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Bone Stress Injuries in Runners: Part 2

Photo by : Tom Robertson Photography

This post will discuss some of the key components of the rehabilitation process that should occur in the case of a bone stress injury (BSI) diagnosis. Setting expectations for the rehab process may help the runner commit to the plan of care and advocate for him/herself within the treatment team in order to promote optimal outcomes. Refer back to Part 1 for more information regarding basic pathophysiology, risk factors, and diagnosis of BSIs.

Outline

Initial Plan and early rehab

• Establish unloading parameters

• Address potential underlying contributing factors 

• Establish initial cross-training guidelines and activity modification

Mid-stage rehab: pain-free Load progression

• Load progression as healing occurs

Return to run

• When to begin and what to expect

Initial Plan and Early Rehab

The initial plan of care is focused on setting the athlete’s expectations for approximate time to return to sport, addressing contributing risk factors, establishing weight bearing restrictions if necessary, and outlining guidance on activity modification. Combining knowledge regarding the anatomical location and imaging grade of BSIs provides a framework to formulate the management strategy and potential time to return to running. Recall the discussion in part one regarding high-risk vs. low-risk sites as well as the BSI grading system:

Warden et al. 2014

Fredricson BSI grading classification:

• Grade 1: Periosteal edema only. Return to sport: 11.4 weeks (+/- 4.5 weeks)

• Grade 2: Bone marrow edema (visible only on T2 weighted sequences). Return to sport: 13.5 weeks (+/- 2.1 weeks)

• Grade 3: Bone marrow edema (visible on T1 and T2 weighted sequences). Return to sport: 18.8 weeks (+/- 2.9 weeks)

• Grade 4: (4a) Multiple discrete areas of intracortical signal changes; (4b) Linear areas of intracortical signal change correlating with a frank stress fracture. Return to sport: 31.7 weeks (+/- 3.7 weeks)

establish Unloading parameters

Low-risk BSI: Unloading guidelines are guided by pain rules. The presence of pain either during or after activity indicates that the pathological bone is being excessively loaded. The goal throughout rehab is for the athlete to remain pain-free. Walking should be limited to performing activities of daily living. If a normal gait pattern cannot be used or symptoms are produced either during or after walking, partial weight bearing using crutches or a walking boot may be indicated until walking becomes pain-free.

High-risk BSIs are also managed with load modification that promotes pain-free movement. However, due to the risk of delayed healing, and risk for progression to complete fracture, the athlete is more likely to undergo a longer period of non-weight bearing compared to low-risk sites. The table below is an example outlined by Warden et al. (2014) based on their clinical experience.

Identification and Initial Management of Potential Risk Factors

As discussed in Part 1, bone health is very complex, and the occurrence of bone injury may indicate an issue with training load management, energy availability, diet, hormone health, bone health, and sleep habits. The initial period following BSI diagnosis is a good time to evaluate and address potential contributing factors, as it is a time when the runner may be most receptive to behavioral change.

• Training Load Management: When the runner returns to training, it may be helpful for them to identify the potential spike in training load, change in running shoes or terrain or lack of recovery that may have lead to his/her injury in the first place. Sometimes the culprit may be obvious, for example a high school cross country runner who increases average weekly mileage from 35 miles/week to 70 miles/week as she initiates training at the collegiate level. A less obvious example would be a case where running mileage was not significantly increased but addition of non-running activity (i.e. skiing) was introduced, or an increase in elevation gain/loss or intensity occurred leading to a large increase in cumulative bone loading. Or, a close look at the runner’s training habits may reveal insufficient rest and recovery to be a contributing factor. By combining knowledge of recent running progressions, changes in training, recovery habits, and life-long physical activity participation, it may be possible to provide a runner returning from a BSI advice regarding future running program design (1).

• Screening for Relative Energy Deficiency in Sport (RED-S) and Female Athlete Triad (or male equivalent): As discussed in part one, the combination of low energy availability, decreased sex hormones (amenorrhea), and low bone mineral density is quite common in runners and places an individual at higher risk for BSI. This combination is called the female athlete triad (Triad), and has more recently become known as Relative Energy Deficiency in Sport (RED-S) due to the inclusivity of males and acknowledgement of the many other physiological and performance based consequences that result. The existence of any of the Triad components should prompt more thorough investigation for the others. Screening and early intervention in adolescent females (and males–see below) for components of the Triad are especially important when you consider that 90% of peak bone mass is attained by 18 years of age. Adolescence is a crucial time for optimizing bone health (3). Keep in mind that consultation for a BSI may be the first time that a runner’s issues associated with RED-S are identified. Questions regarding menstrual regularity, onset of menarche, history of eating disorder, purposeful or accidental low energy availability, and previous stress fracture history should be included. Identification of any issues of concern warrants appropriate referral. The 2014 Female Athlete Triad Coalition Consensus Statement recommends the following risk assessment to be administered in cases where presence of the Triad is suspected (1,3):

Female Athlete Triad: cumulative Risk Assessment

De Souza et al. 2014

Female cross-country runners who fall into moderate-risk category have been shown to be twice as likely as those in the low-risk category to sustain a BSI, and high-risk athletes were nearly 4 times as likely (4).

The risk assessment tool has been modified (see image below) to be applicable to males. Research has shown that each one point increase in cumulative risk score was associated with a 27% increase in prospective BSI risk (5).

modified cumulative risk assessment tool

Kraus et al. 2019

Here is a link to a lecture by Dr. Kathryn Ackerman on the Triad and RED-S that provides a great summary of the current literature on the subject. It specifically addresses bone health beginning at 3:45. Refer back to part 1 for links to even more resources.

• Bone density: BSIs can occur in relatively healthy bones with normal density. So when should the runner consider a bone density scan to assure that underlying bone health is not contributing to the injury? Bone mineral density scan is recommended when one or more of the “high risk” categories are present or two or more of the “moderate risk” categories are present in the Triad Risk Assessment tool (1,3).

