In order to utilise wood and wood fibres in advanced materials, a better understanding of the mechanical material characteristics and the interactions among the components is necessary. For this purpose, FTIR was explored together with mechanical loading as a means of studying the molecular responses to the loading of spruce wood and cellulose paper material. A linear shift of absorption bands was detected as the loading was applied. In relation to the applied stress these shifts were higher under moist conditions than under dry ones but they were similar with regard to the strains applied. There were no shifts detected in bands related to lignin or the hemicelluloses. The results are interpreted as reflecting a parallel arrangement of the load bearing component, the cellulose ordered structure, and the moisture accessible regions in the cellulose microfibril structure. This therefore represents an equal strain loaded system.