I just got done reading an article published by the NSCA and linked from USAW. The article (http://www.teamusa.org/USA-Weightlifting/Media/2016-Wednesday-Word/Wednesday-Word-November-23) dealt with clarification of weightlifting terminology which is not a bad idea on the face of it. We currently have knowledge of a large volume of exercises, many of which have been practiced for as long as barbells have been available. Frequently some exercises are forgotten for long periods of time, rediscovered and then re-named with the intent of branding for the purposes of the rediscoverer. What results is a fairly common exercise with a small number of variations and with each variation being given a specific title for the purpose of branding, rather than for the purpose of avoiding confusion or for making exercise prescription easier.
In the aforementioned article there are specific designations and photos for pulling positions of above the knee, mid-thigh and power position. Depending on the relative limb lengths of the individual in question all three could mean the same position. So what is the point of making such specific designations when writing an article to explore the issue of clarifying nomenclature?
There is a reason to specify lifting from the hang versus lifting off the floor. Likewise for pulling from blocks versus lifting off the floor. For each individual, however, the best results will be achieved by designating the specific starting point depending on the technical difficulties exhibited by the individual or the specific areas of weakness. This is especially true if the individual has proportions that are significantly different from the majority of the lifting population.
For example a person with very long arms and a relatively short torso is going to have a power position where the bar it not very high above the knees because the power position is determined by the relative angles of the knees, hips and ankles and not by the position of the bar at the start of the movement.
The art of coaching is where the coach makes the decision as to the range of motion that is most in need of remediation. These variations on a classic snatch or clean & jerk are all remediation exercises and the coach should be the one to determine where the remediation should be applied rather than to be overly concerned with the name of the starting position.