Search results for "Joints"

A successful backward step correlates with hip flexion moment of supporting limb in elderly people.

2018

Purpose The objective of this study was to determine the positional relationship between the center of mass (COM) and the center of pressure (COP) at the time of step landing, and to examine their relationship with the joint moments exerted by the supporting limb, with regard to factors of the successful backward step response. Methods The study population comprised 8 community-dwelling elderly people that were observed to take successive multi steps after the landing of a backward stepping. Using a motion capture system and force plate, we measured the COM, COP and COM-COP deviation distance on landing during backward stepping. In addition, we measured the moment of the supporting limb joi…

Prediction of response to disease modifying antirheumatic drugs in rheumatoid arthritis.

2010

Abstract Aim To investigate potential predictors of response to conventional DMARDs in RA. Methods Study design – 6-month follow-up prospective study. Participants RA patients with active disease. Intervention and follow-up Introduction of one DMARD. Response to treatment evaluated at 6 months (ACR20 criteria). Analysis Potential predictors of response, patients’ demographics, disease activity, percentages of PBMC subsets expressing P-gp, serum IL-1β, IL-6, IL-8, IL-10, IL-12, TNF-α levels, were evaluated using univariate and multivariate logistic regression analysis. ROC curve analyses were performed in order to obtain thresholds allowing the prediction of response. Results Forty-two patie…

Sports-related injuries in elderly men still active in sports.

1994

By means of a questionnaire with a complementary interview and physical examination, the site and nature of sports injuries were investigated over a 10-year period (1977-1987) in 97 elderly athletes (age range 70-81 years). The athletes were still active in training and competition with a mean competition background of 15 years. Of the subjects studied 30 were strength/power athletes and the remaining 67 endurance athletes. Altogether we found 273 sports-related injuries (169 acute and 104 overuse injuries). Of the injuries 75% had occurred in the lower extremities. The most commonly injured part of the body was the knee (20% of all cases). Sprains of the thigh and knee were the most freque…

Validation of a Dutch diagnostic rule for gout without joint fluid analysis in patients hospitalized for acute monoarthritis

2020

ELECTROCHEMICAL ANALYSIS ON FRICTION STIR WELDED AND LASER WELDED 6XXX ALUMINIUM ALLOYS T-JOINTS

2007

Friction Stir Welding (FSW) and Laser Welding (LW) can be successfully employed to weld aluminium alloys, in many cases overcoming the difficulties encountered with more conventional welding processes like MIG or TIG. The corrosion resistance of the welded joint remains, however, an important issue, especially in applications (like in aircrafts), where corrosion can induce structural failure: the weld region has often lower mechanical resistance in comparison with the parent material and a decrease in its corrosion resistance, especially when the corrosion damage can represent a potential crack initiation site, can be unacceptable in components design. In this work the corrosion resistance …

Experimental design of the bearing performances of flax fiber reinforced epoxy composites by a failure map

2018

Abstract This paper represents the first effort aimed to the investigation of the pin/hole contact stress and failure mechanisms of epoxy composites reinforced with woven flax fabrics, underwent to tensile bearing tests. In particular, the maximum loads and failure modes are evaluated at varying the laminate geometrical configuration. In order to optimize the use of polymer composites reinforced with flax fibers in structural applications, an experimental failure map, identifying main failure modes of mechanically fastened joints, is obtained as function of hole diameter, distance of the hole from the free edge of the laminate and laminate width. Moreover, a theoretical approach based on th…

Defect characterization in Al welded joints by non-contact Lamb wave technique

2006

Abstract The use of air-coupled sensors to detect flaws in Al welded joints and the advantage of Lamb wave for their characterization has been proved. Ultrasonic waves were generated by a pulsed laser and by contact angle-beam transducer, and received by an air-coupled capacitive transducer. Laser-based configuration was used to quickly locate the defect, whereas the angle-beam contact probe configuration to characterize it thanks to the dispersive behavior of Lamb waves. Guided waves allow inspection of the complete thickness with only one scan, permitting to detect and to size both internal and surface defects; their high flexibility in the measurement is due to the various parameters cha…

Bearing strength and failure behavior of pinned hybrid glass-flax composite laminates

2018

Abstract The aim of the present work is to evaluate the influence of external layers of glass woven fabric on the pin-hole strength of flax/epoxy laminates. Single lap bearing tests were carried out to evaluate the fastened joint performances depending on laminate stacking sequence. In order to better identify the mechanical behavior of the hybrid laminate, full glass and flax laminates were also compared. In particular, bearing stress and failure mechanisms were investigated at varying joint geometry. Furthermore, an experimental failure map, clustering main failure modes of pinned hybrid composite laminate, was used to better clarify the relationship between mechanical failure and geometr…

Evolution of the bearing failure map of pinned flax composite laminates aged in marine environment

2020

Abstract Aim of the present paper is to evaluate how the bearing behavior of pinned flax composites can be influenced by their exposition to critical environment such as marine one. To this scope, flax fibers/epoxy pinned laminate was exposed up to 60 days to salt-fog environment, according to ASTM B 117 standard. In particular, samples having different hole diameter (D), laminate width (W), and hole center to laminate free edge distance (E) have been tested under single lap bearing tests at varying the aging exposition time. Following this procedure, an experimental 2D failure map clustering main failure modes was created by placing the experimental results in the plane E/D versus W/D rati…

Experimental Characterization of the Properties of Double-Lap Needled and Hybrid Joints of Carbon/Epoxy Composites

2015

The effect of through-thickness reinforcement by thin 1 mm steel needles (z-pins) on the static tensile strength of double-lap joints of a carbon/epoxy composite was investigated. Two types of joints—z-pinned and hybrid (including glued ones)—were considered. The joints were reinforced in the overlap region with 9, 25, or 36 z-pins. Comparing mechanical properties of the double-lap joints with the corresponding characteristics of their unpinned counterparts, the z-pins were found to be highly effective: the strength and stiffness of the pinned joints increased up to 300% and 280%, respectively. These improvements were due to a transition in the failure mechanism from debonding of the joint …