Final answer:
Proprioceptive Neuromuscular Facilitation (PNF) involves three phases: the passive stretch phase, the isometric contraction phase, and the active assisted phase.
Step-by-step explanation:
Proprioceptive Neuromuscular Facilitation (PNF) is a technique used to improve muscle function and flexibility. PNF involves three phases: the passive stretch phase, the isometric contraction phase, and the active assisted phase.
In the passive stretch phase, the target muscle is passively stretched to its end range of motion.
In the isometric contraction phase, the target muscle contracts isometrically against resistance for a brief period.
In the active assisted phase, the target muscle is actively contracted while being assisted by a partner or device to move into a greater range of motion.