Reflexes rely on stretch receptors in the muscle. These stretch receptors fire and cause muscle contraction when the muscle is stretched. When the doctor taps on your kneecap (for example) the muscle stretches just enough to fire off the receptors, which causes the muscle to contract and then you see your leg do a slight kick.
If your muscles are already contracted (as in a monkey grip), the muscles are already stretched out and the receptors are already stimulated. Any additional stretching caused by the slight hit of a reflex hammer, will not cause a reflex contraction of the muscles.
Therefore, in order to get a proper reflex, the muscles must be relaxed.
because when you are tnse yoor nervous system is busy keeping you stuck in your position when you are relaxed your body isnt busy so you can react quicker
Reflexes are involuntary responses initiated at spinal cord level. One in monkey grip position consciously controls actions . So reflexes are not expressed.
To be more medical cerebral pathways inhibit reflex actions of spinal level.
Higher centers in cerebral cortex inhibit tendon reflexes. That`s why in limbs paralysed on one side due to stroke tendon reflexes lose this inhibition and so are exaggerated.
In monkey grip it`s the reverse.