What does the chain and swivel in handcuffs allow for?

The chain and swivel in handcuffs allows for a twisting motion of the cuffs. This design feature is crucial for the comfort and control of the person being restrained. It prevents the handcuffs from becoming too tight or causing excessive discomfort by allowing the cuffs to move independently of each other. The movement provided by the chain and swivel helps reduce the risk of injury to the individual wearing the handcuffs, as it may minimize pinching while allowing some degree of movement of the wrists.

The design also aids law enforcement officers in maintaining effective control over the restrained individual, as it allows the subject to have a limited range of motion without compromising the overall security of the restraint.