Brugada-type patterns are easily observed in high precordial lead ECGs in collegiate athletes.

BACKGROUND: Displacement of ECG leads can result in unwarranted findings. We assessed the frequency of Brugada-type patterns in athletes when precordial leads were purposely placed upward. METHODS: Four hundred ninety-one collegiate athletes underwent two ECGs: one with standard leads, one with V1 and V2 along the 2nd intercostal space. A positive Brugada-type pattern was defined as ST elevation in V1 or V2 consistent with a Type 1, 2, or 3 pattern in the high-lead ECG. A control group was comprised of 181 outpatients. RESULTS: No Type 1 patterns were seen. In 58 athletes (11.8%), a Brugada-type 2 or 3 pattern was observed. Those with Brugada-type 2 or 3 patterns were more likely male, taller, and heavier. In the control group, 18 (9.9%) had Brugada-type 2 or 3 patterns and were more likely male. CONCLUSIONS: Proper lead positioning is essential to avoid unwarranted diagnosis of a Brugada-type ECG, especially in taller, heavier male athletes.

Biomechanical analysis of football neck collars.

OBJECTIVE: To determine the load-limiting capabilities of protective neck collars used in football through dynamic impact testing. DESIGN: A 50th-percentile male Hybrid III dummy was used in 48 dynamic impact tests comparing The Cowboy Collar, Bullock Collar, and Kerr Collar. A control and each collar were tested at two velocities (5 m/s and 7 m/s), three impact locations (front, top, and side of the helmet), and two shoulder pad positions (normal and raised). SETTING: Research laboratory. PATIENTS: None. INTERVENTIONS: None. Independent variables were the neck collars, impact velocity, and shoulder pad position. MAIN OUTCOME MEASUREMENTS: In addition to range of motion, upper and lower neck forces and moments were measured. RESULTS: With the top impact location, it was found that the Kerr Collar and Bullock Collar reduced head accelerations and force transmission through the neck. With the front impact location, all the collars reduced lower neck moment. The Kerr Collar was also capable of reducing the lower neck force and upper neck moment. With the side impact location, the Kerr Collar substantially reduced lower neck moment. CONCLUSIONS: These reductions in loads correlate with the degree to which each collar restricted the motion of the head and neck. By restricting the range of motion of the neck and redistributing load to the shoulders, neck loads can be effectively lowered.

Differences in hybrid iii and thornt neck response in extension using matched tests with football neck collars.

Anthropometric test devices have been used in sports injury biomechanics research. This study addresses the differences in the head and neck response of the Hybrid III and THOR-NT 50th percentile male crash test dummies when used to evaluate the load limiting capabilities of football neck collars. 24 matched tests were performed with the Hybrid III and THOR-NT; in which they were equipped with shoulder pads, a helmet, and various neck collars. The dummies were then impacted on the front of the helmet using a pneumatic linear impactor to promote extension of the neck. Results from these tests indicate that the Hybrid III generates greater loads than the THOR-NT due to its stiffer neck. The Hybrid III was also more sensitive to impact velocity. The neck collars had different effects on each dummy, typically affecting the Hybrid III's response more. Even though this study looks at a specific application, it highlights differences in neck response between the Hybrid III and THOR-NT.

Force transmission to the mandible by chin straps during head impacts in football.

The objective of this study was to determine the force transmitted to the mandible from the chin strap in football helmets for head impacts. A total of 32 tests were performed comparing front and side impact locations. Each location was tested at two impact velocities (6.5 m/s and 9.0 m/s). Different combinations of neck collars and shoulder pads were tested at each speed and location to account for potential equipment variability between football players. A 50th percentile male Hybrid III dummy was equipped with a helmet, shoulder pads, and various neck collars. Tension load cells were installed on the left and right sides of the chin straps. From the tension values in the chin strap, the force transmitted to the mandible was calculated. With the front impact location, the average peak mandible load was 568 +/- 80 N at 6.5 m/s and 806 +/- 64 N at 9.0 m/s. With the side impact location, the average peak mandible load was 87 +/- 36 N at 6.5 m/s and 170 +/- 80 N at 9.0 m/s. Although there are some overlying assumptions, these values represent a good estimation of the forces acting on the mandible for head impacts in football.