Comfort

Long periods of repetitive motion using computer peripheral products may be associated with nerve, tendon, or muscle injury in your hands, wrists, arms, shoulders, neck, or back. If you experience symptoms such as persistent or recurring discomfort, pain, throbbing, aching, tingling, numbness, burning sensation, or stiffness you should seek a qualified health professional.

Other resources:

http://www.ninds.nih.gov/disorders/carpal_tunnel/detail_carpal_tunnel.htm