The plantar fascia is a multi-layered fibrous tissue that begins at your heel and runs longitudinally along the bottom of your foot and attaches to the base of your 5 toes. The plantar fascia supports the arch of the foot by increasing in tension with weight bearing. Studies show the plantar fascia takes up to 14% of the total load of the foot with weight bearing. It begins to elongate as soon as the heel hits the ground, and continues through the weight bearing phase of gait, acting as a spring to push off for acceleration during walking and running.
Plantar fasciitis occurs when the fascia becomes inflamed secondary to excessive overuse or stress to the tissue. It tends to be degenerative in nature, with microtrauma to the tissue being caused by repetitive stressing of the arch during weight bearing. Studies of the injured tissue show a decrease in blood flow, increased scar tissue formation, and a lack of inflammatory cells. A person with plantar fasciitis will complain of pain in their heel or arch in the morning when they first put weight on their foot or pain after they have been sitting for a long time and then put weight through the foot with their initial step.
There are many factors that can lead to plantar fasciitis. Extrinsic factors are typically training errors. With athletes, there is typically an increase in speed, distance, or intensity of their workouts. Adding plyometrics, hill work, or speed work is a common factor. Improper footwear is another extrinsic factor commonly seen. The cushioning properties of running shoes break down quickly. Running shoes should be replaced every 300 to 500 miles to maximize shock absorption. It is also important to purchase the right type of running shoe for your particular foot and body type.
Intrinsic factors that can lead to plantar fasciitis include leg length discrepancies, excessive rotation of the leg due to muscle imbalances or weakness, and foot type. Both very flat feet and feet with very high arches can be prone to this injury. Decreased dorsiflexion (moving your foot up by raising the front of your foot) can create plantar fasciitis by changing the mechanics of your gait. This loss of dorsiflexion may be caused by a prior injury, or by tight calf musculature.
People who pronate excessively are also more prone to plantar fasciitis. After the foot hits the ground it rolls inward and flattens the arch. This motion is known as pronation. Pronation allows the foot to become flexible and adapt to the ground. Excessive pronation strains the plantar fascia in two ways. First, it creates an overstretching. Secondly, it forces the foot to work harder to push off because it is an inefficient position.
Proper exercise not only helps to speed healing by increasing blood flow, it also allows you to stay in shape. Cross training techniques that are not stressful to the plantar fascia include biking, swimming, and Stairmaster. Walking, running and sports involving running will continue to stress the injured plantar fascia.
Stretching is also helpful. Tight calf muscles can contribute to increased stress on the plantar fasciitis by factors previously mentioned. Gentle, pain-free stretches keep the fiber flexible during the healing phase. This is important to promote proper recovery. However, stretches that induce pain or involve quick movements do more harm than good.
Since pain occurs after long periods of non-weight bearing, before standing up from prolonged sitting or getting out of bed, move the foot in circles one or two minutes to increase blood flow to the tissue for warm up. After this, you should get up slowly and preferably do some easy stretching. As you walk, begin slowly and gradually get to a normal speed.
Recommendations to reduce pain and stress on the plantar fascia include the following:
- Do not walk barefoot and limit footwear with little or no arch support.
- Wear running sneakers or shoes with a cushioned heel and increase arch support at all times.
- Do proper pain-free stretches after workouts, before bed and any other time you want for your calf musculature. Stretching is most effective when you are warmed up. Hold 30 seconds for 3 repetitions.
- Move the foot in continuous pain-free circles for 1-2 minutes before getting out of bed or getting up after prolonged sitting.
- When initiating walking, start very slowly.
- Avoid running and prolonged walking. Continue to do cardiovascular activities such as biking, swimming, Stairmaster, and elliptical for your exercise as long as they do not increase pain.
- Avoid walking and prolonged standing on had surfaces (concrete), soft / unsupported surfaces (sand), and uneven surfaces (rocky trails).
- If you must walk or run, try to have the slope of the road support your arch (i.e. the leg that needs to be supported should be on the downhill side of the slope).
- Use a golf ball to roll along plantar fascia as a massage 5-10 minutes several times per day. Massage increases blood flow to an area, which helps healing and breaks up tissue adhesions that may restrict motion.
- If possible, get someone to show you how to properly tape the foot or try an arch support insertion.
- Night splints can be worn during sleep to keep the foot dorsiflexed, which allows the plantar fascia to rest in a neutral position. The plantar fascia during sleep usually stays in a shortened position. When we first get out of bed and put weight through our feet the plantar fascia stretches out and may result in pain. The type of splint can be determined by your MD or physical therapist.
- Ice may be helpful in the initial stages of the injury. Elevate your foot and put ice on the area for 10-15 minutes. A 5 minute ice massage directly to the painful area may also be helpful. However, evidence suggests there may not be inflammatory cells present with this
injury, especially in the chronic stages. In those cases, heat may be more helpful.
Plantar fasciitis, if not addressed properly, can become a chronic problem, which may
significantly limit activity due to pain and dysfunction. The earlier one gets proper medical
attention the faster the rate of return to activity.