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Full-Text Articles in Medicine and Health Sciences
Measures Of Center Of Pressure And Lower Leg Muscle Electromyography During Landing Before And After Plantar Flexor Stretch, Connor Hill, Brittany Coltrain, Michael Olson
Measures Of Center Of Pressure And Lower Leg Muscle Electromyography During Landing Before And After Plantar Flexor Stretch, Connor Hill, Brittany Coltrain, Michael Olson
International Journal of Exercise Science: Conference Proceedings
Static stretching of the plantar flexor muscles is reported to modify neuromuscular responses to external stimuli. However, it is not known how these muscles respond to external loading in an applied task, such as single-leg drops. Further, if mechanical laxity in the plantar flexor muscles is present after stretching of it is unclear how this laxity will influence the muscle activation and movement patterns of the lower extremities. PURPOSE: This study is intended to further explore the response of the lower extremities to plantar flexor muscle stretch in an effort to understand its impact on potential injury. METHODS: …
Modified Torque Output And Lower Leg Muscle Electromyography After Passive Stretching, Brittany Coltrain, Connor Hill, Michael W. Olson
Modified Torque Output And Lower Leg Muscle Electromyography After Passive Stretching, Brittany Coltrain, Connor Hill, Michael W. Olson
International Journal of Exercise Science: Conference Proceedings
Increased stretch of the plantar flexor muscles is reported to increase tissue laxity of the tendons and reduces force output, but in other studies the tendon biomechanical properties are not affected and force output is not changed after stretch. PURPOSE: To examine the force output and muscle electromyography activity of lower leg muscles to a prolonged passive stretch. METHODS: Five participants (20.6 ± 1.1 yrs: 1.78 ± 0.1 m:, 80.6 ± 9.9 kg) performed maximal plantar and dorsi flexion isometrically while secured to an isokinetic dynamometer. They were seated upright with ~90 deg hip flexion. The knee was …
Effects Of Low-Intensity Fatigue On Motor Unit Firing Properties During Maximal Voluntary Isometric Contractions, Lyric Richardson, Amy Riera, Emma Bozarth, Micheal Luera
Effects Of Low-Intensity Fatigue On Motor Unit Firing Properties During Maximal Voluntary Isometric Contractions, Lyric Richardson, Amy Riera, Emma Bozarth, Micheal Luera
International Journal of Exercise Science: Conference Proceedings
Rehabilitation from injuries impairing the neuromuscular system is often difficult to quantify due to task specificity of the affected or immobilized limb or limbs. Often, exercise regimens with clinical practitioners are designed to progress motor performance to a capacity that reflects muscle force production to pre-injury capacity. Modulation of force production from these tasks are regulated from various mechanism in the central and peripheral nervous system. The neural activation of these systems can be recorded as electrical impulses using several non-invasive techniques. Recently, the ability to examine these during fatiguing exercise has provided further insight into activation patterns and firing …
Electromyographic Analysis Of The Vastus Lateralis And Vastus Medialis Muscles Among Different Crank Lengths In Cycling, Jackson C. Crovella, Karoline M. Wucherer, Joy He, Christiane R. O'Hara
Electromyographic Analysis Of The Vastus Lateralis And Vastus Medialis Muscles Among Different Crank Lengths In Cycling, Jackson C. Crovella, Karoline M. Wucherer, Joy He, Christiane R. O'Hara
International Journal of Exercise Science: Conference Proceedings
Crank length (CL) on a bicycle may influence the total activation and period of activation of the leg muscles. Differences in total muscular activation suggest that CL may alter muscular fatigue. Differences in muscular onset and offset suggest that CL may shift muscle activation periods across a 360 degree crank cycle. PURPOSE: To examine the effects of four different CL (155, 165, 175, and 185 mm) on muscular activation of vastus lateralis (VL) and vastus medialis (VM). METHODS: Nine non-cyclists (6M, 3F, aged 18-55) participated in a single blind randomized cross-over experiment with four CL. Delsys EMG sensors …
A Comparison Of Techniques For Decomposing Surface Electromyography Signals During High-Intensity Contractions A Preliminary Analysis, Lyric Richardson, Micheal Luera, Jocarol Shields, Rob Maclennen, Michael Trevino, Alessandro Delvecchio, Jason Defritas
A Comparison Of Techniques For Decomposing Surface Electromyography Signals During High-Intensity Contractions A Preliminary Analysis, Lyric Richardson, Micheal Luera, Jocarol Shields, Rob Maclennen, Michael Trevino, Alessandro Delvecchio, Jason Defritas
International Journal of Exercise Science: Conference Proceedings
Advancements in surface electromyography (sEMG) have led to discrepancies in identification of high-threshold motor units (MU) following signal decomposition PURPOSE: To examine the differences in MU firing behaviors recorded from two separate sEMG sensors following respective decomposition analysis. METHODS: Following 2 maximal voluntary contractions (MVC), ten (23 ± 3 yrs.; 178.64 ± 5.82 cm; 177.8 ± 17.37 kg) lower body resistance trained males performed a 10 sec submaximal (50%) isometric ramp contraction of the knee extension exercise. Signals were recorded from the vastus lateralis and separately decomposed into their constituent MU action potential trains, then further validated for subsequent analysis …
The Effects Of Two Post-Activation Potentiation Methods On Muscular Activation, Ileana A. Jarquin, Samuel Montalvo, Daniel Conde, Gabriel Ibarra-Mejia, Sandor Dorgo
The Effects Of Two Post-Activation Potentiation Methods On Muscular Activation, Ileana A. Jarquin, Samuel Montalvo, Daniel Conde, Gabriel Ibarra-Mejia, Sandor Dorgo
International Journal of Exercise Science: Conference Proceedings
Post Activation Potentiation (PAP) is an exercise concept based on utilizing a maximal voluntary contraction of the muscles at task to potentiate a dynamic muscular contraction of the same muscles. It is well established that PAP is modulated between performance readiness and muscular fatigue. Heart Rate percentage (HR%) has been used as an indicator of performance readiness and muscular fatigue. PURPOSE: To examine different muscular activation (μV) in response to two different PAP protocols during the vertical jump exercise. METHODS: 8 participants (5 males and 3 females; mean ± SD: Age = 22.6 ± 1.76 years; Height …