Maintenance of plank position is an example of which type of strength develop ment exercise?

The correct option is Isometric.

To understand why this is the correct answer, let's break down the characteristics of strength development exercises and how they apply to a plank position:

1. Isometric Exercises: These are static exercises where the muscles contract, but there is no visible movement in the joints. The muscle length remains constant, and the joint angle does not change. Maintaining a plank position requires you to hold a static posture against gravity, where your core, shoulders, and leg muscles are actively contracting to keep your body aligned without any joint movement. Therefore, it is a classic example of an isometric exercise.

2. Isotonic Exercises: These involve muscle contractions that result in joint movement and changes in muscle length (e.g., push-ups or squats), which have concentric (shortening) and eccentric (lengthening) phases.

3. Isokinetic Exercises: These are performed at a constant speed regardless of the force applied, typically requiring specialized gym equipment that controls the rate of movement.

4. Isonomic: This is not a standard term used to classify strength training exercises.