The Neuroplastic Outcomes from Impaired Sensory Expectations (NOISE) hypothesis: How ACL dysfunction impacts sensory perception and knee stability.

Background: The anterior cruciate ligament (ACL) is integral to maintaining knee joint stability but is susceptible to rupture during physical activity. Despite surgical restoration of passive or mechanical stability, patients struggle to regain strength and prior level of function. Recent efforts have focused on understanding how ACL-related changes in the nervous system contribute to deficits in sensorimotor control following injury and reconstruction.

Walking Slope and Heavy Backpacks Affect Peak and Impulsive Lumbar Joint Contact Forces.

Heavy load carriage is associated with musculoskeletal overuse injury, particularly in the lumbar spine. In addition, steep walking slopes and heavy backpacks separately require adaptation of torso kinematics, but the combined effect of sloped walking and heavy backpack loads on lumbar joint contact forces is unclear. Backpacks with hip belt attachments can reduce pressure under the shoulder straps; however, it is unknown if wearing a hip belt reduces lumbar spine forces.

Somatosensory Information in Skilled Motor Performance: A Narrative Review.

Historically, research aimed at improving motor performance has largely focused on the neural processes involved in motor execution due to their role in muscle activation. However, accompanying somatosensory and proprioceptive sensory information is also vitally involved in performing motor skills. Here we review research from interdisciplinary fields to provide a description for how somatosensation informs the successful performance of motor skills as well as emphasize the need for careful selection of study methods to isolate the neural processes involved in somatosensory perception.

I Can Step Clearly Now, the TENS Is On: Transcutaneous Electric Nerve Stimulation Decreases Sensorimotor Uncertainty during Stepping Movements.

Transcutaneous electric nerve stimulation (TENS) is a method of electrical stimulation that elicits activity in sensory nerves and leads to improvements in the clinical metrics of mobility. However, the underlying perceptual mechanisms leading to this improvement are unknown. The aim of this study was to apply a Bayesian inference model to understand how TENS impacts sensorimotor uncertainty during full body stepping movements.

Novel applications of Bayesian inference clarify sensorimotor uncertainty during stepping movements.

The human nervous system relies on sensory information from the feet and legs to control the way we balance and walk. However, even in healthy individuals this sensory information is inherently variable and clouded with uncertainty. Researchers have found that the central nervous system (CNS) estimates body position amid the uncertainty of sensory signals in a way consistent with Bayesian inference.

Inhibitory signaling as a predictor of leg force control in young and older adults.

As the populations of the United States and developed nations age, motor control performance is adversely impacted, resulting in functional impairments that can diminish quality of life. Generally, force control in the lower limb worsens with age, with older adults (OA) displaying more variable and less accurate submaximal forces. Corticospinal inhibitory signaling may influence force control, with those OA who maintain corticospinal inhibitory signaling capacity achieving steadier forces.

Advanced characterization of static postural control dysfunction in persons with multiple sclerosis and associated neural mechanisms.

Background: Multiple sclerosis (MS) is an autoimmune-based chronic inflammatory disease characterized by the neurodegeneration of the central nervous system and produces postural dysfunction. Quiet or static standing is a complex task carried out through afferent sensory inputs and efferent postural corrective outputs. Currently the mechanisms underlying these outputs remain largely unknown.

Innovative methods measure the neural correlates of proprioception in multiple sclerosis.

The authors of the recently published article "Position sense deficits at the lower limbs in early multiple sclerosis: clinical and neural correlates" (Iandolo R, Bommarito G, Falcitano L, Schiavi S, Piaggio N, Mancardi GL, Casadio M, Inglese M. 34: 260-270, 2020) provide strong evidence for the neural correlates leading to deficits in proprioception in multiple sclerosis. We believe their findings and innovative methodology show promise for how proprioception is measured in this and other clinical populations.

Virtual time-to-contact identifies balance deficits better than traditional metrics in people with multiple sclerosis.

Multiple sclerosis (MS) is a neurodegenerative disease that negatively affects the quality of electrical signaling throughout the central nervous system. Although impaired postural control is one of the most common symptoms in people with MS (PwMS), commonly reported metrics such as center of pressure (CoP) path length and velocity have not been great predictors of fall risk. A relatively new metric, known as virtual time-to-contact (VTC), is a measurement that uses the instantaneous position, velocity and acceleration of the CoP, to predict how long it would take the CoP to reach the boundary of the base of support for every data point in a trial.

The Cognitive Demands of Gait Retraining in Runners: An EEG Study.

High impact forces during running have been associated with tibial stress injuries. Previous research has demonstrated increasing step rate will decrease impact forces during running. However, no research has determined the cognitive demand of gait retraining.