Sports-related concussions (SRC) occur due to biomechanical forces to the head or neck that can result in pathophysiological changes in the brain. The musculature of the cervical spine has been identified as one potential factor in reducing SRC risk as well as underlying sex differences in SRC rates. Recent research has demonstrated that linear and rotational head acceleration, as well as the magnitude of force, upon impact is influenced by cervical spine biomechanics. Increased neck strength and girth is associated with reduced linear and rotational head acceleration during impact. Past work has also shown that overall neck strength and girth are lower in athletes with SRC. Additionally, differences in cervical spine biomechanics are hypothesized as a critical factor underlying sex differences in SRC rates. Specifically, compared to males, females tend to have less neck strength and girth which is associated with increased linear and rotational head acceleration. Although our ability to detect SRC has greatly improved, our ability to prevent SRCs from occurring and decrease the severity of clinical outcomes post-injury is limited. However, we suggest, along with others, that cervical spine biomechanics is a modifiable factor in reducing SRC risk. We review the role of the cervical spine in reducing SRC risk, and how this differs dependent on sex. We discuss clinical considerations for the examination of the cervical spine and the potential clinical relevance for SRC prevention. Additionally, we provide suggestions for future research examining cervical spine properties as modifiable factors in reducing SRC risk.

Ratamess, NA, Kang, J, Porfido, TM, Ismaili, CP, Selamie, SN, Williams, BD, Kuper, JD, Bush, JA, and Faigenbaum, AD. Acute resistance exercise performance is negatively impacted by prior aerobic endurance exercise. J Strength Cond Res 30(10): 2667-2681, 2016-The purpose of the present study was to examine acute resistance exercise (RE) performance after 4 different aerobic endurance (AE) protocols. Eleven healthy, resistance-trained men (21.0 ± 1.2 years) performed a control RE protocol and 4 RE protocols 10 minutes after different AE protocols in random sequence. The RE protocol consisted of 5 exercises (high pull, squat, bench press, deadlift, and push press) performed for 3 sets of 6-10 repetitions with 70-80% of one repetition-maximum (1RM) with 3-minute rest intervals in between sets. The AE protocols consisted of treadmill running at velocities corresponding to: (a) 60% of their V[Combining Dot Above]O2 reserve (V[Combining Dot Above]O2R) for 45 minutes (P1); (b) 75% of their V[Combining Dot Above]O2R for 20 minutes (P2); (c) 90-100% of V[Combining Dot Above]O2R in 3-minute intervals (1:1 ratio) for 5 sets (P3); and (d) 75% of V[Combining Dot Above]O2R (4.5 mph) uphill (6-9% grade) for 20 minutes (P4). Completed repetitions, average power and velocity, heart rate (HR), and ratings of perceived exertion (RPE) were assessed each set. Protocols P1-P4 resulted in 9.1-18.6% fewer total repetitions performed compared with the control RE protocol with the squat experiencing the greatest reduction. Average power and velocity were significantly reduced for the high pull, squat, and bench press after most AE protocols. Ratings of perceived exertion values for the high pull and squat were significantly higher in P1-P4 compared with control. Heart rate was significantly higher during RE after P1-P4 compared with control by 4.3-5.5%. These results indicate acute RE performance is significantly compromised in healthy men after AE exercise of different type, intensity, and duration with largest reductions observed after high-intensity interval exercise.

WBV combined with body weight squats can augment VO2 at 40 Hz of high amplitude and 50 Hz of both low and high amplitudes. This metabolic potentiation remains in effect during subsequent aerobic exercise. WBV did not affect fat oxidation across all vibratory loads.

Sport-related brain injury is very common, and the potential long-term effects include a wide range of neurological and psychiatric symptoms, and potentially neurodegeneration. Around the globe, researchers are conducting neuroimaging studies on primarily homogenous samples of athletes. However, neuroimaging studies are expensive and time consuming, and thus current findings from studies of sport-related brain injury are often limited by small sample sizes. Further, current studies apply a variety of neuroimaging techniques and analysis tools which limit comparability among studies. The ENIGMA Sports Injury working group aims to provide a platform for data sharing and collaborative data analysis thereby leveraging existing data and expertise. By harmonizing data from a large number of studies from around the globe, we will work towards reproducibility of previously published findings and towards addressing important research questions with regard to diagnosis, prognosis, and efficacy of treatment for sport-related brain injury. Moreover, the ENIGMA Sports Injury working group is committed to providing recommendations for future prospective data acquisition to enhance data quality and scientific rigor. Keywords Concussion. ENIGMA. Repetitive head impacts. Sport-related brain injury Sport-related brain injury Sport-related brain injury is a broad term that describes alterations in brain structure and function resulting from mechanical forces to the head sustained while participating in sports. The most common forms of sport-related brain trauma are typically categorized as sport-related concussion (SRC) and exposure to repetitive head impacts (RHI) which may have cumulative effects on brain structure and function. Stages of brain alterations due to sport-related brain injury have been described as acute/subacute, chronic but static, and progressive neurodegenerative decline, as shown in Fig. 1. Sport-related Concussion (SRC) is common in athletes. An estimated 1.6 to 3.8 million people suffer from SRC annually in the United States alone (Daneshvar et al. 2011; Laker 2015; Langlois et al. 2006). SRC occurs in all sports, but incidence rates are highest in contact and collision sports such as football, soccer, rugby, or ice hockey (Guskiewicz et al. 2000; Laker 2015; Marar et al. 2012; Meehan et al. 2010). SRC is characterized by a sudden, but typically, transient impairment in brain function following an impact to the head, face, neck, or body. Symptoms of SRC include headache, dizziness, visual ocular dysfunction, loss of memory, and confusion and resolve within weeks in adults and up to a month in children

Aim: To examine whether neck strength and symmetry are associated with psychological function in athletes with exposure to repetitive head impacts. Methods: Collegiate soccer (n = 29) and limited/noncontact (n = 63) athletes without a history of concussion completed the Brief Symptom Inventory 18 and assessments of isometric neck strength. Neck strength symmetry was calculated as the difference in strength between opposing muscle groups. Results: The results demonstrated that lower neck strength was associated with more symptoms of anxiety, whereas asymmetry in neck strength was associated with more symptoms of somatization and depression in soccer athletes only. Conclusion: These preliminary results suggest that greater neck strength/symmetry is related to better psychological function in athletes who have higher exposure to repetitive head impacts.