• Diet: A dietary screen should be taken, with particular attention paid to possible issues with calcium/vitamin D deficiency, disordered eating, eating disorder, or insufficient food intake. If are suspected to be a contributing factor, the runner should be referred to a qualified sports dietician and potentially a psychologist or therapist to improve ability to properly nourish him/herself for sport. Multiple questionnaires exist for screening for eating disorders and low energy availability including but not limited to:

  • Low Energy Availability in Females Questionnaire (LEAF-Q)

  • Obligatory Exercise Questionnaire

  • Brief Eating Disorder in Athletes Questionnaire (BEDA-Q)

• Sleep habits: Education on importance of adequate sleep should be provided and emphasized due to its importance for general tissue recovery and bone health.

Establish cross training parameters and activity modification

Specific recommendations on what activities will promote wellness and healing will depend on location, severity, presence of pain, and if energy deficiency is identified to be an underlying cause of initial injury. Cross training is a very important component during rehab of BSIs. Cross training includes activities such as swimming, biking, and water jogging and resistance training without overloading the injured bone. But, the athlete and his/her doctor and PT must realize that cross-training restrictions may be necessary to restore a state of energy balance. A collaborative approach should be taken to design a cross-training plan considering optimal bone healing, restoring and/or maintaining adequate energy availability, maintaining fitness and pain-free load capacity, and protecting psychological health.

Being in a state of injury can lead to negative thoughts, sense of social isolation, and loss of identity. These thoughts and feelings can negatively impact outcomes. Practitioners must be aware of the athlete’s psychological state and consider the psychosocial factors associated with outcomes of sports injury rehabilitation. If it seems as though an athlete is not progressing as expected due to psychological barriers, referral to a sports psychologist may be indicated. Adhering to treatment recommendations is paramount, but can be difficult, especially for an individual who has a tendency to push his/her physical limits (a common trait among runners and athletes in general). When a treatment team can harbor trust, confidence, and decrease fear, the athlete will have a higher likelihood for successful return to sport (7).

Below is a diagram I created to summarize the components to consider when devising a cross-training plan:

Created by: Anya Gue, PT, DPT, OCS

If the athlete is diagnosed with RED-S, the the RED-S Clinical Assessment Tool (RED-S CAT) may be used to determine the level of participation in cross-training that is permitted throughout the rehab process (6).

Mountjoy et al. 2015

Mountjoy et al. 2015

Mid-Stage Rehab: Load Progression

While relative overloading is the primary cause for the development of BSIs, recovery is optimized with a balance of rest from aggravating activities and appropriate loading. Appropriate loading can be defined as loading that does not provoke BSI symptoms either during or after activity. When weight bearing pain has resolved and the treatment team believes bone healing is on-track, rehab will continue to focus on pain-free loading progression including weight bearing strengthening and progressive impact activities. Strength training of calves, quads, hamstrings, and hips is important for preparing the athlete’s muscles, joints, and ligaments for return to run, but specific resistance training of the muscles attached to the pathological bone will help promote bone growth and improve its load capacity. Load progression during this stage will be guided by time (respective tissue healing timeline), and pain rules. If pain occurs either during or after an activity, the level of loading must be regressed until further healing has occurred.

Return to Run

The following criteria must be met in order for an athlete to begin a return to run program. This will be determined by the doctor and physical therapist:

• Adequate time has lapsed since onset of symptoms, allowing for bone healing to occur

• All current activities are pain-free

• Strength of the athlete is determined to be sufficient for initiating running

• If RED-S is determined to be a contributing factor, athlete must be demonstrating adherence to treatment plan (see RED-S CAT)

• Good impact tolerance: demonstrates good control, confidence, and pain-free execution of single leg hopping

Below is an example of one option for a return to run protocol that allows a slow, pain-free progression:

As the return to running is initiated, the physical therapist may identify particular biomechanics that could be modified to decrease bone loading. This could include gait modification, running shoe or running surface recommendations. These recommendations should be made on a case-by-case basis. Below are a few examples:

• Step-rate modification: Increasing step rate by 7.5%-10% through gait retraining protocol has been shown to significantly reduce average and instantaneous vertical loading rate as well as peak hip and knee joint work during running (8).

• Change from forefoot strike pattern to rearfoot strike pattern: An individual with a 5th metatarsal BSI may demonstrate a natural gait pattern of forefoot strike which is usually associated with a relatively increased supinated foot position during initial contact. This gait pattern results in increased loading to that 5th metatarsal. This individual may benefit from transitioning to a more rearfoot strike pattern, which is associated with less supinated position at initial contact and decreased loading to the 5th metatarsal.

Summary

Diagnosis of BSIs can be challenging, but accurate and early diagnosis is important for optimal outcomes. Treatment of BSIs involves balancing training load with bone load capacity. Multiple factors can influence prognosis, activity modification guidelines, load progression, and bone load capacity. Rehabilitation progression should be patient-specific with a multiple disciplinary team focused on risk factor modification and pain-free progressive return to sport with least risk for recurrence.

Anya Gue, PT, DPT, OCS

Please feel free to comment or contact me at endurancephysioanya@gmail.com with any questions. Thanks for reading!

References

1. 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.

2. Nattive A, Kennedy G, Barrack MT, Abdelkerim A, Goolsby MA, Arends JC, Seeger LL. Correlation of MRI Grading of Bone Stress Injuries with Clinical Risk Factors and Return to Play: A 5-year prospective study in collegiate track and field athletes. Am J Sports Med. 2013; 41(8): 1930-1941.

