| Running Injuries: How to Fix (Prevent) Them |
| By: Adam Tenforde, MD
Originally Published in: Techniques Magazine Provided by: USTFCCCA Following my running career, I completed medical school, residency, and sports fellowship at Stanford Medical Center and have focused my research and clinical interests on evaluation, treatment and prevention of running injuries. This includes research on risk factors and injury prevention strategies in high school, collegiate and post-collegiate runners. Now in my current role as Assistant Professor at Harvard Medical School as a physician at Spaulding National Running Center and Brigham and Women's Hospital, I have an outpatient sports medicine practice and specialty clinic focused exclusively on runners. My clinical and research interests continue to focus on treatment and prevention of running injuries, given my enjoyment of the sport. In this article, I offer my perspective on methods to optimize health and reduce the risk for injuries within runners. This is grounded in best research practice but also takes into account the practical experiences I had as a former professional runner. First, I review known risk factors for injury. Following, I discuss how to manage these injuries with a goal for prevention. In this article, I offer my perspective on methods to optimize health and reduce the risk for injuries within runners. This is grounded in best research practice but also takes into account the practical experiences I had as a former professional runner. First, I review known risk factors for injury. Following, I discuss how to manage these injuries with a goal for prevention. The most important biological contributor to overuse injuries in females is the Female Athlete Triad. This is described as the interrelationship of nutrition and menstrual health on bone mineral density (Nattiv 2007). The Triad is common and can affect runners at any age. The primary cause of the Triad is low energy availability, defined as the difference in energy intake to energy expenditure standardized to metabolically active tissue (Loucks 2007). Although low energy availability can be accompanied by disordered eating or an eating disorder, in many cases the cause of low energy availability is from accidental or unintentional under fueling. For example, an athlete who has a small breakfast, normal lunch and dinner may have times during the day with insufficient calories consumed to maintain the demands of sport and overall metabolic function. The resulting changes from low energy availability included changes in metabolic and reproductive hormones, including reduced sex hormone estradiol (Ihne and Loucks 2004). Additional changes from low energy availability include reduced sensitivity to growth hormones, suppressed metabolism with reduced thyroid function and elevated stress hormone cortisol. This may manifest as irregular menstrual periods or cessation of menses (amenorrhea) and reduced bone mineral density. The Triad has been shown to be a risk factor for both musculoskeletal overuse injuries and bone stress injuries (Rauh 2010, Tenforde 2013, Barrack 2014). Therefore, identifying the Triad in an athlete with running injuries is important to ensure the underlying biology contributing to her injury has been identified and treated. In conjunction, I recently proposed that male athletes may experience a similar process (Tenforde 2016). As with female athletes, male athletes with inadequate nutrition may have lower sex hormones including testosterone and reduced bone mineral density. While this has been reported in some male athletes, the true prevalence and biological underpinnings have yet to be fully explained. However, this informs my focus on encouraging good nutrition for both female and male runners. In both male and female runners, nutrition including energy availability, calcium, and vitamin D intake remain critical to optimize bone health and overall recovery from demands of sport and prevent injury. Sleep quality may also contribute to injury, although these have not been clearly defined within runners. Runners and the military are both populations that are at high-risk for bone stress injuries. One military investigation identified that a subset of 18 year old males who were assigned to sleep deprivation made to sleep in a vertical position over a three-day period had an increase in bone turnover and 5 percent reduction in bone mass over one week (BenSasson 1994). A separate study mandating six hours of sleep in the military along with training modifications reducing cumulative weekly marching during basic military training resulted in 62 percent reduction in developing a stress fracture (Finestone 2008). Training variables including mileage and running on harder surfaces have been suggested as contributors to overuse injuries. However, a clear threshold of running volume to cause injury has not been fully described. Additionally, increased training volume likely improves performance so a reduction in running volume without clear reason may be met with undesirable consequences of reduced fitness. The biomechanics of running injury have been explored by many investigators. At Spaulding