Design and evaluation of a laboratory-based wheelchair castor testing protocol using community data

Area of Science:

• Biomedical Engineering
• Rehabilitation Engineering
• Materials Science

Background:

• Wheelchair castor failures lead to significant physical, social, and economic burdens for users.
• Existing wheelchair test methods and regulations may not adequately identify poorly designed castors prone to failure.
• The International Society of Wheelchair Professionals (ISWP) identified castor failure as a high priority, recommending a new testing system.

Purpose of the Study:

• To develop a new castor testing protocol incorporating community-relevant exposure data.
• To evaluate the impact of shock, corrosion, and abrasion on wheelchair castor durability.
• To assess how these combined exposures alter castor failure modes and associated injury risks.

Main Methods:

• A castor testing protocol was developed based on community shock, corrosion, and abrasion data.
• Eight different castor models were tested under four conditions: shock alone, corrosion + shock, abrasion + shock, and abrasion + corrosion + shock.
• A total of eight samples per model were evaluated across the four conditions.

Main Results:

• Corrosion and abrasion significantly reduced castor durability by 13% to 100% across tested models.
• The inclusion of corrosion and abrasion altered failure modes in 75% of tested castor models.
• Two-thirds of these altered failure modes were associated with an increased risk of injury to wheelchair users.

Conclusions:

• Community-based factors like corrosion and abrasion substantially decrease wheelchair castor durability.
• The developed testing protocol, including corrosion and abrasion, is crucial for accurately assessing castor performance.
• Incorporating these elements into wheelchair standards could improve user safety and reduce failures.