3. De Souza MJ, Nattiv A, Joy E, et al. 2014 Female Athlete Triad Coalition Consensus Statement on Treatment and Return to Play of the Female Athlete Triad: 1st International Conference held in San Francisco, California, May 2012 and 2nd International Conference held in Indianapolis, Indiana, May 2013. Br J Sports Med. 2014;48:289.

4. Tenforde AS, Carlson JL, Chang A, et al. Association of the Female Athlete Triad Risk Assessment Stratification to the Development of Bone Stress Injuries in Collegiate Athletes. Am J Sports Med. 2017;45(2):302–310.

5. Kraus E, Tenforde AS, Nattiv A, et al. Bone stress injuries in male distance runners: higher modified Female Athlete Triad Cumulative Risk Assessment scores predict increased rates of injury. Br J Sports Med 2019;53:237-242.

6. Mountjoy M, Sundgot-Borgen J, Burke L, et al. The IOC relative energy deficiency in sport clinical assessment tool (RED-S CAT). Br J Sports Med 2015;49:1354.

7. Forsdyke D, Smith A, Jones M, et al. Psychosocial factors associated with outcomes of sports injury rehabilitation in competitive athletes: a mixed studies systematic review. Br J Sports Med. 2016;50:537-544.

8. Willy, RW, Buchenic L, Rogacki K, Ackerman J, Schmidt A, and Willson JD. In‐field gait retraining and monitoring. Scand J Med Sci Sports. 2016;26:197-205.

Bone Stress Injuries in Runners: Part 1

Photo by: Tom Robertson Photography

The topic of bone stress injuries (BSIs) is very complex, and research continues to investigate these injuries so they can be better prevented and appropriately managed. BSIs are quite common among athletes, comprising over 10% of all sport-related injuries, account for up to 20% of all injuries treated in sports medicine clinics, and account for up to 30% of all running related injuries (1-3). I know too many stories of runners who have unsuccessfully tried to run through bone stress injuries, either because they held off too long on seeking diagnosis and treatment, or because their healthcare provider misdiagnosed the injury. The goal of this discussion is to provide a summary of the risk factors, classic symptoms, common locations, and importance of appropriate diagnosis of BSIs. Readers should come away with a better understanding of when they might need to seek help from a qualified medical professional so they may return to running as soon as possible.

What is a bone stress injury?

Simply put, a BSI occurs when a bone is unable to withstand the repetitive loading that is being applied to it. Although they are often referred to as “stress fractures,” these injuries occur along a pathology continuum ranging from a “stress reaction,” involving inflammation of the periosteum and bone marrow, to actual stress fracture where distinct fracture lines are present (2).

Why do bone stress injuries occur?

Bone physiology is extremely complex, but it is important to understand the basics in order to fully respect why a BSI may occur and how to address the underlying cause. Although we think of bones as solid static structures, on a microscopic level, your body is continually breaking down and re-building your bones. In addition to providing structural support for your body, bones are an important calcium storage system. Calcium is essential in many vital bodily functions such as muscle contraction, blood clotting, enzyme function, and heart rhythm. Your body is continually borrowing from the bone calcium stores by breaking down the bone (resorption), and then rebuilding it. In a healthy individual, bone rebuilding occurs at approximately the same, or even higher rate than it is being broken down. This is called skeletal homeostasis and occurs in all individuals, even those who are not exercising. Bone will also remodel specifically in response to being loaded. When a bone experiences stress via either external loads (impact of your body contacting the ground) and/or internal loads (the force applied to the bone by the contraction of the muscles that attach to it), load-induced microtrauma occurs. When the body systems are functioning appropriately, the additional loading is good for stimulating bone growth and remodeling, resulting in a bone that is rebuilt stronger and more acclimated to higher loads.

The following conditions must be in place in order for healthy bone remodeling to occur:

• Adequate energy availability: To put it very simply, this means eating enough calories to support your workouts AND your vital body functions. Sometimes runners don’t realize just how much they need to eat in order to support their activity level. Sometimes, runners purposefully restrict food intake with hopes of losing weight in order to to look a certain way, or with the hopes that they will perform better. When compared to athletes who are not training in a state of low energy availability, physically active individuals in a state of low energy availability tend to eventually present with lower bone mass, altered bone metabolism (favoring bone resorption), reduced bone strength and increased risk for BSIs. Being in a state of low energy availability for even 5 days appears to negatively affect the balance of bone resorption and bone formation (4). Low energy availability seems to be the root cause for many physiological and performance dysfunctions including several of the points discussed below. It is a very large and important topic worthy of ten of it’s own blog posts. If you would like to read more on relative energy deficiency in sport (RED-S), I have provided some links to good resources below:

  • IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. British Journal of Sports Medicine

  • Finding Your Sweet Spot: How to Avoid RED-S (Relative Energy Deficit in Sport) by Optimizing Your Energy Balance. By Rebecca McConville, MS, LDN, CSSD, CEDRD (Board certified sports specialist and eating disorder clinician)

  • Lecture by Dr. Kathryn Ackerman on the Triad and RED-S that provides a great summary of the current literature on the subject. It specifically addresses bone health beginning at 3:45.

• Adequate hormone circulation: Low energy availability is also correlated with a decrease in several hormones that are essential for bone health including the “sex hormones”(estrogen and testosterone), and has a negative effect on some metabolic hormones such as leptin, IGF-1, and peptide YY (5,6). Many of these hormonal changes likely occur to conserve energy for more important bodily functions or to use the body’s energy reserves for vital processes (7).

  • Regular menstruation (in females): Females who stop having regular menstrual cycles (amenorrhea) or experience < 9 menstrual cycles in a year (oligomenorrhea) have demonstrated decreased BMD, altered bone microarchitecture and bone turnover markers, decreased estimates of bone strength and increased risk for bone stress injuries compared with eumenorrhoeic athletes (6,7). This is likely due to a combination of the reduced hormone circulation that results in amenorrhea as well as state of low energy availability that often occurs simultaneously(5). The interrelationship of decreased energy availability, menstrual dysfunction, and poor bone health, is known as the female athlete triad. In women who participate in sports that emphasize aesthetics or leanness, such as ballet or running, the prevalence of amenorrhea can be as high as 69%, compared with 2% to 5% in the general population (8).

