what should my arm and shoulders be doing on the leg drive?

[2ball]

what should my arm and shoulders be doing on the leg drive?

Am I leaving my arms loose and straight so the tension goes to my shoulders or am I flexing my arms a little bit trying to take some of the tension off of my shoulders?

[iain]

Arms should remain straight as they are taking the force of your much stronger legs. The strain should be taken by your Lats. In practice there is a slight tensioning to ensure that your arms are straight at the catch.

[Dangerscouse]

Try not to focus the tension on the shoulders as this will make you tense up too much and leak power. As Iain says focus on the lats, which is a subtle but different type of thought.

I always recommend doing fairly regular shoulder shrugs and deep breaths, especially when doing steady state sessions. You want your upper body to take the strain during the leg drive, but not to be dominant.

[2ball]

I'm using too much arms and my upper back is usually sore after a row. Probably bad forum or because I have a weak upper body compared to my lower body.

[Dangerscouse]

I'm using too much arms and my upper back is usually sore after a row. Probably bad forum or because I have a weak upper body compared to my lower body.

If you're overcompressing at the catch you're not using your legs enough, but there's also a lot of tendons and ligaments in your back that will be getting used that aren't used to the strain. Some soreness isn't unexpected, but bad technique can also be playing a role.

Imagine that you're jumping horizontally when you start the stroke, so you focus more on the push than the pull

[jamesg]

what should my arm and shoulders be doing on the leg drive?

See: https://www.concept2.com/training/rowing-technique as in your other post on posture.

Clearly legs and hips are the strongest items we have, so as far as possible we use them alone; and other groups when the legs have finished.

It should be clear that muscle can only generate power if moving a joint; if there's no joint to move, the muscle function can be static only, ie postural.

[p_b82]

I'd suggest to just hook your fingers over the bar for a few sessions and just gently pull it to your chest, that will help the handle from being pulled too much and can help get more of a feel of engaging the lats vs forearms/biceps.

and / or do some of the drills and break down the stroke into the separate parts (known as pick drills and/or reverse pick drills).

It's also worth either recording yourself, and comparing it to known good form - really slow it down and look at back and leg angles and handle height etc. (or ask for feedback here)

the Force curve is also very useful for a "quick" look at the stroke, it should be a smooth shape; with no big lumps/dips. If your leg drive is weak compared to the rest of the stroke, you will see the peak more to the right; if it's strong in comparison, more to the left. (as a sweeping generalisation). More info on the C2 site though.

[Tsnor]

Goto gym and HANG from pullup bar.

During leg drive you want exactly the same hang. No muscles. Hang.