Search results for " Muscle"
showing 10 items of 1495 documents
Acute Neuromuscular Adaptations in Response to Low-Intensity Blood-Flow Restricted Exercise and High-Intensity Resistance Exercise: Are There Any Dif…
2018
Fatela, P, Reis, JF, Mendonca, GV, Freitas, T, Valamatos, MJ, Avela, J, and Mil-Homens, P. Acute neuromuscular adaptations in response to low-intensity blood flow restricted exercise and high-intensity resistance exercise: are there any differences? J Strength Cond Res 32(4): 902-910, 2018-Numerous studies have reported similar neuromuscular adaptations between low-intensity (LI) blood-flow restricted exercise (BFRE) and high-intensity (HI) resistance training. Unfortunately, none of these experimental designs individualized blood flow restriction (BFR) levels to each participant. Thus, their findings are difficult to interpret. We aimed at comparing the acute effects of LI BFR (80% of abso…
Masticatory muscle activity evaluation by electromyography in subjects with zygomatic implants
2017
Background Zygomatic implants are an alternative treatment in the rehabilitation of atrophic maxilla to promote stability in the stomatognathic system. The aim of this study was to compare the electromyographic (EMG) activity of masseter and temporalis muscles in controls and in individuals with complete implant-supported dentures anchored in the zygomatic bone. Material and Methods Fifty-four volunteers of both genders (mean age 52.5 years) were selected and distributed into two groups: Individuals with zygomatic implant (ZIG; n=27) and fully dentate patients (CG; n=27). MyoSystem-BR1 was used to assess masseter and temporalis muscles EMG activity in different mandibular movements: protrus…
Modulation of spinal cord excitability by subthreshold repetitive transcranial magnetic stimulation of the primary motor cortex in humans.
2001
Repetitive transcranial magnetic stimulation (rTMS) allows the modulation of intra-cortical excitability and may therefore affect the descending control of spinal excitability. We applied rTMS at subthreshold intensity and 1 Hz frequency for 10 min to the left primary motor cortex representation of the flexor carpi radialis muscle (FCR) in 10 subjects and assessed the H and M responses to median nerve stimulation before and after the rTMS. Following rTMS, H wave thresholds significantly reduced by ∼20%. Maximal H but not M wave amplitude significantly increased over the baseline, so that H/M amplitude ratio was increased by 41%. Sham stimulation did not induce any noticeable change in M or …
The efficacy of acupuncture and decompression splints in the treatment of temporomandibular joint pain-dysfunction syndrome
2012
Objectives: The goal of the present study was to evaluate the results of applying acupuncture or occlusal decompression splints in the treatment of patients diagnosed with the temporomandibular joint pain-dysfunction syndrome. Design of the study: We conducted a randomized clinical trial including 20 patients to whom the mentioned treatments were applied. Results were evaluated through an analogue pain scale, measurements of mouth opening and jaw lateral deviation in millimetres, and assessment of sensitivity to pressure on different points: preauricular, masseter muscle, temporal muscle and trapezius. Parameters were evaluated before and 30 days after the treatment. For standardized pressu…
Age-related differences in Achilles tendon properties and triceps surae muscle architecture in vivo
2012
This study examined the concurrent age-related differences in muscle and tendon structure and properties. Achilles tendon morphology and mechanical properties and triceps surae muscle architecture were measured from 100 subjects [33 young (24 ± 2 yr) and 67 old (75 ± 3 yr)]. Motion analysis-assisted ultrasonography was used to determine tendon stiffness, Young's modulus, and hysteresis during isometric ramp contractions. Ultrasonography was used to measure muscle architectural features and size and tendon cross-sectional area. Older participants had 17% lower ( P < 0.01) Achilles tendon stiffness and 32% lower ( P < 0.001) Young's modulus than young participants. Tendon cross-section…
Which muscles compromise human locomotor performance with age?
2014
Ageing leads to a progressive decline in human locomotor performance. However, it is not known whether this decline results from reduced joint moment and power generation of all lower limb muscle groups or just some of them. To further our understanding of age-related locomotor decline, we compare the amounts of joint moments and powers generated by lower limb muscles during walking (self-selected), running (4 m s −1 ) and sprinting (maximal speed) among young, middle-aged and old adults. We find that age-related deficit in ankle plantarflexor moment and power generation becomes more severe as locomotion change from walking to running to sprinting. As a result, old adults generate more pow…
In vivo muscle mechanics during locomotion depend on movement amplitude and contraction intensity
2001
The effects of movement amplitude and contraction intensity on triceps surae and quadriceps femoris muscle function were studied during repetitive hopping. In vivo forces from Achilles and patellar tendons were recorded with the optic fibre technique from eight volunteers. The performances were filmed (200 Hz) to determine changes in muscle-tendon unit length and velocity. When hopping with a small amplitude (23 degrees knee flexion during the ground contact phase), the Achilles tendon was primarily loaded whereas patellar tendon forces were greater in large-amplitude hopping (56 degrees knee flexion). In spite of the different magnitudes of stretch in the quadriceps femoris muscle, the str…
In vivo achilles tendon loading' during jumping in humans
1995
Elastic behaviour of the human tendomuscular system during jumping was investigated by determination of the in vivo Achilles tendon force. A buckle-type transducer was implanted under local anaesthesia around the right Achilles tendon of an adult subject. After calibration, the Achilles tendon force was recorded together with the triceps surae muscle electromyogram activity and high speed filming and ground reaction force during: a maximal vertical jump from a squat position, a maximal vertical jump from an erect standing position with a preliminary counter-movement, and repetitive submaximal hopping on the spot. Jumping heights were 33, 40 and 7 cm in the squat, the counter movement, and t…
Neutral Spine Control Exercises in Rehabilitation After Lumbar Spine Fusion
2014
Lumbar spine fusion (LSF) has been reported to change the biomechanics of the spine and therefore the rehabilitation after LSF is important. In this study, the effect of selected neutral spine control exercises on activation of trunk muscles after LSF was evaluated. Muscle activity was measured by surface electromyography of the rectus abdominis, external oblique, longissimus, and multifidus muscles during 6 exercises in 22 LSF patients (mean age = 59 years; age range = 25-84 years; 50% women). Muscle activity concurrent with trunk flexion and extension during maximal voluntary isometric contraction (MVIC) was used as a reference value. Pain during the effort was assessed with a visual anal…
Persistent unilateral tibialis anterior muscle hypertrophy with complex repetitive discharges and myalgia
1992
Unilateral enlargement of the tibialis anterior muscle associated with complex repetitive discharges occurred over several months in two patients and was preceded by pain and numbness in the lower leg. Neuroradiologic investigations excluded a compressive radiculopathy, but pharmacologic and neurophysiologic studies suggested a neurogenic basis for the muscle hypertrophy. Botulinum toxin A injection into the hypertrophied muscles led to a decreased muscle volume and cessation of muscle pain.