check

[Steven M-M]

Checking my own understanding of check. Are the primary causes of check: (1) pressure on the foot stretcher too soon before the catch mostly from rolling up on the toes too early and (2) starting the drive before the blade is adequately locked in. (I understand that some check is inevitable and some of the very best scullers produce more check but for a briefer period of time: quick in, quick on.)

[Long'n Strong]

I think it's both.

1). Uncontrolled "throwing" of the body towards the stern, which could be interpreted as pressure on the footboard and,
2). Driving against the footboard before the blade is secured in the water. I consider pressure on the footboard to be a different beast to driving off the footboard.

[Steven M-M]

Thanks, L&S. I was also thinking both. Maybe uncontrolled throwing of the body into the stern is a 3rd and body lean into the catch a 4th. Given the scullers/rowers mass this could be independent of pressure on the footboard.

[petermech]

Checking my own understanding of check. Are the primary causes of check: (1) pressure on the foot stretcher too soon before the catch mostly from rolling up on the toes too early and (2) starting the drive before the blade is adequately locked in. (I understand that some check is inevitable and some of the very best scullers produce more check but for a briefer period of time: quick in, quick on.)

http://www.biorow.com/RBN_en_2006_files ... News07.pdf

Here is a link to Biorow July 2006. In the letter it mentions seat speed during the recovery. With this in mind I think if you pull up hard at the beginning of the recovery the hull will move under the rower however the rower then has to slow down the seat earlier going into the catch and the hull slows down as they push the footboard with the feet.
So one thing to watch for is how fast they are popping the knees up as the legs first start to move on the recovery.

Other thoughts.
If the body is diving down into the catch after the legs have stopped I think that you are spending time with the boat going slow.
If a person does not have good flexibility they may use momentum to get into the catch however if they dive in they may have to lift up with the back to start the drive. That would add in a pitch motion which can add to the visual.

At race pace the boat is moving its fastest during the recovery. Rush the recovery too much and you spend less time moving fast.

I remember watching a race long ago and the order finish was the ratio of drive time with blade in the water verses blade in the air during the drive. The crews that spent the most time with the blade in the water during the drive finished progressively ahead those that spent a higher ratio during the driving with the blades in the air.

[oldman]

The simplest explanation is that rowers are moving toward the finish line faster than their boat. If it's sudden we are more likely to see it. If it takes awhile or if it's just one man (see J. D-Smith in Rio) then the damage is less obvious. Seat recovery speed has some impact on check but it's the timing of seat drive speed that is the culprit. An excellent video is from John Driessen: https://www.youtube.com/watch?v=Oh1CPoY9_4I (Relaxation and Rhythm in Rowing).

[jrd]

The simplest explanation is that rowers are moving toward the finish line faster than their boat. If it's sudden we are more likely to see it. If it takes awhile or if it's just one man (see J. D-Smith in Rio) then the damage is less obvious. Seat recovery speed has some impact on check but it's the timing of seat drive speed that is the culprit. An excellent video is from John Driessen: https://www.youtube.com/watch?v=Oh1CPoY9_4I (Relaxation and Rhythm in Rowing).

This is fantastic, a really elegant way of thinking about and understanding it. Thanks for sharing.

[bd_sculler]

Your boat speed is the average of the maximum speed and the minimum speed.

That is not correct.

The average value of a function over an interval is the area under the curve divided by the length of the interval. The function in question is the speed.

Trying to maximize the average of the maximum and minimum speeds during the stroke could lead to a flawed technique such as an exaggerated fast hands away and body swing forward at the finish, causing a heavier load at the start of the drive.

[petermech]

The simplest explanation is that rowers are moving toward the finish line faster than their boat. If it's sudden we are more likely to see it. If it takes awhile or if it's just one man (see J. D-Smith in Rio) then the damage is less obvious. Seat recovery speed has some impact on check but it's the timing of seat drive speed that is the culprit. An excellent video is from John Driessen: https://www.youtube.com/watch?v=Oh1CPoY9_4I (Relaxation and Rhythm in Rowing).

I don't fully agree with you. The mass of the rowers in the boat is more then the boat which has an affect on the amount of motion between the two. If they pull the legs up quick the boat will go towards the bow under them. That is shooting the bow towards the finish line. That hull acceleration under the rowers can not be maintained. If you slow down the knee popping up it changes how the stern motion looks compared to someone that pulls hard up with the legs/knee near the beginning of the recovery.
I would say that seat speed affect timing such as how long the recovery takes and when some forces need to be applied. That affects the acceleration of the boat under the rowers.