title: Strain rate effects on the mechanical properties and fracture mode of skeletal muscle.
abstract: The present study aimed to characterize the mechanical response of beagle sartorius muscle fibers under strain rates that increase logarithmically (0.1mm/min, 1mm/min and 10mm/min), and provide an analysis of the fracture patterns of these tissues via scanning electron microscopy (SEM). Muscle tissue from dogs' sartorius was excised and test specimens were sectioned with a lancet into sections with nominal length, width, and thickness of 7, 2.5 and 0.6mm, respectively. Trimming of the tissue was done so that the loading would be parallel to the direction of the muscle fiber. Samples were immediately tested following excision and failures were observed under the SEM. No statistically significant difference was observed in strength between the 0.1mm/min (2.560±0.37MPa) and the 1mm/min (2.702±0.55MPa) groups. However, the 10mm/min group (1.545±0.50MPa) had a statistically significant lower strength than both the 1mm/min group and the 0.1mm/min group with p<0.01 in both cases. At the 0.1mm/min rate the primary fracture mechanism was that of a shear mode failure of the endomysium with a significant relative motion between fibers. At 1mm/min this continues to be the predominant failure mode. At the 10mm/min strain rate there is a significant change in the fracture pattern relative to other strain rates, where little to no evidence of endomysial shear failure nor of significant motion between fibers was detected.
authors.affiliation: Biomaterials and Biomimetics, New York University College of Dentistry, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Shapiro
authors.affiliation: Biomaterials and Biomimetics, New York University College of Dentistry, United States.
authors.forename: Nick
authors.initials: N
authors.lastname: Tovar
authors.affiliation: Biomaterials and Biomimetics, New York University College of Dentistry, United States.
authors.forename: Daniel
authors.initials: D
authors.lastname: Yoo
authors.affiliation: Orthopedic Surgery, Hospital for Joint Diseases, United States.
authors.forename: Micheal
authors.initials: M
authors.lastname: Sobieraj
authors.affiliation: Mechanical and Aerospace Engineering, NYU-Poly, United States.
authors.forename: Nikhil
authors.initials: N
authors.lastname: Gupta
authors.affiliation: Dept of Otolaryngology, New York University School of Medicine, United States.
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Branski
authors.affiliation: Biomaterials and Biomimetics, New York University College of Dentistry, United States. Electronic address: pc92@nyu.edu.
authors.forename: Paulo G
authors.initials: PG
authors.lastname: Coelho
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs; D008855:Microscopy, Electron, Scanning; D018485:Muscle Fibers, Skeletal / Q000737:chemistry* / Q000648:ultrastructure*; D013048:Specimen Handling; D013312:Stress, Physiological
keywords: Biomechanical; Dog; Fracture; Muscle; Testing