Statistical treatment of oxygenation-related data in muscle tissue.

Muscle oxygenation is determined not only by the flow and oxygen content of the supplying blood but also by the density of the capillary network, the heterogeneity of the distribution of the capillaries and the properties and distribution of the muscle fibres. The distribution of the capillaries is adequately analysed by the method of capillary domains, which also allows to link capillaries to individual fibres. Thus, capillarisation can be linked to cell properties like fibre cross-sectional surface area and perimeter, and oxygen consumption of the individual muscle fibres. However, in order to meaningfully characterise tissue properties, such linkage has to be done for groups of cells. Since most of the data are not normally distributed – domains are lognormally distributed, but how fibre cross-sectional areas are distributed is unknown – a dedicated statistical analysis is required, particularly since none of the variables is independent.