Effect of moment of inertia and physical profile on restricted motion swing speed

The maximum swing speed of an implement is an important performance parameter in many sports. It is understood that moment of inertia (MOI) has an effect upon the swing speed of an implement and numerous studies have found a very similar relationship between swing speed and MOI. These different studies considered different movements which suggested that skill was less important than physique to this relationship. The aim of this work was to quantify the relationship between swing speed and moment of inertia and to determine whether a participant's physical characteristics are related to their swing speed performance. A series of eight visually identical rods, with varied MOI were swung in a heavily restricted, maximal motion. Feedback was supplied to the participants about their motion and all trials were recorded with a Motion Analysis Corporation motion capture system. The results found that a similar exponential relationship exists between swing speed and MOI. It was also found that a participant's maximum work done is significantly related to their swing speed. This is a relationship that could be used to predict a participant's swing speed for a specific MOI implement. More work is to be carried out on a larger population in order to be confident in the power of the relationships found.