Whenever runners gather to talk about their trials and tribulations, a topic shared as a "rite of passage" is the ominous stress fracture. It is a mystery affliction with runners in that a minor ache or pain progresses to an intense pain seemingly overnight. Initially, it is the type of annoyance that is not considered important enough to note in a running log, and it persists at a level that most feel they can run through.

A stress fracture is a tiny break in the meshwork of a bone. So small is this fracture that it cannot be seen on an x-ray in the early stages. A bone scan may be the only way to detect a stress fracture at this state. Bone is a living tissue, not just a ceramic casting. It is somewhat like a coral reef, a meshwork of tissue forming some of the strongest structures in our bodies. The outer layer of the bone is the periosteum, a thin layer containing many nerve endings and blood vessels that become inflamed and softened in the early stages of a stress fracture.

Many stress fractures (of tibia, fibula, or pubic arch) can occur when weak or imbalanced muscles become fatigued and pull excessively on the periosteum of the bone. Many people mistake the symptoms at this state to be tendinitis or "shin splints." This stage is the crucial "make or break" point. Further aggravation (running) will result in the formation of tiny fractures and exquisite pain. Other stress fractures, i.e, in the metatarsals, result because bone does not adapt to stress as readily as muscle. Weight-bearing exercise such as running normally strengthens bone. Excessive stress, or microtrauma, causes the breakdown rate of bone to exceed the repair rate, creating a weakness that leads to fracture.

Many stress fractures are related to improper training methods. By eliminating or controlling the risk factors listed below, you can reduce your likelihood of becoming a victim:

- sudden increase in miles

- hard running surfaces

- decreased shoe flexibility & cushioning

- downhill running

- racing too much

- muscle imbalances

- gait imbalances and unequal leg length

- in females, menstrual abnormalities or calcium deficiencies

If you recognize the problem at the "make or break" stage, you can take steps to preclude the formation of a fracture and speed recovery. Ice massage over the affected area for no more than five minutes at a time, combined with a modification of training to a non weight-bearing aerobic exercise is recommended until pain has subsided. Return to training should be a gradual process involving a switch to softer surfaces, such as grass or horse trails, and a concentration of strengthening weak and imbalanced muscle groups. This may not sound appealing, but it is much more pleasant than a three-month layoff from running due to a stress fracture. Seek the advice of a professional if you are unsure of your symptoms or if they worsen.

Once a full-blown stress fracture occurs, the best treatment is rest! Stress fractures will usually heal in 8 to 10 weeks, although some may require extended rest to avoid a recurrence. Aerobic fitness may be maintained through non weight-bearing exercises such as swimming or running in a pool with a 'wet- vest." The appropriate exercises will vary depending on the location of the fracture.

Following the above advice may help you avoid the stress of stress fractures!

Neil McLaughlin, a graduate of St. John's University and New York Chiropractic College, is a certified chiropractic sports physician and member of the ACA and VCA council on Sports Injuries and Physical Fitness. Ron Kuhk, the top area finished in the 1991 Marine Corps Marathon (6th, 2:26), is a graduate of Virginia Tech and New York Chiropractic College. Drs. McLaughlin and Kulik practice at the Commonwealth Chiropractic Center of Reston, where they treat many of the top area runners.