1,471 research outputs found
Assessment in mathematics: A multimedia resource for preservice teachers
It is commonly accepted that teachers teach the way they were taught and that innovation is difficult to achieve. In this project, the theoretical framework of situated cognition or situated learning has been used to design an interactive multimedia resource that allows preservice teachers to become aware of different assessment strategies in mathematics education, and how to apply them. The resource enables users to encounter the authentic use of a range of assessment strategies and to view their interpretations from multiple perspectives which include the teacher's decision-making processes, the child's thinking, expert opinion and written documentation
An EPR investigation of the dynamic Jahn-Teller effect in SrCl2-La/2 plus/
Second-order solutions of Hamiltonian functions for EPR study of Jahn-Teller effect in SrCl2-La/2 plus
Does the Powersâ„¢ strap influence the lower limb biomechanics during running?
Previous research has reported a prevalence of running related injuries in 25.9% to 72% of all runners. A greater hip internal rotation and adduction during the stance phase in running has been associated with many running related injuries, such as patellofemoral pain. Researchers
in the USA designed a treatment device 'the PowersTM strap' to facilitate an external rotation of the femur and to thereby control abnormal hip and knee motion during leisure and sport activities. However, to date no
literature exists to demonstrate whether the PowersTM strap is able to reduce hip internal rotation during running.
22 healthy participants, 11 males and 11 females (age: 27.45 ±4.43 years, height: 1.73 ± 0.06m, mass: 66.77 ±9.24kg) were asked to run on a 22m track under two conditions: without and with the PowersTM strap. Threedimensional motion analysis was conducted using ten Qualisys OQUS 7 cameras (Qualisys AB, Sweden) and force data was captured with three AMTI force plates (BP600900, Advanced Mechanical Technology, Inc.USA). Paired sample t-tests were performed at the 95% confidence interval on all lower limb kinematic and kinetic data.
The PowersTM strap significantly reduced hip and knee internal rotation throughout the stance phase of running. These results showed that the PowersTM strap has the potential to influence hip motion during running
related activities, in doing so this might be beneficial for patients with lower limb injuries. Future research should investigate the influence of the PowersTM strap in subjects who suffer from running related injuries, such as patellofemoral pain
Influence of the Powersâ„¢ strap on pain and lower limb biomechanics in individuals with patellofemoral pain
Background: Abnormal biomechanics, especially hip internal rotation and adduction are known to be associated with patellofemoral pain (PFP). The PowersTM strap was designed to decrease hip internal rotation and to thereby stabilise the patellofemoral joint.
Objectives: This study aimed to investigate whether the PowersTM strap influenced pain and lower limb biomechanics during running and squatting in individuals with PFP.
Methods: 24 individuals with PFP were recruited using advertisements that were placed at fitness centres. They were asked to perform a single leg squat task (SLS) and to run on an indoor track at their own selected speed during two conditions: with and without the PowersTM strap. Immediate pain was assessed with the numeric pain rating scale. Three-dimensional motion and ground reaction force data were collected with 10 Qualisys cameras and 3 AMTI force plates.
Results: Immediate pain was significantly reduced with the PowersTM strap (without the PowersTM strap: 4.04±1.91; with the PowersTM strap: 1.93±2.13). The PowersTM strap condition significantly increased hip external rotation by 4.7° during the stance phase in running and by 2.5° during the single leg squat task. Furthermore, the external knee adduction moment during the SLS and running increased significantly.
Conclusion: This study assessed the effect of the PowersTM strap on lower limbs kinematics and kinetics in individual with PFP. The results suggest that the PowersTM strap has the potential to improve abnormal hip motion. Furthermore, the PowersTM strap demonstrated an ability to significantly reduce pain during functional tasks in patients with PFP
How does acute pain influence biomechanics and quadriceps function in individuals with patellofemoral pain?
