Final answer:
Isometric contractions occur when muscles produce tension without changing the angle of a skeletal joint. They involve sarcomere shortening and increasing muscle tension, but do not move a load. Isometric contractions are important for maintaining posture, bone, and joint stability.
Step-by-step explanation:
An isometric contraction occurs as the muscle produces tension without changing the angle of a skeletal joint. Isometric contractions involve sarcomere shortening and increasing muscle tension, but do not move a load. Isometric contractions are active in maintaining posture and maintaining bone and joint stability. Most actions of the body are the result of a combination of isotonic and isometric contractions working together.