By Leda McDaniel
You may be familiar with the terms “shin splints” and “stress fractures.” But, did you know that technically these both fall into the same broad category of what are called “bone stress injuries”? As they discuss In Podcast Episode #31 of More Than Miles: “It’s going Tibia Okay: Bone Stress Injuries,” physical therapists Dr. Kate Mihevc Edwards and Dr. Kacy Seynders explain that there is a continuum of bone stress injuries; at the less severe end of that spectrum are “shin splints” and “stress reactions” and (if not taken care of early) those could progress to more serious injuries like stress fractures.
Let’s break down (not literally!) what is meant by bone stress injury. One factor to consider that may set an athlete up to develop this type of injury is not allowing enough recovery time between hard training sessions or cycles. Bones (like other body tissues) exist in a dynamic cycle of tearing down and rebuilding that goes on constantly. Excess stress or loading (especially high impact loading) can place significant forces on bone that may be okay during one or a few training sessions, but without proper recovery time could lead to net breakdown of that tissue and associated injuries (i.e., bone stress injury).
Equally important in rebuilding healthy body tissues, bone included, is that you need to be taking in enough calories and “nutrient dense” calories at that! As a continuation of their discussion on the More Than Miles Podcast Episode #30: Dr. Courtney Gleason: RED-s, Menopause, and bone, Dr. Kate Mihevc Edwards and Dr. Kacy Seynders talk about important factors to consider for optimum bone health for athletes in the subsequent episode of the podcast: Episode #31 More Than Miles: “It’s going Tibia Okay: Bone Stress Injuries”
They begin their discussion by talking again about “RED-s” (Relative Energy Deficiency in Sport) One factor they mention is that taking in enough calories as an athlete can be tricky if an individual does not know how to fuel for their activity or if there are other factors contributing to a need for increased calories. For example, new mothers will have a greater caloric need if they are breast feeding (up to 500 more calories per day!) and they also need to be careful that they get enough calcium for bone health because of losing this nutrient in breast milk.
As mentioned above, there are multiple ways that an athlete or active individual may not be getting adequate calories for their activity level. Dr. Kate says she likes to think about “Energy availability” like a math equation:
“ENERGY AVAILABILITY” =
Energy you are putting in (food you eat!) – Energy you are using up
Dr. Kate and Dr. Kacy emphasize how important your nutrition can be by saying “you get out what you put in and you would not put unleaded gas in a Ferrari!” The amount of food/calories cannot be the only factor to consider, eating good quality food and a balance of macronutrients would be the ultimate goal. This could mean an increase of just 200 calories for some individuals. A wise investment could be to work with a registered dietician if athletes are unsure of what good nutrition may look like to support optimum training and performance.
Beyond just not knowing how to fuel for activity, Kacy discusses another potential cause of low energy availability, which is disordered eating. Body image issues could play a role in disordered eating and athletes may feel increased pressure regarding body weight or appearance if they are competing in a sport where body “look,” or aesthetics is part of the sport (e.g., dance or diving) or in a sport where societal messages may place pressure on an athlete to look a certain way (e.g., endurance sports like running, biking, swimming).
One potential cause for bone stress injuries could be dietary related (RED-s) and another potential cause could be biomechanical. An example of this may be a runner who consistently runs with a narrow “base of support” or foot strike width (i.e., feet landing too close together or crossing over midline) and by doing this places added force on the outsides of their foot. This would lead to more stress at that outside border of the foot and may lead to a stress fracture or injury at the 5th metatarsal bone (a common stress fracture location).
The most common locations for bone stress injuries in runners are:
Sacrum or Lumbar Spine
If an individual is having pain with running, walking or other weight bearing activities and that pain is sharp or aching near a bone they may be suspicious of a bone stress injury.
Other Key signs and symptoms of bone stress injuries could include:
Pain with high impact loading (e.g., jumping, sprinting)
Soreness or “tightness” at muscles near where they attach to bone
Pain that increases as you run farther (vs. tendon injuries (“tendinopathies”) sometimes “warm up” and feel better the farther you get into your run)
Focused tenderness at bone (vs. a broader area of pain)
Tuning fork test that causes pain
These are all great ways to start to suspect a bone stress injury. But, to truly diagnose a bone stress injury with certainty requires some form of diagnostic imaging like X-Ray or MRI. With X-Ray, not all stress fractures will show up immediately and so it is suggested that you wait 7-10 days to get this type of imaging. MRIs are more sensitive to pick up on stress fractures and can even pick up on “stress reactions” if there is associated bone marrow “swelling” that shows up on the image.
If an athlete has a bone stress injury the good news is that, as Dr. Kate says, “Bone heals 100%!” But, the tough news is that bone takes a LONG time to heal. It takes at least 6-8 weeks, if not 8-10 weeks to see bone healing on imaging and it could take up to 6 months or a year to fully heal! During this time it can be helpful to work with a physical therapist to guide some of the early rehab and maximize function in areas surrounding the injury. Once there has been some rest and recovery at the site of the bone stress injury and some healing has taken place it may be appropriate to start a “return to run” progression. The safest way to start to introduce back some running would be with a walk/jog program. Most runners could benefit from some coaching on how to do this (and why it is necessary!). In many cases, recovery from bone stress injury may be best if an individual has a team of healthcare support including a registered dietician, physical therapist, and potentially a psychologist or orthopedic doctor.
In bone stress injuries, just like with most injuries, prevention may be the best cure! Knowing how to fuel well, build in recovery, and work to improve running biomechanics could all help reduce risk of bone stress injuries.
Other tips to avoid bone stress injuries include:
Progress training volume gradually over weeks and months
Make sure you are eating enough nutrient dense foods to fuel your activity as an athlete (if you are unsure about this working with a registered dietician can be a great investment)
Track your weekly and monthly training volume and build in appropriate recovery time
Work with a running coach or trained physical therapist to address muscle imbalances or improve running form and biomechanics
Change training variables such as surface you are running on or intensity of workouts gradually over time
For a more in-depth discussion of bone stress injuries with Dr. Kate and Dr. Kacy check out: