Table 1. Reference values for physical load factors as risk factors for neck/shoulder, and
elbow/wrist/hand disorders based on recent reviews and some original studies.

	Neck/Shoulder	Elbow/Wrist/ Hand
Repetition / recovery	· Repetitive upper extremity motions (Bernard, 1997) · Repetitive neck movements (Bernard, 1997) (Ariens et al., 2000) · Repetitive work under time constraints (Cassou et al., 2002) · >15 shoulder movements·min-1 (Andersen et al., 2002) · Increased levels of muscle activity with few periods of low activity (micro-pauses) during repetitive movements (van der Windt et al., 2000) · Lack of recovery time during ³ 80% of working time (Andersen et al., 2002)	· Cycle time <30s or ³50% of cycle time repeating the same sub-cycle (Silverstein et al., 1986) · Cycle time <1min (high risk) or 10s (highest risk) (Leclerc et al., 2001) · Overall level of hand activity above 6.6 rated with 1-10 visual-analog scales (Latko et al., 1999) · High repetition (Bernard, 1997) · Manually intensive work (Kurppa et al., 1991)
Force	· Forceful arm and hand movements with same  muscle groups (Bernard, 1997) · Used force ³10% of MVC (Andersen et al., 2002) · Heavy physical work load (van der Windt et al., 2000) · Used arm force (Ariens et al., 2000) · Static loading of neck-shoulder muscles (Bernard, 1997)	· Gripping force >4kg (Silverstein et al., 1986) · Lifting>16kg·h-1 or 6-15kg>1 time· h-1 for 50% of working time (Devereux et al., 2002) · Forceful repetitive work (Viikari-Juntura and Silverstein, 1999)
Posture	· Sitting at work >95% of working time (Ariens et al., 2001a) · Neck flexion >20° >70% of working time (Ariens et al., 2001a) · Neck flexion >45° >10 % of working time (Ariens et al., 2001a) · Neck flexion >20° ³ 66% of work cycle time (Andersen et al., 2002) · Rotated neck >1 h·day-1, arm above shoulder level >1 h·day-1 (Miranda et al., 2001b) · Arm flexion/abduction >90° >10% of work cycle (Punnett et al., 2000) · Awkward and static postures (van der Windt et al., 2000) · Extreme neck postures (Bernard, 1997) · Duration of work with a hand above shoulder level (Viikari-Juntura et al., 2001)	· Posture combinations, no clear limits (Bernard, 1997) · Use of pinch grip, extreme wrist posture >1/3 of working time (Stetson et al., 1993) · Extreme forearm, wrist and finger postures (Viikari-Juntura and Silverstein, 1999)
Vibration	· Hand-arm vibration (van der Windt et al., 2000) · Low-frequency vibration when using a hand-held power tool (Kihlberg and Hagberg, 1997) · Hand-arm vibration (Ariens et al., 2001a)	· High-frequency vibration when using a hand-held power tool (Kihlberg and Hagberg, 1997) · Hand-arm vibration (Viikari-Juntura and Silverstein, 1999)