Film from the side
The sequence is obvious on video and invisible from the seat.
Because the back is doing a job the legs were supposed to start.
The stroke has an order: legs drive, body swings, arms finish, and the reverse coming back. Break the order and the lumbar spine absorbs the load that the quads and glutes should have taken.
Ratio is the second problem. Rushing the recovery raises stroke rate, wrecks the catch and makes everything feel harder for a worse split.
Training then has to be mostly easy. Rowers who train every session at a moderate burn plateau quickly; adding genuinely easy volume and a small amount of hard work is what moves the numbers.
The sequence is obvious on video and invisible from the seat.
Hard sessions only count if the rest were not.
We coach technique and training, not injuries.
Twenty minutes, free, on sequence, damper and where to start.