Search results for "Muscle"
showing 10 items of 3397 documents
The effect of a failure and submaximal blood flow restriction resistance exercise protocol on changes in muscle size, strength and swelling
2016
Masteroppgave i idrettsvitenskap - Universitetet i Agder 2016 Introduction: Blood flow restricted resistance exercise (BFRRE) can induce rapid increases in muscle size, strength and swelling. No previous research has investigated the importance of conducting BFRRE to voluntary failure and few studies has been carried out to investigate associations between swelling and muscle size. Therefore, the aim of the present study was twofold (1) compare changes in muscle size and strength between a failure (FA) and submaximal (SU) BFRRE protocol (2) investigate associations between swelling and muscle size. Methods: Seventeen untrained men had their legs randomized to FA and SU protocols. The interv…
DL_Track : Automated analysis of muscle architecture from B-mode ultrasonography images using deep learning
2023
B-mode ultrasound is commonly used to image musculoskeletal tissues, but one major bottleneck is data analysis. Manual analysis is commonly deployed for assessment of muscle thickness, pennation angle and fascicle length in muscle ultrasonography images. However, manual analysis is somewhat subjective, laborious and requires thorough experience. We provide an openly available algorithm (DL_Track) to automatically analyze muscle architectural parameters in ultrasonography images or videos of human lower limb muscles.
 We trained two different neural networks (classic U-net [Ronneberger et al., 2021] and U-net with VGG16 [Simonyan & Zisserman, 2015] pretrained encoder) one to detect …
How does a simulated soccer match affect regional differences in biceps femoris muscle architecture?
2017
Soccer is played by thousands of athletes across the globe and its participation increases the overall risk of injury, in particular, hamstring strain injuries (HSI). Biceps femoris (BF) has been shown to be involved the in 5 out of 6 HSI cases and risk factors including fatigue and short BF fascicle length (FL) have been identified. Furthermore, previous studies suggest that different muscle regions may undergo different strains during dynamic tasks, which could contribute to injury risk. The primary aim of this study was to evaluate the effects of a soccer match on regional differences in the BF muscle architecture. A secondary aim was to assess the reliability of the extended field of vi…
Increased Joint Mobility Is Associated With Impaired Transversus Abdominis Contraction
2022
Increased joint mobility is a risk factor for joint injury, but muscle function may be able to compensate for it. Current evidence suggests reduced force production capacity in people with hypermobility. However, little is known about the lumbar spine. The purpose of this cross-sectional study was to assess whether there was a link between joint mobility and transverse abdominis and multifidus muscles contraction, muscles ascribed a core-stability role. Using a modified quantitative version of the Beighton scale (BOM score), we measured joint mobility of 30 middle-aged individuals without low back pain. These scores were correlated with magnetic resonance imaging–derived measures of transve…
Tendon length estimates are influenced by tracking location
2022
Abstract Purpose Measurement of medial gastrocnemius (MG) tendon length using ultrasonography (US) requires the muscle–tendon junction (MTJ) to be located. Previously, the MG MTJ has been tracked from different proximo-distal locations near the MTJ, which could influence estimates of tendon length change due to the different characteristics of the aponeurosis and tendon. We used US to evaluate the effect of tracking point location on MG MTJ displacement during maximal and submaximal (10, 20 and 30% of the non-injured maximal) isometric plantar flexion contractions. Methods Displacement behaviour of MTJ was tracked from (1) the exact MTJ; and (2) from an insertion point of a muscle fascicle …
The effects on riding performance using active vs passive recovery during a simulated motocross race
2017
Aleix Ollé Casanovas. 2017. The effects on riding performance using active vs passive recovery during a simulated motocross race. University of Jyväskylä. 53p. The aim of the present study was to examine the effect of active and passive recovery methods in order to improve physical performance between motocross races. Exercise induced muscle damage post motocross racing was assessed as well. Participants performed 2 races of 30 minutes with one hour break in between. During the break they performed either active or passive recovery protocols. Specific motocross performance outcomes and athlete’s physical conditions were measured during, and before and after every motocross race. Lap times (…
Physical Performance During the Menopausal Transition and the Role of Physical Activity
2020
Abstract Background To examine longitudinal changes in physical performance during the menopausal transition and the role of physical activity (PA) in these changes. Methods Based on follicle-stimulating hormone levels and bleeding diaries, women (47–55 years) were classified as early (n = 89) and late perimenopausal (n = 143) and followed prospectively until postmenopausal status, with mean duration of 17.5 and 13.8 months, respectively. Physical performance was measured by handgrip force, knee extension torque, vertical jumping height, maximal walking speed, and 6-minute walking distance. Physical activity was self-reported and categorized as inactive, low, medium, and high. Longitudinal …
Perimenopausal women show modulation of excitatory and inhibitory neuromuscular mechanisms.
2021
Background Menopausal transition exposes women to an early decline in muscle force and motor function. Changes in muscle quality and function, especially in lower limbs, are crucial, as they expose individuals to increased risk of falls. To elucidate some of the related neuromuscular mechanisms, we investigated cortical inhibition and peripheral muscle twitch force potentiation in women during the early and late stages of perimenopause. Methods Participants were 63 women aged 48–55 years categorized as early (EP, n = 25) or late (LP, n = 38) perimenopausal according to serum follicle-stimulating hormone (FSH) levels and menstrual diaries. EP women had an irregular menstrual cycle and FSH 2…
Comparison of inter-trial recovery times for the determination of critical power and W' in cycling
2017
Critical Power (CP) and W’ are often determined using multi-day testing protocols. To investigate this cumbersome testing method, the purpose of this study was to compare the differences between the conventional use of a 24-h inter-trial recovery time with those of 3 h and 30 min for the determination of CP and W’. Methods: 9 moderately trained cyclists performed an incremental test to exhaustion to establish the power output associated with the maximum oxygen uptake (p V O2max), and 3 protocols requiring time-to-exhaustion trials at a constant work-rate performed at 80%, 100% and 105% of p VO2max. Design: Protocol A utilised 24-h inter-trial recovery (CP24/W’24), protocol B utilised 3-h in…