Sensitivity of Thoracolumbar Spine Musculoskeletal Model Loading in Neutral Standing and Forward Flexion Static Postures to Thoracic Disc Stiffness.

This study aimed to quantify the sensitivity of a thoracolumbar musculoskeletal model with a flexible thoracic spine and articulated ribcage to disc flexural stiffness variation inherent from in-vitro cadaveric data. The model was personalized to a normal weight subject, whose upper body segmental masses and centers of mass were computed using a body-shape-based approach. Joint flexural stiffness curves were defined based on in-vitro flexion-extension moment-rotation data from several specimens taken at various thoracic levels, with stiffness variation reaching 1.

Effect of Anthropometry on Plantar Pressure Distribution during Gait in Overweight Male Subjects.

Traditionally, research on plantar pressure in overweight/obese populations has predominantly focused on dividing the plantar surface into two or three regions, considering factors such as body mass index (BMI), age, and gender. This study took a more comprehensive approach, incorporating various anthropometric measurements representing body shape, including arm, leg, and shoulder lengths, as well as thigh, chest, waist, hip, and ankle circumferences. Utilizing retrospective data from overweight but healthy male subjects, the study yielded results revealing robust correlations with Euclidean measurements, circumferential measurements, and circumferential ratios.

Ground Reaction Forces and Moments in Stroke Survivors: Experimental versus AnyBody Model Predictions.

Multibody dynamics models and simulations offer an efficient alternative to traditional methods, such as force plates, pressure sensing mats, and instrumented treadmills, for computing ground reaction forces (GRF) and moments (GRM), valuable in the quantification of the gait of neurological patients. Accurate determination of GRF and GRM magnitudes, with a specific focus on the disruptive shear components affecting gait, is essential for post-stroke gait assessment and rehabilitation. This study explored the predictive capability of musculoskeletal models equipped with foot contact elements, by comparing them with experimental data from a published dataset.

An endogenous GLP-1 circuit engages VTA GABA neurons to regulate mesolimbic dopamine neurons and attenuate cocaine seeking.

Recent studies show that systemic administration of a glucagon-like peptide-1 receptor (GLP-1R) agonist is sufficient to attenuate cocaine seeking. However, the neural mechanisms mediating these effects and the role of endogenous central GLP-1 signaling in cocaine seeking remain unknown. Here, we show that voluntary cocaine taking decreased plasma GLP-1 levels in rats and that chemogenetic activation of GLP-1-producing neurons in the nucleus tractus solitarius that project to the ventral tegmental area (VTA) decreased cocaine seeking.

Mechanisms underlying the distinct K+ dependencies of periodic paralysis.

Patients with periodic paralysis have attacks of weakness precipitated by depolarization of muscle. Each form of periodic paralysis is associated with unique changes in serum K+ during attacks of weakness. In hypokalemic periodic paralysis (hypoKPP), the mutation-induced gating pore current causes weakness associated with low serum K+.