Therefore we hypothesise, in our model, that stresses at the LB and IF in the scapula have been similarly reduced by an average 22.5% in our Hpr mice (Fig. 7(A) open symbols). Using this information on altered muscle strength and weight, we can correlate the stress distribution in the scapula, and its alterations during rickets, to the evolving mineral particle nanostructure. We plotted mineral particle

alignment and degree of mineralisation versus applied stress for the oldest (10 weeks) wild type and Hpr mice in our data set. In wild type mice we observed a statistically significant (p < 0.05; Student's t-test) difference in mineral degree of orientation between two sites

where low and high stresses are expected ( Fig. 7(A)). Regions with expected increased stresses on the scapula are associated with an increased degree buy NU7441 of mineral particle orientation, as well as mean mineral concentration. However, in Hpr mice, alterations in nanostructural properties are affected by the combined result of weaker skeletal check details muscles and impaired mineralisation. We used the reported grip strength (per unit body weight) of murine model called Hyp homologues of X-linked hypophosphatemic rickets at the same age (10 weeks) [28] as a proxy for muscular force, and compared our experimental data (degree of orientation) with the normalised grip strength and muscle weight for wild type and Hyp mice ( Fig. 7(B)). A positive association between the two muscular parameters (grip strength and muscle weight) and the two mineralisation parameters (degree of orientation and mean mineral concentration) was observed. The grip strength, muscle weight, mineral particle degree of orientation and mineral concentration of Hyp mice were all lower than those of wild type mice. This finding suggests that abnormal changes in muscle forces in disease conditions are associated with reductions in the degree of mineral particle alignment. To demonstrate

the link between increasing muscular force and the development of nano-structural parameters requires that greater muscle strength/mass Myosin is associated with higher degree of mineral particle orientation, independent of body size variations. In this study we have demonstrated that degree of orientation, predominant orientation and mean mineral content increases with age in intramembranously ossifying bone. Several previous studies have shown a positive correlation between muscle strength and bone strength index [35] and BMD [30], [31] and [36] independent of measures of body size. However, the correlation between development of muscle strength and nano-structural parameters was not investigated.