Your calves ache when you exercise and you don’t know why. Achy shins are a common complaint among active people and runners are at high risk, especially those who run long distances. However, anyone who is active can be sidelined by an achy shine. Two of the most common causes of pain in the calf are shin splints and stress fractures. How can you tell the difference between the two?
Know Your Calf Muscles
The function of the muscles that make up your calves is to flex your leg at the knee joint and flex your feet at the ankles. You use your calf muscles when you walk, jump, and run, but they really come into play when you pick up the pace. During a sprint or a jump, your calf muscles must generate a significant amount of force to get your legs off the ground.
Three muscles make up the calf. The biggest one called the gastrocnemius runs down the back of the lower leg. Underneath the large gastrocnemius or gastroc, is the smaller soleus muscle. Another tinier muscle called the plantaris runs between the gastrocnemius and soleus. It starts on the lateral side of the gastrocnemius muscle and attaches to the medial aspect of the heel bone. These muscles run from the level of the knee down to the heel. These muscles work together to flex your legs and feet.
What Are Shin Splints?
The discomfort of shin splints is often mild, but if you ignore it, this common malady can become quite painful. Another name for shin splints is medial tibial stress syndrome, an appropriate name since repeated stress and overuse of the medial part of the tibia or shinbone causes shin splints.
Shin splints are more often due to overuse than an acute injury. They develop when the muscle and bone tissue (periosteum) in the leg are moved repetitively. That’s why they’re so common in runners. The discomfort may come on gradually after a sudden increase in physical activity. Runners are at a high risk when they suddenly change the distance they run, the frequency of their workouts, or introduce sprints into their routine when they aren’t accustomed to sprinting.
Running up or down hills can also stress the muscles in the calves enough to cause shin splints. Anatomical problems in the feet also increase the risk of shin splints. For example, having very high arches or flat feet both increase the risk as this impacts how much stress your tibial has to absorb when your foot strikes the ground.
Shin splints often occur after sudden changes in physical activity. These can be changes in frequency, such as increasing the number of days you exercise each week. Changes in duration and intensity, such as running longer distances or on hills, can also cause shin splints.
How do you know if you have shin splints? You might experience pain or tenderness along the medial aspect of your tibia. The pain often worsens with activity and persists even after the workout is over. Some people can press on a spot along the medial aspect of their tibia and identify an area of point tenderness or swelling.
Stress Fractures of the Tibia
The tibia bone can also develop one or more small cracks in the bone called stress fractures. A tibial stress fracture can cause some of the same symptoms as shin splints, making it harder to distinguish between the two. Like shin splints, a tibial stress fracture causes pain, soreness, and sometimes swelling along the tibial bone during or after exercise. If the pain is along the medial side of the lower leg, it’s hard to distinguish a stress fracture from shin splints.
Who gets them? People who run, jump, and do gymnastics are more prone to stress fractures due to repetitive trauma to the lower legs. As with shin splints, the risks of getting one increases with a sudden increase in training or mileage. Women also appear to be more prone to stress fractures.
It’s important to distinguish between a stress fracture and shin splints since stress fractures require at least six weeks of rest to heal properly. Continuing to exercise with shin splints is uncomfortable and may prolong the condition but exercising with a stress fracture will delay healing and can even lead to larger fractures. Plus, continued stress on the tibia can cause incomplete or abnormal healing that leads to chronic problems with the affected leg.
Is It Shin Splints or a Stress Fracture?
Shin splints and stress fractures both cause calf pain and discomfort when you bear weight on the leg. When you press on the tibial bone, shin splints will usually feel uncomfortable along a significant part of the bone, several inches. In contrast, the pain of a stress fracture is often localized to a small, discrete area. The pain of a stress fracture may also worsen over time, if you don’t rest, as the fracture can extend itself. In some cases, it can turn into a full-blown fracture.
Unless you have very mild symptoms, it’s best to get calf pain checked out by a health care professional. Physical examination may be useful for distinguishing between the two, but a more definite test is an MRI scan. An MRI can identify a stress factor and involves no radiation. It’s important to distinguish between shin splints and a stress fracture since the latter can cause future problems if it goes undetected. There are several other conditions that can cause calf pain, including compartment syndrome, Achilles tendonitis, and a blood clot in the leg.
How to Prevent Stress Fractures and Shin Splints
The best way to not deal with the discomfort of shin splints and stress fractures is to prevent them. Some people who develop shin splints roll their feet inward when they run. Sometimes, you can correct this problem with an orthotic or by wearing a shoe with good stabilization. Visit a sports medicine physician or podiatrist and have them analyze your feet and recommend an appropriate orthotic or shoe. Also, vary your training by cross-training so you aren’t exposing your legs to the same repetitive stress.
Some studies also suggest that strengthening the calf muscles may lower the risk of stress fractures. For example, a 2009 study found that runners who developed stress fractures had smaller muscle size and bone strength. So, keep strength training! It’s one of your best defenses against muscle loss, muscle weakness, and injury.
References:
- Ortho Info. “Shin Splints”
- Ortho Info. “Stress Fractures”
- Med Sci Sports Exerc. 2009 Dec;41(12):2145-50. doi: 10.1249/MSS.0b013e3181a9e772.
