Muscle–tendon arrangement and intramuscular nerve distribution of flexor digitorum superficialis in the siamang (Symphalangus syndactylus), western lowland gorilla (Gorilla gorilla gorilla), western chimpanzee (Pan troglodytes verus), and Japanese macaque (Macaca fuscata) - Emura, Kenji; Hirasaki, Eishi; Arakawa, Takamitsu (Anatomical Science International, 2023)