As a young runner or athlete, kids move quickly in various directions and planes. It takes a lot of energy and mechanics of the body and brain to make things come together during practice or competition. When you extend one part of the body, you are flexing another and no matter how "smooth you move" you are still putting your body at risk and under a lot stress. That is why an active warm-up before a workout and a good static cool down after is so important.
The difference between a child athlete and an adult are not just their size and density, it is also their musculoskeletal make-up that differ. Our musculoskeletal system includes bones, muscles and joints that all work together. For a child there are also "growth plates" which are located at the ends of the longer bones such as the arms and legs. These plates are areas of growing tissue near the end of the bones and a young person has finished growing, these soft areas are replaced with solid bone. Take note, the growth plate is the weakest part of the growing skeleton and injuries to these areas are usually called fractures (contact your pediatrician for more detailed information) and need to be properly taken care of. REMEMBER, never play through the pain!
The next time you drop our kids off at practice, take the time to watch their warm-up routine and their cool down. It's important to share with your kids how important it is to get the warm-up in and socialize later. After practice, it is our responsibility as parents to make sure the kids perform a good static stretch immediately after practice or before going to bed. This will keep the body flexible and not stiffen after practice. Also, it is a great idea to stress the need for WATER before, during and after practice/competition as well. Their muscles need the oxygen to work at full capacity. Always remember that the muscles protect bones and with kids their growing plates as well!