Of course, like all exercises, this is how I do Bent Over Rows. Other people may have different opinions.
Keep a slight bend in your knees and your torso at a 30-45-degree angle to the floor. While maintaining the natural arch in your lower back by holding your head up, grasp the bar with a shoulder-width, overhand grip and lift the bar into your lower midsection, moving your shoulder blades back on the ascent. Then reverse the movement, controlling the bar on the descent.
If you find your knees getting in the way, you need to move your butt back, straighten your legs a little, sit on your heels and increase the lower back arch.
Bent over rows fit into your fat loss workout program as a BACK EXERCISE. Of course like all compound exercises they work the whole body but 90% of the work gets done by the back.
Take a look at this video of me doing the Bent Over Row exercise that I pulled from the FLS coaching area and let me know if you have any questions: