Immobility or Stillness
As Peter Levine points out, freeze and immobility are not the same. Freezing is an involuntary state of the musculature enforced by the dorsal vagal system during a time of great distress. During freezing, mental and emotional clarity is impaired and biochemically the body is undergoing oxidative and adrenergic stress. Immobility on the other hand, is a voluntarily entered state associated with clarity and serenity. Immobility plays a role in hypnotic trance, meditation, the moment of falling asleep, surrender, and part of sex, at least in the receptive role of sex.
The trauma response may cause a dysregulation in which immobility, because it is close enough to freezing, is difficult or avoided. This can explain the finding that even a history of non-sexual trauma causes difficulty in sex, especially for women, where at a critical point, immobility plays a role in the orgasm response.
In yogasana, the corpse pose (savasana) is an exercise in immobility. Milton Erickson often performed serial deep hypnotic inductions without any suggestions--the trance itself was healing. In erotic play, bondage is usually not about coercion, since after all the 'top' only fulfills the bottom's wish. Rather the binding provides, certainly symbolically, and if realistically done, literally, the immobility that makes the physiology work for the receptive role.