Question

multiple choice question

when lifting something heavy, which type of contraction occurs first?

isotonic
isometric

Explanation:

Define contraction types

Using the Muscle Contraction Types knowledge point

• Isometric contraction: Muscle develops tension but does not shorten, meaning no movement occurs.
• Isotonic contraction: Muscle changes length while maintaining constant tension, resulting in movement.

Analyze tension development

Using the Internal Tension and External Tension knowledge points
When lifting a heavy object, the muscle must first build up enough internal tension to overcome the external load (resistance) of the object before any actual shortening or movement can begin. During this initial phase of building tension without movement, the contraction is isometric. Once the tension exceeds the load, the muscle begins to shorten, transitioning into an isotonic contraction. Therefore, isometric contraction occurs first.

Answer:

• Isotonic
• Isometric (Correct answer)