Deadlift refers to the lifting of dead (without momentum) weight, such as weights lying on the ground. It is one of the few standard weight training exercises in which all repetitions begin with dead weight.
There are two positions one can approach when doing the deadlift, which include the conventional deadlift and sumo-deadlift. In most other lifts there is an eccentric (lowering of the weight) phase followed by the concentric (lifting of the weight) phase. During these exercises, a small amount of energy is stored in the stretched muscles and tendons in the eccentric phase, if the lifter is not flexible beyond the range of motion.
Typically, there are two grips used: overhand (pronated) or a mixed overhand-underhand (supinated) (sometimes called “offset,” “staggered,” “alternating”, or “mixed”) grip. Depending on forearm strength, the overhand grip may result in the bar potentially rolling about. Mixed grip is capable of neutralizing this through the “physics of reverse torsion.” The mixed grip allows more weight to be held for this reason.
In order to prevent the bar from rolling out of the hands, some lifters have been known to use an Olympic weightlifting technique known as the hook grip. This is similar to an overhand grip, but the thumbs are inside, allowing the lifter to “hook” onto them with the fingers. The hook grip can make it easier to hold heavier weights using less grip strength, and keeps both shoulders and elbows in a symmetrical position.
While it theoretically takes much of the stress off of the joints which might be created by the twisting of a mixed grip it has the disadvantage of being extremely uncomfortable for the thumbs, something which those who advocate it says will pass once a lifter becomes accustomed to it.
Another, but rarely used method is a combination of the mixed overhand-underhand grip and the hook grip, preferred by people who lift heavier weights than their grip can handle, but who don’t want to rely on lifting straps or other supportive gear.