National Running Center in Cambridge, Massachusetts we have one of only a few centers in the U.S. focused exclusively on treating runners. I have an outpatient running medicine clinic to evaluate injuries and ensure optimal treatment is provided. The director of the Spaulding National Running Center is Dr. Irene Davis, who has completed over two decades of research focused on running injuries. She applies her expertise to evaluation and management of these injuries in each runner. Our approach to managing runners is to ensure soft and well-aligned landings to reduce the impact on joints, muscles, tendons and other structures. The goal is to address an injury and prevent future overuse injuries from developing. Dr. Davis has demonstrated that with patellofemoral pain, poor hip strength can contribute to impaired alignment of the hip in relationship to the knee. When the hip is strengthened in isolation, the running mechanics may not be fixed due to the higher demands of running (Willy and Davis, 2011). Dr. Davis has shown that gait retraining is possible to improve the alignment and function of runners with patellofemoral pain and other overuse injuries in the lower extremity. Second, higher impact loading (the rate of force delivered to the leg when initially contacting the ground) has been shown to contribute to overuse injuries in runners (Davis 2015). Higher impact loads are typically identified in runners with a heel strike pattern. Heel rear foot strike patterns have been observed in a majority of runners. These impacts can be reduced through changing the way the foot strikes the ground, and running with a more forefoot strike pattern. The overall anatomy of a runner may contribute to injury. This includes deficits in strength, flexibility, alignment and other considerations. For example, some runners have a leg length discrepancy that may contribute to mechanics of a running injury. The difference in leg length may be the result of a functional or apparent or structural leg length discrepancy. The former difference in leg length may be due to strength or flexibility issue such as poor abdominal or gluteal muscle strength that changes the position of the pelvis and causes one leg to appear a different length than the other. Some runners may have a true difference in leg length due to a history of fracture or congenital contributors. The contributors of anatomy to bone stress injuries have also been described. In females, the presence of reduced calf girth, or leg length discrepancy, may predispose to development of a bone stress injury (Bennell 1996). Bone geometry has also been described as a contributor to bone injury, although this is difficult to evaluate in a clinical setting, it does highlight the importance of optimizing bone density and strength to reduce the risk of injury. EVALUATION AND MANAGEMENT OF AN INJURY Effective management and prevention of injuries is critical and runners. This is especially considering the limitations that running injuries create, there is a high rate of injury and reinjury. Here, I outline my approach and take a management of running injuries. Additionally, the goal of my research is to keep runners healthy, so I also outline my thoughts on injury prevention. The key to effective management of a running injury is to identify the underlying cause(s) and address each to facilitate a safe and optimal return to play and reduce the risk of reinjury. When I see a runner, I take a detailed history characterizing running history, including training variables such as mileage, and their competition schedule. I obtain detailed past running and overuse injuries, while also asking about prior orthopedic injuries and medical issues that can contribute to an injury. On physical exams, I take a comprehensive approach to evaluating each injury. In addition to evaluating static alignment, I will request the patient perform a single leg squat to get a better sense for their overall lumbopelvic strength and mechanics of the kinetic chain. Foot mechanics are also important to evaluate to ensure optimal foot strength and balance. I also will evaluate the anatomy at the site of the primary injury. Management of the injury depends on the type and location of the injury. An acute ligament injury or bone stress injury may require initial immobilization or non-weight bearing to facilitate healing. In contrast, most tendon and joint conditions may require activity modification to reduce pain. In most cases, physical therapy to restore biomechanics and correct movement patterns is important to facilitate a safe return to running. A short course of anti-inflammatory medications may be reasonable initially, although long-term use is not desirable and does not fix the under-lying cause of pain. Addressing the underlying biological, biomechanical, and other considerations is important to facilitate a safe return to sport and reduces the risk of future injuries. BIOLOGY I routinely will screen for the Triad in athletes. For any female athlete who I have concern for a bone stress injury, I will obtain additional information on risk factors including eating habits and behaviors, menstrual history (including