The document discusses flexibility, including definitions of flexibility and range of motion. It explains that flexibility is important for joints like the ankles, hips, and shoulders. It also discusses how to assess flexibility for different parts of the body, including the arms, legs, trunk, and ankles through exercises like the arm lift, zipper test, trunk rotation, and ankle flex. The principles of overload, progression, and specificity are also explained in relation to developing flexibility.

1. Chapter 10: Flexibility Lesson 10.1: Flexibility Facts Self-Assessment 10: Arm, Leg, and Trunk Flexibility