the ability to mechanically align the foot; absence of good arch supports, causing the arch to flatten.
A useful guideline for a safe training progression is "the 10% rule." Limit increases in distance or intensity to 10% a week. For example, if a person is running 60 minutes at a session, 4 times a week, or 240 minutes, she or he can probably increase the running time to 264 minutes (240 + 10%), the following week if all else remains the same.
Terrain is also an important factor in training. Running 30 minutes on hills is very different from running 30 minutes on flat surfaces in terms of the forces on the legs and feet. Work up gradually to increase your running time on hills. Also lean forward when running downhill. If you run on a banked or crowned surface, vary the direction you run in so you alternate which leg is higher and which leg is lower on the bank. If you know concrete or asphalt is causing you discomfort, try running on a cinder or composite track. If you are going on vacation and are not used to running on sand or grass, don't spend your whole vacation doing it.
Good running shoes are vital to injury prevention. Shoe technology continues to improve and change rapidly. Buy your shoes from a reputable dealer who knows runners and his stock well. Your shoe dealer should be able to guide you in choosing proper shoes for flat feet or high-arched feet and your particular running style.
If you're a likely plantar fasciitis victim, stretching and flexibility exercises for the hamstring/buttocks and achilles/calf muscles are critical (see page 21 for a program).
There are three types of stretching: ballistic, slow, and dynamic. Ballistic (or bouncing) stretching occurs when you repeatedly do a quick stretch followed by a quick contraction. This can result in muscles tears and is no longer a recommended technique for stretching. Slow stretching involves going down to a point at which you feel tightness in the muscle and then push a little more and hold for 30-60 seconds. While a recommended method of stretching, it can result in thinning and weakening the tendon attached to the muscle.
However, dynamic stretching working and exercising the tightened muscle in the outer range of motion increases the range of motion by lowering the muscle's tension. You also increase the collagen tissue (which makes up the tendon and muscle) in that end range and increase the strength in that range.
Ice for 5 to 10 minutes for pain relief after activity. (If you use ice massage, go no more than 5 minutes.) You can ice up to 5 times per day. Icing beyond 10 minutes makes the body respond to lowered temperatures by increasing blood flow to the area, resulting in increased inflammation.
Use heel lifts or heelcups. Adhesive taping of the foot can temporarily support the arch and decrease the stress on the plantar fascia. Taping can be used for 1 to 3 weeks continuously or just with activity. If you get good temporary relief with tape, but the pain doesn't settle down within 3 weeks when the tape is not used, this is an indication you have a mechanical problem and orthotics may be indicated. To tape your foot, flex your foot to 90 degrees at the ankle and tape as shown here. In some cases, it may be necessary to use four strips crossing under the foot instead of two.
As the pain subsides, begin strengthening and flexibility exercises. Make sure you work painfree (or don't increase your pain while doing these exercises).
When you no longer have pain when arising in the morning, and you have no tenderness when pressing on the plantar fascia, gradually return to running following the guidelines presented under "Prevention."
If you start treatment within several weeks of onset, it usually takes a minimum of 6 weeks of rest until the foot is no longer tender when pressed on, and you can then resume running. If you have had symptoms for several months and continued to train anyway, it will take at least 3 months and often 6 months for plantar fascia pain to go away.
If your plantar fasciitis is not improving after 6 weeks of the home treatments mentioned here, it is time to see your physician. Surgery may be considered as a last resort if all else has failed to provide relief.
You can prevent plantar fasciitis with good training habits, good shoes, and preventative strengthening and flexibility exercises. If you begin to develop plantar fasciitis, stop and analyze what could be causing it and make changes to return yourself to full function. Rather than trying to run through the pain, learn to listen to your body. The longer you ignore plantar fascial pain, the worse it's going to get and the longer it will take to rehab you back to your previous level of running.
Soleus stretch: Same as above, but start with your knee bent so that you feel a slight stretch in your calf or achilles. Maintain the angle of your knee throughout the stretch.
