This paper presents the use of light-sheet photonic force for parallel mechanical loading, and demonstrates high-throughput quantitative 3D micromechanical imaging. We quantify the micromechanical heterogeneity of fibrous collagen matrices and perform live-cell imaging of cell-mediated ECM micromechanical dynamics. Our 4D imaging of micromechanical dynamics of cell-mediated ECM deformations enabled observations that, to our knowledge, have never been reported by other techniques. For further information check our paper Light-sheet photonic force optical coherence elastography for high-throughput quantitative 3D micromechanical imaging.