THREE-DIMENSIONAL MULTI-SEGMENTED SPINE JOINT REACTION FORCES DURING COMMON WORKPLACE PHYSICAL DEMANDS/ACTIVITIES OF...

Area of Science:

• Biomechanics
• Spine Mechanics
• Occupational Health

Background:

• Existing spine reaction force models often focus only on the L5/S1 or L4/L5 joints.
• This limited scope overlooks the forces experienced by most intervertebral joints.

Purpose of the Study:

• To develop and validate a clinically applicable, noninvasive model for quantifying inter-segmental spine joint reaction forces.
• To assess these forces across six spinal regions during common workplace physical demands.

Main Methods:

• A segmental spine model was employed to calculate joint reaction forces.
• Subjects performed four ambulatory activities: level walking, obstacle crossing, stair ascent, and stair descent.

Main Results:

• Significant differences in bodyweight-normalized vertical joint reaction forces were observed between tasks.
• Stair descent resulted in higher peak forces (12.12±1.32 N/kg) compared to level walking (8.05±3.19 N/kg).

Conclusions:

• The segmental spine model effectively estimates joint reaction forces.
• Task-specific demands significantly influence peak reaction forces within the segmental spine.