Downward bending motion
Main active muscles: trapezius, biceps, forearm and deltoid.
first step
Sit in a sturdy chair with your feet flat on the ground. Hold a dumbbell in each hand, put your arms straight at your sides and palms forward. Keep your back straight and your eyes straight ahead.
Second step
Keep your upper body still, bend your elbows and lift the dumbbell to your shoulders.
Third step
Don't pause, turn your wrist so that your palm faces forward. Hold the dumbbell above your head. Pay attention to keep the distance between the two dumbbells when lifting. Stop when your arms are fully extended. The dumbbell should be above your head, and your body should be a little forward. Stop and slowly put the dumbbell down in the opposite direction.
Pay attention to the regulation of breathing.
Precautions:
Don't bend your shoulders. Don't move your arm backwards when you hold the dumbbell above your head. Don't bow your back. Don't bend your wrist.