As we look into the Dynamics there are a variety of crucial patterns we must understand. As we look at those patterns we typically look at internal factors and external factors. For example, when considering kinetics we have both internal kinetics and external kinetics to study. What do I mean by that? Biomechanically we are using our muscles to create forces inside the body, however we also use those internal forces in a way that we apply forces outside the body.
There are two main places we apply the external forces - one of them in the handle of the club. Simply put we need to apply forces in the handle to swing the club effectively. The second main place we apply external forces into the ground, creating what we call your ground force pattern. So forces in the handle and forces in the ground comprise what we are mostly studying when talking about external forces.
We often say, "Force creates Motion!" To that extent the forces are applied before the motion occurs. So if you've seen something in motion the forces needed to put it in motion have already done their job. This reminds me that at some point we need to understand what can be observed and what needs to be measured to be more thoroughly understood.
One of the tricky things about understanding the kinetic forces and when we apply them is that we can not see them. This is why we use force plate and other technologies to help us better understand how they work and what valid patterns exist. The good news for you, the golfer, is that a qualified coach who has worked with the technology long enough can often assess what is happening and what is needed without the technology. That doesn't mean the technology is unnecessary, because their are critical times when the technology is needed to help us understand the best preferences for the golfer.
Besides addressing the Kinetics related to playing golf we also discuss Kinematics. Golfers often ask, what is the difference between Kinetics and Kinematics? A simple view is that Kinetics involve the force applications you cannot see, and Kinematics involves the motions that can be visually observed. For example, there are many sequencing patterns we can visual observe, and there ae many types of techniques and actions we can visually identify. However we can't see the forces that created those techniques and actions.
When talking about Kinematics we often address what is called the Kinematic Sequence. The original Kinematic Sequence research focused on Rotational Velocities and identified a recommended sequencing between the components being monitored. In reality we swing in 3-Dimensional Space, which means there are likely 3 Kinematic Sequences - one addressing the rotational components, another addressing lateral components and one addressing vertical components.