By Allison Schroeder; James Onate, PhD, AT, ATC, FNATA; and Thomas Best, MD, PhD
Roughly 60% of overuse injuries in high school athletes occur in the lower extremities, injuries that are increasing in number as more students participate in sports. Treatment involves rest and correction of biomechanical deficiencies, and should be individualized to each athlete.
The number of student-athletes participating in US high school sports has been gradually increasing, and reached a total of 7,795,658 student athletes (4,527,994 male and 3,267,664 female) in 2013-2014.1 Many high schoolers play multiple sports or play year round and do not limit their sports to a single competitive season, with some athletes spending more than 18 hours per week participating in athletics.2 There has also been a trend toward early and intense training, frequent competition, and single-sport specialization, with the goal of competitive success.3,4
It has been speculated that, as the popularity and intensity of high school athletics continues to increase, the number of athletes sustaining overuse injuries will also increase as a result of excessive tissue stresses combined with inadequate recovery periods.5,6 Although there is no consensus on the definition of an overuse injury, it is generally accepted that these injuries result from repetitive microtrauma without sufficient time for recovery from the cumulative tissue loads.5,7-10 Overuse injuries may involve the muscle-tendon unit, bone, articular cartilage, physis, or bursa.6
The incidence and prevalence of overuse injuries are difficult to quantify because they may not result from time lost from sport or they may go undiagnosed as an athlete will play through them until end of the season and then improve with rest during the offseason.
Reports estimate that the proportion of all sports injuries due to overuse ranges from 45.9% to 54%.8,11,12 During the 2013-2014 academic year, a summary report of 100 US high schools indicted that the overall rate of sports injuries, both acute and chronic, was 2.18/1000 athletic exposures (AE).13 A five-year study from the same database revealed that overuse injuries represented 7.7% of all injuries, with an injury rate of 1.5/10,000 AE (1.26/10,000 AE in boys and 1.88/10,000 AE in girls).14 A recent cross-sectional retrospective study by Stracciolini et al of 1614 patients aged 5 to 17 years indicated that 52% of the injuries sustained were related to overuse.15 Fifty percent of overuse injuries cause less than one week of time away from sport, but 4.5% of these injuries have led to medical disqualification for the season.14
In perhaps the largest study to date, girls’ track and field (3.82 injuries/10,000 AEs) and girls’ field hockey (2.93 injuries/10,000 AEs) were the high school sports with the highest injury rates, with the lower leg and knee being the most frequently injured body sites, respectively.14 Overall, the body site most likely to be injured by an overuse mechanism was the lower leg, followed by the knee, shoulder, and foot.14 Overuse injuries to the lower extremities (including injuries to the thigh/upper leg, knee, lower leg, ankle, and foot) accounted for 62.6% of all overuse injuries.14 The aforementioned study by Stracciolini et al indicated that 60.7% of all overuse injuries occurred in the lower extremities.15
Risk factors for overuse injury are typically divided into intrinsic and extrinsic causes.6
Intrinsic risk factors in high school athletes include prior injury,16-18 weakness in bone and cartilage during skeletal maturation,19-21 anatomic alignment abnormalities (pes planus, pes cavus, excessive lumbar lordosis, joint hypermobility),22-24 changes in biomechanics with the growth spurt,25,26 individual strength and conditioning levels,27-30 and presence of the female athlete triad (inadequate caloric intake, amenorrhea, low bone mineral density).31,32
Extrinsic risk factors include increased volume and intensity of sports participation, less recovery time between bouts of exercise,3,33 participation in sports involving repetitive movement (ie, running),14,15 and improper sizing or poor maintenance of equipment (specific data are lacking).6 Recently, sports specialization has been found to increase the risk of overuse injuries independently in athletes that specialize in a single sport (after accounting for age and number of hours spent training per week).34
Common lower extremity injuries
Patellofemoral pain syndrome (PFPS), stress fractures, and apophysitis are three of the most common overuse injuries of the lower extremities. PFPS is the most common diagnosis in sports medicine and is more common in female athletes and runners.35,36 Pain is exacerbated by jumping, climbing stairs, and sitting for extended periods.37
