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

Abstract

Objective: The quantification of inter-segmental spine joint reaction forces during common workplace physical demands. Background: Many spine reaction force models have focused on the L5/S1 or L4/L5 joints to quantify the vertebral joint reaction forces. However, the L5/S1 or L4/L5 approach neglects most of the intervertebral joints. Methods: The current study presents a clinically applicable and noninvasive model which calculates the spinal joint reaction forces at six different regions of the spine. Subjects completed four ambulatory activities of daily living: level walking, obstacle crossing, stair ascent, and stair descent. Results: Peak joint spinal reaction forces were compared between tasks and spine regions. Differences existed in the bodyweight normalized vertical joint reaction forces where the walking (8.05[Formula: see text][Formula: see text][Formula: see text]3.19[Formula: see text]N/kg) task had significantly smaller peak reaction forces than the stair descent (12.12[Formula: see text][Formula: see text][Formula: see text]1.32[Formula: see text]N/kg) agreeing with lower extremity data comparing walking and stair descent tasks. Conclusion: This method appears to be effective in estimating the joint reaction forces using a segmental spine model. The results suggesting the main effect of peak reactions forces in the segmental spine can be influenced by task.