The lower portion of your body is tougher than you might realize. Your lower leg, ankles, and feet have the tall task of bearing the brunt of your entire body weight any time you perform an activity that involves standing. So it’s easy to see that these forces can be rather substantial. As a result, the structures that support these regions are designed to be strong and durable in order to handle the regular, significant strain that is placed on them.
But extreme durability does not mean invincible, and there are limits to what these structures can do. When the lower leg, ankles, or feet, get overworked or over-trained, or if they aren’t strong or flexible enough to handle the demands placed on them, problems can arise that typically lead to injury and pain. There are many painful conditions that may develop in this region of the body, and most are considered overuse injuries that usually develop gradually from improper load management or training mistakes. Three of the most common lower extremity issues are shin splints, Achilles tendinitis, and plantar fasciitis, and below, we discuss some key details about these disorders by answering a series of frequently asked questions.
Q: What causes shin splints?
A: Medial tibial stress syndrome, more commonly referred to as shin splints, is a condition that develops when too much stress being placed on the tibia (shinbone). There are several muscles that attach to the tibia and provide it with support, including the posterior tibialis, soleus, and flexor digitorum longus muscles. Shin splints occur when any of these muscles is overworked, usually from repeated activities or after suddenly increasing the duration, frequency, or intensity of your workout. This leads to strain on the tibia and causes the muscles to also become strained at their insertion on the bone. The most common symptom is pain in the middle or bottom third of the inside of the shin, which usually gets worse with activity and decreases with rest. Runners and athletes involved in sports with lots of running are at the highest risk for developing shin splints, while those with flat feet or high arches also have an elevated risk.
Q: What can I do to relieve shin splint pain?
A: There are a number of changes you can make to your exercise routine and daily life to help you avoid further aggravation of the tibia and reduce your pain levels. We recommend the following:
- Take a break from physical activity and exercise, which can exacerbate your pain
- Apply ice to your shins for 5–10 minutes, 1-3 times a day
- Gently stretch the muscles around your shin or try self-massaging the region
- Always wear properly fitting shoes, especially while running or exercising; go to a specialty shoe store to have your gait analyzed, which will help you determine which shoes are best
- Slowly and gradually build your fitness level and avoid making extreme changes to your exercise regimen
- If you are an avid runner, try integrating some cross-training into your exercise routines like swimming or biking to reduce pressure on your legs
Q: What is Achilles tendinitis?
A: The Achilles tendon connects the calf muscle to the heel bone. It is the largest and strongest tendon in the body, and is capable of withstanding loads of up to 2,000 pounds when running. Achilles tendinitis is an extremely common overuse injury that involves inflammation of this tendon. It occurs most frequently in runners, particularly those who do lots of speed training or uphill running, or after suddenly increasing the intensity or duration of runs without ample recovery. This constant strain causes small micro-tears in the Achilles tendon and eventually leads to the characteristic inflammation and resulting symptoms. Most patients with Achilles tendinitis experience pain that comes on gradually as a mild ache in the back of the leg or above the heel, which may get worse after running or climbing stairs.
Q: What's the difference between Achilles tendinitis and Achilles tendinosis?
A: Tendinitis means "inflammation of a tendon," while tendinosis is a term used to describe a chronic—or long-term tendon injury. Thus, if a patient has Achilles tendinitis and doesn't address it or change their routine, it will further strain and damage of the tendon. Over time, this repeated trauma can lead to Achilles tendinosis, which is a more serious condition. Unlike tendinitis, inflammation is no longer present, but the damaged Achilles tendon instead becomes hard, thickened, and scarred. There is also degeneration at the cellular level in tendinosis that can include changes to the structure of the tendon, which does not occur in tendinitis. Together, this results in a loss of strength and can lead to further injury.
Q: What is plantar fasciitis?
A: The plantar fascia is a thick, connective band of tissue that runs across the bottom of the foot and connects the heel to the toes. It's a tough structure designed to absorb significant forces from standing, walking, and running, but can get damaged when it takes on too much stress. The result is a condition called plantar fasciitis, or inflammation of the plantar fascia, which is the most common cause of heel pain. This typically results in a stabbing pain near the heel that's most noticeable upon waking up and after standing for too long. Long-distance runners, individuals with flat feet or high arches, and those who are overweight or regularly perform any other weight-bearing activity are all at increased risk for plantar fasciitis.
Q: What other conditions can cause heel pain?
A: Although Achilles tendinitis and plantar fasciitis account for a significant proportion of all heel pain cases, they are not the only causes. Other conditions that may be responsible include the following:
- Intrinsic muscle strain: the intrinsic muscles are several smaller muscles located on the bottom of the foot, which support the arch of the foot and are sometimes referred to as the "core" muscles of this area; any of these muscles can become strained from overactivity, which leads to symptoms similar to plantar fasciitis
- Abductor hallucis tendinopathy: the abductor hallucis is another muscle that spans the arch of your foot, from the inner heel to the big toe; this muscle can be stressed when the foot continuously rolls inward and from other actions that strain the arch, which leads to tendinopathy; because the abductor hallucis covers a similar area as the plantar fascia, pain in this area is often mistaken for plantar fasciitis
- Heel bursitis: each heel has a bursa, which is a fluid-filled sac that cushions and lubricates the tendons and muscles that slide over the bone; this bursa can become inflamed from rapid increasing the intensity of one’s workout schedule, and the symptoms are often similar to those from Achilles tendinitis
In our next post, we'll walk you through three key stretches that you can perform on your own to lower your pain levels from any of these conditions.