Stress fractures represent bone’s inability to repair itself through remodeling and are being recognized with greater frequency in the pediatric population.37 Metatarsal stress fractures have been found to be more common in runners, while tibial stress fractures were found to be more common in tennis and basketball, but are also common in runners.38,39 A sudden increase in training intensity is speculated to be a major risk factor for stress fractures, no matter the age of the athlete or the sport.40-42
It is important to identify high-risk stress fractures, which comprise up to 10% of all stress fractures and include fractures of the tension side of the femoral neck, the patella, the anterior tibia, the medial malleolus, the talus, the tarsal navicular, the sesamoids, and the base of the fifth metatarsal. If not treated properly, these injuries can result in nonunion, chronic pain, or both.6,43,44
Apophysitis injuries occur because, in the adolescent, the site of attachment between the tendon and bone is weaker than the tendon itself.45 These injuries most commonly occur at the tibial tubercle, distal patella, calcaneus, and the base of the fifth metatarsal. Osgood-Schlatter disease (tibial tubercle apophysitis) typically presents when patients are aged between 10 and 15 years, is often bilateral, is exacerbated by impact and deceleration (running, jumping, cutting), and is more common in boys and those undergoing a rapid growth spurt.46-48
Sinding-Larson-Johansson syndrome (apophysitis of the inferior pole of the patella) typically presents when children are aged between 9 and 12 years and is aggravated by jumping and running. Sever disease (calcaneal apophysitis) is the leading cause of heel pain in adolescent athletes and leads to 8% of all pediatric overuse injuries.49 It is most commonly seen in sports requiring running, jumping, and plantar flexion.50 Iselin disease (fifth metatarsal apophysitis) typically appears in athletes aged between 8 and 15 years and is more common in cutting sports that create inversion stress on the ankle and require activation of the peritoneal muscles.49,51,52
Although tendinitis is less common in adolescents than in adults, iliotibial band (ITB) tendinitis is encountered in adolescent runners and cyclists.53 Lower extremity varus alignment, overpronation from high arches, and lateral tilt of the pelvis predispose athletes to ITB tendinitis.54
The mainstay of treatment following an overuse injury is traditionally rest and physical therapy (PT) to address physical deficiencies. Although many practitioners recommend “rest” and “activity modification” following an overuse injury, there is not an exact formula that can be used to calculate when it is safe for an athlete to return to modified activity and when to return to full activity.
The amount of rest and activity modification depends on many factors, including the injury type, severity, and level of intensity of play to which the athlete wishes to return. The athlete’s pain level should be frequently assessed and the treatment plan modified as necessary throughout the return-to-play and rehabilitation process. There is currently debate regarding whose decision it should be to allow an athlete to return to play (physician, athletic trainer, physical therapist, parents, coach, athlete, etc), though shared medical decision-making has been historically recommended.55,56
The use of objective evidence-based screening assessment processes to address biomechanical asymmetries and movement deficiencies is vitally important in the treatment of overuse injuries. Clinicians are often focused on asymmetrical movement patterns indicating a stability or mobility impairment, but caution should be noted that overall movement performance assessment is critical to proper movement assessment and subsequent treatment plans.
A clinical example would be the use of the single-leg hop for distance test to assess for functional deficits following a lower extremity injury. A patient may have large asymmetries with significant performance deficits in the injured leg due to lack of strength, range of motion deficits, or dynamic postural control inefficiency. However, even if movements are symmetrical, this does not mean they have adequate movement efficiency to avoid injury. A current clinical phenomenon that we are evaluating in our research laboratory is that individuals with overuse injury may have created a bilateral compensation pattern that may cause degradation in performance while maintaining symmetry across limbs.
Therapeutic interventions focused on asymmetry and performance outcomes should clinically emphasize sequential movement focus areas with initial focus on proper muscle activation, followed by an emphasis on the development of proper joint stability and mobility. Following the acquisition of proper muscle activation and stability and mobility, a movement focus, depending on the biomechanical deficiencies and movement demands of the individual, should be addressed to acquire adequate strength, power, endurance, and sport skill application specific to the activity’s demands.
