The hang clean is a basic variation of the clean with a number of variations and purposes.
With a clean grip, lift the bar to the standing position. Lower the bar under control to the chosen hang position (most often mid-thigh, knee or right below the knee). Once reaching the hang position, initiate the clean by pushing against the floor with the legs first. Drive the legs against the floor and extend the hips aggressively, keeping the bar in close proximity to the body and bringing it into contact with the upper thigh as you reach complete extension. After extending, pick up and move your feet into your squat stance while pulling your elbows high and to the sides to move yourself down into a squat under the bar while keeping the bar and your body as close to each other as possible. Turn the elbows around and up into the clean rack position as you sit into the squat, stabilize, and recover to a standing position.
High-Hang: Upper thigh
Hang: Top of knee caps
Knee: Bar at knee caps
Below knee: Bar just below knees
Straps are not recommended for hang clean or any clean variations because of the risk of wrist injury.
The hang position needs to be specified when prescribing the hang clean. Generally if no qualifier is present, a hang clean is done from a starting position with the bar just above the knee. High-hang is usually upper thigh, mid-hang at mid-thigh, and low-hang just below the knee.
The purpose of the hang clean can vary depending on its application. It can be an exercise to help teach beginners to clean that is often easier than lifting from the floor because of the abbreviated movement and the ability to ensure proper positioning and balance at the start of the second pull. As a training exercise, the common purpose is to develop better force production in the extension and more aggressiveness in the pull under due to the limited time and distance to accelerate and elevate the bar. Another purpose is use as a lighter clean variation for lighter training days (weights naturally limited for most lifters relative to the clean, and somewhat less work for the legs and back to allow more recovery for subsequent training sessions).
Hang clean reps should be kept to 1-3 per set. If being used for technique work, weights should remain light (around 75% or lighter); for work on aggressiveness in the extension and/or pull under the bar, heavier weights should be used (75% and above); for use as a lighter clean variation on a lighter training day, weights can be as heavy or light as needed for the athlete at that time, but a loose guideline would be about 70-80%.
The hang clean can be done from any hang position—any starting point above the floor itself qualifies as a hang clean. The lift can be done with or without a pause in the hang position (i.e. with a countermovement or from a dead stop). A hang clean can also be done by lifting from the floor directly to the hang position and pausing before initiating the clean rather than starting from a standing position and lowering to the hang—however, this variation would be more accurately called a segment cleanor pause clean. The lift can be done with or without straps, and can be done without the hook grip to emphasize grip strength.