  • Males don’t menstruate, but…: Although males do not experience menstrual cycles, they can experience a similar condition as the female athlete triad called exercise-related male hypogonadism, which is characterized by a deficiency in the production of testosterone – a critical male reproductive hormone. Like the Triad, it is often correlated with a state of low energy availability, and decreased bone mineral density. Symptoms are less obvious in males, and blood-work is necessary for proper diagnosis, but one of the more noticeable symptoms is loss of morning erections and/or decreased libito (9,10). See link below for a great resource to better understand hypothalamic amenorrhea and male hypogonadism:

    • No Period, Now What: Website with may blog posts on this topic. You may also purchase the book here as well.

    • Hypogonadism in Exercising Males: Dysfunction or Adaptive-Regulatory Adjustment? Hackney 2020

• Adequate vitamin D and calcium: Even when a runner is taking in enough calories to support training loads, adequate levels of vitamin D and calcium are essential for good bone health. Low levels result in decreased bone strength and higher risk for BSI (5).

• Appropriate training load progression: Too much load applied to a bone that is not accustomed to being loaded (i.e. increasing running mileage too quickly) will increase risk of BSI (3). Bones are dynamic and will remodel over time to acclimate to progressively higher training loads, but too much too soon will result in eventual injury. Just like a chair that is build to withstand 200 lbs of weight may break if 300 lbs of weight is placed on it. Training load management is also a very complex topic and important for prevention and treatment of all running related injuries. Below are links to a few articles I have written on these topics:

  • Avoid Training Error, Avoid Injury: A post I wrote on the Endurance Physio Blog in 2018.

  • Injury Prevention Though Training Load Management: An article I wrote for The Cycling House in 2019. This one is more focused on cyclists and triathletes, but the concepts are very applicable to runners.

• Adequate rest: It takes time to repair the bone tissue. Training will provide a stimulus for bone remodeling to occur, but too many successive training bouts without recovery time will not allow for the rebuilding phase to occur and the bone will break down at a faster rate than it can be rebuilt.

• Adequate sleep: Sleep deprivation is associated with a higher risk for reduced bone health due to alterations in the balance between bone resorption and remodeling (11).

Where do BSIs usually occur?

The most common sites for BSI in runners include the medial tibia, femoral shaft, fibula, calcaneus, and metatarsal bones, but can also occur in the pelvis, sacrum, lumbar spine, femoral neck, anterior tibia, and navicular (see images below for an idea of some of these common anatomical locations where pain may be experienced) (2,3). Any bone could technically become injured, but these are the ones that are most likely to occur.

Low risk vs high risk locations

BSIs are categorized as being in either a “low risk” or “high risk” site depending on the location. “High risk” sites tend to be more susceptible to fracture propagation with more severe consequences if fracture does complete, and they are more susceptible to delayed union. These require a higher level of attention and may require surgical intervention. “Low risk” sites have more reliable healing patterns and low risk for fracture completion. The sites for high risk fractures include the fifth metatarsal, the anterior tibia, the navicular, the femoral neck, the patella, the medial malleolus, the talar neck, and the first metatarsal sesamoids (2,3,12).

Warden et al. J Orthop Sports Phys Ther. 2014

Where would it hurt? (not all locations are shown below)

Medial tibia: usually in the distal 1/3 and will be particularly painful in one small area as opposed to along the entire tibial shaft

Navicular (High risk due to poor blood supply and non-union potential)

Calcaneus (Some sources categorize as high risk)

Fifth metatarsal (High risk due to poor blood supply and non-union potential)

Sacrum or spine. Not high risk, but should raise suspicion for potential of low energy availability or poor bone health

Fibula

2nd metatarsal

Femoral shaft

Anterior tibia (High risk due to vulnerability to fully fracture and associated complications if it does)

Not pictured: Femoral neck, and pubic ramus which present as deep groin pain. (Just couldn’t bring myself to publish a crotch-shot :)

(High risk due to vulnerability to fully fracture and associated complications if it does)

How are BSIs diagnosed?

BSIs are diagnosed based on symptom quality, location, and diagnostic imaging. Common symptoms include:

• Pain reproduction with palpation to the injured bone: This is difficult if the bone is not superficial, such as femoral neck.)

• Pain at rest or at night: in more severe cases

• Palpable bone callus and/or visible swelling: Bone callus may be present after the BSI has been present for several weeks. The callus formation is part of the bone healing process.

• Symptom reproduction with impact and/or forceful activation of the muscles that attach to the bone

• Pain that increases throughout a duration of a run: Often there are tendons that run in the vicinity of the suspect bone, making it difficult to differentiate tendon from bone. But unlike tendon injuries, bone pain tends to gradually increase throughout the duration of a run whereas tendon pain generally decreases once it is warmed up.

• Pain that results in limping or inability to tolerate running at all. Bone pain may initially be subtle enough that running remains tolerable without gait alterations, but generally will increase in severity to the point where running is intolerable.

If a BSI is suspected, recommendation is complete avoidance of painful activity until the bone is fully healed, as it will not heal if it continues to be loaded. This is different from tendon injuries, where some pain during running is often allowed, as tendon responds well to loading compared to complete rest. This will be further discussed in part two of this blog series.

When is diagnostic imaging indicated?

