Load carriage is a human universal used to transport children and other resources (e.g., water). Load placement (e.g., back or side) can vary, which influences an individual's gait. Previous studies have assessed the energetic cost of center-of-mass placement  (COMP) and head-load placement (HLP), but the kinematic changes during combined loads are less understood. Lumbar bending and arm swing amplitude were collected from participants (N=19) using OpenCap as they walked for four load conditions: unloaded (UL), back-loaded (BL), back-loaded-with-empty-bucket (BEB), and head-loaded (HL). All loaded conditions were 7.3kg, approximately 10% of the participant's mass. Conditions were differentiated as COMP (BL) or HLP (BEB and HL). Participants were not habitual head load carriers and used one arm to support HLP (one arm swing). Normal arm swing was maintained for COM conditions. Using a multifactorial ANOVA, COM induces lumbar flexion while HLP induces lumbar extension (p=0.011). Additionally, a difference in arm swing amplitude was found (p=0.058). Normal arm swing (COM) had low swing amplitude while one arm swing (HLP) had a high amplitude, with the highest arm swing occurring during BEB. These findings imply that even when loaded mass is the same, different load positions are associated with kinematic changes that will have important energetic impacts and the potential for changes in skeletomuscular changes particularly via lumbar extension. These data are specifically relevant to understanding the demands placed on individuals around the world who carry water and/or children for long distances, particularly in places experiencing extreme drying during climate change.

Chronic stress has been associated with maladaptive behaviors in both human and animal research models, but the underlying mechanisms are unclear. In this research study, we sought to define whether stress induces neural inflammation in the ventral tegmental area, the brain region primarily responsible for regulating reward consumption, learning, memory, and addictive behaviors through moderating dopamine release in other brain areas. To do this, male Sprague-Dawley rats were subjected to a chronic intermittent stress paradigm that included stressors such as wet bedding, delayed feedings, social isolation, strobe lights, and forced swims. Following the chronic stress intervention, brain sections were collected from control and experimental groups. Subsequently, immunohistological analysis was performed of microglia and astrocytes, cell types known to mediate inflammatory responses within the brain. By assessing inflammation in the ventral tegmental area through fluorescent microscopy and quantitative morphological analysis of these glial cell types, we will establish whether inflammation in this key brain region regulating motivation may be involved in the harmful behavioral outcomes often associated with chronic stress.