Straighten the legs keeping the back straight as you lift the weight in line with the top of the thighs. The arms hang straight down in front of you. Keep the elbows at your sides.
Concentric contraction: Breathe out. Flex the elbows fully.
Eccentric contraction: Breathe in. Lower the bar with control (2-4 seconds). Keep the elbows down at your sides. Repeat until the desired number of repetitions are completed.