The compliance of each mat sample was measured as the ratio of the displacement to load as the peak load of 1000 N was attained (i.e. at 20 seconds). A more compliant, and hence more comfortable mat would displace more under a given load than a stiffer mat. To illustrate this point, consider that concrete displays no noticeable deflection when stepped on and is therefore considered stiff and relatively uncomfortable to walk upon. On the other hand, carpeting "deforms" readily when stepped on and is considered soft or compliant and is relatively more comfortable to walk upon. In a similar test, it is that the more "comfortable" carpet would experience a greater displacement for a given load t than the concrete. The same is true of mats.

The creep relaxation of each mat was evaluated from the time variations of the displacement once the constant load of 1000 N had been obtained. A parameter reflecting the relaxation of each mat is expressed as a percentage given by the following equation:

where Δd is the increase in displacement to maintain the constant force of 1000 N and df is the displacement recorded just as a force of 1000 N was attained. This parameter measures the relative amount that the mat "sinks" once it has been loaded, and hence how much "support" the mat provides. A completely supportive mat (no further displacement once the load had been reached) would have a value of this parameter of 1 or 100%. In order to demonstrate the relevance of this parameter consider the familiar example of a mattress. A mattress is considered to provide support if an individual does not, in effect, "sink-in:" the analogous concept is applied to mats herein.

The energy absorbed by a mat during impact was measured using a technique similar to that used in the resilience experiment described above. However, in these experiments, the 2.5" diameter mat sample was mounted to a hammer identical to the impacting anvil. Again, both hammers were mounted at the end of a 3' aluminum rod and allowed to sing with a pendulum motion. The velocity of each anvil after impact was measured in a manner similar to that described above. The energy absorbed by the mat was taken as the loss in kinetic energy of the system, which assumed that the energy absorbed by the rest of the system is small in comparison to that absorbed by the mat. Specifically, the absorbed energy was calculated from the flowing relation from the impact velocity, vimp, the velocity of the hammers following impact, v1out and v2out for the impacting and sample hammers, respectively:

The support is shown in two successive bar charts in terms of the parameter defined by equation (1), above evaluated 40 seconds after the load of 1000 N was attained. The first is shown plotted against a scale from 0 to 120% in order to include the poorest performing mat, the typical rubber mat which has a support value of 40%. All other mats scored above 80%, as shown on the scale of the second support bar chart which better illustrates the differences observed between the other five mats. The mats rank as follows in terms of support: (1) Barefoot type i - 97%, (2) Ergomat - 96%, (3) vinyl top sponge mat - 94%, (5) sponge vinyl - 81% and (6) typical rubber mat - 40%. The resilience of the mats is show in the next bar chart.

The energy absorbed by the mats is shown in the following bar chart. Several tests were run on each individual mat, and the data shown in the chart represents the values calculated from the average of all tests. The mats rank as follows: (1)Ergomat - 39.5%, (2)sponge vinyl - 28.7%, (3)domed mat - 27.7%, (4)Barefoot Type I - 27.5%, (5)typical rubber mat - 24.9%, (6)vinyl top sponge mat - 11.1%. It should be noted that the differences between the second and fourth ranked mats are less than 1.5% which is on the order of the error in these measurement. As a result, not much significance can be attributed to the differences observed in this test between the sponge vinyl, the domed mat and Barefoot Type i.