What are the two differences between Isotonic Contraction and Isometric Contraction?

Isotonic Contraction:

1. A contraction in which a muscle shortens against a load.

2. It results in movement and performance of work, e.g. contraction of leg muscle during walking.

Isometric Contraction:

1. A contraction in which a muscle is unable to shorten.

2. No movement is produced, the tension developed is dissipated absent heat, e.g. fore arm carrying load.