runningStress fractures are common in those new to running and sport, women, and certain ethnic groups. The most common sites are the shins, hips and feet. Stress fractures occur because the forces placed on your bone exceed its ability to adapt. This results in a stress response and causes the bone to break from the inside out. The pain is often misinterpreted as muscular which gives the runner a false sense of security. The most common muscular diagnosis for leg pain is Shin Splints. Shin Splints is not a legitimate diagnosis as it is actually describing what is happening to the muscle in your leg… the splinting response. The muscles in your leg will seize or spasm in response to bone injury thus the term splint. To put this in perspective one would use a splint to stabilize a broken bone, torn tendon or a torn ligament. So your body’s normal response to bone injury is to “splint” the area by tightening the muscles in that area.

There are four things that commonly occur in the shin region, one of which is stress fractures. The first is Posterior Tibialis tendinitis. The second is bone and marrow edema in the tibia. The third is Periostitis of the tibia and lastly there is stress fractures of the tibia or fibula.

  1. Shin Splints a.k.a. Posterior Tibialis Tendinitis can occur in those new to running and sport or those runners that traumatically increase their overall distance too quickly. The Posterior Tibialis muscles job is to contract eccentrically during the stance phase of gait. In effect it is trying to slowly lower your arch as you make impact with the ground in an effort to stabilize your foot. Your foot hits the ground 1500 – 2000 times per mile during running and you land with 3 to 5 times your body weight. It takes time for the posterior Tibialis muscle to adapt and strengthen to this repetitive strain on it. For this reason if it gets overworked it will strain, thus resulting in tendinitis. “itis” means inflammation. Inflammation is not a primary condition, meaning, it is your body’s normal response to injury, in this case the tendinitis is resulting from micro tears in the tendon where it attaches to the bone. In addition to its primary action the Tibialis Posterior muscle also acts as a shock absorber. Once injured it does not function well in this capacity which leads to excessive impact on the bone and can result in stress fractures.
  2. Bone Marrow Edema occurs in the hollow cavity of bone called the medullary cavity. Due to repetitive impact and your body’s inability to dissipate it the cells inside of your bone can swell. This places excess pressure inside the bone and results in pain and will eventually lead to stress fracture if not rested properly. The problem is the excess pressure that is building inside the bone needs to find a way out and will result in the bone cracking as the pressure tries to leave the medullary cavity. Bone marrow edema is treated in a similar fashion as stress fractures.
  3. Periostitis is inflammation of the thin layer of skin that surrounds the bone. The periosteum is the region where the tendon fuses onto the bone. Due to the repetitive pulling by the tendon on the periosteum it will sometimes inflame and can even detach from the bone resulting in significant pain and an inability to run. Periostitis is a serious condition and is also treated similar in fashion to stress fractures.
  4. Stress Fractures are the end result of repetitive excess strain on the muscle, tendon and bone without giving your body enough time to adapt. If given time to adapt muscles tendons and bones will grow back bigger, better, and stronger. This is known as Wolfe’s law. This law states that by providing stress in the proper amounts your body will adapt to that stress by growing stronger in response to it. There are a few ways to diagnose a stress fracture. One way is to jump up and down on the affected leg and record whether or not there is significant pain in the area that hurts during or after running. In our clinic we use a pulsed ultrasound over the affected region. If any pain is present stress fracture is suspected. Over the years I have learned that there is one ominous sign, in particular … limping after running. Runners will often claim that their leg does not hurt much while running but that they limp afterwards. Limping after running is never good and should make you highly suspicious of bone marrow edema or stress fracture. X-rays do not typically show stress fractures or bone marrow edema. MRI is considered the gold standard of imaging for stress fracture, periostitis, bone marrow edema and Tibialis Posterior tendinitis. If you’re insurance does not cover MRI or you have a large deductible SDRI can get you a cash price for only $500.

SDRI's Alter-GAt the San Diego Running Institute we treat running and sports related injuries. We employ the latest technology including Alter G rehabilitation which allows the runner with stress fractures to continue running without further injury and accelerate the healing response. Alter gravity treadmill training takes advantage of two important sports medicine principles. The first is Wolfe’s law. By lowering one’s body weight thus decreasing the amount of impact on the bone the Alter G allows the runner to continue running without further injury and also stimulates the bone in the proper amount so that it grows back bigger, better and stronger. The second principle is called the S.A.I.D principle, this stands for Specific Adaption to an Imposed Demand. What this means is that by running on the altered gravity treadmill your body will adapt specifically to the demands imposed by running and will get bigger, better and stronger for the next running session that will be imposed. Gone are the days of archaic physical therapy which places a runner in a situ