The kneeling single hand curl is an extremely useful way of rebalancing your biceps if one side is stronger than the other. It is done in the kneeling position simply because this eliminates using other parts of the body to create the momentum to do the bicep curl. So, the starting position is, holding a dumbbell in each hand, hang your arms down by your side with your palms pointed in. Retaining the dumbbell in the same position, lift the left hand dumbbell upwards toward your shoulder ensuring that it is only the elbow which bends – ensure your right arm remains static. After a number of repetitions, simply swap over to your right hand.