Active and Passive Insufficiency

Question 1

What is Active Insufficiency?

Answer 1

Textbook: The inability of a Two-Joint muscle to shorten simultaneously at both joints

Simplified: think what are the actions of the two joint muscle. If both actions occur at this muscle this puts the muscle into active insufficiency

Ex: Elbow Flexion and Shoulder Flexion places the biceps brachii into Active Insufficiency

Plantar Flexion + Knee Flexion places the Gastroc into Active Insufficiency

Question 2

What is Passive Insufficiency

Answer 2

Textbook: The inability of a Two-Joint muscle to lengthen simultaneously at both joints

Simplified: Think of the opposite actions of that muscle, this puts them on stretch putting them into passive insufficiency

Ex:
Shoulder and Elbow Extension places the biceps brachii into passive insufficiency

Dorsiflexion + Extension places the Gastroc into passive insufficiency

Knee Extension + Hip Flexion places the hamstrings into passive insufficiency