Isotonic Contraction 

From the earlier mnemonics we can see that:

Iso - Constant 

Tonic - Movement

Contraction - Tension

From this we can understand that:

Isotonic contraction = constant movement while the muscles are in tension, or:

Isotonic Contraction - Muscle contraction that results in limb movement

There are two types of isotonic contraction

A. Concentric contraction - Shortening of the muscle and the muscle in tension (a shortening of the muscles)

B. Eccentric contraction - Lengthening of the muscle and the muscle in tension (a lengthening of the muscles)

1. Isotonic contractions occur when you: 

Move a dumbbell in a bicep curl upwards and downwards.

2. Completing a full squat downwards and back up is an example of an isotonic contraction. 

3. A press up is an example of an isotonic contraction.