If a BSI is suspected, the following algorithm concept may be used in order to guide if, when, and what type of imaging is necessary (13):

Wright et al. 2015

Imaging is often an part of the diagnostics required for appropriate treatment of BSIs and will allow for a more accurate diagnosis and prognosis, and is paramount if the suspected BSI is in a high risk location. X-rays will often come up negative unless the BSI is quite severe and has been present for several weeks. MRI is the most sensitive and specific way to identify the presence and severity of a BSI. One way to help classify the severity and prognosis of the injury is use of the Fredericson classification system, which is based off or MRI results (14):

• Grade 1: Periosteal edema only

• Grade 2: Bone marrow edema (visible only on T2 weighted sequences)

• Grade 3: Bone marrow edema (visible on T1 and T2 weighted sequences)

• Grade 4: (4a) Multiple discrete areas of intracortical signal changes; (4b) Linear areas of intracortical signal change correlating with a frank stress fracture

It is important to understand that an X-ray will not detect the lower grade bone stress injuries. Understanding the severity/grade of BSI is important for helping your medical provider devise an optimal treatment plan, and for the injured athlete to gain a better understanding of how long it may take to return to running. Approximate return to sport timelines for male and female track and cross-country runners have been reported as follows (14):

• Grade 1: 11.4 weeks (+/- 4.5 weeks)

• Grade 2: 13.5 weeks (+/- 2.1 weeks)

• Grade 3: 18.8 weeks (+/- 2.9 weeks)

• Grade 4: 31.7 weeks (+/- 3.7 weeks)

You can see that BSIs often result in a long time away from sport, so early detection is key for expediting this relatively long recovery, especially if the suspect region is in one of the more “high risk” sites that was discussed earlier. Not only is appropriate diagnosis essential for a proper rehabilitation to occur, it is important for individuals to know if they have had a BSI, since they can be a signal of decreased bone health, underlying energy deficiency, or endocrine dysfunction. Multiple BSIs and/or BSIs that occur in certain regions such as the femoral neck, pelvis, sacrum, spine (due to the type of bone present in these regions) should be a reason for receiving a bone density scan and blood work (15). Make sure to consult with a sports medicine doctor who can help decide when further testing is needed to minimize risk for future BSIs.

Click here for part two, which will discuss management, rehabilitation, and return to running following bone stress injury

Anya Gue, PT, DPT, OCS

Please feel free to comment or contact me at endurancephysioanya@gmail.com with any questions. Thanks for reading!

References

1. Fredericson M, Jennings F, Beaulieu C, and Matheson G. Stress fractures in athletes. Top Magn Reson Imaging. 2006; 17(5):309-25.

2. Song SH, Koo JH.   Bone Stress Injuries in Runners: a Review for Raising Interest in Stress Fractures in Korea.  J Korean Med Sci. 2020;35(8):e38.

3. 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.

4. Papageorgiou M, Dolan E, Elliott-Sale KJ, Sale C. Reduced energy availability: implications for bone health in physically active populations. Eur J Nutr. 2018;57(3):847–859.

5. Goolsby MA, Boniquit N. Bone Health in Athletes. Sports Health. 2017;9(2):108–117.

6. Ackerman KE, Cano Sokoloff N, DE Nardo Maffazioli G, Clarke HM, Lee H, Misra M. Fractures in Relation to Menstrual Status and Bone Parameters in Young Athletes. Med Sci Sports Exerc. 2015;47(8):1577–1586.

7. Mountjoy M, Sundgot-Borgen JK, Burke LM, et al. IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update. Br J sports med. 2018;52:687-697.

8. Nazem TG, Ackerman KE. The female athlete triad. Sports Health. 2012;4(4):302–311.

9. Tenforde AS, Barrack MT, Nattiv A, et al. Parallels with the female athlete triad in male athletes. Sports Med. 2016;46:171–82.

10. Hackney, AC. Hypogonadism in Exercising Males: Dysfunction or Adaptive-Regulatory Adjustment? Front Endocrinol. 2020.

11. Staab JS, Smith TJ, Wilson M, Montain S, Gaffney-Stomberg, E. Bone turnover is altered during 72 h of sleep restriction: a controlled laboratory study. Endocrine. 2019;65: 192–199.

12. Chen YT, Tenforde AS, Fredericson M. Update on stress fractures in female athletes: epidemiology, treatment, and prevention. Curr Rev Musculoskelet Med. 2013;6(2):173–181.

13. Wright AA, Hegedus EJ, Lenchik L, Kuhn KJ, Santiago L, Smoliga JM. Diagnostic Accuracy of Various Imaging Modalities for Suspected Lower Extremity Stress Fractures: A Systematic Review With Evidence-Based Recommendations for Clinical Practice. Am J Sport Med. 2016;44(1):255–263.

14. Nattive A, Kennedy G, Barrack MT, Abdelkerim A, Goolsby MA, Arends JC, Seeger LL. Correlation of MRI Grading of Bone Stress Injuries with Clinical Risk Factors and Return to Play: A 5-year prospective study in collegiate track and field athletes. Am J Sports Med. 2013; 41(8): 1930-1941.

15. Marx RG, Saint-Phard D, Callahan LR, Chu J, Hannafin JA. Stress Fracture Sites Related to Underlying Bone Health in Athletic Females. Clin J Sport Med. 2001;11:73-76.

Exercise Spotlight: Shoulder I's, T's, H's, and Y's

Whether you are a climber, swimmer, hockey player, ball sport enthusiast, dog-ball-thrower, or are simply looking for a few upper body exercises to add into a comprehensive strength routine, this series of stabilization exercises is a good place to start. They are great for working the posterior rotator cuff and scapular retractors as well as thoracic and cervical stabilization. The primary muscles targeted are:

• The infraspinatus, and teres major

• Lower, middle, and upper traps

• Thoracic paraspinals

• Cervical multifidi and paraspinals

Here are some great reasons to incorporate these exercises into your life:

• Shoulder stabilization and strengthening

• Warm-up to prep for higher level upper body strengthening

• Postural correction

• Improving shoulder and upper thoracic mobility

If you are experiencing pain with these exercises, you may consider consulting with your doctor or physical therapist before continuing.

