Handcuffs, also known as manacles or shackles, were a type of restraint that limited an individual's wrist movement.
In 1974, Corporal Erich Kilheffer placed handcuffs on a disoriented man who had been possessed by Redjac when he arrested him for espionage. Later, Gary Seven was placed in handcuffs when he was held prisoner by the Chrysalis Project. (ST - The Eugenics Wars novel: The Rise and Fall of Khan Noonien Singh, Volume 1)
In 2264, Alexander Lazarus placed manacles on Spock when he captured him on Gamma Alpha V. However, Spock used a simple mathematical progression to unlock the manacles. (TOS comic: "The Legacy of Lazarus")