The flag is red in American football and yellow in Canadian football, so it contrasts with the officials' penalty flags. This is thrown by a coach when he wishes to contest challenge a referee's decision.
Tristen Webster, who is a football offensive and defensive lineman at the Tennessee School for the Deaf, suffered a horrific ankle injury last season. As the Vikings’ practice was winding down one September evening in Knoxville, the coaches called for an unscripted scrimmage. “It was a loose ball situation and he ended up in a big pile,” said Tracy Webster, Tristen’s father. No one knows exactly what happened next, but Tristen’s coaches could hear him screaming from the bottom of the pile at the end of the play. “His foot was turned around almost 180 degrees,” Tracy said. “His whole ankle was basically destroyed.” X-rays would later show that Tristen suffered broken bones and torn ligaments and tendons.
One should evaluate the hydration status of athletes before starting any rigorous sports activity. Athletes should begin all exercise sessions well hydrated. A recent study found two-thirds of the pediatric athletes evaluated were dehydrated before practice. There are several ways to approximate hydration status. Assuming the athlete is properly hydrated, pre-exercise body weight should be relatively consistent throughout the entire exercise session. One should determine the percentage difference between the post-exercise body weight and also determine the baseline hydrated bodyweight. The post-exercise weight should be no more than 2 percent less than the pre-exercise weight. A simple method to determine hydration status is to compare urine color (from a sample container) with a urine color chart. A light “straw” color (1 or 2) is indicative of being well hydrated while a dark color (5 or 6) represents significant dehydration. Measuring urine specific gravity with a refractometer is less subjective than comparing urine color and can also be used. For color analysis or specific gravity, midstream urine should be collected for consistency and accuracy. Since body weight changes during exercise give the best indication of hydration status, one should determine an athlete’s weight and urine measurement before the exercise session and then determine their weight after exercise to estimate fluid balance. All athletes participating in sports requiring weight classes such as wrestling or rowing should have their hydration status checked at weigh-in to ensure they are not dehydrated. A urine specific gravity less than or equal to 1.020 or urine color less than or equal to 4 should be the upper range of acceptable on weigh-in. Procedures such as taking diuretics, exercising in rubber suits or in a sauna to reduce body weight
The adult brain is a three-pound organ that basically floats inside the skull. It is surrounded by cerebral spinal fluid, which acts as a shock absorber for minor impacts. When the brain moves rapidly inside the skull, a concussion has technically occurred. One common scenario that can lead to a concussion is a direct blow to the head or a whiplash effect to the body. The impact rapidly accelerates the head, causing the brain to strike the inner skull (i.e., the coup). When the head decelerates and stops its motion, the brain then hits the opposite side of the inner skull (i.e., the contrecoup). The second common scenario is a rotational concussion, in which the head rapidly rotates from one side to another causing shearing and straining of brain tissues. In either case, delicate neural pathways in the brain can become damaged, causing neurological disturbances.