Final answer:
Loss of control of the teres minor and deltoid muscles can lead to atrophy, causing a decrease in muscle size and weakness, affecting shoulder movement.
Step-by-step explanation:
Loss of control of the teres minor and the deltoid muscles results in an inability to properly move the shoulder or arm. This condition can lead to atrophy, which is a decrease in the size of a structure, such as a muscle, due to nonuse. When muscles like the teres minor and deltoid are not used, they can shrink and weaken, which could affect the range of motion and strength of the shoulder joint.