Sitting against a wall in a squat position would be an example of

Sitting against a wall in a squat position would be an example of static muscular endurance.
In this case, your muscle is not moved so it called static. This exercise also promotes your endurance since the exercise is count by time, not reps. This kind of exercise is easier to do since it doesn't need tools or large space.

Sometimes it also called isometric endurance since the muscle length is not changed(isometric).

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