Discover the most talked about and latest scientific content & concepts.

Journal: Journal of athletic training


  To test a helmetless-tackling behavioral intervention for reducing head impacts in National Collegiate Athletic Association Division I football players.

Concepts: College football, American football


As sports reinitiate around the country, the incidence of COVID-19 among youth soccer athletes remains unknown.


Patellofemoral pain (PFP) is among the most common injuries in recreational runners. Current evidence does not identify alignment, muscle weakness, and patellar maltracking or a combination of these as causes of PFP. Rather than solely investigating biomechanics, we suggest a holistic approach to address the causes of PFP. Both external loads, such as changes in training parameters and biomechanics, and internal loads, such as sleep and psychological stress, should be considered. As for the management of runners with PFP, recent research suggested that various interventions can be considered to help symptoms, even if these interventions target biomechanical factors that may not have caused the injury in the first place. In this Current Concepts article, we describe how the latest evidence on education about training modifications, strengthening exercises, gait and footwear modifications, and psychosocial factors can be applied when treating runners with PFP. The importance of maintaining relative homeostasis between load and capacity will be emphasized. Recommendations for temporary or longer-term interventions will be discussed. A holistic, evidence-based approach should consist of a graded exposure to load, including movement, exercise, and running, while considering the capacity of the individual, including sleep and psychosocial factors. Cost, accessibility, and the personal preferences of patients should also be considered.


In the spring of 2020, US schools closed to in-person teaching and sports were cancelled to control the transmission of coronavirus disease 2019 (COVID-19). It is critical to understand the mental and physical health of adolescent athletes during this time.


 Identification of strategies to prevent spinal injury, optimize rehabilitation, and enhance performance is a priority for practitioners. Different exercises produce different effects on neuromuscular performance. Clarity of the purpose of a prescribed exercise is central to a successful outcome. Spinal exercises need to be classified according to the objective of the exercise and planned physical outcome.

Concepts: Physical exercise, Exercise, Sports training


Overtraining syndrome (OTS) and related conditions cause decreased training performance and fatigue through an imbalance among training volume, nutrition, and recovery time. No definitive biochemical markers of OTS currently exist.


Weakness or decreased activation of the hip abductors and external rotators has been associated with lower extremity injury, especially in females. Resisted side stepping is commonly used to address hip weakness. Whereas multiple variations of this exercise are used clinically, few data exist regarding which variations to select.


After knee-joint injury, pain, effusion, and mechanoreceptor damage alter afferent signaling, which can result in quadriceps inhibition and subsequent weakness. The individual contributions of each factor to inhibition remain unclear due to confounding knee-joint injuries and indirect experimental models.


Context :  After an intense bout of exercise, foam rolling is thought to alleviate muscle fatigue and soreness (ie, delayed-onset muscle soreness [DOMS]) and improve muscular performance; however, no empirical evidence confirms this belief. Potentially, foam rolling may be an effective therapeutic modality to reduce DOMS while enhancing the recovery of muscular performance. Objective :  To examine the effects of foam rolling as a recovery tool after an intense exercise protocol through assessment of pressure-pain threshold, sprint time, change-of-direction speed, power, and dynamic strength-endurance. Design :  Controlled laboratory study. Setting :  University laboratory. Patients or Other Participants :  A total of 8 healthy, physically active males (age = 22.1 ± 2.5 years, height = 177.0 ± 7.5 cm, mass = 88.4 ± 11.4 kg) participated. Intervention(s) :  Participants performed 2 conditions, separated by 4 weeks, involving 10 sets of 10 repetitions of back squats at 60% of their 1-repetition maximum , followed by either no foam rolling or 20 minutes of foam rolling immediately, 24, and 48 hours postexercise. Main Outcome Measure(s) :  Pressure-pain threshold, sprint speed (30-m sprint time), power (broad-jump distance), change-of-direction speed (T-test), and dynamic strength-endurance. Results :  Foam rolling substantially improved quadriceps muscle tenderness by a moderate to large amount in the days after fatigue (Cohen d range, 0.59 to 0.84). Substantial effects ranged from small to large in sprint time (Cohen d range, 0.68 to 0.77), power (Cohen d range, 0.48 to 0.87), and dynamic strength-endurance (Cohen d = 0.54). Conclusions :  Foam rolling effectively reduced DOMS and associated decrements in most dynamic performance measures.

Concepts: Exercise physiology


Historically, methods of monitoring training loads in runners have used simple and convenient metrics, including the duration or distance run. Changes in these values are assessed on a week-to-week basis to induce training adaptations and manage injury risk. To date, whether different measures of external loads, including biomechanical measures, provide better information regarding week-to-week changes in external loads experienced by a runner is unclear. In addition, the importance of combining internal-load measures, such as session rating of perceived exertion (sRPE), with different external-load measures to monitor week-to-week changes in training load in runners is unknown.