Squat velocities Monday Dec. 12-2016

After repeating that squat 160 kg x 8-reps on Thursday and doing some Snatch Grip Push Press behind neck and associated stuff on Friday, I thought I better bump up the squat weight today to 170 kg and shoot for 6-reps. Todays first rep of 0.57 m/s looks great, but that measure is a little incorrect, the bar came up a little on the forceful lock-out (this is called signal artefact)...so it gives a slightly higher score than really occurred.  This will happen occasionally with any measurement device, especially with whippy olympic bars (eg. squatting with >160 kg with an Eileko olympic bar) or when there is an abrupt deviation in technique (as in my case today).  But the bar movement meant the bar was slightly out of the "meat groove" on my shoulders and made all the following reps hard to stabilize.  The last rep was artificially harder due to trying to stabilize the bar as it was moving on my shoulders ~ the velocity of this sixth rep was 0.31 m/s, which is typical of my "max effort"  velocity when lifting more than 5-reps.  But the second last rep was 0.45 m/s, which is "comfortable".  And any velocity loss of > 40% across a set in the squat pretty much means you are busting your arse.  But my take home point here is that this set was harder than it should have been because I jammed the bar up on lock-out and got the bar out of the groove or shelf on my back.  All the following reps were a battle trying to stabilize the bar as I squatted.  Other exercises in todays session were Push Press behind neck (5x5, technical & velocity oriented), sumo deads from 2-inch (up to 150 kg x 12-reps ~ I was pissed off at myself because of the squats), press behind neck (3x10) and incline DB rows (5x10).