Final answer:
The answer to the question is A. True. Isometric contractions involve the muscle increasing in tension while maintaining the same length, especially when the muscle's force cannot overcome a heavy load.
Step-by-step explanation:
With regards to the question - With isometric exercises the muscle does not shorten, muscle length does not change - the answer is A. True. An isometric contraction happens when the muscle produces tension without a change in muscle length or the angle of a skeletal joint. This is because the tension in the muscle does not surpass the resistance of the load being acted upon.
During an isometric exercise, sarcomere activation and shortening might occur but only to a point. Even with increasing muscle tension, the overall length of the muscle remains constant. Isometric exercises are commonly used for posture maintenance and enhancing joint stability.