Final answer:
A PMA-Certified Pilates Teacher assesses a client's readiness to progress based on their movement proficiency, as this is central to motor control theory. It reflects not just strength or endurance but the ability to perform movements with correct form and control.
Step-by-step explanation:
According to motor control theory, a PMA-Certified Pilates Teacher determines that a client is ready to progress when they demonstrate movement proficiency. This is because physical training significantly affects muscle appearance and performance, with structural proteins being added to muscle fibers in a process called hypertrophy, increasing their diameter.
Conversely, when these structural proteins are lost, and muscle mass decreases, this is referred to as atrophy. To determine readiness to progress, factors such as muscle strength, balance, muscular endurance, and other capabilities are assessed by professionals such as physiotherapists. However, for a Pilates teacher, the emphasis is on how well the client performs movements with correct form and control, which falls under the realm of movement proficiency.