Having your testicles kicked / squeezed / stomped lower testosterone / fertility?

[freakyfetish]

Human sexuality is vast, wonderful, and sometimes freaky. There is one fetish called "ballbusting", which is more or less self-explanatory. A dominant female using bodily or otherwise appendages to hit/kick/slap/knee to cause pain to a man's testicles and humiliating him in the process. She may also squeeze or stand on the testicles. This may cause a variety of medical symptoms associated with blunt force trauma afterwards, depending on the severity of the sexual play. For some (though not me), the desire to have their testicles tortured in a more hardcore  "medical" way by having one or more medical needles shoved through the testicles themselves like a skewer. Others are more into attaching weights to their testicles and causing a high amount of tension in all the tensile material in the scrotum / testicles / cords themselves. I've even see videos where a cattle prod or some type of electrical device was used to shock the testicles.

I would like to restrict my question on the most popular version of testicle torture fetish, which is "ballbusting", typically co-morbid (in medical terminology) with having a "foot fetish" so the torture is simply done using parts of the human body. Though please free to make any additional comments should you wish.

1) Can leydig cells / the androgen production process be damaged / impaired through repeated blunt force trauma such as being kicked / stomped in the testicles repeatedly or through excessive pressure by having them squeezed manually or stood on by the weight of a human body as distributed through a foot? If so, is the damage / impairment temporary or permanent? ie, do the leydig cells fully regenerate? I imagine one could draw an axis of "intensity" vs "frequency", could there be some trade off for "optimal safe play" where long term damage does not occur?
2) The effect on fertility / spermatogenesis? Assuming no testicular rupture / torsion, but otherwise moderate to severe swelling with possible varicoceles / internal bleeding (hematoma).

People in the fetish community are often grasping around in the dark, relying on anecdotal evidence. I was however, able to get some indication about "needle play", as tests have been conducted on rat testis with needles to mimic "fine needle aspiration" as that is a valid medical procedure in certain circumstances for male health. No one goes around attaching weights to testicles either, so a complete lack of information on that one. But as for repeated kicking / squeezing, any damage done that way would either be accidental or self-inflicted, so it would be either difficult to gather data or be unethical to do so for large scale epidemiological studies. The few I have seen are more like excerpts from isolated medical cases where a one off severe trauma has occurred, which is not really comparable to the long term effects of fetish sexual play.

When I raised the possible health effects of "ballbusting" with a physician, Captain Obvious answered more or less that "it's not good" and "don't". Quite. But that is not the same thing indicating how bad it is, particular long term if as part of a sexual lifestyle.

I am trying to ascertain answers or approximated / best educated guess answers to these questions because I am concerned about the long term impact of these fetishes on male hormone levels and eventual fertility.