Table 2. Summary of physical risk factors for neck/shoulder and elbow/wrist/hand symptoms in VDU work

	Neck/shoulder	Elbow/wrist/hand
VDU work time in general, repetition	· Continuous VDU working time (Fredriksson et al., 2002) · VDU work time >15 h·week-1 in workers during first year at a new job (Gerr et al., 2002) · Computer use almost all the time at work (Jensen et al., 2002) · Repeated movements without notable postural variation (Jensen et al., 1998) · Repeated movements (same finger, hand or arm movements many times·min-1 at least 75% of working time) (Jensen et al., 1998)	· Duration of employment in the same job using VDU (Jensen et al., 2002) · Repeated movements (same finger, hand or arm movements many times·min-1 at least 75% of working time) (Jensen et al., 1998) · Computer use almost all the time at work (Jensen et al., 2002) · Computer use >20 h·week-1 and limited rest break opportunity (Bergqvist et al., 1995a)
Mouse work demands	· Mouse use per se (Jensen et al., 1998) · Increased muscular activity in neck extensor muscles when using mouse in comparison with use of keyboard (Laursen et al., 2002) · Arm abduction when using mouse (Cook et al., 2000) · Non-neutral position of arm (Aarås et al., 2001a) · ‛Non-optimally located’ mouse (Karlqvist et al., 1996)	· At least 5.6 hours of mouse use / week (Karlqvist et al., 1996) · Repeated movements when operating the mouse (arm>2.5/min, elbow >10/min, wrist > 10/min) (Jensen et al., 1998) · Static posture when operating the mouse (wrist ulnarly deviated and extended) (Jensen et al., 1998) · Mouse use time (Fogleman and Brogmus, 1995) · Non-neutral position of arm (Aarås et al., 2001a) · ‛Non-optimally located’mouse (Karlqvist et al., 1996)
Keyboard work demands	· Conventional keyboard design (geometric design reduced symptoms) (Tittiranonda et al., 1999c) · Keyboard above elbow level (Bergqvist et al., 1995a) · Elbow height lower than ‛J’ key height, wrist extension (Marcus et al., 2002)	· Conventional keyboard design (geometric design reduced symptoms) (Tittiranonda et al., 1999c)
Screen	· Disturbing reflections on the computer screen (Jensen et al., 2002) · Computer screen height ( < 20° viewing angle) (Psihogios et al., 2001)	· Disturbing reflections on the computer screen (Jensen et al., 2002)
Sitting posture	· Sitting at work >95% of time, neck flexion >20°>70% of time, neck flexion >45° >10 % of time (Ariens et al., 2001a)
Workplace design	· Telephone shoulder rest (Marcus et al., 2002)	· No support for forearm (Bergqvist et al., 1995a) (Lintula et al., 2001)