Which term means lengthening?

• A. Expand
• B. External
• C. Extension
• D. Fatigue

Answer: (C)

Lengthening is described by extension. In anatomy and movement, extension refers to straightening a joint or increasing the distance between two segments, which lengthens the limb. For example, extending the elbow straightens it and increases the distance from shoulder to hand. Expand is a general term for making larger, but not the precise biomechanical action of lengthening in this context. External means outside, and fatigue means tiredness, so they don’t fit the concept of lengthening.