Final answer:
Muscle spindles and Golgi tendon organs are two types of muscle proprioceptors needed by the CNS for effective control of motor output.
Step-by-step explanation:
The two types of muscle proprioceptors needed by the CNS for effective control of motor output are muscle spindles and Golgi tendon organs.
Muscle spindles are stretch receptors that detect the amount of stretch or lengthening of muscles. They provide information about muscle length and help regulate the degree of muscle contraction. On the other hand, Golgi tendon organs are tension receptors that detect the force of muscle contraction. They are located at the junction of muscles and tendons and provide information about muscle tension to prevent excessive force and injury.