I have shoulder and arm problems from using a computer (8+ hours/day). There is a paddling stroke I use when I start to get tired; it takes a little practice... Bend your elbows very little; almost locking them straight. See how much power you can generate from rotating at the waist and pushing with the top hand. It looks a little funny and you can't avoid bending the elbows somewhat but it takes a lot of the pressure out of your shoulders and biceps. It's a great abs workout too.