Insect antennae are important mechanosensory and chemosensory organs. Insect appendages, such as antennae, are encased in a cuticular exoskeleton and are thought to bend only between segments or subsegments where the cuticle is thinner, more flexible, or bent into a fold. There is a growing appreciation of the dominating influence of folds in the mechanical behavior of a structure, and the bend...

Anthropoids and tarsiers are the only vertebrates possessing a postorbital septum. This septum, formed by the frontal, alisphenoid, and zygomatic bones, separates the orbital contents from the temporal muscles. Three hypotheses suggest that the postorbital septum evolved to resist stresses acting on the skull during mastication or incision. The facial-torsion hypothesis posits that the septum r...

We analyzed midline kinematics and obtained electromyograms (EMGs) from the superficial red muscle at seven longitudinal positions in four largemouth bass swimming steadily at standardized speeds of 0.7, 1.2, 1.6, 2.0 and 2.4 lengths s-1. Analysis of variance was used to test for significant variation attributable to both speed and longitudinal position. EMGs propagated posteriorly were unilate...

In the latter half of the nineteenth and early part of the twentieth centuries surgeons and anatomists studied the movements of the spinal column, both in the living and in the cadaver (Weber and Weber 1836, Schulthess 1899, Lovett 1905, Virchow 1907, Fick 1910, Strasser 1913). These researches culminated in the work of Lovett (1905), who concluded that the spine is a tube of unequal flexibilit...

The components of the effective internal lateral pressure arising from the lipid headgroups and the lipid chains in bilayer membranes are deduced from the conditions for interfacial equilibrium and the spontaneous bending moments within the component monolayers. The latter are obtained from the intrinsic curvature that is deduced from X-ray diffraction measurements on the corresponding inverted...

Our understanding of the evolution of frog locomotion follows from the work of Emerson in which anurans are proposed to possess one of three different iliosacral configurations: 1) a lateral-bending system found in walking and hopping frogs; 2) a fore-aft sliding mechanism found in several locomotor modes; and 3) a sagittal-hinge-type pelvis posited to be related to long-distance jumping perfor...

STUDY DESIGN Descriptive, cross-sectional design of healthy young adults. Continuous motion monitoring of the cervical spine performed outside of a laboratory setting. OBJECTIVE The objective of this study was to quantify the daily frequency and magnitude of neck motion in healthy human subjects using continuous motion monitoring. SUMMARY AND BACKGROUND DATA Daily frequency and magnitudes o...

OBJECTIVE To compare the biomechanical properties of cervical arthroplasty to a ventral slot procedure and pin-polymethylmethacrylate (pin-PMMA) fixation. SAMPLE POPULATION Fresh cadaveric cervical (C2-T1) spines from 6 large dogs. METHODS Four spinal conditions were studied in each spinal specimen: intact, disk arthroplasty, ventral slot, and fixation with smooth pin-PMMA at C5-C6 interver...

BACKGROUND Total disc replacement (TDR) and total facet replacement (TFR) have been the focus of recent kinematics evaluations. Yet their concurrent function as a total joint replacement of the lumbar spine's 3-joint complex has not been comprehensively reported. This study evaluated the effect of a TFR specifically designed to replace the natural facets and supplement the function with the nat...