Safer chairs for elderly patients: design evaluation using electromyography and force measurement

Area of Science:

• Gerontology
• Biomechanics
• Human Factors Engineering

Background:

• Patient falls in hospitals disproportionately affect the elderly.
• Inpatient recovery necessitates patient mobility, including sitting in chairs.
• Ergonomic design of patient chairs is crucial for safe recovery but is understudied.

Purpose of the Study:

• To investigate the ergonomic requirements of safe patient chairs.
• To examine the effect of armrest position on physical effort during sit-to-stand transitions in elderly women.

Main Methods:

• Utilized a test chair with adjustable armrests (height and distance).
• Measured physical effort using surface electromyography (sEMG), load cells, and video recording.
• Recruited 15 elderly women to perform Stand-to-Sit-to-Stand (St-Si-St) transitions.

Main Results:

• Physical effort exhibited non-linear responses to armrest height and distance adjustments.
• Minimum physical effort was observed when armrests were positioned higher and farther apart compared to typical patient chairs.

Conclusions:

• Armrest ergonomics significantly influence the physical effort required for elderly patients.
• Patient chair designs with higher and wider armrests may improve safety and facilitate recovery for elderly individuals.