the age of menarche and history of irregular menstrual periods), prior bone stress injuries or diagnosis of low bone mineral density. Any athlete who meets the moderate or high-risk categories for the recently published Female Athlete Triad Coalition statement on return to play (De Souza 2014) is further evaluated by a bone endocrinologist who has expertise in evaluating and managing the Triad. This often includes obtaining blood work, a bone density scan, and visiting with a nutritionist to ensure energy requirements and other important micronutrient needs are being met. For male athletes, there is limited research on who to screen for impaired bone health. I will consider further workup including obtaining DXA scan for male athletes with a history of recurrent bone stress injuries or those who sustain a fracture at higher risk sites, including the sacrum or pelvis. I recommend all athletes meet the Institute of Medicine requirements for calcium and vitamin D. The calcium recommendations for athletes ages 9-18 is 1300 mg of calcium daily. For pre-menopausal females and male athletes under age 70, recommendations for calcium are 1000 mg daily. Vitamin D requirements are 600 IU daily, although some medical providers will advocate for additional supplementation. To meet calcium requirements, I recommend obtaining calcium intake from food sources, as foods rich in calcium are often fortified with vitamin D and have other important components to bone health, including providing a source of calories, protein and other micronutrients. For those without dairy or milk allergy, I advocate for obtaining food through milk or dairy products. One study showed that for each additional cup of skim milk consumed reduced fracture risk by 62 percent (Nieves 2010)! In contrast, Vitamin D intake can be difficult to obtain by diet alone and is reasonable to take a supplement to ensure adequate intake. BIOMECHANICS When a runner has an injury, I evaluate training history. This includes changes in training volume, intensity, running surface or use of new footwear or racing patterns. However, a model of attributing running injuries to training errors is too simplistic and often misses other complex contributors to injury. Additionally, non-specific advice to "run less" without clear evidence or direction is too simplistic and may not allow runners to achieve optimal fitness. Therefore, my evaluation will consider both the influence of training and evaluate the biomechanics of the joint, tissue or bone that contributed to the injury. This is often achieved through formal physical therapy. For any athlete, it's always important to consider the full kinetic chain and address all factors that contribute to an injury. For example, when I evaluate knee pain in a runner I also consider the influence of the spine, hip and foot/ankle as each region may result in abnormal mechanics and forces on the knee that contribute to the injury.
Most runners achieve better mechanics and function through formal physical therapy. I choose physical therapy programs with medical providers are accustomed to working with athletes. While the goal of "PRICE" (Protection, Rest, Ice, Compression and Elevation) may be reasonable for initial management of certain injuries, telling the athletes what he or she can do is just as important. Cross-training is important to maintain aerobic fitness for runners. A runner with access to a pool can typically perform deep water running for most injuries. Land-based cross-training including elliptical trainer or stationary bike can usually be incorporated into treatment once an athlete is without weight bearing restrictions Runners can also be predisposed to recurrent injuries. When an athlete has a history of recurrent or multiple injuries, I often explore further evaluation and treatment including gait evaluation at the Spaulding National Running Center. During our two-hour evaluation, we collect instrumented treadmill values of impact loading. Our runners are videotaped running in their preferred standard shoes and running mechanics are comprehensively reviewed to understand the cause of their injury. This evaluation includes a physical therapy evaluation of strength and flexibility issues. Treatment for runners who choose gait retraining is executed in two stages. The first stage is the preparatory phase where the emphasis is addressing strength and flexibility deficits. Once runners meet criteria to transition to gait retraining, the focus is on improving both alignment and changing foot strike patterns to reduce impacts. Dr. Davis has demonstrated that running with a forefoot strike pattern using minimalist running shoes reduces impact loading. Higher impacts have been shown to contribute to many overuse injuries, including tibia bone stress injuries and other overuse running injuries. PREVENTION Much of my research has focused on prevention of running injuries, primarily with a focus on optimizing bone health. My practical recommendations include developing optimal strength, flexibility and mechanics to improve overall running patterns. I am also addressing biological factors including sleep and nutrition. In all runners, nutrition