Effects of bilateral swing-away grab bars on the biomechanics of stand-to-sit and sit-to-stand toilet transfers

Abstract

Purpose: Kinetic characteristics of transfers to and from a toilet performed using bilateral grab bars are not fully quantified to inform grab bar design and configuration. The purpose of this study was to (1) determine effects of bilateral swing-away grab bars on peaks of ankle, knee and hip joint moments during grab bar assisted stand-to-sit and sit-to-stand transfers; and (2) determine effects of three different heights and widths of swing-away grab bars on the same kinetic characteristics.

Methods: Healthy subjects (N = 11, age 25–58 years) performed stand-to-sit and sit-to-stand transfers with and without grab bars. In transfers with grab bars, 9 grab bar configurations were tested by varying their height from the floor (0.787 m, 0.813 m, 0.838 m; 31″–33″) and width, the distance of each grab bar from the toilet’s centerline (0.330 m, 0.356 m, 0.381 m; 13″–15″). Motion capture, force plate and inverse dynamics analysis were used to determine lower limb joint moments.

Results: The use of bilateral grab bars generally reduced the peak magnitude of extension moments at lower limb joints during stand-to-sit and sit-to-stand transfers (p < .05), except the ankle joint moments during stand-to-sit transfers. Relatively few differences in peak joint moments were found between studied grab bar widths or heights.

Conclusion: The obtained results suggest that the studied ranges of grab bar configurations reduce moment demands on the leg joints and thus decrease difficulty and required lower limb muscle effort to perform the transfers.

Implications for Rehabilitation

• Maximizing the benefits of assistive technology in the built environment requires a careful assessment of their spatial and configurational dimensions, especially in respect to the needs and abilities of the intended users.

• Examining the kinetic characteristics of transfers to and from a toilet using the swing-away grab bars is useful for informing grab bar design and configuration recommendations for assisted living and skilled nursing facilities.

• Our findings suggest that the swing-away grab bars located at certain ranges are a reasonable alternative to the grab bars mandated by the current Americans with Disabilities Act (ADA) Accessibility Guidelines.

• Future research investigating the effects of grab bars on transfer performance should consider additional factors, such as a wider range of abilities and transfer methods of the users.

Keywords:

• Stand-to-sit transfer
• sit-to-stand transfer
• toilet transfer
• grab bar
• accessibility guidelines
• older adults
• kinetics

Acknowledgements

We thank Sarah E. Melgen and Sarah A. Endicott for their help with subject recruitment and experiments.

Disclosure statement

The authors report no conflicts of interest.

Additional information

Funding

The study was supported by the Mayer-Rothschild Foundation (formerly known as the Hulda B. & Maurice L. Rothschild Foundation at the receipt of the grant), Chicago, IL, [grant 48366DU].