There are many different ways to masturbate. This is true for men at least. I can’t speak from any informed perspective, but I imagine it’s the same for women too.
I’m not naive enough to think Ann Summers profits from selling elaborate cake-mix stirrers. But by necessity, assume I’m speaking from the male perspective from this point on.
These masturbation techniques are typically passed around by teenage boys in the midst of the hormonal storms of puberty, like some sort of memetic contraband.
Some of these techniques can be quite elaborate and far-fetched, which can result in someone ending up in, at best, a stand-up routine; at worst,rushed to Accident & Emergency.
One such technique is “the stranger”, which is mentioned regularly in sitcoms. It involves the self-indulger making his arm go numb, then using the numbed limb to masturbate with. With no feeling in the arm, it supposedly feels like someone else is doing it.
I’ve honestly never tried this, and don’t know anyone who has. It seems ridiculous though, for several reasons.
Firstly, the lack of feeling in your arm is due to compressing nerves and blood vessels, scrambling nerve signals and blood supply to said nerves.
I’ve had a numb arm before (for unrelated reasons) and I can envisage many logistical problems with trying to use it for such an act.
Firstly, it’s a weird, uncomfortable sensation (what with the heat/pain conducting nerves being the first to recover, hence the prickly, burning sensation that can be experienced). I can’t imagine maintaining arousal in such a state, but maybe that’s just me?
Secondly, when I have a numb limb, I can’t do much with it. What with nerve signals being scrambled, fine motor control and proprioception (awareness of where your body is and what it’s doing) are reduced.
Self manipulation must be a tricky prospect when your arm has lost all feeling.