Stress fractures are a common musculoskeletal injury that occurs due to overuse. Too much load on a certain area of the body, whether through repetitive movements or higher intensity activity, can surpass the shock-absorbing capabilities of muscle and place excessive pressure on bone. This type of injury can be cumbersome, as it typically requires several weeks of rest to heal (1,2). Understanding the demands being placed on your musculoskeletal system and ensuring the right amount of rest is important to preventing stress fractures (1).
Muscles, bones, ligaments, tendons, and other soft tissues work together to generate movement and distribute load properly. Good form is one important aspect of preventing injuries – there are certain positions and movements that our musculoskeletal system is suited for, and going too far outside of that zone can result in strains, sprains, tears, and more. Another aspect is getting sufficient rest and reducing fatigue. Our muscles usually help absorb impact and reduce the force on our bones, but this protective effect is diminished when our muscles are fatigued (1). Both of these elements are related to stress fractures. Pain with activity is the main symptom; x-rays are often used to diagnose the condition (1).
This type of injury is especially common in a few groups, including runners, tennis players, basketball players, gymnasts, and military recruits (1-5). The lower leg has the highest incidence of stress fractures, particularly in the tibia (shin bone), the navicular bone in the ankle, and fifth metatarsal (the outermost long bone in the foot). This is thought to be because of the impact against the ground experienced by the lower leg when running and jumping (3,4).
Research has delved further into the risk factors of stress fractures, in addition to identifying demographics with high incidence rates. Anatomical data suggest that having thinner tibia or larger external rotation of the hip are linked to a higher risk (5). In military recruits specifically, a group of researchers found that acute weight loss in combination with intensive daily training was associated with stress fracture; this may reflect a sudden, drastic increase in physical activity and/or loss of bone mineral density (3). A highly influential study measured the biomechanics of runners with a history of stress fracture compared to matched controls without. The major finding was that loading rates and tibial shock levels were significantly higher in those with a history of stress fracture, highlighting the role of impact on the development of this condition (2). Finally, women are at higher risk, with some data estimating double the incidence compared to men (1,2).
Though stress fractures may seem like relatively minor musculoskeletal injuries, proper management is essential for full recovery. Stress fractures can easily worsen if not properly rested, and a minority of cases can turn into a long-term issue for the patient (1). The long recovery period can also interrupt training or competitions (1,2,3,4,6).
Conservative treatment for stress fracture is immobilization and no weightbearing for several weeks (1,4,6). Research suggests that immobilization with limited weightbearing is less successful than fully removing load on the injured bone (6). Some cases may require surgery, especially if the bone has a complete fracture and the pieces become displaced from their original positions (5). In addition, some data suggest that tibia stress fracture requires surgery in a greater percentage of cases, whereas navicular stress fracture can largely be managed conservatively (5).
The risks of stress fractures are real and should be treated seriously by athletes, coaches, recruits, instructors, and anyone else who suspects injury. Fortunately, many are able to return to sport after appropriate treatment.
References
[1] “Stress Fractures.” American Academy of Orthopaedic Surgeons. Updated October 2007. https://orthoinfo.aaos.org/en/diseases–conditions/stress-fractures/
[2] Milner, C. E., Ferber, R., Pollard, C. D., Hamill, J., & Davis, I. S. (2006). Biomechanical Factors Associated with Tibial Stress Fracture in Female Runners. Medicine & Science in Sports & Exercise, 38(2), 323–328. doi:10.1249/01.mss.0000183477
[3] Armstrong, D. W., Rue, J.-P. H., Wilckens, J. H., & Frassica, F. J. (2004). Stress fracture injury in young military men and women. Bone, 35(3), 806-816. doi:10.1016/j.bone.2004.05.014
[4] Mallee, W. H., Weel, H., van Dijk, C. N., van Tulder, M. W., Kerkhoffs, G. M., & Lin, C.-W. C. (2014). Surgical versus conservative treatment for high-risk stress fractures of the lower leg (anterior tibial cortex, navicular and fifth metatarsal base): a systematic review. British Journal of Sports Medicine, 49(6), 370–376. doi:10.1136/bjsports-2013-093246
[5] Giladi, M., Milgrom, C., Simkin, A., & Danon, Y. (1991). Stress fractures. The American Journal of Sports Medicine, 19(6), 647–652. doi:10.1177/036354659101900617
[6] Khan, K. M., Fuller, P. J., Brukner, P. D., Kearney, C., & Burry, H. C. (1992). Outcome of conservative and surgical management of navicular stress fracture in athletes. The American Journal of Sports Medicine, 20(6), 657–666. doi:10.1177/036354659202000606