Use of two test methods to ensure accurate surface firmness and stability measurements for accessibility

The firmness and stability of indoor and outdoor surfacing are critical to the accessibility and safety of all environments for people with mobility impairments and/or who use mobility devices. ASTM F1951 laboratory test procedures include pass/fail criteria for determining playground surface accessibility by comparing the work to propel up a 1:14 (7.1%) grade ramp to that of the test surface in a wheelchair. A portable instrumented surface indenter (ISI) was developed to validate that accessibility results obtained in the laboratory are maintained in the field where the surface is installed and used.

Accessibility measurements have been made on indoor and outdoor surfaces tested in the laboratory using both the ASTM F1951 and the ISI over 13 years. Correlations between these two methods were calculated.

A strong correlation has been demonstrated for the sum of the ISI firmness and stability results compared to the sum of the ASTM F1951 straight propulsion and turning results (R²=0.9006).

The portable ISI can be used to verify that the firmness and stability of an installed surface in the field correlates to the accessibility results of the surface tested in the laboratory concurrently according to ASTM F1951 and the ISI. Implications for Rehabilitation The Instrumented Surface Indenter (ISI) allows for surfaces in all environments to be tested for firmness and stability, which is critical for wheelchair user safety, especially during rehabilitation when learning to use a wheelchair. The ISI allows for surfaces in all environments to be tested for firmness and stability, which increases access to all indoor and outdoor surfaces, thereby improving the quality of life for people who have mobility impairments and/or use mobility devices, such as canes, crutches, walkers, and wheelchairs. Using the ISI to test the firmness and stability of installed playground surfaces increases access to playgrounds for children with mobility impairments, facilitating developmentally critical peer-play opportunities for children who use mobility devices. Using the ISI to test the firmness and stability of installed playground surfaces increases access to playgrounds for people with mobility impairments, allowing adults who use a mobility device to supervise and play with children in their lives.