NSCF Certified Personal Trainer Practice Exam 2025 - Free Personal Trainer Practice Questions and Study Guide

The choice of barbell box squats using a stability ball instead of a box stands out as the most concerning option due to the inherent instability and risk factors involved. When a stability ball is used in place of a traditional box for squats, it significantly alters the support and balance that the lifter would normally have. This modification can compromise the safety of the exercise because the ball can easily roll or shift, which increases the likelihood of losing balance.

Moreover, performing barbell box squats requires a certain level of stability and control, particularly as the weight increases. Substituting a stability ball eliminates that solid foundation, which is critical for maintaining proper technique, especially under heavier loads. The potential for falling or twisting an ankle or knee can lead to serious injury.

In contrast, the other exercises listed—dumbbell lunges, push-ups, and bodyweight squats—are generally performed with a lower risk of severe injury when done with proper form. They provide more grounding and control during execution, and while they can lead to strain or minor injuries if performed incorrectly, they do not carry the same immediate threat that the use of a stability ball for box squats does.