When working in an office, "It's common for people to think they're supposed to sit upright at right angles," MacLeod says. "But there's no science to that. ... All studies show you should actually lean back in a semi-crouched position. ... One of the reasons is when you're leaning back with a good back rest, the weight of your upper body is transferred to that backrest. Sitting upright tends to make you round out your back in the wrong direction."
You should also let your hands rest in a semi-relaxed position when typing. "The optimal posture for the wrist is not straight up and down like holding a bouquet of flowers, and not flat side to side like playing the piano," MacLeod says. "It's actually halfway in between. Your wrists should be positioned similar to driving a car, when you place your hands at the 10 and two position [of a steering wheel]. That way, your hand is slanted forward and a little bit to the side."