Objectives:
Beside pathophysiological factors, pain is believed to play a crucial role in the progression of patellofemoral pain (PFP). However, the isolated effect of pain on biomechanics and quadriceps function has not been investigated in PFP. Thus, this study aimed to investigate the effect of pain on quadriceps function and lower limb biomechanics in individuals with PFP.
Methods:
Twenty-one individuals with PFP (11 males and 10 females, age: 29.76 ±6.36 years, height: 1.74 ± 0.09m, mass: 70.12 ±8.56kg) were measured at two different occasions: when not and when experiencing acute pain. Peak quadriceps torque (concentric, eccentric and isometric) and arthrogenic muscle inhibition (AMI) was assessed. Three-dimensional motion analysis and surface electromyography of the quadriceps and hamstrings muscles were collected during running, a single-leg-squat and step-down task. The normality was assessed using the Shapiro-Wilk test and a MANOVA was performed at the 95% confidence interval.
Results:
AMI increased significantly in acute pain. The net muscle activation of the knee extensors and flexors decreased during running in acute pain. The lower limb biomechanics and the quadriceps torque did not change in acute pain.
Discussion:
It appears that even if individuals with PFP experience pain they can still deliver maximal quadriceps contractions and maintain their moving patterns without biomechanical changes. However, the overall reduced activation of the quadriceps and the increased AMI indicate the presence of quadriceps inhibition in acute pain.
Key words: patellofemoral pain, knee, PFP, AKP, inhibition, quadriceps, strength, pai
Critical elements in nonsulphide Zn deposits: A reanalysis of the Kabwe Zn-Pb ores (central Zambia)
The Kabwe Zn-Pb deposit (central Zambia) consists of a cluster of mixed sulfide and non-sulfide orebodies. The sulfide ores comprise sphalerite, galena, pyrite, chalcopyrite and accessory Ge-sulfides (±Ga and In). The non-sulfide ores comprise: (1) willemite-dominated zones encasing massive sulfide orebodies and (2) oxide-dominated alteration bands, overlying both the sulfide and Zn-silicate orebodies. This study focuses on the Ge, In and Ga distribution in the non-sulfide mineralization, and was carried out on a suite of Kabwe specimens, housed in the Natural History Museum Ore Collection (London). Petrography confirmed that the original sulfides were overprinted by at least two contrasting oxidation stages dominated by the formation of willemite (W1 and W2), and a further event characterized by weathering-related processes. Oxygen isotopic analyses have shown that W1 and W2 are unrelated genetically and furthermore not related to supergene Zn-Pb-carbonates in the oxide-dominated assemblage. The δ18O composition of 13.9-15.7‰ V-SMOW strongly supports a hydrothermal origin for W1. The δ18O composition of W2 (-3.5‰ to 0‰ V-SMOW) indicates that it precipitated from groundwaters of meteoric origin in either a supergene or a low-T hydrothermal environment. Gallium and Ge show a diversity of distribution among the range of Zn-bearing minerals. Gallium has been detected at the ppm level in W1, sphalerite, goethite and hematite. Germanium occurs at ppm levels in W1 and W2, and in scarcely detectable amounts in hemimorphite, goethite and hematite. Indium has low concentrations in goethite and hematite. These different deportments among the various phases are probably due to the different initial Ga, In and Ge abundances in the mineralization, to the different solubilities of the three elements at different temperatures and pH values, and finally to their variable affinities with the various minerals formed
Concurrent validity of two-dimensional video analysis of lower-extremity frontal plane of movement during multidirectional single-leg landing
Objectives: Establish the concurrent validity between 2D video analysis and 3D motion analysis of frontal plane lower limb movements during multidirectional landing tasks.
Design: Correlation study
Setting: University Biomechanics laboratory
Participants: 34 (19 male, 15 female) uninjured physical active individuals
Main outcome measures: knee abduction and hip adduction angles during a variety of single leg landing tasks.
Results: 2D knee abduction showed an association with 3D knee abduction angle ranging from r = 0.17-0.42 across the tasks, with r² values ranging between 0.03-0.17. 2D hip adduction angle in both legs reported a strong and significant correlation with 3D hip adduction angle, ranging from r = 0.70-0.90 across all tasks. Linear regression analysis (r²) revealed that 49–81% of 3D hip adduction angle can be explained by 2D measurement.
