Figure 3.

Measurement of load-induced tensile strain on the mouse tibial surface and FRAP-based quantification of load-induced fluid flow velocity and shear stress in the LCS. A, B) Strain-displacement (A) and strain-force relationship (B; n=9) measured by the strain gauge under compressive axial loading in the Ca²⁺ or FRAP imaging region. Strain-force data demonstrated a linear relationship over a 1- to 11-N loading range [Strain (με) = 193.186 × force (N), R² > 0.99]. C) Representative plots of the normalized fluorescence recovery ratio of a lacuna sequentially subjected to photobleaching under 0-N static loading and 4-, 6-, and 8-N cyclic mechanical loading. D) Log-transformed plot of the recovery ratio with the slope representing the characteristic transport rate, k. E) Linear regression for the average transport enhancement (k/k₀) within 20 tested lacunae at varying loading conditions (4-, 6-, or 8-N peak load magnitude). F) Overall power relationship between fluid velocity and transport enhancement (k/k₀) using the 3-compartment LCS transport model. G, H) Peak LCS fluid flow velocity and shear stress in the cell body (G) and canaliculi (H) calculated from a 3-compartment LCS model at the loading magnitudes tested.