Individuals with hemiparetic stroke abnormally perceive their elbow torques when abducting their paretic shoulder.

Objective: Individuals with hemiparetic stroke exhibit an abnormal coupling between shoulder abduction and elbow flexion, or flexion synergy, due to an increased reliance on cortico-bulbospinal pathways. While this motor impairment is well documented, its impact on how movements are perceived remains unexplored. This study investigates whether individuals with hemiparetic stroke accurately perceive torques at their paretic elbow while abducting at their shoulder.

Impact of Arm Dominance and Location on Detecting Electrotactile Stimuli During Voluntary Motor Activation in Older Adults.

Activation-related sensory gating is important for sensorimotor control, filtering signals irrelevant to a task. Literature on brain lateralization suggests that motor activation patterns during sensorimotor control differ depending on arm dominance. Whether the lateralization effect extends to how sensory signals modulate during voluntary sensorimotor control remains unaddressed.

Perception of Torque is Impacted by a Subset of Features Related to the Motor Command.

Accurate perception of one's self-generated torques is integral to sensorimotor control. Here, we examined how features of the motor control task, specifically the variability, duration, muscle activation pattern, and magnitude of torque generation, relate to one's perception of torque. Nineteen participants generated and perceived 25% of their maximum voluntary torque (MVT) in elbow flexion while simultaneously abducting at their shoulder to 10%, 30%, or 50% of their MVT in shoulder abduction (MVT[Formula: see text]).

Impact of Abducting at the Shoulder on Perceiving Torques about the Elbow.

Literature indicates that an individual's perception of their self-generated torques is largely influenced by their descending motor commands. These studies often rely on between-limbs matching protocols, which can introduce confounding factors when interpreting results from populations with unilateral impairments. Here, we demonstrate how changes in descending motor commands impact one's perception of torques using a single-arm protocol.

Accuracy of older adults in judging self-generated elbow torques during multi-joint isometric tasks.

Successful execution of daily activities requires accurate perception of the torques one generates about multiple joints. Even so, previous studies are mostly limited to an individual's perception when torques are generated about a single joint. Consequently, this study investigates how accurately individuals judge torques at their arm during a multi-joint task.

Individuals With Hemiparetic Stroke Accurately Match Torques They Generate About Each Elbow Joint.

Successful execution of a task as simple as drinking from a cup and as complicated as cutting food with a fork and knife requires accurate perception of the torques that one generates in each arm. Prior studies have shown that individuals with hemiparetic stroke inaccurately judge their self-generated torques during bimanual tasks; yet, it remains unclear whether these individuals inaccurately judge their self-generated torques during unimanual tasks. The goal of this work was to determine whether stroke affected how accurately individuals with stroke perceive their self-generated torques during a single-arm task.

Development of a Training Game to Coordinate Torques Produced Between Arms.

The ability of individuals to accurately judge the forces that they generate is integral to seamlessly controlling their movements during everyday life. Individuals with chronic hemiparetic stroke have been shown to be impaired when matching forces between arms; this impairment may make activities as simple as carrying a tray challenging. Our goal was to develop a training protocol that individuals with stroke could use to improve their accuracy in judging the torques that they generate between arms.

Using simple clinical measures to predict insulin resistance or hyperglycemia in girls with polycystic ovarian syndrome.

Background: Polycystic ovarian syndrome (PCOS) includes insulin resistance (IR) and impaired glucose tolerance (IGT) in youth, and a greatly elevated risk of type 2 diabetes in adulthood. Identifying IR is challenging and documenting IGT requires an oral glucose tolerance test (OGTT).

Objective: Identify easily applied surrogate measures for IR and IGT in girls with PCOS.

Insulin Resistance in Youth Without Diabetes Is Not Related to Muscle Mitochondrial Dysfunction.

Context: Obesity, insulin resistance (IR), and diabetes are increasing in youth, especially in girls. IR is associated with muscle mitochondrial dysfunction in youth and adults with diabetes. However, it is unknown whether this relationship is present in youth prior to development of diabetes.