What is defined as the ability to move a joint through its normal range of motion?

Agility is the ability to rapidly change direction and body position under control, which is a neuromuscular coordination skill unrelated to joint range of motion.

Stability refers to the ability to control and maintain the position of a joint or body segment, which depends on strength and motor control rather than passive tissue extensibility.

Flexibility refers to the capacity of muscles, tendons, and connective tissue surrounding a joint to permit full, unrestricted movement through the joint's normal range of motion. This is the foundational definition used across exercise science and rehabilitation frameworks, distinguishing it from strength- or coordination-based physical qualities.

Hypomobility describes a condition of reduced or restricted joint range of motion - it is the pathological opposite of normal mobility, not a definition of the ability to move through a full range.