Joint Moments and Powers in Healthy Young Adults During Stair Negotiation

The primary objective of this study was to determine lower limb joint moments and powers of stair negotiation in healthy young individuals. These results will provide baseline information for future studies with elderly and clinical populations designed to prevent falls that occur during stair negotiation. In previous stair negotiation studies, researchers investigated joint moments and powers initiating stair ascent in front of the stairway. Starting farther away from the stairway allows individuals to stabilize gait velocity and thus, exclude the influence of velocity on joint moments and powers generated during stair ascent. Ten young, healthy individuals underwent gait analysis during stair negotiation. Two way repeated measures ANOVA was used to determine the differences between two different conditions, starting farther away from the stairway (C1) and starting in front of the stairway (C2), for two consecutive steps (s1 and s2) on the stairway performed by the same leg. A motion analysis system was used to collect the three-dimensional spatial trajectories of the markers (joint angle data). Ground reaction forces were collected using two AMTI force platforms embedded in the first and the third stair treads. Our results demonstrated that ankle power absorption (PA1) was significantly higher during the s1 and s2 in C1 than during the s1 in C2. PA1 was significantly greater during s2 than during s1 in condition 2. Ankle power generation (PA2) was significantly higher during s2 than s1 in C1. The hip power absorption (PH2) was significantly higher during s1 in C1 than during s2 in C1, and s1 and s2 in C2. PH2 was significantly higher during s1 in C2 than s2 in both C1 and C2. These findings iv showed that the way individuals approach stairs will have a different affect on the ankle and the hip joints which has to be considered in future studies in stair negotiation

Do lower-extremity joint dynamics change when stair negotiation is initiated with a self-selected comfortable gait speed?

Previous research on the biomechanics of stair negotiation has ignored the effect of the approaching speed. We examined if initiating stair ascent with a comfortable self-selected speed can affect the lower-extremity joint moments and powers as compared to initiating stair ascent directly in front of the stairs. Healthy young adults ascended a custom-built staircase instrumented with force platforms. Kinematics and kinetics data were collected simultaneously for two conditions: starting from farther away and starting in front of the stairs and analyzed at the first and second ipsilateral steps. Results showed that for the first step, participants produced greater peak knee extensor moment, peak hip extensor and flexor moments and peak hip positive power while starting from farther away. Also, for both the conditions combined, participants generated lesser peak ankle plantiflexor, greater peak knee flexor moment, lesser peak ankle negative power and greater peak hip negative power while encountering the first step. These results identify the importance of the starting position in experiments dealing with biomechanics of stair negotiation. Further, these findings have important implications for studying stair ascent characteristics of other populations such as older adults

Chronic use of inhaled corticosteroids in patients admitted for respiratory virus infections: a 6-year prospective multicenter study

International audienceInhaled corticosteroids (ICS) have been associated with increased risk of pneumonia. Their impact on respiratory virus infections is unclear. We performed a post-hoc analysis of the FLUVAC cohort, a multicenter prospective cohort study of adults hospitalized with influenza-like illness (ILI) during six consecutive influenza seasons (2012–2018). All patients were tested for respiratory virus infection by multiplex PCR on nasopharyngeal swabs and/or bronchoalveolar lavage. Risk factors were identified by logistic regression analysis. Among the 2658 patients included, 537 (20.2%) were treated with ICS before admission, of whom 282 (52.5%, 282/537) tested positive for at least one respiratory virus. Patients on ICS were more likely to test positive for non-influenza respiratory viruses (25.1% vs. 19.5%, P = 0.004), especially for adenovirus (aOR 2.36, 95% CI 1.18–4.58), and respiratory syncytial virus (aOR 2.08, 95% CI 1.39–3.09). Complications were reported in 55.9% of patients on ICS (300/537), primarily pneumonia (171/535, 32%). Among patients on chronic ICS who tested positive for respiratory virus, 14.2% (40/282) were admitted to intensive care unit, and in-hospital mortality rate was 2.8% (8/282). Chronic use of ICS is associated with an increased risk of adenovirus or RSV infections in patients admitted for ILI