What is the key characteristic of a third class lever system?

A third class lever system is defined by the arrangement where the force is applied between the fulcrum and the load. This configuration allows for greater range of motion and speed of the load being moved. In practical terms, this means that as a smaller force (such as a muscular effort) is exerted, it can move a heavier load over a larger range than the force being applied.

An example of this is the bicep curl, where the elbow acts as the fulcrum, the force comes from the contraction of the bicep muscle, and the load is held in the hand. This lever system is widely utilized in the human body due to its efficiency in enhancing movement and speed rather than maximizing strength or load capacity.

Understanding this structure is crucial for analyzing how forces work in various biomechanical activities and helps inform practices in rehabilitation and strength training.