Plantar Fasciitis and Hamstring Tightness

Plantar fasciitis is a common cause of heel pain in adults. Several risk factors have been identified for developing the condition, although an exact cause has yet to be found. A 2011 study found that patients with tight hamstrings (the large muscles in back of the thigh) were 8.7 times more likely to experience plantar fasciitis than those without tightness1. These findings have led to speculation about how hamstring flexibility relates to heel pain.

A lot of attention has been given to the relationship between tight calf muscles and heel pain. Inflexibility in the calf muscles can limit ankle dorsiflexion. Loss of ankle motion then causes the arch to flatten out, potentially adding stress to the plantar fascia. Because the hamstring muscles attach farther away from the heel it’s not clear if they have a similar effect.

Tight Hamstrings and Plantar Fascia

Hamstring tightness was first connected to plantar fasciitis in 2005, when a group of researchers found that tight hamstrings may cause prolonged loading on the front of the foot leading to repetitive strain of the plantar fascia2.  Studies so far on the topic have only shown correlation, so it’s impossible to say whether tension in the hamstrings is a cause of the condition, a result of calf muscle tightness, or a completely unrelated finding.

People with tight hamstrings are very likely to have tight calf muscles (gastrocnemius and soleus). This relationship may explain some of the researchers’ findings. Very little hamstring flexibility is required for walking which makes the connection hard to determine. Jonathan Labovitz, the lead author of the most recent study, suggests that because of their long lever arm a small decrease in hamstring flexibility could have a big effect on the plantar fascia.

Nervous System Involved

Another possible explanation of how tight hamstrings are connected to at least some cases of plantar fasciitis involves the nerves of the leg. The sciatic nerve travels down the back of the thigh to the knee. It then continues as the tibial nerve through the calf before dividing into several small branches that innervate the bottom of the foot.

Irritation of the nerve anywhere along its course may produce a movement restriction that presents in the same manner as hamstring inflexibility3. Compression or tension of the nerve may produce the symptoms commonly associated with plantar fasciitis and could also cause the hamstring to appear tight4.

So we have three scenarios where the hamstrings might be related to heel pain:

  • Tension in the hamstrings can increase stress through the plantar fascia by way of a long lever arm, a change in forefoot loading, or a mechanism yet to be investigated.
  • Hamstring tightness does not cause plantar fasciitis, but is commonly found along with ankle inflexibility which is the more likely contributor to the problem.
  • Nerve tension or irritation can mimic hamstring tightness and can also be an underlying cause of heel pain in the absence of true hamstring inflexibility.

If hamstring tightness is a suspected contributor to plantar fasciitis, it’s reasonable to suggest hamstring stretching as a viable treatment. Since the exact link between the hamstrings and plantar fasciitis symptoms is not exactly clear, ankle flexibility and nerve mobility should also be addressed.

Hamstring Flexibility Tests

Before going into the actual stretches, first it would be helpful to define tight hamstrings. There are three tests you can easily do to gauge flexibility. For all three tests, failing to get the leg at a right angle to your body (or close to it) would show hamstring tightness.

The 90/90 Test:

When lying on your back, place one leg out straight and hold the other leg with both hands behind the knee and the thigh at a 90 degree angle to the floor. Keeping your upper leg stable, try to extend your knee and straighten the leg.

The Active Straight Leg Raise:

Lie on your back with both legs out straight. Raise one leg into the air as high as you can without bending you knee.

The Passive Straight Leg Raise:

Start in the same position as the active straight leg raise, but this time loop a towel or belt over your foot and pull your leg up into the air using your arms while keeping the knee straight.

Hamstring Stretches

Almost all forms of stretching have been found to increase flexibility, as long as the exercises are performed on a regular basis over a period of at least 4-8 weeks. All of the positions used in the flexibility tests could also be used as effective stretches.

Towel Stretch

This is a passive stretch that targets both the hamstring and calf muscles. A towel is placed over the ball of the foot and the leg is brought up until a gentle stretch is felt in the back of the leg. A static stretch like this would typically be held for 30 seconds. It is important that the knee remains straight. The placement of the towel should cause the ankle to bend toward you which helps stretch the calf as well as the nerves in the leg.

Towel Hamstring Stretch

 

Standing Rotation Stretch

This is a semi-active stretch in that it involves some movement of the leg. Place the heel of the leg being stretched on a chair or any other stable object about 15 inches off the ground. Bend forward at the waist while still maintaining an arch in the lower back until a gentle pull is felt in the back of the leg. The ankle of the leg being stretched should be dorsiflexed or pulled in toward the body (the opposite of pointing your toes). Once a stretch is felt, rotate the foot on the chair back and forth, making clockwise and counterclockwise motions. Rotating the leg in this way allows tension to be applied to the three separate muscles that make up the hamstrings.

Hamstring Rotation

 

Calf Stretching

This is the standard wall stretch. More information about this exercise can be found in an earlier post about how to perform the wall stretch properly.

Wall Calf Stretch

 

Neurodynamics

Nerve entrapment or limited nerve mobility may only be culprits in a subset of patients with symptoms of plantar fasciitis, but the nervous system is always involved when there is pain in the body. It’s difficult to determine if the muscles themselves are restricting range of motion or if it is the nervous system not allowing the movement as a protective response. In either case, consistent stretching should be effective at increasing hamstring range of motion.

Nerve stretching, as a treatment, usually differs from muscle stretching in that the stretch position is only held for a few seconds at a time. The three stretches pictured above will provide movement to the nerves that travel into the heel, particularly if the ankle is held in dorsiflexion. Individual nerves can be brought under tension by adding movements (e.g. neck flexion, foot eversion) although a complete discussion of nerve mobility is beyond the scope of this article.

Summary

Hamstring tightness has been linked to plantar fasciitis, although a cause and effect relationship has not been established. Tight hamstrings may have an effect on the biomechanics of the foot potentially leading to the development of heel pain. It is also possible that concurrent calf muscle tightness or nerve irritation may be factors. Hamstring stretching should be considered as a treatment for the condition as long as ankle flexibility and nerve mobility limitations are also addressed. Performing stretching exercises consistently is more important than the actual choice of exercises to target the hamstring range of motion.

Update: For a complete program check out my Treatment Guide for Plantar Fasciitis 

Sources

  1. Labovitz JM, Yu J, Kim C. The role of hamstring tightness in plantar fasciitis. Foot Ankle Spec. 2011 Jun;4(3):141-4.
  2. Harty J, Soffe K, O’Toole G, Stephens MM. The role of hamstring tightness in plantar fasciitis. Foot Ankle Int. 2005 Dec;26(12):1089-92.
  3. Orchard J, Farhart P, Leopold C. Lumbar spine region pathology and hamstring and calf injuries in athletes: is there a connection? Br J Sports Med 2004;38:502–504.
  4. Alshami AM, Souvlis T, Coppieters MW. A review of plantar heel pain of neural origin: differential diagnosis and management. ManTher, 2008;13:103-11.

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