AFAA Personal Trainer Certification Practice Exam 2025 - Free Personal Trainer Practice Questions and Study Guide

The term "closed kinetic chain" refers to a situation where both ends of a segment of the body are fixed, typically in contact with a surface—like the ground. This means that movements occurring during these exercises involve multiple joints and muscle groups working together, making it a functional and stable way to train.

In this context, the correct choice highlights that in a closed kinetic chain, the fixed position of the feet (or hands, depending on the exercise) allows for effective movement of the upper body. For instance, during a squat, the feet remain in contact with the ground while allowing the hips, knees, and other related joints to move together in a coordinated manner.

The other choices lack the fundamental characteristics of closed kinetic chain movements. While one mentions movement with fixed ends, it does not capture the collaborative nature of closed chain activities where the entire body engages in a compound manner.