Stress injuries begin as early-stage bone softening which, if poorly managed, can progress to full-blown fractures. Traditionally these injuries were managed by resting for 6-8 weeks before returning to physical activity, however this approach actually leaves patients worse off: with higher chance of re-injury and delayed return to sport timeframes (1).
Our bones are constantly remodelling themselves by laying down new bone cells. These cells are laid down according to where load passes through the bone, meaning we get stronger bone in the areas that need it most. Failing to load the bone means these cells aren’t laid down as much and the bone becomes softer. This is why simply resting for a prolonged period can actually worsen stress injuries, as the athlete returns to sport with an even weaker bone. Instead of resting, someone with a stress injury should be hitting the gym to load the bone safely through resistance training, combined with a carefully programmed gradual return to activity.
Bone stress injuries don’t happen out of the blue–there are always biomechanical factors that contribute to why an athlete develops a stress injury in a specific location (1). These also need to be addressed otherwise the injury will tend to re-appear.
SportsTec patient Emily presented to us with a stress reaction of her tibia, having started training for a half marathon. Assessing her gait showed her rear-foot to angle outwards (evert) more than her unaffected side. Increased rear-foot eversion increases the torsional (rotating) forces that are absorbed by the shin bone and so can elevate the chances of developing a stress fracture here (2).
We found her ankle range of motion to be significantly reduced on her affected leg, (likely due to an old ankle sprain which was never properly rehabilitated) which increases the risk of tibial stress fracture (3). You can see the difference between her ankles in the pictures below as she performs a knee-to-wall test:
Before returning Emily to her old running volume, we have been working on mobility exercises like the one in the video below using a powerband to assist in improving her dorsiflexion range to reduce her chances of re-injury.
In addition to internal biomechanical factors, technical errors such as poor running form can increase our risk of developing a stress fracture. Female runners with an increased vertical load ingrate (quicker absorption of impact from the ground) have a significantly increased risk of getting a stress fracture in their tibia (4). Easy technique changes such as simply being instructed to run“quietly” can massively reduce this loading rate (5), and so it is important that an athlete’s technique is looked at carefully before returning to sport so that these errors can be corrected.
Of course, for all these interventions to be effective, we need to be sure that the bone is actually capable of laying down the cells it needs to be strong. Bone stress injuries can be part of larger metabolic issues, such as thyroid disease, hormonal deficiency, and low body weight. That is why we work closely with GP’s to try and catch these medical issues before they progress
- Warden SJ, Davis IS, Fredericson M. Management and prevention of bone stress injuries in long-distance runners. J Orthop Sports Phys Ther. 2014;44(10):749‐765. doi:10.2519/jospt.2014.5334. https://pubmed.ncbi.nlm.nih.gov/25103133/
- Milner CE, Hamill J, Davis IS. Distinct hip and rearfoot kinematics in female runners with a history of tibial stress fracture. J Orthop Sports Phys Ther. 2010;40(2):59‐66. doi:10.2519/jospt.2010.3024
- Hughes LY. Biomechanical analysis of the foot and ankle for predisposition to developing stress fractures. J Orthop Sports Phys Ther. 1985;7(3):96‐101. doi:10.2519/jospt.19188.8.131.52 https://pubmed.ncbi.nlm.nih.gov/18802276/
- Milner CE, Ferber R, Pollard CD, Hamill J, Davis IS. Biomechanical factors associated with tibial stress fracture in female runners. Med Sci Sports Exerc. 2006;38(2):323‐328. doi:10.1249/01.mss.0000183477.75808.92. https://pubmed.ncbi.nlm.nih.gov/16531902/
- Phan X, Grisbrook TL, Wernli K, Stearne SM, Davey P, Ng L. Running quietly reduces ground reaction force and vertical loading rate and alters foot strike technique. J Sports Sci. 2017;35(16):1636‐1642. doi:10.1080/02640414.2016.1227466. https://pubmed.ncbi.nlm.nih.gov/27594087/