Let’s break down the movements/stages of using a rower effectively.
We start with the “catch”. Here your arms are straight, head is in a neutral position and your shoulders are level not hunched over. Your upper body should be leaning forward from the hips making sure your shoulders are in front of your hips. Lastly shins are vertical (or as vertical as your body allows). Shins should never move beyond perpendicular and your heels can lift as needed.
Next we have the “drive”. This goes in order of legs, back, arms. You start the drive by pressing with your legs and then swing back through the vertical position then adding the arm pull. Hands should always move in a straight line to and from the flywheel while your shoulders remain low and relaxed.
The end of the pull or “finish” is next. In this phase the upper body is leaning back slightly, using your core muscles for support. Legs will be fully extended, and the handle is held lightly and is below your ribs. Shoulders stay low while your wrists and grip is relaxed, and wrists are flat.
The end stage is the “recovery” which goes arms, back, legs. Here you start with extending your arms until they are straight then you elan from the hips towards the flywheel. Once your hands clear your knees you can bend your knees and gradually slide the seat forward. You then prepare for the next stroke by returning to the catch position with your shoulders relaxed and shins vertical.