Pay attention to the specific cueing discussed in the videos

Please comment below or email endurancephysio@gmail.com with any questions!

Exercise Spotlight: The PUSH-UP!

Push-ups can be a great full body exercise that is easy for anyone to perform anywhere. All you need is a floor. You may think of the push-up as being predominantly an arm strengthening exercise (pecs and triceps), but if you perform it properly, you will also provide your core, and scapular stabilizers (serratus anterior) a great workout as well. If you are not using these muscles and properly aligning your body, you may be placing excess sheering, compressive, or torsional loads to the shoulder or spine. Below, Tara and Anya outline some key points to think about the next time you do a push up and provide a great example of good technique vs. poor technique with the push-up exercise. 

Avoid Training Error, Avoid Injury

By: Anya Gue, PT, DPT

Many runners have taken the winter moths to take a little break from running and embrace the snow and, for some, the gym. As the temperatures rise, the snow melts, and the birds start chirping, its hard not to lace up those shoes and hit the trail. Especially if you've maintained some decent fitness over the winter, it can be easy to ramp up those miles rather quickly... a quick jog down the river path, a huff up to the "M,"and what's that I hear..., Jumbo's open? Got to hit that! If you're not careful, you may find that you are increasing your running mileage too quickly. How quickly is too quickly? As you may guess, the answer is very dependent on the person as well as underlying fitness, running intensity, ability to recover, and previous running injury history. When a runner increases running volume and/or intensity too rapidly, it is referred to as "training error." While there are so many articles, blogs, and social media posts outlining various stretches and exercises to perform in order to prevent injury, the topic of training and recovery tactics is often overshadowed and underemphasized. I can't tell you how often I have runners come into the clinic saying, "I was doing so well until..." Running related injuries are often due to a relative overuse (tissue overload) due to the repetitive nature of the activity, so you can see why management of your training loads and learning to listen to your body is an essential skill in injury prevention. 

In this post, I will outline and discuss some principles and tactics you may want to consider and practice in order to avoid injury due to training error and follow up with a few examples. In a series of following posts, I will dive a little deeper into some tools you may use to monitor composite training loads, how to manage cross training in the "on" season, and how psychological factors may contribute to training error. 

For now, lets dive into some tips to get you started:

1) Record your training It only takes a few minutes to jot down your distance, time, and effort for a particular run or cross training activity. This doesn't have to turn into an obsession of paces and perfect distances/times, but you can think of it as simply gathering data. By tracking your workouts, you can have a way to see if you have any rapid jumps in quantity or intensity. If you develop a seemingly random ache/pain or unwanted fatigue, it helps to be able to look at the training history to find a possible cause. Often, people find that they either significantly underestimate or overestimate how much they are training. Either of these can lead to injury or sub-optimal performance.

2) Follow the concept of the "10% rule". Yes, it feels painfully slow in the beginning, but there have been multiple studies indicating a significant increased injury risk when running mileage is increased by >10% over consecutive weeks. This "rule" does not have to be followed strictly, and should vary a little depending on experience, time taken off from running, etc. I tend to use a 10%-30% rule, allowing for a little higher jumps on occasion when a runner has either maintained a good base, or has not had a reduced volume for a very long time, and/or has been cross-training appropriately. However, to have the lowest risk of injury, you would want to stick to 10%. You can find a link to a summary of an article published in JOSPT that discusses some evidence behind the 10% rule Here. If you participate in activities other than running on a regular basis, you do have to account for the stress of these activities as well. I will talk about how to account for the cumulative stress of all of these activities in the a future blog post.

3) Keep long run distance increase between 0.5-2 miles/week. It makes sense that your body may not respond well to a jump in a long run of 6 miles one week straight to 10 miles the next (if it's been months since you've run that far), even if you still manage to adhere to the "10% rule." When weekly mileage is relatively low (10-30 miles/week), your long run should not increase by more than 1 mile. If you are a veteran runner, or you've managed to get your weekly mileage up to 40-50 miles/week, you may be able to safely increase that long run by 1-2 miles at a time as long as you were able to complete your previous long run without any negative outcomes. 

4) Plan your training! For some, this may be a weekly outline of the approximate total weekly mileage and where it's distributed. For others, it may be a 3-6 month periodized training schedule with hopes to peak for goal races. In order to follow the previous suggestion of gradual progressive increase in mileage, you have to plan a little so you don't find yourself nearing end of your week with an already 15% increase in weekly mileage only to be tempted by an invite on a social 10 miler that jacks up that increase into the >30%. Planning your training progression may also help you avoid rapid jumps in training volume that occur out of necessity when you realize you have a big race in 1 month that you had to sign up for 6 months ago (because that's how things tend to be now), and realize that your volume is no where near where it should be in order to be adequately prepared.  Making at least a loose outline of where you want to spend your miles can be very helpful in giving you an idea of the reality of what your running week should look like. You don't have to stick to it to the exact 10th of a mile and you can always alter as you go depending on outside life influences, and fatigue levels.

 5) Plan your recovery! Even more important than planned training is planned recovery.  Even the best training plan is only as effective as the recovery. While high training loads are essential for improving physical and psychological fitness for improved performance, there has been ample evidence suggesting that performance will decline if adequate recovery is not allowed. Recovery does not only include rest from physical activity, it also includes obtaining adequate sleep, and nutrition. Fatigue occurs when training demands are high, and recovery is low. Of course fatigue is  to be expected with any training plan, but know that your performance will decline and your injury risk will increase if your recovery is consistently inadequate and your fatigue levels continue to increase over a prolonged period of time.

