Comparing the effect of technique, Lehman et al. (2004) compared the latissimus dorsi muscle activity during the cable - pulley seated row performed with and without full retraction of the scapula at the peak contraction region. (strengthandconditioningresearch.com)
Note: Most people have completely lost the ability to retract their shoulder blades, mostly because we sit behind desk and are front communicators so very little activity actually requires full retraction. (barbrothersgroningen.com)
3) From full retraction and depression, slowly over a 6 - 10 second count lower yourself to an active hang. (barbrothersgroningen.com)