What is the primary focus of Proprioceptive Neuromuscular Facilitation (PNF)?

The primary focus of Proprioceptive Neuromuscular Facilitation (PNF) is increasing muscle flexibility. PNF is a manual stretching technique that involves both stretching and contracting the muscle group being targeted. This method facilitates greater increases in flexibility through reflex stimulation of the muscle's neuromuscular system. By using both passive and active muscle actions, PNF effectively allows the muscles to achieve a deeper stretch and promote overall flexibility improvement. The technique often involves a partner or therapist who assists in applying resistance during the contraction phase, further enhancing muscle elongation during the subsequent stretching phase.

This is why option B accurately represents the main purpose of PNF, distinguishing it from other exercise modalities that may focus on speed, strength, or cardiovascular health.