Search results for "Stiffne"
showing 10 items of 533 documents
Effect of static foot posture on the dynamic stiffness of foot joints during walking
2018
Background The static foot posture has been related to the development of lower limb injuries. Research question This study aimed to investigate the dynamic stiffness of foot joints during gait in the sagittal plane to understand the role of the static foot posture in the development of injuries. Methods Seventy healthy adult male subjects with different static postures, assessed by the Foot Posture Index (FPI) (30 normal, 20 highly pronated and 20 highly supinated), were recruited. Kinematic and kinetic data were recorded using an optical motion capture system and a pressure platform, and dynamic stiffness at the different stages of the stance was calculated from the slopes of the linear r…
Dynamic Flexion Stiffness of Foot Joints During Walking
2016
Background: Dynamic stiffness can be used for studying foot pathologic abnormalities and for developing prostheses and orthoses. Although previous works have studied the role of ankle joint stiffness during gait, other foot joints have not yet been analyzed. We sought to characterize the dynamic stiffness of the ankle, midtarsal, and metatarsophalangeal joints during normal walking.Methods: Kinematics and contact data from four healthy individuals during walking were registered with a three-dimensional motion analysis system and a pressure platform. Stance phases with flexion moment-angle linear relationships were identified, and dynamic stiffnesses were calculated from the slope of their l…
Age-related neuromuscular function during drop jumps.
2007
Muscle- and movement-specific fascicle-tendon interaction affects the performance of the neuromuscular system. This interaction is unknown among elderly and consequently contributes to the lack of understanding the age-related problems on neuromuscular control. The present experiment studied the age specificity of fascicle-tendon interaction of the gastrocnemius medialis (GM) muscle in drop jump (DJ) exercises. Twelve young and thirteen elderly subjects performed maximal squat jumps and DJs with maximal rebound effort on a sledge apparatus. Ankle and knee joint angles, reaction force, and electromyography (EMG) from the soleus (Sol), GM, and tibialis anterior (TA) muscles were measured tog…
Reduced stretch reflex sensitivity and muscle stiffness after long-lasting stretch-shortening cycle exercise in humans
1998
It has been suggested that during repeated long-term stretch-shortening cycle (SSC) exercise the decreased neuromuscular function may result partly from alterations in stiffness regulation. Therefore, interaction between the short latency stretch-reflex component (M1) and muscle stiffness and their influences on muscle performance were investigated before and after long lasting SSC exercise. The test protocol included various jumps on a sledge ergometer. The interpretation of the sensitivity of the reflex was based on the measurements of the patellar reflexes and the M1 reflex components. The peak muscle stiffness was measured indirectly and calculated as a coefficient of the changes in the…
Arterial stiffness indexes in acute ischemic stroke: Relationship with stroke subtype
2010
INTRODUCTION: No study has evaluated both arterial stiffness indexes (PWV and Aix) in patients with an acute cerebrovascular event. The aim of our study was to evaluate arterial stiffness indexes in subjects with acute ischemic stroke and to evaluate the relationship between these indexes and other clinical and laboratory variables. MATERIALS AND METHODS: We enrolled all consecutive patients with a diagnosis of acute ischemic stroke admitted to the Internal Medicine Department at the University of Palermo between November 2006 and January 2009, and hospitalized control patients without a diagnosis of acute ischemic stroke. The type of acute ischemic stroke was classified according to the TO…
Do Stretch Durations Affect Muscle Mechanical and Neurophysiological Properties?
2016
International audience; The aim of the study was to determine whether stretching durations influence acute changes of mechanical and neurophysiological properties of plantar flexor muscles. Plantar flexors of 10 active males were stretched in passive conditions on an isokinetic dynamometer. Different durations of static stretching were tested in 5 randomly ordered experimental trials (1, 2, 3, 4 and 10×30-s). Fascicle stiffness index, evoked contractile properties and spinal excitability (Hmax/Mmax) were examined before (PRE), immediately after (POST0) and 5 min after (POST5) stretching. No stretch duration effect was recorded for any variable. Moreover, whatever the stretching duration, st…
Relationship between albumin excretion rate and aortic stiffness in untreated essential hypertensive patients
2004
. Objectives. To evaluate, in a group of nondiabetic essential hypertensive patients with normal renal function, the relationship between albumin excretion rate (AER) and carotid-femoral pulse wave velocity (PWV), as an index of aortic stiffness. Design. Cross-sectional study. Setting. Outpatient hypertension clinic. Subjects. Seventy patients with mild-to-moderate essential hypertension, aged 42 ± 8 years, never pharmacologically treated. All subjects underwent routine laboratory tests, 24-h ambulatory blood pressure (BP) monitoring, measurement of carotid-femoral PWV, by means of a computerized method, and AER. Results. Microalbuminuric patients (AER ≥ 20 μg min−1; n = 19), when comp…
Influence of age and sex on aortic distensibility assessed by MRI in healthy subjects
2010
International audience; Abstract: Magnetic resonance imaging (MRI) is particularly well adapted to the evaluation of aortic distensibility. The calculation of this parameter, based on the change in vessel cross-sectional area per unit change in blood pressure, requires precise delineation of the aortic wall on a series of cine-MR images. Firstly, the study consisted in validating a new automatic method to assess aortic elasticity. Secondly, aortic distensibility was studied for the ascending and descending thoracic aortas in 26 healthy subjects. Two homogeneous groups were available to evaluate the influence of sex and age (with an age limit value of 35 years). The automatic postprocessing …
Relationship of Metabolic Syndrome With Pulse Pressure in Patients With Essential Hypertension
2006
BACKGROUND: Pulse pressure is largely dependent on arterial stiffness. Recent studies have documented reduced large artery compliance in nondiabetic subjects with metabolic syndrome (MS). The aim of our study was to analyze, in a group of patients with essential hypertension and without diabetes mellitus, the influence of MS on clinic and 24-h pulse pressures. METHODS: A total of 528 hypertensive subjects, aged 18 to 72 years, who were free of cardiovascular and renal diseases were enrolled. Of the subjects, 41% had MS. In all subjects routine blood chemistry, echocardiographic examination, and 24-h ambulatory blood pressure monitoring were performed. RESULTS: When compared with subjects wi…
Ambulatory Arterial Stiffness Index (AASI) is Unable to Estimate Arterial Stiffness of Hypertensive Subjects: Role of Nocturnal Dipping of Blood Pres…
2018
BACKGROUND: Ambulatory Arterial Stiffness Index (AASI) has been proposed as an indirect and simpler method to estimate the Arterial Stiffness (AS). AASI, calculated from a set of data collected during a 24-hours ambulatory blood pressure monitoring (ABPM), is defined as 1 minus the regression slope of diastolic on systolic blood pressure (BP) values. For a given increase in diastolic BP, the increase in systolic BP is smaller in a compliant compared to a stiff artery; the stiffer the arterial tree, the closer AASI is to 1. AASI was demonstrated to predict cardiovascular mortality, cerebrovascular events and to be associated with target organ damage. Taking into account the almost complete a…