Skin elasticity (suction-probe viscoelasticity)

Method

Viscoelastic recovery of a skin site drawn into a suction probe, reported as a dimensionless ratio — most often gross elasticity R2, sometimes net elasticity R5 or biological elasticity R7 — at a defined site after a standardised acclimatisation period. The parameter and the site are recorded on the edge, because R2 and R5 are different ratios of the same deformation curve and are not interchangeable.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

19 papers, 8 randomised trials among them. The instrument is RECORDED rather than bound because suction probes from different manufacturers report the same viscoelastic construct; the parameter within the curve is what must not be swapped, and it lives on the edge. A rising value is improvement. Frequently reported in the same sentence as skin water content and water flux, which are different properties measured by different probes at the same visit.