is important for both health and running performance. Female runners should be aware that changes in menstrual periods, including increased time between periods or cessation of menses during training, is not a normal physiological response to exercise. Changes in menstrual function are concerning for inadequate nutritional intake to meet the demands of sports participation and require further evaluation with a sports medicine provider familiar with runners. Male runners arguably can have similar deficits in their health in the setting of suboptimal nutrition although this can be more challenging to evaluate. I recommend male runners with unexplained recurrent injuries, especially fractures be seen by a sports medical provider that will evaluate nutrition along with other potential causes of injury. Additionally, calcium and vitamin D intake are both critical to health. Male and female runners ages 9-18 require 1300 mg of calcium and 600 IU vitamin D. Pre-menopausal females and males under 70 require 1000 mg of calcium and 600 IU vitamin D. Recommendations are 1200 mg of calcium daily for post-menopausal females and male runners over 70 given increased the risk for osteopenia or osteoporosis. Calcium intake from diet is typically recommended as a primary source of calcium, especially given that foods rich in calcium are often fortified with vitamin D, represent a good source of energy (calories), and have other important macronutrients including protein and phosphorus. Skim milk has been shown to reduce the risk of fracture in young adult females, with each additional cup of skim milk consumed per day reducing the risk for fracture by 62 percent (Nieves 2010). While runners typically get sun exposure from running outside, this is not sufficient to meet vitamin D needs. Dietary supplements are reasonable to ensure adequate vitamin D intake. Finally, the value of quality sleep cannot be overemphasized. Most Americans do not get adequate sleep, and runners have increased demands to obtain sleep to optimize recovery from both demands of sport and overall life. Impaired sleep has been shown to cause up to 5 percent bone loss within one week, and this could place runners at increased risk for fracture when combining with demands of running (BenSasson 1994). Biomechanics of runners can affect alignment and impacts encountered during running. An excessive impact has been shown to increase the risk of running injuries (Davis 2015). Abnormal mechanics from poor core strength, along with foot mechanics including excessive pronation, as well as other muscle strength and flexibility deficits may also contribute to injury risk. In general, I advocate for strengthening programs to incorporate both lumbopelvic core strengthening (including abdominal muscles and gluteal muscles) along with the foot core (McKeon, 2014) consisting of foot strengthening exercises (both extrinsic muscles of calf, tibialis anterior and peroneal muscles) along with the smaller muscles that make up four layers of muscle in the foot. While foot orthotics and different types of shoes to provide support are viewed as ways to modify mechanics, I would advocate for ensuring the strength of the foot and overall mechanics are first addressed. During childhood and adolescence, peak bone mass is gained (Baxter-Jones). Across studies in different forms of sports, runners do not see consistent gains in bone mass and strength compared to other athletes (Tenforde and Fredericson, 2011). In contrast, sports involving jumping and multidirectional loading including ball sports may reduce fracture risk when performed at a young age (Fredericson 2005, Tenforde 2013). Therefore, encouraging a variety of sports, including ball sports during childhood and early adolescence may improve bone quality and reduce the risk of fractures, especially if performed for more than two years (Tenforde 2015). Finally, periodization of training and body awareness (where each athlete is told to "listen to your body") typically allows for an appropriate increase of training volume while still reducing the risk of injury. Approaching sports medicine care through a multidisciplinary team to ensure the wellbeing of runners may result in greatest long-term success in our sport. In summary, running injuries are common and occur at a high rate. Best treatment and prevention of injuries includes optimal nutrition, sleep, optimizing bone and muscle strength, and ensuring optimal biomechanics for each runner. Dr. Adam Tenforde is a physician who specializes in non-surgical sports medicine. He completed his training in Physical Medicine and Rehabilitation at Stanford with training on management of musculoskeletal conditions affecting the spine, joints, and tendons. Additionally, he completed a sports medicine fellowship at Stanford. Prior to becoming a physician, Dr. Tenforde was an All-American long-distance runner and contributor to multiple national championship teams at Stanford and competed as a professional athlete at the Olympic Trials. He provides care as part of the Running Medicine sub-specialty clinic at the Spaulding National Running Center. |
Running Injuries: How to Fix (Prevent) Them
