A Complete Guide to Bone Stress Injury in Runners
What is a Bone Stress Injury?
A Bone Stress Injury (BSI) is a stress reaction/fracture to the bone
A runner’s worst nightmare: A BSI is an overuse injury of the bone, associated with repeated loading of bone by strenuous weight-bearing activities (like running!)
Defined as “focal failure of bone tissue to repeated loading that results in localized pain and/or an increased risk of complete bone fracture to typically tolerable loads.” (2)
Our bones are constantly changing
Our skeletons are dynamic and our bones are constantly remodeling (breaking down so they can build back stronger). When us runners ask too much of our bodies, don’t fuel properly, or have hormone imbalances, bones break down faster than they can be rebuilt. When this happens, runners wind up with stress reactions
What are causes of bone stress injuries?
Overuse
Poor Nutrition
Inadequate Recovery Time
Poor Bone Density
Grade/Severity of Bone Stress Injury
BSI’s are graded by how they look on MRI. A grade 1 stress reaction is the lowest severity, with grade 4 being the most serious. The grade of BSI can have a large effect on recovery and return to running timeline after fracture
Grade 1: Periosteal edema only— think bad shin splints!
Grade 2: Bone marrow edema
Grade 3: Bone marrow edema (more significant than 2)
Grade 4: Fracture line visualized
ALL BSI grades require some time off of running (usually between 6 and 16 weeks) (1)
Common Sites of Stress Fracture in Runners
FOOT
Metatarsal Bone Stress Injury
The metatarsals are the long bones in the foot that form our toes. They are often our first touch point to the ground with running gait, and therefore, take the brunt of impact from if our muscles are not strong or our mobility is poor. 90% of bone stress injuries in runners occur in the 2nd, 3rd or 4th mets!
Signs & Symptoms: Dull, achy, pin point pain that hurts with running, walking or jumping. Especially side or top of foot pain.
Navicular Bone Stress Injury
The navicular bone supports the arch of the foot and is considered a “high risk fracture site”, meaning there is low blood flow to the area and fractures here sometimes require surgery to fully heal. This also means a longer time away from running.
Signs & Symptoms: Dull, achy, pin point pain (in the arch or inside of the foot) that hurts with running, walking or jumping
Differential Diagnosis: Plantar fasciitis, posterior tibial tendinitis
LOWER LEG
Tibial Bone Stress Injury
Tibial BSI are one of the most common sites of stress fractures for runners. Tibial BSI can start as shin splints, and if not treated properly, can progress to a tibial stress reaction/fracture.
Signs & Symptoms: Dull, achy, pin point pain along the inside of the shin that hurts with running, walking or jumping
Differential Diagnosis: posterior tibial tendinitis, shin splints
Tibial Stress Injury can be any where along the yellow highlight (common areas shown in red)
The Bright Side!
MOST tibial BSI are “low risk” and Runner’s can typically continue with weight bearing cross training and heavy strength training. Tibial BSI generally have the fastest healing time and crutches are not needed.
PELVIS AND HIP
Femoral Neck Bone Stress Injury
Femoral neck BSI can be difficult to catch. They typically present as groin, hip flexor or thigh pain that does not improve with exercise. Recovery from femoral BSI is generally long and conservative (think crutches). Cycling and weight bearing exercises including strength training are usually restricted for a period.
Signs & Symptoms: Unable to hop on one leg, clicking/catching/instability, pain with hip flexion, occasionally pain down the leg into the thigh/knee with running
Differential Diagnosis: hip flexor tendinitis, adductor/groin strain, hip labrum tear
Sacral Bone Stress Injury
Sacral BSI are not super common, but do occur in long distance runners. The sacrum is a key stone bone in the pelvis, and is responsible for lots of weight bearing through the lower extremities. Recovery from a sacral BSI is generally long and conservative (think crutches and a long period of non-weight bearing).
Signs & Symptoms: Low back pain on one side that worsens with running, can be misdiagnosed as SI joint pain, sacral pain that is tender to palpation
Differential Diagnosis: SIJ pain, low back pain, poor post partum posturing
Testing for Bone Stress Injury in Runners
The only way to truly rule a stress fracture in or out for runners is with MRI imaging. However, MRI’s can be expensive and difficult to schedule. If you have the following symptoms, you should seeks a physical therapist who specializes in runners for an exam…
Pin point pain with weight bearing activities in any of the locations listed in this blog (starts with running, but as it progresses can feel with walking as well)
Dull and achy with activity but sometimes laying in bed at night or even inactivity
Pain during running that worsens vs gets better over the course of a run
Tenderness over bone
Pain with single leg hopping/jumping
The above symptoms coupled with the following medical history can increase likelihood of BSI
History of disordered eating
History of previous stress fracture or low bone density
Significant increase in mileage
Loss of menstruation cycle (if you are a person who menstruates)
Bone Stress FAQ’s
How long do I need to take off of running?
Most BSI require anywhere from 8-24 weeks off of running. Your doctor will determine this timeline based on grade/severity of the stress reaction, location of the injury and your general and running history
What can I continue to do during the recovery period?
It depends on the type of injury, but generally with “low risk” and low grade BSI, you can continue to strength train and perform low impact cross training (cycling and swimming). In fact, if allowed, we highly encourage strength training when recovering from bone stress injury. Strengthening your body will help support a healthy return to run.
Let’s not forget, rest, sleep and adequate nutrition are ways to recover!
Can I jump right back into running after my alotted “time off”?
NO! Your doctor should prescribe a “return to run” protocol based on the severity of your BSI. Most return to run after injury start with agility, plyometric and strength exercises, ease into a run/walk progression, and then we can start building the mileage in a safe, gradual way! We have to consider your body’s adaptation zone has shifted and your bones, muscles, tendons are getting used to loading again!
Should I restrict my eating during my time off?
NO. We hear this question a lot. It is SUPER important to continue to fuel adequately and not restrict during the recovery period. Contact our favorite sports nutritionists to help you through this time of healthy and rest
Other Bone Stress Injury Resources
Sources:
1.) Warden SJ, Hoenig T, Sventeckis AM, Ackerman KE, Tenforde AS. Not all bone overuse injuries are stress fractures: it is time for updated terminology. Br J Sports Med. 2023 Jan;57(2):76-77. doi: 10.1136/bjsports-2022-106112. Epub 2022 Nov 14. PMID: 36376061; PMCID: PMC9812969.
2.) Hoenig, T., Ackerman, K.E., Beck, B.R. et al. Bone stress injuries. Nat Rev Dis Primers 8, 26 (2022). https://doi.org/10.1038/s41572-022-00352-y
3.) Nussbaum ED, Gatt CJ Jr, Bjornarra J, Yang C. Evaluating the Clinical Tests for Adolescent Tibial Bone Stress Injuries. Sports Health. 2021 Sep-Oct;13(5):502-510. doi: 10.1177/1941738120988691. Epub 2021 Feb 12. PMID: 33576312; PMCID: PMC8404772.
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