Back mechanics. Back Injuries

1. Back Mechanics

Presented by QBE
Loss Control Services

2. Back Injuries Statistics

• 25% of low back injuries account for 95%
of costs of low back injuries
• NIOSH- 70% of general public will have
back pain in their lifetime
• 80% of back pain caused by inadequate
exercise
• Back injuries account for 25% of all WC
claims and 33-44% of all WC costs

3. Spinal Column

4.

The spine is made up of 33
vertebrae. The upper 24 vertebrae
are separated by a jelly filled
layered ligaments called disks.
These disks act as shock
absorbers for the spine.
The facet joints are the back part
of the vertebrae that form the
channel for the spine.
The lumbar region are the five
large vertebra composing the lower
back, allowing the back to bend
forward and back.

5. Spinal Column

6. Discs and Force

7. Herniated Discs

8. Lower Spine

9. Spine Range of Motion

Flexion/
Extension
C2-3
C3-4
C4-5
C5-6
C6-7
C7-T1
T1-2
T2-3
T3-4
T4-5
T5-6
T6-7
T7-8
T8-9
T9-10
T10-11
T11-12
T12L1-2
L2-3
L3-4
L4-5
L5-S1
0
10
20
Degrees
30

10. Spine Range of Motion

Lateral
Flexion
C2-3
C3-4
C4-5
C5-6
C6-7
C7-T1
T1-2
T2-3
T3-4
T4-5
T5-6
T6-7
T7-8
T8-9
T9-10
T10-11
T11-12
T12L1-2
L2-3
L3-4
L4-5
L5-S1
0
10
20
Degrees
30

11. Spine Range of Motion

Rotation
C2-3
C3-4
C4-5
C5-6
C6-7
C7-T1
T1-2
T2-3
T3-4
T4-5
T5-6
T6-7
T7-8
T8-9
T9-10
T10-11
T11-12
T12L1-2
L2-3
L3-4
L4-5
L5-S1
0
10
20
Degrees
30

12. Back Mechanics

13. Danger Zones

14. Anatomy of Proper Lifting

15. Anatomy of Proper Lifting

If you are out of
physical shape can
also result in increased
loads when we
improperly lift.

16. Balance of Forces

17. Balance of Forces

Without Weight
Torso
Arms
Head
? lb x 2 in = (65 lb x 9 in) + (15 lb x 15 in) + (25 lb x 24 in)
? X 2 in = 1410 lbs
Force on Back = 705 lbs

18. Balance of Forces

With Weight
Torso
Arms
Head
Object
? lb x 2 in = (65 lb x 9 in) + (15 lb x 15 in) + (25 lb x 24 in) +(20 lb x 36 in)
? X 2in = 2130 lbs
Force on Back = 1065 lbs

19. Equivalent Forces

20. Relative Disk Pressure

21. Relative Disk Pressure Sitting Posture