We show that for any positive operator monotone function $f$ the inequality $\int_{[0,\infty)} f(t) \, \mathrm{d} \left\lVert E^{Δ_{\varphi,ψ}}(t) ξ_ψ\right\rVert^2 + f'_\infty \varphi(1-s(ψ)) \geq \frac{f(1)}{2} \Bigl( \varphi(1) + ψ(1) - \lVert \varphi - ψ\rVert \Bigr)$ holds, where $\varphi, ψ\in \mathcal{M}_{*,+}$ are two normal positive linear functionals on a von Neumann algebra $\mathcal{M}$, and $Δ_{\varphi,ψ}$ is the associated relative modular operator. Choosing $f(t) = t^s$ with $s \in [0,1]$, the Powers-Størmer-Ogata inequality is recovered.