Search results for "SCIC"

Concentric force enhancement during human movement

2001

In order to understand the possible mechanisms contributing to enhanced concentric performance in stretch-shortening cycle exercises in vivo the present study examined knee extension torque, electromyogram (EMG) activity and fascicle length of the vastus lateralis muscle in maximal and submaximal human movements. Maximal concentric knee extensions (120 degrees s(-1)) were done after pre-stretch and pre-isometric conditions by nine volunteers. During shortening at the knee angle of 115 degrees (180 degrees = extended) the knee extension torque was found to be greater in pre-stretch condition (272 vs. 248 N m, P < 0.05) although the torque level prior to shortening was smaller than in pre-iso…

The use of ultrasound to study muscle–tendon function in human posture and locomotion

2013

Analysis of human movement has traditionally relied on measures such as kinematics, kinetics and electromyography. These measures provide valuable information about movement performance and make it possible to draw inferences about muscle and tendon function. Musculoskeletal models are also used frequently to examine the relationship between joint kinematics and muscle-tendon behaviour, and have provided important insights into both healthy and clinical gait. However, muscles interact with compliant tendons during movement, which complicates interpretation of muscle and tendon function based on external measures such as joint kinematics. Accordingly, methods have been developed that enable …

2019

Muscle architecture is an important component of muscle function, and recent studies have shown changes in muscle architecture with fatigue. The stretch-shortening cycle is a natural way to study human locomotion, but little is known about how muscle architecture is affected by this type of exercise. This study investigated potential changes in medial gastrocnemius (MG) muscle architecture after exhaustive stretch-shortening cycle exercise. Male athletes (n = 10) performed maximal voluntary contractions (MVC) and maximal drop jump (DJ) tests before and after an exercise task consisting of 100 maximal DJs followed by successive rebound jumping to 70% of the initial maximal height. The exerci…

G.P.232

2014

Spinal muscular atrophy (SMA) and Pompe disease (PD) are common neuromuscular disorders during childhood causing progressive weakness of proximal muscles with gait disturbances, loss of ambulation and breathing difficulties. Whereas SMA is the result of a neurogenic atrophy caused by mutations in the SMN1 gene, PD is a lysosomal glycogen storage disease (type II) due to mutations of the GAA gene responsible for the enzyme activity of acid alpha-1,4-glucosidase. PD is treatable by enzyme replacement therapy, but in SMA there is no established curable therapy. We report on a child with genetically proven SMA type III and PD caused by mutations in the SMN1 and GAA genes. A 3 years old girl pre…

Sterol Regulatory Element Binding Transcription Factor-1 Gene Variation and Medication Load Influence White Matter Structure in Schizophrenia

2014

&lt;b&gt;&lt;i&gt;Background:&lt;/i&gt;&lt;/b&gt; Diffusion tensor imaging (DTI) studies have shown a widespread disruption of white matter (WM) microstructure in schizophrenia. Furthermore, higher fractional anisotropy (FA) has been consistently correlated with the severity of psychotic symptoms. Antipsychotic drugs (APDs) affect lipid homeostasis. Gene polymorphisms in sterol regulatory element binding transcription factor (SREBF)-1 and SREBF-2 have been associated with schizophrenia. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; In a sample of 65 patients affected by chronic schizophrenia, we investigated the effect of ongoing APD medication, SREBF-1 rs11868035&lt;b&gt; &lt;/b&gt;polymo…

REGIONAL DIFFERENCES IN BICEPS FEMORIS FASCICLE LENGTH AND PENNATION ANGLE AFTER A SIMULATED SOCCER MATCH

2017

Background Hamstring Strain Injuries (HSIs) represent 12% of all injuries in soccer players, and their incidence has increased in recent years. Between 53%-84% of HSIs involve the Biceps femoris muscle (BF). Recent studies have shown that soccer players with shorter BF fascicle length (FL) suffer more HSIs and exhibit regional differences in FL and pennation angle (PA) along BF. It is unclear whether there is any regional difference in the degree of change of these parameters after a soccer match. Objective Describe changes in BF muscle architecture after a simulated soccer match. Design Controlled laboratory study. Pre and Post single session. Setting Laboratory. Amateur Level. Participant…

Physical activity predicts population-level age-related differences in frontal white matter

2018

AbstractPhysical activity has positive effects on brain health and cognitive function throughout the lifespan. Thus far, few studies have examined the effects of physical activity on white matter (WM) microstructure and psychomotor speed within the same, population-based sample (critical if conclusions are to extend to the wider population). Here, using diffusion tensor imaging and a simple reaction time task within a relatively large population-derived sample (N = 399; 18–87 years) from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN), we demonstrate that physical activity mediates the effect of age on white matter integrity, measured with fractional anisotropy. Higher self-repor…

La messa alla prova dopo il dictum della Consulta: indenne ma rivisitata e in attesa di nuove censure

2019

Con la sentenza n. 91 del 2018, la Consulta ha avuto modo di offrire una rivisitazione "ad ampio spettro" dell'istituto della sospensione del procedimento con messa alla prova, affrontandone diversi aspetti fondamentali. La pronuncia - pur esprimendosi in termini di inammissibilità o di infondatezza delle questioni sollevate - può essere considerata un importante spartiacque nell'elaborazione ermeneutica della fattispecie, risolvendo alcuni problemi interpretativi e, al contempo, ponendone in luce di nuovi.

Triceps surae fascicle stretch is poorly correlated with short latency stretch reflex size

2015

Introduction: The short latency stretch reflex (SLR) is well described, but the stimulus that evokes the SLR remains elusive. One hypothesis states that reflex size is proportional to muscle fiber stretch, so this study examined the relationship between these 2 parameters in human triceps surae muscles. Methods: Achilles tendon taps and dorsiflexion stretches with different amplitudes and preactivation torques were applied to 6 participants while electromyography and muscle fascicle length changes were recorded in soleus and medial gastrocnemius (MG). Results: In response to tendon taps, neither fascicle length nor velocity changes were correlated with SLR size in either muscle, but acceler…

Effects of muscle activation on shear between human soleus and gastrocnemius muscles

2015

Lateral connections between muscles provide pathways for myofascial force transmission. To elucidate whether these pathways have functional roles in vivo, we examined whether activation could alter the shear between the soleus (SOL) and lateral gastrocnemius (LG) muscles. We hypothesized that selective activation of LG would decrease the stretch-induced shear between LG and SOL. Eleven volunteers underwent a series of knee joint manipulations where plantar flexion force, LG, and SOL muscle fascicle lengths and relative displacement of aponeuroses between the muscles were obtained. Data during a passive full range of motion were recorded, followed by 20° knee extension stretches in both pass…