Bicycle stretch: Lie on your side. Keeping your top leg straight, bring your knee toward your nose until you feel a slight stretch in the hamstring. Maintaining this angle at your hip, start pretending you are pedalling a bicycle with the top leg. Make sure you feel a slight stretch each time your knee is straight. Reps: 10-30 for each leg.
If you feel any pops or clicks in your hip or back, try raising the top leg a little (making the thighs further apart) to eliminate the popping.
Keep your toes straight, with the toe pads on the floor. Use your fingers to help raise all the metatarsal heads (the ball of your foot). Do not let your toes curl under keep them long. Now relax. Reps: 7-10 for each foot.
As this exercise gets easier, let your fingers do less of the work until your toes can do the exercise unassisted. This can take up to three weeks. When your strength has improved to this point, you can progress to the following three exercises, which are best done in stocking feet on a slippery floor.
Active metatarsal head raising: Stand with your weight on both feet. Raise your metatarsal heads (the ball of your foot) while keeping your toes from curling under and maintaining your heel on the ground. Relax. Reps: 6-7. Do one foot at a time.
If you do more reps than you are ready for, you may well develop cramping in your foot. I once had a client who thought if seven reps were good, 10 were better. For good measure, she did the 10 reps 10 times in a day, and then she was unable to walk the next day from having used a set of muscles she had never exercised before. Please don't overdo it.
If you can do the previous exercises, you are ready for the next two.
Inchworm: Stand with your weight on one foot. Raise the metatarsal heads of the unweighted foot while you pull its heel closer to your toes. Next, raise your toes toward the ceiling, and then relax your whole foot with it flat on the floor. Your foot should move like an inchworm across the floor. Reps: 6-7 for each foot.
Horsepawing: Stand with your weight on one foot and the other foot slightly in front of you. Raise the metatarsal heads on the front foot. Lift your heel ever so slightly off the ground, maintaining the raised metatarsal heads, and pull your foot toward you so that it ends up behind you. Return this foot to the starting position in front of you. You should really feel this one in your arch.
Reps: 6-7 for each foot.
Toe pushups: Sit in a chair with your feet resting on the floor. Raise your heel as high as you can while keeping your toes flat on the floor. This is the starting position. Using your toe muscles, roll your foot upward until the weight of your foot is resting on the ends of your toes, like a dancer standing on point in toe shoes. Roll back down to the starting position. Reps: 10-20 for each foot.
The next three exercises start without any weight. When you get to 30-50 reps without pain, use a one-pound weight and drop your reps to 10-15. Gradually work back up to 30-50 pain-free reps. Move up to a two-pound weight and drop your reps back to 10-15. If you develop a sharp pain, stop. If you have gradually increasing pain along the outside or inside of your lower leg, stop for a few days. When you resume, drop your reps to the number you can do without pain.
You can make an inexpensive weight by taking an old sock and filling it with one pound of rice, beans, or sand. Tie off the end of the sock. Pin it around your foot just above your toes.
Ankle evertor strengthening: Lie on your side with your feet hanging off the end of your bed or a weight bench. Bend the toes of the foot that is closer to the ceiling slightly toward your head. This is the starting position. Now raise your toes toward the ceiling while keeping the rest of your leg stationary. Return to the starting position. Reps: 10-15. Now point your toes slightly away from your head. This is the starting position. Raise your toes toward the ceiling. Return to the starting position. Reps: 10-15.
Ankle invertor strengthening: Same as above, but do the exercises with the foot that is closer to the floor.
Dorsiflexor strengthening: Sit on a desk, table, or counter so that your feet don't touch the ground. Let your feet dangle comfortably. Bend your foot upward as far as you can comfortably go. Do not let your foot pull inward or outward. Return to the starting position. Reps: 10-15.
Allison Andrews Boldridge, M.A., P.T., is a senior staff physical therapist at Carle Foundation Hospital in Urbana, Illinois, treating orthopedic outpatients. Prior to moving to Illinois, she was the physical therapist for the North Carolina School of Performing Arts, treating primarily dancers.