A Chinese finger trap is a gag toy used to play a practical joke on unsuspecting children and adults. The finger trap is a simple puzzle that traps the victim's fingers in both ends of a small cylinder woven from bamboo. The initial reaction of the victim is to pull their fingers outward, but this only tightens the trap. The way to escape the trap is to push the ends toward the middle, which enlarges the openings and frees the fingers. The single ended version sold as a "girlfriend trap" has been available since at least 1870 when it was recorded as a "Mädchenfänger" or "girl catcher".
Design
The tightening is simply a normal behavior of a cylindrical, helically wound braid, usually the common biaxial braid. Pulling the entire braid lengthens and narrows it. The length is gained by reducing the angle between the warp and weft threads at their crossing points, but this reduces the radial distance between opposing sides and hence the overall circumference. The more one pulls, the more the circumference shrinks and the trap tightens. The same effect is used in specialized textile manufacturing, the Vivien Kellemscable grip, Indonesian woven fruit presses, and by fly-fishers. Chinese finger traps are not intended for use as restraint devices. Strong victims of the prank may break the bamboo strips when they pull outwards, attempting to free their fingers and stretching the trap beyond its limits.
Variants
One variation on the Chinese finger trap has uses in orthopedic medicine—namely, providing even pressure to the patient's digit and at the same time immobilizing the joints—and serves a similar purpose as a traction device. Its development goes back to Austria in 1870 when Dr. Steinberger, a dentist at the Rudolfsspital in Vienna, reported the discovery of his doctoral student Schmall, who got the idea to use the toy ″Mädchenfänger" for the extension of fingers and arms. The principle was adapted for the use in surgery, and already in 1873 termed "Schmall'sches Extensionsgeflecht". Another variant is the towing sock. It uses the same principle to seize the end of a cable to be pulled through a tube or tunnel.
Cultural influence
The Chinese finger trap is also a common metaphor for a problem that can be overcome by relaxing, i.e. not trying too hard to solve it; for example, in Acceptance and Commitment Therapy. The gag has been used in a number of films and television productions, such as the Stan Laurel short Dr. Pyckle and Mr. Pryde, the Our Gang short Moan and Groan, Inc., the "This Little Wiggy" episode of the American show The Simpsons in 1998, the "Fore, Father" episode of the showFamily Guy in 2000, the Dexter's Laboratory episode "Unfortunate Cookie", the Milo Murphy's Law episode "Murphy's Lard" ', The Addams Family in 1991, the ' episode "The Last Outpost |The Last Outpost", in which Lt. Commander Data is stumped by the device, and the Bob's Burgers episode "Midday Run". The trap was also featured in the book seriesThe Heroes of Olympus, most notably The Mark of Athena, the joke a source of humor and a solution in the climax.
