Medicine and Health Sciences Commons^™

Individual Responses For Muscle Activation, Repetitions, And Volume During Three Sets To Failure Of High- (80% 1rm) Versus Low-Load (30% 1rm) Forearm Flexion Resistance Exercise, Nathaniel D. M. Jenkins, Terry J. Housh, Samuel L. Buckner, Haley C. Bergstrom, Kristen C. Cochrane, Cory M. Smith, Ethan C. Hill, Richard J. Schmidt, Joel T. Cramer

Kinesiology and Health Promotion Faculty Publications

This study compared electromyographic (EMG) amplitude, the number of repetitions completed, and exercise volume during three sets to failure of high- (80% 1RM) versus low-load (30% 1RM) forearm flexion resistance exercise on a subject-by-subject basis. Fifteen men were familiarized, completed forearm flexion 1RM testing. Forty-eight to 72 h later, the subjects completed three sets to failure of dumbbell forearm flexion resistance exercise with 80% (n = 8) or 30% (n = 7) 1RM. EMG amplitude was calculated for every repetition, and the number of repetitions performed and exercise volume were recorded. During sets 1, 2, and 3, one …

Biomechanical Investigation Of Elite Place-Kicking, Chase M. Pfeifer

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Many studies aim to understand the fundamentals of kicking commonly displayed by soccer players [4,6,10,16,17,18,24,25,28,29,30,34,36,38,40]. Of those studies, most are limited to a two-dimensional (2D) analysis using high-speed cameras for position tracking or utilizing electromyography to observe the activity of select muscles [4,6,18,25,29,36]. The few studies that investigate kicking using a three-dimensional (3D) model are limited in their position tracking capabilities and focus mainly on joint flexion potentials and foot speed.

This dissertation is a comprehensive biomechanical analysis (kinematic and EMG) of the field-goal place-kicking techniques of four elite kickers in American football. Data were compared and contrasted with ball …

Impaired Regulation Post-Stroke Of Motor Unit Firing Behavior During Volitional Relaxation Of Knee Extensor Torque Assessed Using High Density Surface Emg Decomposition, Spencer A. Murphy, Reivian Berrios, P. Andrew Nelson, Francesco Negro, Dario Farina, Brian D. Schmit, Allison Hyngstrom

Physical Therapy Faculty Research and Publications

The purpose of this study was to use high density surface EMG recordings to quantify stroke-related abnormalities in motor unit firing behavior during repeated sub-maximal knee extensor contractions. A high density surface EMG system (sEMG) was used to record and extract single motor unit firing behavior in the vastus lateralis muscle of 6 individuals with chronic stroke and 8 controls during repeated sub-maximal isometric knee extension contractions. Paretic motor unit firing rates were increased with subsequent contractions (6.19±0.35 pps vs 7.89±0.66 pps, P

Transient Visual Responses Reset The Phase Of Low-Frequency Oscillations In The Skeletomotor Periphery., Daniel K Wood, Chao Gu, Brian D Corneil, Paul L Gribble, Melvyn A Goodale

Brain and Mind Institute Researchers' Publications

We recorded muscle activity from an upper limb muscle while human subjects reached towards peripheral targets. We tested the hypothesis that the transient visual response sweeps not only through the central nervous system, but also through the peripheral nervous system. Like the transient visual response in the central nervous system, stimulus-locked muscle responses (< 100 ms) were sensitive to stimulus contrast, and were temporally and spatially dissociable from voluntary orienting activity. Also, the arrival of visual responses reduced the variability of muscle activity by resetting the phase of ongoing low-frequency oscillations. This latter finding critically extends the emerging evidence that the feedforward visual sweep reduces neural variability via phase resetting. We conclude that, when sensory information is relevant to a particular effector, detailed information about the sensorimotor transformation, even from the earliest stages, is found in the peripheral nervous system.

The Effect Of Antagonist Muscle Sensory Input On Force Regulation, Tanya Onushko, Brian D. Schmit, Allison Hyngstrom

Physical Therapy Faculty Research and Publications

The purpose of this study was to understand how stretch-related sensory feedback from an antagonist muscle affects agonist muscle output at different contraction levels in healthy adults. Ten young (25.3 ± 2.4 years), healthy subjects performed constant isometric knee flexion contractions (agonist) at 6 torque levels: 5%, 10%, 15%, 20%, 30%, and 40% of their maximal voluntary contraction. For half of the trials, subjects received patellar tendon taps (antagonist sensory feedback) during the contraction. We compared error in targeted knee flexion torque and hamstring muscle activity, with and without patellar tendon tapping, across the 6 torque levels. At lower torque …

The Effect Of A Five-Week Exercise Intervention Using Emg Biofeedback On Scapular Stabilizer Muscle Activation And Scapular Kinematics., Samantha Gunderson

Scholars Week

This study investigated the effects of a five-week EMG biofeedback intervention on scapular stabilizer muscle activation, and scapular kinematics, in a healthy population. Twenty subjects participated in the study (n = 10 exercise with biofeedback, n = 10 exercise only). Both groups participated in exercises targeted at activating the serratus anterior and lower trapezius muscles three days a week for five weeks. The exercise with biofeedback group completed a biofeedback session once a week. All subjects were tested at baseline, week 6, and week 8 for muscle activation of the upper trapezius (UT), lower trapezius (UT), and serratus anterior (SA), …

