Musculus peroneus longus in foetal period

Background: The lateral compartment of the leg, due to its distal and concurrent superficial positioning, is a multiple trauma site. Detailed knowledge of compar- timentum lateralis cruris (CLC) structure is crucial for physicians. Musculus peroneus longus (MPL) is located within the structures of the CLC most superficially. There is a lot of data on the morphology of the MPL but there is no publication analysing in detail its anatomy in the foetal period. The aim of the study was to determine the variability of metric and morphological parameters of MPL in a studied period of prenatal ontogenesis. Materials and methods: The analysis included 207 human foetuses (101 males and 106 females) at calendar age from 113 to 222 days. The analysed material comes from the local anatomy collection. Foetuses were stored in typical pres- ervation solutions. Access to the muscle was obtained on the basis of standard preparation techniques. The authors evaluated the metric parameters of the muscle showing the presence of variable dynamics of metric increments of the examined muscle in particular age classes. Results: In the studied period of prenatal ontogenesis, MPLs of the foetuses in-creased by about 60% in the length and width dimension and by about 100% in the thickness dimension. The topography of the initial and final muscle attachment was also evaluated. Statistically significant dimorphic differences were found in some aspects of muscle attachment topography. Conclusions: The analysis of the place of the origin and insertion of MPL showed a relatively large variety of these features.