Wrist Curls

The Wrist Curls are simple exercises with an isolation "nature", they work the inner lower parts of the
foreams. This group of six different muscles is responsible for the lifting of the hand towards the arm. By performing the Wrist Curl you can increase muscle mass and strenght endurance, improve grip strength and increase the stabilizing effect in all exercises where healthy and strong foreams play a key role. Such exercises can be: Barbell Rows, Chin-Ups and even Deadlifts.

Options

According to the instrument used

• Bar - allows the use of heavier weights with a shorter range of motion, it used mainly for muscle mass gain. Prevents rotation keeps the wrists stable;
• Dumbbell - allows for a bigger range of motion, and better concentration on the different heads, suitable for people with injuries and forearm differences (one is bigger than the other etc.), allows for wrist rotation (not reccomended);
• Bands - Allows for progressive increase in the load on the positive part of the movemet and a progressive decrease in load during the negative, very good option for mass and strenght . Allows rotation in the wrists.

According to performance

• Dynamic - full range of motion, good for mass and strength.
• Static - performed by keeping the forearm in a static neutral, suprinated and completely flexed position(hand facing inner elbow), good for endurance.

According to the range of motion

• With a full range - the hand is closed into a fist brought as far down as possible and raised as far as possible, keep a close fist during the whole movement
• With extra long range - in the lower part of the movement, the thumb releases the grip, the hand opens and the dumbbell falls down on your hook like positioned fingers - this variation includes an increased load due to the closing of the hand, which puts stress on closing-hand and finger muscles.
• With partial range of motion - a shorter range of motion is only reccomended for sets with repetitions under 10.

Method of execution

Preparation

1. Sit and grasp dumbbell with underhand grip. 
2. Rest forearm on thigh with wrist just beyond knee.(If you're new to the movement use a bench instead)

Execution

1. Allow dumbbell to roll out of palm down to fingers. 
2. Raise dumbbell back up by gripping and pointing knuckles up as high as possible. 
3. Lower and repeat.

Recommendations:

• If you feel pain or discomfort in the wrist while performing the dynamic variation with added weight, try perfroming the band or static variation instead.
• If you're working with a heavy weight, use partial range of motion and do not allow the wrist to take the load on itself or perform the static variation.
• During the performance do not push away your wrists or elbows off the bench, they should be always in contact with the surface you've placed them on.
• Do not use the extra long variation with a weight that you can't perform at least 30 reps with the normal full range of motion.
• In case you're new to the movement - don't do the exercise on your thights, there is a risk of your legs moving thus making the probability of an injury much greater.

Relevancy

The exercise is suitable for implementation in periods of mass gain or functional strenght.The Wrist Curl is best put in workouts for arms and back.
(sources:exrx.net)