Analysis of the forearm rotational efficiency in extant hominoids: new insights into the functional implications of upper limb skeletal structure.

摘要: Abstract The greatly diversified locomotor behaviors in the Hominoidea impose different mechanical requirements upper limb of each species. As forearm rotation has a major role locomotion, skeletal structures involved this movement may display differences among taxa that reflect functional adaptations. To test this, we use biomechanical model quantifies rotatory capacity pronator teres (rotational efficiency) from measurements. Using large sample hominoids, aim to identify morphological adaptations confer mechanics motion and assess advantage these Forearm positions along pronation–supination range where rotational efficiency is maximal depend on orientation humeral medial epicondyle differ taxa. Our results indicate are related mode. Knuckle-walkers exhibit more posteriorly directed, which, elbow angles close extension, causes be pronated forearm. Species with significant amount arboreal such as vertical climbing, i.e., Pongo spp., Pan troglodytes Gorilla gorilla, proximally oriented epicondyles, flexion, leads maximum efficiencies supinated Hylobatidae, less epicondyle, show their closer neutral position throughout most flexion–extension range, which linked brachiation taxon. In humans, epicondylar thus fall between terrestrial hominoids. This enhanced manipulative skills limb. conclusion, current analysis indicates habits extant hominoids therefore can used for inferences fossil