A Subject-Specific Approach to Detect Fatigue-Related Changes in Spine Motion Using Wearable Sensors

Area of Science:

• Biomechanics
• Occupational Health
• Wearable Technology

Background:

• Workplace injuries often stem from muscle fatigue-related kinematic changes.
• Individual responses to fatigue vary, necessitating subject-specific analysis methods.
• Objective tools are needed to detect these kinematic changes for injury prevention.

Purpose of the Study:

• To assess if wearable inertial measurement units (IMUs) and a spine motion composite index (SMCI) can quantify subject-specific spine kinematic changes during repetitive tasks.
• To determine if the SMCI correlates with measures of global trunk muscle fatigue.

Main Methods:

• Ten healthy adults performed repetitive spine flexion-extension tasks.
• Spine kinematics were captured using wearable IMUs on the pelvis and T8 vertebrae.
• Subject-specific SMCIs were calculated and correlated with fatigue measures (VAS, maximal lift strength).

Main Results:

• The SMCI significantly increased from baseline starting at set 4, indicating changes in spine motion.
• Significant correlations were found between the SMCI and both perceived fatigue (VAS) and maximal lift strength.
• The SMCI effectively quantified subject-specific kinematic alterations related to muscle fatigue.

Conclusions:

• Wearable IMUs combined with the SMCI provide an objective method for detecting subject-specific changes in spine kinematics associated with muscle fatigue.
• This approach holds potential for reducing workplace injuries by identifying individuals at higher risk.
• Subject-specific kinematic analysis is crucial for accurately assessing muscle fatigue in occupational settings.