The clearance space under the work surface should provide adequate room for the users legs when in the upright seated posture and at least one other of the seated reference postures. This can be accomplished by using Method 1 or Method 2.
Method 1 – Upright and Reclined Seated Postures
The following dimensions represent clearances that accommodate the majority of users (5th percentile female to 95th percentile male) when in a seated posture where the top of the legs are about parallel with the floor.
Minimum dimensions (Figure 1)
- 20 inches (52 cm) wide.
- 17 inches (44 cm) deep at knee level.
- 24 inches (60 cm) deep at foot level.
- 4 inches (10 cm) high at the foot.
Variable dimensions (“rollover” the image)
- Height is adjustable between 20 and 27 inches (50 and 69 cm) near the user. (Figs. 1 and 2)
Method 2 – Upright, Reclined, and Declined Seated Postures
The following dimensions accommodate the largest operator clearance spaces (5th percentile female to 95th percentile male). Thus, specifications conforming with Method 2 will meet Method 1 requirements. This method also includes postures where the knee is slightly lower than the buttocks (declined-seated).
Variable dimensions (“rollover” the images)
- Adjustable between 20 and 28 inches (50 and 72 cm) high at the hip. (Figures 1 and 3)
- Adjustable between 20 and 25 inches (50 and 64 cm) high near the user’s knee. (Figures 1 and 3)