Sternoclavicular (SC) dislocation is a rare injury of the upper extremity. Treatment of posterior SC dislocation ranges from conservative (closed reduction) to operative (open reduction with or without surgical reconstruction of the SC joint). To date, we are unaware of any literature that exists pertaining to this injury or its treatment in elite athletes. The purpose of this case report is to describe a posterior SC joint dislocation in a professional American football player and to illustrate the issues associated with its diagnosis and treatment and the athlete's return to sports. To our knowledge, this case is the first reported in a professional athlete. He was treated successfully with closed reduction and returned to play within 5 weeks of injury.
Concussion is common in many sports, and the incidence is increasing. The medical consequences after a sport-related concussion have received increased attention in recent years since it is known that concussions cause axonal and glial damage, which disturbs the cerebral physiology and makes the brain more vulnerable for additional concussions. This study reports on a knocked-out amateur boxer in whom cerebrospinal fluid (CSF) neurofilament light (NFL) protein, reflecting axonal damage, was used to identify and monitor brain damage. CSF NFL was markedly increased during 36 weeks, suggesting that neuronal injury persists longer than expected after a concussion. CSF biomarker analysis may be valuable in the medical counselling of concussed athletes and in return-to-play considerations. Level of evidence IV.
A common sequela of concussions is impaired reaction time. Computerized neurocognitive tests commonly measure reaction time. A simple clinical test for reaction time has been studied previously in college athletes; whether this test is valid and reliable when assessing younger athletes remains unknown. Our study examines the reliability and validity of this test in a population of high school athletes.
Two American High Schools.
High school athletes (N = 448) participating in American football or soccer during the academic years 2011 to 2012 and 2012 to 2013.
All study participants completed a computerized baseline neurocognitive assessment that included a measure of reaction time (RT comp), in addition to a clinical measure of reaction time that assessed how far a standard measuring device would fall prior to the athlete catching it (RT clin).
MAIN OUTCOME MEASURES:
Validity was assessed by determining the correlation between RT clin and RT comp. Reliability was assessed by measuring the intraclass correlation coefficients (ICCs) between the repeated measures of RT clin and RT comp taken 1 year apart.
In the first year of study, RT clin and RT comp were positively but weakly correlated (rs = 0.229, P < 0.001). In the second year, there was no significant correlation between RT clin and RT comp (rs = 0.084, P = 0.084). Both RT clin [ICC = 0.608; 95% confidence interval (CI), 0.434-0.728] and RT comp (ICC = 0.691; 95% CI, 0.554-0.786) had marginal reliability.
In a population of high school athletes, RT clin had poor validity when compared with RT comp as a standard. Both RT clin and RT comp had marginal test-retest reliability. Before considering the clinical use of RT clin in the assessment of sport-related concussions sustained by high school athletes, the factors affecting reliability and validity should be investigated further.
Reaction time impairment commonly results from concussion and is among the most clinically important measures of the condition. The device evaluated in this study has previously been investigated as a reaction time measure in college athletes. This study investigates the clinical generalizability of the device in a younger population.
A video abstract showing how the RT clin device is used in practice is available as Supplemental Digital Content 1, http://links.lww.com/JSM/A43.
Linemen are at high risk for knee cartilage injuries and osteoarthritis. High-intensity movements from squatting positions (eg, 3-point stance) may produce high joint loads, increasing the risk for cartilage damage. We hypothesized that knee moments and joint reaction forces during lineman-specific activities would be greater than during walking or jogging. Data were collected using standard motion analysis techniques. Fifteen NCAA linemen (mean ± SD: height = 1.86 ± 0.07 m, mass = 121.45 ± 12.78 kg) walked, jogged, and performed 3 unloaded lineman-specific blocking movements from a 3-point stance. External 3-dimensional knee moments and joint reaction forces were calculated using inverse dynamics equations. MANOVA with subsequent univariate ANOVA and post hoc Tukey comparisons were used to determine differences in peak kinetic variables and the flexion angles at which they occurred. All peak moments and joint reaction forces were significantly higher during jogging than during all blocking drills (all P < .001). Peak moments occurred at average knee flexion angles > 70° during blocking versus < 44° in walking or jogging. The magnitude of moments and joint reaction forces when initiating movement from a 3-point stance do not appear to increase risk for cartilage damage, but the high flexion angles at which they occur may increase risk on the posterior femoral condyles.
This study quantified the mechanical interactions between an American football cleat and eight surfaces used by professional American football teams. Loading conditions were applied with a custom-built testing apparatus designed to represent play-relevant maneuvers of elite athletes. Two natural grass and six infill artificial surfaces were tested with the cleated portion of a shoe intended for use on either surface type. In translation tests with a 2. 8-kN vertical load, the grass surfaces limited the horizontal force on the cleats by tearing. This tearing was not observed with the artificial surfaces, which allowed less motion and generated greater horizontal force (3.2 kN vs. 4.5 kN, p < 0.05). Similarly, rotation tests generated less angular displacement and greater torque on the artificial surfaces (145 N m vs. 197 N m, p < 0.05). Translation/drop tests, in which the foot-form was launched into the surfaces with both horizontal and vertical velocity components generated less peak horizontal force on the natural surfaces than on the artificial surfaces (2.4 kN vs. 3.0 kN, p < 0.05). These results suggest a force-limiting mechanism inherent to natural grass surfaces. Future work should consider implications of these findings for performance and injury risk and should evaluate the findings' sensitivity to cleat pattern and playing conditions.
Sport Business, The Daily Global Journal Database Guide.
The following materails are supplements to the presentations provided as part of theCurrent Issues in Sports Law CLE Seminar on July 11, 2014.