Analysis of the muscle-bone relationships in frog's hindlimb.

MIRIAM CORINA VERA; JOSÉ LUIS FERRETTI; GUSTAVO ROBERTO COINTRY; VIRGINIA ABDALA

Austin, Tx

Congreso; ASBMR 2022 Annual Meeting; 2022

American Society for Bone and Mineral Research

The Mechanostat Theory states that osteocytes sense both the intensity and directionality of the strains induced by mechanical usage and modulate the bone design accordingly. Anuran species are ideal for analyzing the muscle-bone relationships related to the different mechanical stresses induced by their locomotor modes and habitat uses. This work aimed to explore the relationships between indicators of the force of the four hind-limb relevant muscles of locomotion and the mechanical properties of femur and tibia fibula in preserved samples of three anuran species with different habitat use (aquatic, arboreal) and locomotion modes (swimmer, jumper, walker/climber). We measured the anatomical cross-sectional area of each dissected muscle and correlated it with the moments of inertia and bone strength indices assessed by pQCT in antero-posterior (AP) and lateral axes (L). Significant, species-specific covariations between muscle and bone parameters were observed. In the arboreal jumper species (Boana faber) and walker species (Phyllomedusa sauvagii) all muscles except for the semimembranosus showed significant correlations. In the jumper one, the correlations were mostly with the AP-bone parameters (xMI and XBSI) at distal section (quadriceps femoris), medial section (plantaris longus) and medial and proximal section (peroneus). In the walker/climber species the correlation were mostly with AP (xMI and xBSI) and L-bone (yMI and yBSI) parameters along the femur (quadriceps femoris), and at distal and proximal sections (plantaris longus and peroneus). In the aquatic species (Pseudis platensis) the femur muscles correlated significantly mostly with the lateral bone parameters (yBSI and xBSI), meanwhile the tibia fibula muscles correlated also with antero-posterior parameters. The muscles correlated at distal section (quadriceps femoris), distal and mid-diaphysis sections (semimembranosus), along the bone (plantaris longus) and distal and proximal section (peroneus). These results show that bones will be more or less resistant to lateral and antero-posterior bending according to the different mechanical challenges of locomotion in aquatic vs. arboreal habitats, evidencing that the same muscles can orient bone modeling in different directions. This study provides new evidence of the muscle-bone relationships in three frog species, highlighting the crucial role of muscle in determining the biomechanical properties of bones