Conclusion: It might be difficult to explain 3D knee abduction angle using 2D video analysis during single leg landing tasks, whereas 2D hip adduction angle is a strong predictor or 3D hip adduction angle. It would appear 2D video analysis has strong concurrent validity when assessing hip adduction angle, but it is weak when assessing knee abduction angle during a variety of single leg landing tasks
Frontal plane projection angle predicts patellofemoral pain: prospective study in male military cadets
Background: Patellofemoral pain (PFP) is a major source of knee pain. Identifying who may develop PFP is of paramount importance.
Purpose: To assess whether Frontal plane projection angles (FPPA) and hand held dynamometry (HHD) strength measures can predict development of PFP
Study Design: Prospective evaluation of individuals undertaking a military training programme
Methods: Male military recruits were enrolled and prospectively followed up from enrolment to completion of 12-weeks training. Lower limb kinematics (FPPA, Q-angle, hip adduction angle, knee flexion, ankle dorsiflexion, and rearfoot eversion angle) measured during running, single leg squatting (SLS), and single leg landing (SLL) and isometric muscle strength of hip abductors and knee extensors.
Results: Body mass, hip abductor muscle strength, Q-angle during SLS and SLL, FPPA during SLL all significantly different between the PFP and non-injured groups and predicted PFP, highest predictor variable was FPPA during SLL (Odds Ratio=1.13, P=0.01). A FPPA≥5.2° during SLL predicting PFP with a sensitivity of 70% and a specificity of 70%.
Conclusion: Participants who developed PFP had a number of physical factors significantly different than the non-injured group, most predictive was a larger FPPA during SLL, with angles greater than 5.2° associated with a 2.2x greater risk
Randomized multicentre pilot study of sacubitril/valsartan versus irbesartan in patients with chronic kidney disease: United Kingdom Heart and Renal Protection (HARP)- III—rationale, trial design and baseline data
BACKGROUND:
Patients with chronic kidney disease (CKD) are at risk of progression to end-stage renal disease and cardiovascular disease. Data from other populations and animal experiments suggest that neprilysin inhibition (which augments the natriuretic peptide system) may reduce these risks, but clinical trials among patients with CKD are required to test this hypothesis.
METHODS:
UK Heart and Renal Protection III (HARP-III) is a multicentre, double-blind, randomized controlled trial comparing sacubitril/valsartan 97/103 mg two times daily (an angiotensin receptor-neprilysin inhibitor) with irbesartan 300 mg one time daily among 414 patients with CKD. Patients ≥18 years of age with an estimated glomerular filtration rate (eGFR) of ≥45 but <60 mL/min/1.73 m2 and urine albumin:creatinine ratio (uACR) >20 mg/mmol or eGFR ≥20 but <45 mL/min/1.73 m2 (regardless of uACR) were invited to be screened. Following a 4- to 7-week pre-randomization single-blind placebo run-in phase (during which any current renin-angiotensin system inhibitors were stopped), willing and eligible participants were randomly assigned either sacubitril/valsartan or irbesartan and followed-up for 12 months. The primary aim was to compare the effects of sacubitril/valsartan and irbesartan on measured GFR after 12 months of therapy. Important secondary outcomes include effects on albuminuria, change in eGFR over time and the safety and tolerability of sacubitril/valsartan in CKD.
RESULTS:
Between November 2014 and January 2016, 620 patients attended a screening visit and 566 (91%) entered the pre-randomization run-in phase. Of these, 414 (73%) participants were randomized (mean age 63 years; 72% male). The mean eGFR was 34.0 mL/min/1.73 m2 and the median uACR was 58.5 mg/mmol.
CONCLUSIONS:
UK HARP-III will provide important information on the short-term effects of sacubitril/valsartan on renal function, tolerability and safety among patients with CKD
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