Therapeutic interventions focused on the traditional specific adaptations to imposed demand (SAID) principle57 should be adhered to when developing therapeutic intervention plans with proper flexibility in programmatic sequence based on the patient’s physical (eg, muscle soreness or inflammation) and mental responses (eg, fatigue or boredom). A multifactorial approach to PT allows individuals to focus on the wide array of potentially contributing factors that often lead to overuse injuries; dosage, technique, fatigue, activation patterns, asymmetries, performance outcomes, anatomical alignments, neurological demands, etc.58-60
Modalities and bracing are often used as an adjunct to rest and PT, but limited studies have examined their use in adolescents. Their risks and benefits have been inferred from studies in the adult population and are based on use in clinical practice. Ice and heat are commonly used following injury. Oral acetaminophen may be helpful for short-term pain relief. Several small randomized trials support the use of topical nonsteroidal anti-inflammatory gel for short-term pain relief, but it has not been shown to have long term benefits.61 Glucocorticoid injections may reduce pain initially, but have worse long-term outcomes in children than adults and carry the risk of tendon rupture; their use in adolescents who still have open physes is contraindicated.62,63
Massage therapy and myofasical release have been found to result in faster healing of sprained and strained muscles, and also relieve muscle tension and stiffness, reduce muscle pain, and increase joint flexibility and range of motion, all factors that can contribute to the treatment and prevention of overuse injuries.64,65 However, the utility of massage in injury prevention is still unknown.66
Injury-specific bracing may also be useful in the treatment of overuse injury, for example, bracing has been shown to prevent anterior knee pain.67
Footwear, foot orthoses, and massage have also been used as therapeutic interventions for overuse injury treatment and prevention. A systemic review and meta-analysis of 23 studies concluded there is little evidence to support the use of foot orthoses in treating overuse injuries, but there is more evidence to support the use of orthoses in preventing lower limb overuse injuries, though many studies included in the meta-analysis were of poor quality.68
An additional study indicates that 20% of lower extremity overuse injuries can be prevented with foot orthoses.69 The study reported no difference between custom and prefabricated foot orthoses in the prevention of lower extremity overuse injury, but it is important that they are contoured to the foot and are not just shock-absorbing insoles.68 The main reason athletes discontinue the use of foot orthoses is discomfort.68,70 Some studies also point to the use of minimalist footwear and gait retraining as new methods to reduce lower extremity overuse injuries, especially in runners.71
Prevention is the best form of treatment
It is believed that the majority of overuse injuries are preventable; therefore, being able to adequately identify athletes at greatest risk is very important.6 In spite of the preventable nature of these injuries, studies outlining successful overuse injury prevention methods are lacking.6
A 2014 position statement by the American Medical Society for Sports Medicine (AMSSM) gave several recommendations for consideration in overuse injury prevention.6 However, these statements were based on only inconsistent or limited patient-oriented evidence or consensus, usual practice, or expert opinion.6 The AMSSM recommended limiting training workload by limiting participation time and scheduling rest periods and individualizing these modifications based on the athlete’s age, growth rate, and injury history.6 They supported preseason strength and conditioning training as well as prepractice neuromuscular training to reduce the risk of lower extremity injuries.6
A recent systematic review and meta-analysis by Lauersen et al indicated that strength training was more effective than proprioceptive training for preventing overuse injuries, while stretching before or after exercise showed little effect on the prevention of overuse injuries.72 The AMSSM also recommended use of proper fitting equipment, especially since ill-fitting equipment can alter biomechanics.6
Finally, it is important to identify prior injury patterns, assess for early sports specialization, and determine menstrual (dys)function in female athletes.6 The National Athletic Trainers Association (NATA) also published a position statement on the prevention of overuse injuries in adolescent athletes.11 The strongest evidence supported the recommendation for education of pediatric athletes, parents, and coaches about the signs and symptoms of overuse injuries, and athletes being instructed to notify an adult when such symptoms occur, as ways to prevent overuse injuries.11 The NATA position statement also found strong evidence to support the statement that preventive training programs, both preseason and in-season, that focus on neuromuscular control, balance, coordination, flexibility, and strengthening of the lower extremities may also reduce the overall risk for overuse injuries, especially among athletes with a previous overuse injury.
According to a recent study, athletes and their parents should also be counseled on the increased risk of overuse injuries in young athletes who specialize in a single sport.34
Allison Schroeder is a medical student at The Ohio State University College of Medicine in Columbus. James Onate, PhD, AT, ATC, FNATA, is an associate professor in the School of Health and Rehabilitation Sciences at The Ohio State University. Thomas Best, MD, PhD, is professor and Pomerene Chair, Division of Sports Medicine, Department of Family Medicine, at The Ohio State University.
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