Shin splints, stress fractures, compartment syndrome, tendinitis and more.
The shin or lower leg includes everything between the knee and ankle, and is a prime spot for pain in runners. Let’s look at the anatomy of the area and some of the most common problems runners get in and around their shins.
The tibia is the large bone of the lower leg; the fibula is the thin bone along the outer aspect of the lower leg. There are four compartments in the lower leg, each of which includes several muscles along with a nerve, artery and vein. Tissue known as fascia surrounds each compartment. The muscles in these compartments control motion of the foot and ankle. Many of the thigh muscles attach to the top of the tibia and fibula. Differentiating between specific causes of lower leg pain may be difficult due to overlapping symptoms.
SHIN SPLINTS
This term is used to describe pain along the inner tibia. Typically the pain involves a third or more of the bone. The pain develops while running and resolves afterwards; it usually improves with continued training. The inner aspect of the tibia will be tender to touch, with no area more tender than another. There may be mild swelling in the lower leg.
The pain is due to microscopic tears of the muscle away from the lining of the bone. Predisposing factors include overpronation and running on hard surfaces. Shin splints are more common in novice runners. Treatment of the problem includes icing after exercise, appropriate footwear or possibly arch supports and changing running surface. Improving flexibility of your calf muscles and the strength of the muscles in the front and sides of your lower leg are important in treating and preventing this problem. To strengthen the muscles of the lower leg, place a weighted ring on your foot. Point your foot up, in and out 10 times; perform three sets. The pain usually subsides as fitness improves.
STRESS FRACTURE
Also a source of bony pain, a stress fracture is an injury to bone due to repetitive microtrauma. Bone responds to stress by becoming stronger; the stress causes bone resorption, which is followed by bone building, as long as the stress isn’t overwhelming. With excessive stress, resorption is greater than the building phase, leading to microscopic trauma and microfractures. Repetitive microfractures result in a stress fracture.
The typical presentation is bony pain with impact. Initially the pain develops during the run, but may even resolve during the course of the run. Over time, the pain is present throughout the run and may be present while walking. Mild swelling may be present in the lower leg. Continued impact on a stress fracture can result in a complete fracture through the bone.
On clinical examination there is a specific area of significant bony tenderness. There is pain or even inability to hop on the single leg. X-rays will not reveal abnormalities for at least two weeks and possibly much longer. MRI and three-phase bone scans can detect stress fractures much earlier.
Stress fractures in runners tend to occur in the lower aspect of the fibula and in the upper and lower aspects of the tibia. They can also (though less commonly) occur in the front of the tibia; this stress fracture can be problematic in healing due to the shape of the tibia.
Treatment begins with stopping impact activities. A boot, cast or crutches may be required if there’s pain present when walking. Nonimpact cross-training may be performed. In some cases, a long air cast (stirrup brace that covers the lower leg) may allow a more rapid return to running. Otherwise, most athletes can return to a gradual running program in six to eight weeks.
The reason for developing the stress fracture should be determined. Increasing training too quickly (intensity and/or distance) is the most common cause of this injury. A low bone density and possibly a low vitamin D level can predispose to stress fracture. Training schedules, diet and for women, menstrual history, should be reviewed to find risk factors for the development of stress fractures and any problems detected should be corrected.
COMPARTMENT SYNDROME
During exercise, muscles swell, increasing in volume by up to 20 percent. If the fascia that surrounds one or more of the compartments is too tight to allow the swelling to occur, it acts like a tourniquet, restricting blood flow and putting pressure on the nerve. This causes pain and possibly numbness in the lower leg and foot. The muscles may not function normally.
The runner with chronic exertional compartment syndrome complains of pain that develops at a certain point during the workout and becomes progressively worse, often to the point of having to slow or end the run. Slapping of the foot as it strikes the ground is another common complaint. The symptoms will resolve within a short while after the exercise stops, as the swelling resolves. Because of this, the runner’s leg usually seems normal when examined by a medical professional.
Compartment syndrome is diagnosed by measuring the pressure in each of the compartments in the involved legs before and immediately after a run. (The run is usually performed on a treadmill and is continued until significant symptoms develop.) The treatment for compartment syndrome is surgery, after which most athletes are able to return to full activities.
TENDINITIS
This is a common problem in the lower leg. Tendons are part of a given muscle that attaches to a bone. Inflammation of the tendon causes pain when the muscle is stretched or contracted. The tendon may swell; strength and flexibility are both diminished. The tendon will be tender to touch.
