Soft silicone multi-layer dressings are commonly used for pressure ulcer (pressure injury) prevention, yet their effectiveness varies based on design, construct, and material properties. This study evaluated the protective efficacy of a new multi-layer dressing, ALLEVYN COMPLETE CARE (ACC, Smith & Nephew Limited), which incorporates an advanced structure facilitating the dissipation of shear forces through internal layer-on-layer frictional sliding within the dressing. Using a combination of experimental frictional energy absorber effectiveness (FEAE) testing and computational finite element modelling, we quantified the capacity of this dressing to mitigate strain and stress concentrations in the soft tissues of the supported posterior heel. The dressing demonstrated considerable frictional sliding between its adjacent layers, resulting in FEAE = 93% under simulated, clinically relevant usage conditions. This was associated with the dissipation of shear forces and alleviation of strain/stress concentrations in the skin and underlying soft tissues below the dressing. The dressing completely eliminated the stress and strain peaks at the top quartiles of the strain/stress domain (with reference to a no-dressing case). This work provided valuable insights into advanced testing methods and beneficial design principles for pressure ulcer prevention dressings. Earlier investigations concluded that a previous-generation ALLEVYN LIFE dressing achieved high levels of FEAE and thus provided protection. Our findings here establish that the next-generation dressing, ACC, demonstrates even greater protective capacity.