Designing instrumented walker to measure upper-extremity's efforts: A case study

Area of Science:

• Biomechanics and Rehabilitation Engineering
• Orthopedics and Sports Medicine

Background:

• Spinal cord injury (SCI) frequently leads to shoulder pain, particularly during walker use.
• Existing methods for measuring grip forces in walkers are often economically prohibitive.
• A need exists for cost-effective instrumentation to assess upper-extremity biomechanics in SCI patients.

Observation:

• Custom load cells were fabricated to overcome the high cost of commercial multidirectional load cells.
• A VICON motion analysis system and inverse dynamic methods were employed for comprehensive gait analysis.
• Upper-extremity forces and moments were measured in individuals with SCI using different walker types.

Findings:

• Higher shoulder and elbow flexion-extension moments were observed in SCI patients using walkers.
• Increased superior-inferior shoulder forces and anterior-posterior elbow and wrist forces were recorded.
• Minimal differences in measured forces and moments were found between a two-wheel walker and a basic walker.

Implications:

• The developed instrumented walker provides a feasible method for quantifying upper-extremity biomechanics in SCI.
• Findings highlight specific joint loading patterns that may contribute to shoulder pain in SCI patients.
• This research can inform the design of more ergonomic walkers and targeted rehabilitation strategies for SCI.