Medicine knows quite a few devices to hinder movements, but usually with the aim of preserving, protecting or reestablishing one's health. Plasters, corsets etc. do fall into this category.
There are a number of uses where, still for the ultimate benefit of the patient, a restraint is used as such. One such example is the legendary straightjacket in psychiatric use. Other items are being used across many other medical departments.
In the theatre during surgery hands and arms may be tied down to avoid unwanted movements or touching of sterile areas, which could happen despite the patinet's good intentions.
Quite a few illnesses may cause a blurred consciousness, sometimes due to fever or agony. Some restrains are deviced to keep patients in bed or in location, other to keep their hands off medical equipment.
Typical designs use fabric, plastic or leather and very little metal, if any. Locking may use ordinary buckles or locking mechanisms which do look quite different to an ordinary padlock. Velcro may be used sometimes, which goes with the hands being tied apart and one hand not being able to reach the wrist. The strap attached to such a cuff is either tied out of reach or, sometimes a first knot limits the range, a second one out of reach secures the first not to be untied.
It has to be noted that keeping persons immobilized for more than a short time can lead to serious circulation conditions. Pain in limbs is definitively a major alarming signal!
Especially in psychiatry the emphasis is one the use of nonmetal materials, as one wants to avoid patients to inflict injuries to themselves. also cuffs are often quite wide as to distribute the load when pulled strongly.
In contrast to the arrest situation, such restraints have to be suitable for long-term wear. Also some police cuffs are designed to hurt when one fights them, being thought as a deterrent. This is unacceptable for a medical device.
Danger of decubitus for persons which are immobile.
Economy class syndrom for persons having to do with confined
space and little possibility for movements. Pain in the limbs,
especially in the leg, should be taken very seriously.