Motor Control Commons^™

Comparing Strength Testing Measures And The Association Of Strength And Body Composition In Young Children, Abigayle R. Spong

Theses and Dissertations--Kinesiology and Health Promotion

Muscle strength is an important component of physical fitness; however, measuring it with isokinetic dynamometry (IKD) is expensive and requires dedicated space. Handheld dynamometry (HHD) provides a practical alternative for field and clinical settings. Thus, the purpose of this study was to compare peak knee flexion and extension torque measured by IKD and HHD in 37 children (ages 5-11 years) and examine relationships with body composition. Participants completed a RAMPing protocol at 90^o knee flexion consisting of two warm-up contractions at 50% and 75% effort followed by three maximal voluntary isometric contractions. Body composition was assessed via DXA scans. …

Biomechanical Effects Of Exercise-Based Interventions In Chronic Nonspecific Low Back Pain: A Systematic Review And Meta-Analysis, Lara De Vecchi Machado

Theses and Dissertations--Kinesiology and Health Promotion

Chronic nonspecific low back pain (CNLBP) is the leading cause of years lived with disability worldwide and represents a complex, multifactorial, and heterogeneous condition. It is characterized by substantial interindividual variability in muscle activation patterns, lumbo-pelvic coordination, and movement strategies. Although exercise is widely recommended as a first-line intervention and its clinical benefits are well established, the biomechanical mechanisms underlying functional improvement remain fragmented in the literature and are rarely synthesized quantitatively.

This dissertation conducted a systematic review with meta-analysis to investigate the biomechanical effects of exercise-based interventions in individuals with CNLBP. A total of 39 studies were included and …

You’Re Too Slow! Self-Selected Volitional Efforts Reveal Unexploited Neuromuscular Reserve Capacity Compared To Maximal Efforts During Fatiguing, Load Equated Resistance Exercise, Brian Benitez

Theses and Dissertations--Kinesiology and Health Promotion

This investigation examined how movement intent influences neuromuscular excitation strategies during fatiguing resistance exercise, comparing maximal intended concentric efforts versus self-selected volitional efforts during load-equated Smith machine back squat exercise to quantify reserve capacity and characterize underlying neuromuscular mechanisms. Twenty-three resistance-trained participants (12 males, 11 females) completed a repeated-measures design, with replication, across six visits, performing smith machine back squat repetitions-to-failure at 70% 1RM under maximal intent (accelerate rapidly) and volitional intent (self-selected effort) conditions. Maximal voluntary isometric contractions used rapid (instantaneous 10-second effort) and ramp (5-second build-up, 5-second maximal) protocols. Surface electromyography (sEMG) was recorded from vastus lateralis and …

Effect Of Sleep Restriction On Quadriceps’ Strength And Voluntary Activation, Scott Sigrist

Theses and Dissertations--Kinesiology and Health Promotion

Background: As little as three nights of sleep restriction reduces muscle strength. More than one-third of Americans are chronically sleep restricted (< 7.0 hours/night) and are at risk of muscle weakness (dynapenia). Presently, the mechanistic cause of sleep restriction-induced dynapenia (SRID) has not been elucidated. Rapid changes in muscle strength are typically driven by short-term changes in muscle contractility or voluntary recruitment. The purpose of this study was to investigate how sleep restriction affects muscle contractile function and voluntary recruitment. Methods: A sample of 12 subjects (age 24.8 ± 2.6y) underwent isometric and isokinetic knee extensor muscle testing following 3d of adequate sleep (SA; 8.05 ± 0.45h), 3 d of sleep restriction (SR; 5.02 ± 0.05h), and 7d of washout (WO, 8.27 ± 0.50). The morning (7-11a local time) following the last day of each sleep period, subjects performed muscle strength testing using an isokinetic dynamometer. Subjects sat upright with the dominant leg secured at 60⁰ of knee flexion to optimize maximal quadriceps torque. They then performed 3 maximal voluntary isometric contractions (MVICs) of the quadriceps. Then subjects performed 6 submaximal contractions at 15, 30, 45, 60, 75, and 90% of the greatest MVIC. Next, subjects completed an interpolated twitch experiment while on the isokinetic dynamometer to assess voluntary activation. Finally, subjects completed 5 repetitions of isometric contractions, in descending order, at speeds of 300, 240, 180, 120, and 60 degree/s. From these methods we measured the highest MVIC, calculated the voluntary activation (VA), measured twitch properties, and compared the torque-EMG relationship. One-way repeated measures ANOVA were used to compare sleep, MVIC, and VA values, two-way (time x twitch property) repeated measures ANOVA was used to compare twitch properties and the torque-EMG relationship. Results: MVIC torque decreased following SR compared to SA before and after sleep restriction (SA: 217.1 ± 69.4 Nm vs. SR: 199.4 ± 67.1 Nm, p = 0.032). MVIC after WO (219.2 ± 54.2 Nm) was significantly greater than SR (p = 0.018) but was not significantly different from SA (p = 0.991). Although peak isokinetic torque decreased with increasing velocity (p < 0.001), there was no significant effect of sleep or sleep x speed interaction. Peak twitch torque and rate of torque
development, but not relaxation rate, were significantly greater in the potentiated state, but no significant effect of sleep or sleep x time interaction was noted. Sleep 3 condition did not significantly affect voluntary activation (SA: 86.3 ± 11.1% v. SR:86.6 ± 11.9% v. WO 87.7 ± 11.1%; p = 0.695). The torque output at various levels ofelectromyography (EMG) activity was not significantly different among sleep conditions (p = 0.383). The mean power frequency (MPF) of the VL was …

Analysis Of Push-Up And Pull-Up Variants To Develop An Upper Extremity Model, Ashley Carlene Wimsett

Theses and Dissertations--Kinesiology and Health Promotion

Musculoskeletal Injuries are the most common cause of severe long-term pain and physical disability. Push-Ups and Pull-Ups are effective dynamic exercises that mimic high level function activities, such as those used in the military. The model developed allows for researchers to analyze the forces and moments associated with the shoulder, elbow and wrist, to further assess function in military personnel, athletes and the active population. The model also follows the guidelines set forth by the International Society of Biomechanics (ISB).

