Duration for the Isometric exercises

My question is for how much time the patient should performing the contraction of muscles while performing the isometric exercise. The current recommendation is that the isometric execises should be held for 6 second. But there are authorities out there who recommend that isometric contraction should be held for 10 seconds. What is the current concept in this regard?

Please, also tell me how many numbre or repitions should be performed while doing the excercise of for back patient, and the patients with neck problems

Hi,

Man was designed to move not being statues so forget the isometric "thing".

Some evidences show that isometric is not a solution.