SATRA releases revised test methods

Describing the changes to two footwear component evaluations.

A 2025 revision of the SATRA TM183 ‘Whole shoe cushioning assessment test’ has been published. This method uses a tensile tester in compression mode and an articulated foot to slowly press down onto a footwear whole bottom assembly and measure the energy absorbed for a force increment of 600 N. This energy absorption is the measure of the cushioning (see also SATRA TM159:2024 – ‘Cushioning properties’ for a similar test on footbeds as components).

In the SATRA TM183 test, the foot has two metal pads – one domed, one barrelled – which are used to represent the heel and ball areas of the foot. These are covered with a proprietary cellular polyurethane foam as a simulated flesh. The main change in the 2025 revision is to update the commercial reference to this foam. For ease of testing, it is also preferred to remove the upper, as this gives the articulated foot a better and more precise access to the correct location on the insole or footbed. There is a new illustration in support of this. Being manufactured in polyurethane, the covering will not have an indefinite life. It should therefore be renewed periodically, based on annual checks of its own cushioning (according to SATRA TM159).

TM184 also updated

SATRA TM184 – ‘Friction of insocks’ has also been revised in 2025. This test measures the friction available between standard hose and the footwear insock. There is a contactor foot using the same ‘fleshy’ cellular polyurethane foam as in the SATRA TM183 method described above. The reference to this foam has also been updated in this test method, and a warning about its longevity has been added. The test relies on a minimum length of at least 100 mm of the insock material. Any complex insock involving multiple materials would need to have each component tested in swatch form. Backing foams can make a difference to performance, so these should be included where relevant.

The photo above sows the SATRA TM183 test being conducted.

Publishing Data

This article was originally published on page 4 of the March 2025 issue of SATRA Bulletin.

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