An Examination Of The Effects Of Bilateral And Unilateral Very Short-Term Dcer Training On Strength And Neuromuscular Responses Within The Lower Limb Bilateral Deficit, Mark Travis Byrd

Theses and Dissertations--Kinesiology and Health Promotion

The very short-term resistance training (VST) model, utilizing only 2-3 training sessions, has been used to examine early phase skeletal muscle, neural, and performance adaptations. The VST model has previously been used to examine these early phase adaptations in bilateral and unilateral, isometric, isokinetic, and dynamic muscle actions in the limbs of the upper- and lower-body. The bilateral deficit (BLD) is a phenomenon in which the sum of the forces produced unilaterally is greater than the force produced bilaterally during maximal contraction of the limbs. The appearance of a bilateral deficit has been be related to various factors; including training …

A Singer’S Stress: Yoga And Meditation Techniques In The Collegiate Voice Studio, Zackery David Morris

Theses and Dissertations--Music

Often neglected in voice study is the understanding that a singer’s instrument lives in his/her body and therefore cannot be packed away like other musical objects. Yoga and mindfulness compliment the belief of a whole body instrument. Data gathered on college campuses report that stress and anxiety are on the rise, thus reinforcing the need for MBSR and yoga as beneficial and proven tools for stress relief. The current state of research in the realm of mental health in colleges merits the study of a cohesive layout of these exercises and their expected outcomes in singing as well as stress …

Muscle Synergy During A Single Leg Standing Test In Ambulatory Children With Cerebral Palsy, Brennan L. Smith

Theses and Dissertations--Kinesiology and Health Promotion

INTRODUCTION: Cerebral Palsy (CP) is a sensorimotor disorder characterized by dysfunctional motor coordination, balance problems, and loss of selective motor control. Motor coordination exhibited as co-contraction, has been subjectively quantified using gait analysis, but recent studies have begun to objectively analyze the amount of co-contraction by collecting electromyography (EMG) data. Center of pressure excursion (COPE) measurements collected during a single leg standing test (SLST) have shown to be more valid measurements of balance in populations with motor disabilities than a SLST alone. A recent study has correlated increased COPE velocity with a lower fall risk as determined by reported fall …

Effect Of Levodopa-Carbidopa Intestinal Gel On Non-Motor Symptoms In Patients With Advanced Parkinson's Disease, David G. Standaert, Ramon L. Rodriguez, John T. Slevin, Michael Lobatz, Susan Eaton, Krai Chatamra, Maurizio F. Facheris, Coleen Hall, Kavita Sail, Yash J. Jalundhwala, Janet Benesh

Neurology Faculty Publications

Background: Levodopa-carbidopa intestinal gel (LCIG; carbidopa-levodopa enteral suspension in the United States), delivered via percutaneous gastrojejunostomy (PEG-J) and titrated in the inpatient setting, is an established treatment option for advanced Parkinson's disease (PD) patients with motor fluctuations. However, long-term prospective data on the efficacy of LCIG on non-motor symptoms and the safety of outpatient titration are limited.

Methods: In this 60-week, open-label phase 3b study, LCIG titration was initiated in an outpatient setting following PEG-J placement in PD patients. The efficacy of LCIG on motor and non-motor symptoms, quality of life, and safety was assessed.

Results: Thirty-nine patients were enrolled …

Differences In The Muscle Activity For Baseball Hitters Of Varying Skill, Ethan M. Stewart

Theses and Dissertations--Kinesiology and Health Promotion

INTRODUCTION: Muscle activity and timing of the swing phases may contribute to the differences we see in athletes at different skill levels. The purpose of this study is to analyze the differences between mean muscle activity, peak muscle active and time to peak muscle activity for select muscles in the lower extremity as well as the differences between start times for swing phases and bat velocity prior to impact for a skilled and recreational group. METHODS: Twelve healthy subjects were split into two groups based on competitive level and analyzed hitting off of a tee. RESULTS: No significant differences were …

Training Strategies And Movement Assessments In Athletes And Non-Athletes, Matthew David Lewis

Theses and Dissertations--Kinesiology and Health Promotion

This dissertation is composed of three manuscripts based on two studies related to training and assessment methods used to evaluate change and overall quality in measures of performance, postural control, and functional movement. Study one evaluated the effect of sand training on athletic performance and postural control. Study two investigated the effect of scoring strata of the deep squat (DS) component of the Functional Movement Screen (FMS) on the weight-bearing lunge test (WBLT), Star Excursion Balance Test (SEBT), and Lateral Flexion Test (LFT) in 101 male and female college students.

Study one results included significant overall improvements of the five …

Use Of A Video Game Based Balance Training Intervention On The Balance And Function Of Children With Developmental Disabilities, Gina C. Siconolfi-Morris

Theses and Dissertations--Rehabilitation Sciences

Many children with developmental disabilities (DD) have physical impairments and limitations in their participation. Rehabilitation research often focuses on either physical impairments or participation restrictions, when both need to be investigated. The purposes of these two studies were to evaluate an at home therapist directed video game balance training intervention on balance, gait velocity (GV), hip strength and activities of children with DD. The pilot study was a single-subject non-concurrent multiple baseline design. Balance measures included: weight bearing symmetry; center of pressure area and velocity; time to boundary mean minima and standard deviation; and timed up and go. The participant’s …