Most beginners have problems to keep their spine straight doing rows. Instead a flat bench, you can use a couple of chairs, and practice at home. Keeping your spine straight is essential to avoid injuries.
Place your right knee and right hand on the chairs (bench). Bend your torso from your waist until is parallel to the floor. Bend your left knee if necessary.
Pick up the dumbbell with the left hand, with the palm facing your torso. Do not bend your wrist! The forearm should not do work.
Exhale and pull the dumbbell, keeping your elbow close to your side and keeping the torso stationary.Concentrate on squeezing the back muscles.
Inhale and slowly back to the starting position.
Repeat with the other side 🙂