6) Listen to your body! This can be difficult if you have made a training plan and are determined to stick to it no matter what. Even the best laid plans for training and recovery do not always align with what your body needs when you are in the midst of training. Remember that your ability to recover is highly dependent on many extrinsic factors that can change from day to day. It's impossible to know how you will respond to a given training load. Learning how to listen to your body and respect when it may need an extra rest day or when you might be better off skipping a track workout can be very tricky, but so important! So I say, have a plan, but be ready to deviate from it and modify as you go.

Now, consider this equation:

Fitness - Fatigue = Performance

Usually, the end-goal of training is to increase your performance ability. Lets use this equation in a hypothetical case of  a runner who decided to start training for  marathon after a winter of mild-moderate activity. Let's look at how his equation may look (relative to his running fitness and performance specifically) throughout his training cycle and where he could go wrong if adequate rest is not observed (rating on 1-10 scale with 1 associated with low, and 10 associated with high):

He has maintained some fitness through the winter with his skiing and gym workouts and begins to run more consistently. He feels a bit slower than he has been, but his legs are fresh:

Fitness (4) - fatigue (2) = Performance (2)

As he continues to progressively increase training loads, his equation shifts:

Fitness (7) - fatigue (4) = Performance (3)

He listens to his body, plans a easier week:

Fitness (7) - fatigue (1) = Performance (6)

*He's getting faster!

But lets say, he decides, "wow, I'm really starting to see some improvements, I'm gonna really train hard, because I might just be able to crush this race!" He chooses not to rest, even though his body is tired:

Fitness (7) - fatigue (6) = Performance (1) 

*Even though he has not lost fitness, his performance level drops

He is upset to see a drop in his tempo run pace, and decides he is not training hard enough, so he continues to ramp up the effort:

 Fitness (7) - fatigue (8) = Performance (-1)

*Uh-oh. Thing's are not looking good. I don't even know what a negative performance means since these numbers are arbitrary, but it seems like it would be associated with increased injury risk, or perhaps a product of "overtraining" 

In this example,  you can see how recovery can effect your ability to progress your performance and how psychological factors may inhibit your ability to properly practice rest and recovery

Here are a few more examples that tie together all of the above tips.

A) Image of an individual's training log who demonstrates several issues in her training progression (this is not a real person, but it is very similar to many that I have seen):

Experienced runner who has been running very little over the winter. She is signed up for a 50k at the end of June.

Although it appears that this individual was fairly conservative with the increased mileage by starting out with relatively short runs, you can see several places where she demonstrates "training error": 1) She is inconsistent and demonstrates several very large jumps in weekly mileage; 2) she was a bit too aggressive, I would say, with her relatively large increase in long run mileage (orange); 3) She has NO rest days in the weeks of May 5th-June 4th (yellow). Unfortunately, she was not able to participate in her race due to development of knee pain. BUMMER!

B) Image of an individual's training log who demonstrates wise training progression

Moderately experienced runner who did not run much at all for the past 4 months...should have started a little sooner if he had hoped to be up at 50 mile weeks back in June...

This individual followed the 10%-15% rule. But, you can see that he was not running a 50 mile week until the end of July. You can also see how slow the progress was in the initial 4-5 weeks. It's great to take a period of time during the year where you run less or not at all, but know that if you have hopes to be running high mileage weeks or long races over the summer, you need to plan your progression carefully and start building your base back up at an appropriate rate, and you need to give yourself adequate time to get to your goal weekly mileage or long-run mileage. 

Unfortunately, there is no cookie-cutter way to train. Everyone is different in baseline fitness levels, ability to recover, and susceptibility to "over-doing it." Another huge factor in how well an individual may tolerate progressive increase in training load is underlying tissue strength and tolerance to load. Additionally, we have not even discussed how training intensity and cross training fit into a training plan or how phycological factors can lead to training error. Stay tuned for more discussion regarding these issues on this in the next post!

Please feel free to comment or contact me at endurancephysioanya@gmail.com with any comments or questions. 

Thanks for reading! Happy spring running

Pelvic Health Physical Therapy Following Abdominal or Pelvic Surgery

The months after a major abdominal or pelvic surgery can leave you feeling discouraged, lost, and unsure about how to begin feeling like your former self again. Never fear, pelvic health physical therapy is here! Endurance Physio’s Tara Mund is passionate about helping patients navigate their post surgical recovery and safely return to a healthy active lifestyle.

Whether you had a C-section delivery, hysterectomy, prostatectomy or hernia repair surgery, it is undeniable that the pelvic floor and core muscle function is altered post operatively. Taking the time to re-establish correct pelvic floor and core muscle activation can make all the difference between a successful recovery and a frustrating injury prone journey.

In addition to training pelvic floor and core muscle function, scar tissue is also a common concern following surgery. Physical therapy can help manage this with scar tissue mobilization to keep you moving well. Diaphragmatic breathing, stretching and self scar mobilization are all tools you can use to maximize your recovery with your home exercise program.

Finally, once you have re-trained your pelvic floor and core muscles and are managing scar tissue, it’s time to learn how to gradually resume activity. Walking is often a good place to start, but for how long, how often, and when to progress can be unclear. Even if you have been cleared by your doctor, your body may not feel ready to get back into running or your old weight lifting routine just yet. This is where individualized attention from a professional can be an invaluable tool to help guide this process. Endurance Physio will give you step by step instruction on how to gradually progress, focusing on your specific target areas of weakness while learning excellent form and body mechanics. We will teach you how to take care of your new body and potentially make it even better than it was before!

For those of you who may be a bit more competitive in your sport, did you know that at Endurance Physio we have both a biking and a running specialist? Jamie Terry, DPT and Anya Gue, DPT are able to perform specialized bike fitting as well as video running analysis. No matter what your goals are, at Endurance Physio we are here and ready to help guide you as far as you can dream to take it.

