What are some common joint locks used in ground fighting, and how are they applied?

In ground fighting, joint locks are effective techniques that target an opponent's joints to apply pressure, create discomfort, and potentially force a submission. Joint locks can be utilized in various positions and transitions on the ground, allowing fighters to manipulate their opponent's limbs and joints to gain control. Here is an in-depth explanation of some common joint locks used in ground fighting and how they are applied:

1. Armbar (Juji-gatame):
The armbar is a popular joint lock that targets the elbow joint. It involves controlling an opponent's arm and extending it to hyperextend the elbow joint, causing significant discomfort and potential injury. The armbar can be executed from various positions such as the guard, mount, or side control, and it often requires the fighter to secure their opponent's arm between their legs and apply leverage by extending their hips and pulling down on the opponent's wrist.
2. Kimura (Ude-garami):
The Kimura lock targets the shoulder joint and is effective for controlling an opponent or inducing a submission. To apply the Kimura, the fighter secures their opponent's wrist and traps their arm, then applies leverage by rotating the opponent's shoulder joint away from their body. This lock can be executed from positions like side control or the top half guard.
3. Americana (Ude-garami):
Similar to the Kimura, the Americana focuses on the shoulder joint. It involves controlling the opponent's arm and applying pressure by driving their wrist towards their head while pinning their upper arm to the ground. The Americana can be executed from positions like side control or the mount.
4. Straight Ankle Lock (Ashi-garami):
The straight ankle lock targets the ankle joint. It involves securing the opponent's foot and applying pressure by extending or hyperextending the ankle joint. The fighter typically uses their legs, hips, and body positioning to create leverage and generate force. Straight ankle locks can be executed from various positions such as the guard, half guard, or when countering takedown attempts.
5. Heel Hook (Ashi-garami):
The heel hook targets the opponent's knee joint and is a highly effective submission technique in ground fighting. It involves securing the opponent's foot and applying torque to the heel and knee joint by manipulating the opponent's leg and foot positioning. Heel hooks can cause severe damage to the knee joint, and their usage may be regulated or prohibited in certain grappling competitions due to their potential for injury.
6. Kneebar (Hiza-gatame):
The kneebar focuses on the knee joint and involves applying pressure by hyperextending or torquing the joint. The fighter secures the opponent's leg and applies leverage by controlling the lower leg while creating distance between their hips and the opponent's knee. The kneebar can be executed from positions such as the guard or when countering leg attacks.

It is important to note that joint locks should be applied with caution and under controlled circumstances to avoid causing serious injury. Proper training, understanding of body mechanics, and respect for training partners' safety are crucial when practicing and applying joint locks in ground fighting. Mastery of these joint locks allows fighters to effectively control and submit opponents, providing a powerful arsenal of techniques in their ground fighting repertoire.