Achilles tendinitis is common in runners. The posterior tibialis (inner aspect of the ankle) and the peroneal (outside aspect of the ankle) tendons may also be inflamed. Common causes of Achilles tendinitis include a sudden increase in hill work or speed work. In addition, switching from training shoes to racing shoes without having worn the racing shoes in a long time may aggravate the Achilles tendon because of the racing flat’s lower heel. Overpronation may cause inflammation of the posterior tibialis tendon, while a stiff, underpronated gait may inflame the peroneal tendon.
Treatment for tendinitis includes icing for 15 to 20 minutes three to four times a day, adjusting training to decrease the off ending stressors and modifying footwear when indicated. The peroneal and posterior tibialis muscles can be strengthened with the exercises described in the section on shin splints. Stretch the Achilles tendon once you’ve warmed up with easy jogging.
As flexibility improves, strengthen the Achilles this way: with the heels hanging off the back of a step, the heels should be lowered and raised repeatedly. Do this slowly at first, then more quickly as your strength improves. Then progress to single leg raises, starting slowly and gradually increasing speed over training sessions. Add some heel lifts to shoes when the Achilles tendon is painful; this will alleviate some of the stress on the tendon. As pain resolves and flexibility and strength improve, the lifts may be removed.
Prolonged problems with the Achilles tendon may cause degenerative changes, known as tendinosis. The treatment is similar to tendinitis. Recalcitrant cases may be treated with deep tissue massage and manipulation (such as active release therapy), injections with platelet-rich plasma and similar substances and, as a last resort, surgery. Cortisone injections shouldn’t be performed in the Achilles tendon due to the risk of rupture and weakening of the structure during the first 10 to 14 days following the injection.
INFLAMMATION
The large calf muscles (gastrocnemius and soleus) may occur due to a sudden injury, in which the muscle tears. This most commonly occurs in the inner belly of the gastrocnemius at the junction of the muscle and the tendon. When this happens, you might feel a pop. Pushing off will be extremely painful.
There will be mild swelling and possibly some bruising in the leg. Treatment includes using a boot and/or crutches. Ice should be used often. As pain subsides, strength and flexibility exercises as discussed in the section on Achilles tendinitis should be performed. When the runner is able to weight bear on the affected leg without pain, heel lifts should be added to the shoes. Progress the exercises as discussed above. Lesser injuries, in which the muscle is inflamed, but not torn, may be treated like tendinitis.
COMPRESSION OF THE POPLITEAL ARTERY
Compression of this artery during exercise is an uncommon but potentially severe source of pain. This usually occurs at the level of the knee. With compression of the artery, blood flow to the leg muscles is diminished, causing significant pain until the exercise stops. The blood flow needs to be evaluated during exertion to diagnose this problem, and surgery is the treatment.
“HELP ME GET BETTER!”
Use medication cautiously. Short-term use (five to seven days) of nonsteroidal anti-inflammatory medications (such as ibuprofen and naproxen) may help relieve pain, as long as there isn’t a contraindication to usage, such as gastrointestinal, liver or kidney problems. Even then, these medications should be used with caution. There is equivocal data in the scientific literature on use of NSAIDs with stress fractures; several studies have suggested that these medications may impede the healing of fractures. You may use acetaminophen for pain control if there are no medical contraindications to its usage.
If you have a stress fracture, discontinue running until your health care provider gives you the green light. Compartment syndrome will not resolve without treatment. When the symptoms are severe enough, options are surgery or eliminating running. A torn gastrocnemius usually precludes running due to pain. You can continue some running in the case of the other problems. This involves decreasing the distance and intensity of workouts, with the amount of modification determined by the severity of the symptoms. The goal is to minimise symptoms while running; in addition to running, you can cross-train if it doesn’t aggravate the problem. Training should be increased gradually and ice should be used following the workout. Don’t forget to perform the strength and flexibility exercises as training increases.
FLAT OUT NECESSARY
Wear your racing shoes for at least half of your speed workouts and tempo runs. Before a marathon, do at least two long runs in the shoes you’ll wear on race day. Otherwise, you’re likely to get lower leg soreness immediately after or even during your race.
Sport podiatrist Brian Fullem says, “When you consider that racing flats often have less than 2-3cm of cushioning in the heels, it’s easy to see why suddenly subjecting your legs to such a large difference can strain the calf muscles.” If you haven’t been wearing racing flats on a regular basis, introduce them slowly by wearing them on a series of post-run striders a couple of times a week. Says Fullem, “Then gradually build up to a full workout, starting with shorter workouts. For example, if your track workout ends with 200- or 400-metre repeats, put on the flats for this portion of the workout.”