Exercise Spotlight: The Basic Clamshell

If you're gonna do 'em, do 'em RIGHT!

So you're lying on your living room floor going through the motions of a clamshell because you read in Runner's World that it would make your knee feel better, or keep you from getting injured during your marathon training (or because your physical therapist said you should;-). You finally decide you've done enough because you kind of feel like you could lay there and do them all day and you're antsy to get on to your run or ride, or ski etc. You feel some sense of gratification because you at least tried to do something good for yourself, but you're still a little confused as to what the exercise did for you. If this sounds familiar, then you are either doin' it wrong, or you don't need to be doin' it at all!

Refer to the following videos and explanation of when the clamshell exercise may be an appropriate exercise to incorporate into a strength or rehabilitation routine

Although it is not very functional, requires only a relatively small amount of actual movement, and, quite frankly, looks a little silly, the clamshell has it's time and place for being an effective exercise to incorporate into a rehab, prehab, or general strength routine.  

Inappropriate use of the clamshell:

• Performing with poor technique (see the video)
  • Allowing pelvis to rotate towards the ceiling as you lift the knee
  • Anteriorly tilting pelvis as you lift the knee
• Performing without sufficient loading or functional application 
  • If you are trying to actually build strength and muscle hypertrophy and it takes 20 or even 50 reps to begin to fatigue the muscle, you are not going to effectively build strength or hypertrophy the muscle. Instead, you will need to add load with the use of a resistance band around the knees and create fatigue within 10-15 repetitions
  • If you are working on using the muscles during biking and running, you had better also be performing some kind of exercise that will fatigue the muscle in a more functional motion such as single leg squatting, lunging, and plyometrics. 

Appropriate use of the clamshell:

• For "neuromuscular awakening": Perform as a warm-up prior to higher level exercises in order to improve the central nervous system recruitment of the muscle so you are able to use them during higher loading, more complex functional exercises, or even prior to participating in your sport of choice. 
• For isolated hypertrophy and strengthening: You may add a resistance band in order to around the knees in order to increase load and fatigue with fewer reps (perform 3sets of 10-15). When I say fatigue, I mean, you can't do any more without breaking technique and your butt is burning!
• To build muscular endurance of the hip abductors/lateral rotators You may use it as a part of a side lying series  that will work on improving the neuromuscular connection, and building endurance in the most important hip stabilizing muscles (Refer to additional videos for ideas here)
• For strengthening when weight bearing exercise is not an option due to injury or post-operative status

EMG studies have shown that, when performed against gravity, the clamshell exercise requires a relatively small amount of gluteus maximus (GMax) and gluteus medius (GMed) compared to some other exercises (single leg squats, side plank with hip abduction, lunges etc). However, many folks who would benefit from gluteal strengthening need to do so because of an imbalance in their hip musculature. They tend to  overdevelop the large powerful muscles such as flexors (TFL, rectus femoris)  and the muscles that are meant to stabilize the hip and pelvis become underdeveloped and subsequently weak. In order to restore a proper strength ratio of these muscles, it is essential that one chooses an exercise that will work the weaker muscles more than the already overly developed ones. Otherwise, your imbalance will only continue to exists and potentially become even more pronounced. In order to strengthen the gluteals without those larger muscles taking over, one must first isolate and activate them to assure they can find them and utilize them in more functional and higher load exercises. The clamshell is a great place to start. 

In order to get the most out of this exercise, it must be performed with excellent technique. If you perform clamshells and are unable to feel significant muscular fatigue,

then you are probably not performing it appropriately! 

Thanks for reading! 

Anya Gue, DPT

Clamshells...They are so glamorous! 

Fixing the Leak

Urinary Incontinence: physical therapy can help!

Urinary incontinence is something that is very common among women and men in the United States. It is a problem that is often ignored and accepted as a normal part of aging, or something that all moms deal with after childbirth. Incontinence can be embarrassing to talk about, and since there is an entire aisle dedicated to this in the stores, it must just be part of life right? Actually, many people are not aware that there are simple things that can be done to address urinary leakage and pelvic health physical therapy can help.

The specific type of treatment for incontinence is very individual and dependent on your symptoms and muscle function. That is why it is important to seek care from a professional instead of googling “how to do a Kegel” or even following a generic handout in an attempt to strengthen your pelvic floor muscles. Depending upon whether you are experiencing urge urinary incontinence, stress urinary incontinence, or a mix of both, your treatment could include strengthening, muscle re-training, bladder training, fluid intake modification or a combination of these.

Tara Mund, DPT, is Endurance Physio’s pelvic health specialist and she has been helping women and men address urinary incontinence in Missoula for the past 10 years. Tara understands the importance of a customized treatment approach to meet your individual needs and goals. Whether that means running a marathon or just playing with your kids, Endurance Physio wants to see you get back to being the best version of yourself!

Contact Endurance Physio to make an appointment (926-2150), or email Tara with any questions at Endurancephysiotara@gmail.com.

Endurance Physio is Taking Care of Missoula Moms

Tara Mund, DPT, Endurance Physio’s pelvic health specialist, is committed to helping moms get back to doing the activities they love. Pregnancy and childbirth can pose many challenges for a women’s body. When it’s time to get back to being physically active, many moms are left confused as to what to do and when to start. There are also other common factors such as C-section delivery, diastasis rectus abdominus, and urinary incontinence that further complicate this decision. Although tempting, putting on your old running shoes and heading straight out for a jog is not your best plan for safely getting back into shape.

Tara emphasizes the importance of first building foundational strength with focus on pelvic floor, core, hip, and postural muscles. Pelvic health physical therapy can provide you with a systematic, individualized plan to get back to all of your previous activities feeling strong and confident.

Tara hiking with her two kids this summer

Contact Endurance Physio to make an appointment (926-2150), or email Tara with any questions at Endurancephysiotara@gmail.com.