Comparison Of Ballet And Modern Dance In Terms Of Kinetics, Kinematics And Muscle Activation During Landing For College Dancers, Yayoi Jones

Health and Kinesiology Theses

The dance leap is one of the most difficult techniques to accomplish, and improper landing is a common reason for injuries. The incidence of foot and ankle injuries among modern dancers is much lower than among ballet dancers. Therefore, the purpose of this study was to investigate how modern technique is different from ballet technique and the benefits each provide for both ballet and modern dancers. The primary hypothesis was that ballet dancers would demonstrate greater typical risk factors associated with foot and ankle injuries during landing compared to the modern dancers. The secondary hypothesis was that the ballet leap …

Six Weeks Habituation Of Simulated Barefoot Running Induces Neuromuscular Adaptations And Changes In Foot Strike Patterns In Female Runners, Iman Akef Khowailed, Jerrold S. Petrofsky, Everett Lohman, Noha Daher

College of Health & Human Services (TUN) Publications and Research

BACKGROUND: The aim of this study was to examine the effects of a 6-week training program of simulated barefoot running (SBR) on running kinetics in habitually shod (wearing shoes) female recreational runners.
MATERIAL AND METHODS: Twelve female runners age 25.7±3.4 years gradually increased running distance in Vibram FiveFingers minimal shoes over a 6-week period. The kinetic analysis of treadmill running at 10 Km/h was performed pre- and post-intervention in shod running, non-habituated SBR, and habituated SBR conditions. Spatiotemporal parameters, ground reaction force components, and electromyography (EMG) were measured in all conditions.
RESULTS: Post-intervention data indicated a significant …

Electromyographic Analysis Of Hip Muscle Activity During Stair Climbing: A Pilot Study, Alexander Barney, Mary Loken, Paige Torgerson, Lyndsey Wunderlich

Physical Therapy Scholarly Projects

Introduction: Prior to this study, little evidence exists for a quality predictive tool correlating maximum velocity contraction (MVC) strength of the hip abductor muscles to walking and stair climbing (ascending/descending, side-stepping) ability. Stair climbing is an important functional activity of daily living and as physical therapists we are involved in training clients to ascend/descend stairs safely, which can be difficult for clients with hip abductor muscle weakness. Subjects: Eleven females voluntarily agreed to participate in this study. All participants were under the age of 30 years old, nonpregnant, physical therapy students without a current musculoskeletal injury. Methods: …

Emg Analysis Of Latissimus Dorsi, Erector Spinae And Middle Trapezius Muscle Activity During Spinal Rotation: A Pilot Study, Jamie Flint, Toni Linneman, Rachel Pederson, Megan Storstad

Physical Therapy Scholarly Projects

Purpose/Hypothesis: Rotation of the spine, a complex movement that has yet to be fully understood, occurs regularly in activities of daily living (ADLs) and sport performance. Rotation (twisting) of the spine is a contributing factor in low back pain pathology and, by reports, has been associated with up to 60% of all back injuries. One of the largest muscles of the back, the latissimus dorsi (LD), is the only muscle to attach to the spine, pelvis, ribs, scapula, and humerus, and has the potential to impact the spine during many different activities. To date, there is limited research on …

Electromyographic Analysis Of Sit To Stand Dependent Transfers With And Without Education On Lifting Technique, Jordan Braun, Samantha Stegman, Alex Wohl

Physical Therapy Scholarly Projects

PURPOSE: The purpose of this study was to assess if there was a change in electromyography (EMG) activity in the back or leg muscles when performing a dependent sit-to-stand lift before and after a brief proper lifting intervention.

SUBJECT: The subjects in this study included 10 female third-year doctoral physical therapy students from the University of North Dakota that were all in good health with no significant pathology of either their backs or lower extremities.

INSTRUMENTATION: The EMG activity was recorded by the Noraxon ™ TeleMyo 2400R G2 transmitter and a TeleMyo 2400 SG150 unit. Knee flexion …

The Effects Of Bag Style On Muscle Activity Of The Trapezius, Erector Spinae And Latissimus Dorsi During Walking In Female University Students, R. Hardie, R. Haskew, J. Harris, Gerwyn Hughes

Kinesiology (Formerly Exercise and Sport Science)

Back pain is common in adolescents which has been associated with carrying a bag. However, there is little research examining the effects of bag style in female adolescents. The aim of the study was to investigate the effects of different bag conditions on muscle activity of the trapezius, erector spinae and latissimus dorsi muscles in female university students during walking. Twelve female university students walked on a treadmill for 5 minutes at 1.1 m/s during five conditions; control, 1 strapped rucksack, 2 strapped rucksack, ipsilateral shoulder strap and contralateral shoulder strap, each containing 10% bodyweight. Electromyography for the trapezius, erector …

Gender Difference In Lower Limb Muscle Activity During Landing And Rapid Change Of Direction, Gerwyn Hughes, N Dally

Kinesiology (Formerly Exercise and Sport Science)

Objectives: The purpose of the study was to examine gender differences in lower limb muscle activity during jump landing and rapid change of direction. Equipment and Methods: Surface electromyography (EMG) of the rectus femoris, biceps femoris and gluteus maximus were recorded for 10 male and 10 female basketball, volleyball or netball players performing five repetitions each of two tasks; 1) landing from a maximal height vertical jump and, 2) 45º rapid change of direction on their dominant leg. Independent sample t-tests were conducted to determine sex differences and paired samples t-tests were conducted to determine task differences in peak EMG …