An armlock in grappling is a single or double joint lock that hyperextends, hyperflexes or hyperrotates the elbow joint and/or shoulder joint. An armlock that hyperflexes or hyperrotates the shoulder joint is referred to as a shoulder lock, and an armlock that hyperextends the elbow joint is called an armbar. Depending on the joint flexibility and integrity of a person, armlocks that hyperrotate the shoulder joint can also hyperrotate the elbow joint, and vice versa.

Obtaining an armlock requires effective use of full-body leverage in order to initiate and secure a lock on the targeted arm, while preventing the opponent from escaping the lock. Therefore, performing an armlock is less problematic on the ground, from positions such as the mount, side control, or guard. Armlocks are more difficult to perform when both combatants are standing up, though the stand-up variants are a focus in certain systems such as Chin Na. Furthermore, a failed armlock can sometimes result in the opponent escaping and obtaining a dominant position.

Ronda Rousey (born February 1, 1987) is an American judoka and mixed martial artist and the current Strikeforce Women's Bantamweight Champion. She has finished all of her opponents by armbar in the first round. She formerly trained at the Olympic Training Center in Wakefield, Massachusetts under guidance of Jimmy Pedro and is now part of Team Hayastan in Santa Monica, California.

Rousey trains under Gokor Chivichyan and Edmond Tarverdyan of the Glendale Fighting Club in Glendale, CA. Rousey also trains with Leo Frincu and Gene Lebell, along with Team Hayastan fighters such as Manny Gamburyan, Karen Darabedyan, Sako Chivitchian and Sevak Magakian. She is managed by Darin Harvey of Fight Tribe MMA.

Rousey is currently the #1-ranked pound-for-pound female MMA fighter in the world by MMARising.com, and is ranked #1 at 135 pounds and #2 at 145 pounds according to the Unified Women's MMA Rankings.

At just 17, Rousey qualified for the 2004 Olympic Games in Athens, becoming the youngest judo player in the entire Games. Also in 2004, Rousey won a gold medal at the 2004 World Junior Judo Championships in Budapest, Hungary.

Relson "Campeão" Gracie is a retired professional Brazilian Jiu-Jitsu fighter and martial arts personality. He is a member of the Gracie family. Relson currently lives in Hawaii where he still teaches Gracie Jiu-Jitsu at his academy in Honolulu. There are many Relson Gracie affiliated academies and associations throughout the U.S. which keep him traveling regularly.

Relson is the second oldest son of Helio Gracie, who along with Carlos Gracie, is credited for innovating the Kodokan Judo taught by Mitsuyo “Count Koma” Maeda into what is now known as Gracie or "Brazilian" Jiu Jitsu. Relson began learning the art of Gracie Jiu-Jitsu at the age of two, began competing at the age of ten, and earned his black belt when he was 18. He went 22 years undefeated as the Brazilian Jiu-Jitsu National Champion.

Although Relson's techniques are deeply rooted in Gracie Jiu-Jitsu, Relson also emphasizes "street effective" techniques. Relson's Jiu-Jitsu has evolved to help defend yourself in a survival situations where there are no rules.