Testing the kinetic chain

The body is set up in a series of links called the kinetic chain. It's easy to think of the body as a set of individual segments that do not interact or influence each other: you have your shoulders that you use to generate propulsion during your pull, your legs that help with the kick, the torso that assists with body rotation, and so on. However, all of these segments are in fact linked together, much like the links of a chain. What happens in one part of the body is influenced by what is happening in other parts of the body. When viewed this way, the force you can generate with your pull is affected by a variety of other factors:

• Leg strength and the effectiveness of the kick
• Core stability and the ability to maintain a streamlined body position
• Strength in the muscles of the upper back that stabilize the shoulder blades

In a strong kinetic chain, forces are shared among the various muscle groups throughout the body, and power can flow from one segment to another. Any weakness in the kinetic chain, whether it is because of a lack of flexibilityor a strength deficit, can have far-reaching effects. When one link is weak, it places greater stresses on the other body parts and can quickly lead to injury. Why did you develop that tendinitis in your shoulder? Is it truly because you have weak rotator cuff, or could it be because you have poor core stability or an asymmetry in your stroke that requires the injured shoulder to do more work than it should? There are several tests (I'm going to write about them in my next post) you can use to assess swimmers' physical strengths and weaknesses along with the health of their kinetic chain. As you perform the following tests, realize that there are no swimming-specific data to compare your results to. However, the tests still have incredible value. Test your swimmers at the start of each season to establish a benchmark in each area and identify areas of weakness and then retest them periodically to assess improvements.