Dynamic assessment for low back-support exoskeletons during manual handling tasks

Area of Science:

• Biomechanics
• Ergonomics
• Human-Robot Interaction

Background:

• Exoskeletons can mitigate low back injury risk during manual lifting.
• Current assessment methods often focus on peak biomechanical values, neglecting movement-specific effects.
• Limited understanding of exoskeleton performance across all movement phases hinders adoption.

Purpose of the Study:

• To develop and validate a functional analysis method for assessing exoskeleton effectiveness.
• To quantify biomechanical differences throughout lifting movements with exoskeleton use.
• To investigate the relationship between kinematic restrictions and lumbar load reduction.

Main Methods:

• Functional analysis based on ANOVA to evaluate biomechanical variables over time.
• Interpolation technique to estimate exoskeleton assistive torque.
• Ten male participants performed lifting tasks with a 10-kg box under symmetric and asymmetric conditions.

Main Results:

• Significant lumbar load reduction observed during all lifting phases (flexion, lifting, laying).
• Exoskeleton use led to reductions in kinematic variables, indicating motion restriction.
• Functional analysis revealed that exoskeletons reduce lumbar load by restricting kinematic variables, particularly at larger trunk angles.

Conclusions:

• Functional analysis provides a comprehensive method for evaluating exoskeleton performance throughout a task.
• Exoskeletons effectively reduce lumbar load and alter movement kinematics.
• Findings suggest exoskeletons are most beneficial at larger trunk angles, with limited effect below 25°.