Partisan Selective Exposure in COVID-19 News

Partisan selective exposure to online COVID-19 news articles is hypothesized to increase one’s exposure time to politically opinion-reinforcing news when exposed to a more opinion-reinforcing news environment and to increase one’s exposure time to politically opinion-challenging news when exposed to a more opinion-challenging news environment. This blocked 2x3 within-subjects experimental study crossed partisan stance (Pro Jokowi vs. Pro Anies) as the blocking factor with news conditions as the experimental factors (Pro vs. Contra vs. Control). The study randomly assigned 216 participants living in the Jakarta metropolitan area during the COVID-19 pandemic to two experimental and one control group for each stance (Pro Stance, Contra Stance, Control). Data shows how participants significantly spent more time on politically opinion-reinforcing news when in the Pro Stance condition, compared to when in the Contra Stance condition, and compared to when in the Control condition. Participants only significantly spent more time on politically opinion-challenging news when in the Contra Stance condition as compared to when in the Pro Stance condition, but not significantly as when compared to in the Control condition. The study took a look at how partisan selective exposure may play out in a certain news environment and found how a polarized news environment would lead to a more polarized exposure, which could get disastrous as it may play a role in people’s behavior towards the COVID-19 pandemic. Hence, getting ourselves accustomed to perspectives from an equal news environment could lead us to be less polarized, and therefore be wiser at determining our standpoints towards the COVID-19 pandemic.

Effects of Cognitive Over Postural Demands on Upright Standing Among Young Adults

A growing body of research has shown that static stance control (e.g., body sway) is influenced by cognitive demands (CD), an effect that may be related to competition for limited central resources. Measures of stance control have also been impacted by postural demands (PD) (e.g., stable vs. unstable stances). However, less is known of any possible interactions between PD and CD on static stance control in populations with intact balance control and ample cognitive resources, like young healthy adults. In this study, among the same participants, we factorially compared the impact of PD with and without CD on static stance control. Thirty-four healthy young adults wore inertial measurement units (IMU) while completing static stance tasks for 30 seconds in three different PD positions: feet apart, feet together, and tandem feet. After completing these tasks alone, participants performed these tasks with CD by concurrently completing verbal serial seven subtractions from a randomly selected three-digit number. For two dependent measures, path length and jerk, there were main effects of CD and PD but no interaction effect between these factors. For all other stance control parameters, there was only a PD main effect. Thus, adding a cognitive demand to postural demands, while standing upright, may have an independent impact on stance control, but CD does not seem to interact with PD. These results suggest that young healthy adults may be less sensitive to simple PD and CD due to their greater inherent balance control and available cognitive resources. Future work might explore more complex PD and CD combinations to determine the boundaries under which young adults’ resources are taxed.

Standing on a Double-Seesaw Device is an Easy Way to Modify the Coordination Between the Two Feet for Controlling Upright Stance: Assessment Through Weight-Bearing Asymmetry

Healthy young subjects were instructed to modify their weight-bearing asymmetry when standing on a double-seesaw device. The results indicated decreased and unchanged amplitudes in the center-of-pressure movements under the unloaded and loaded legs, respectively. In addition, a concomitant increased contribution of the more loaded leg and a decreased contribution of the pressure distribution mechanism along the mediolateral axis were observed in the production of the resultant center of pressure, its amplitude remaining constant. Thus, contrary to what was previously reported for stance control on solid ground, one of the main characteristics of a double-seesaw device, by preventing increased amplitudes on the loaded side during weight-bearing asymmetry, would be to facilitate a greater independency of the feet in the stance control process.

Biomechanical responses of young adults with unilateral transfemoral amputation using two types of mechanical stance control prosthetic knee joints

Background: Prosthetic knee joint function is important in the rehabilitation of individuals with transfemoral amputation. Objectives: The objective of this study was to assess the gait patterns associated with two types of mechanical stance control prosthetic knee joints—weight-activated braking knee and automatic stance-phase lock knee. It was hypothesized that biomechanical differences exist between the two knee types, including a prolonged swing-phase duration and exaggerated pelvic movements for the weight-activated braking knee during gait. Study design: Prospective crossover study. Methods: Spatiotemporal, kinematic, and kinetic parameters were obtained via instrumented gait analysis for 10 young adults with a unilateral transfemoral amputation. Discrete gait parameters were extracted based on their magnitudes and timing. Results: A 1.01% ± 1.14% longer swing-phase was found for the weight-activated braking knee (p < 0.05). The prosthetic ankle push-off also occurred earlier in the gait cycle for the weight-activated braking knee. Anterior pelvic tilt was 3.3 ± 3.0 degrees greater for the weight-activated braking knee. This range of motion was also higher (p < 0.05) and associated with greater hip flexion angles. Conclusions: Stance control affects biomechanics primarily in the early and late stance associated with prosthetic limb loading and unloading. The prolonged swing-phase time for the weight-activated braking knee may be associated with the need for knee unloading to initiate knee flexion during gait. The differences in pelvic tilt may be related to knee stability and possibly the different knee joint stance control mechanisms. Clinical relevance Understanding the influence of knee function on gait biomechanics is important in selecting and improving treatments and outcomes for individuals with lower-limb amputations. Weight-activated knee joints may result in undesired gait deviations associated with stability in early stance-phase, and swing-phase initiation in the late stance-phase of gait.