Acute effects of suspension training and other perturbative sources on lower limb strength tasks

Actualment, els dispositius de suspensió són un dels materials més utilitzats per produir pertorbació i enfortir de forma global la majoria de grups musculars. Encara que, manquen evidències dels seus efectes sobre l’extremitat inferior. Així, l’objectiu principal d’aquesta tesi doctoral va ser quantificar la producció de força, l’activitat muscular i la magnitud de la pertorbació a l’esquat búlgar i altres exercicis de l’extremitat inferior en condicions d’inestabilitat. Es van analitzar 18 estudis per dur a terme una revisió sistemàtica (estudi 1) i 75 participants físicament actius van ser reclutats per realitzar els diferents estudis transversals sobre els efectes dels dispositius de suspensió, les superfícies inestables i les vibracions mecàniques (plataforma vibratòria i vibració superposada) en exercicis de l’extremitat inferior (estudis 2-6). Es va confirmar que l’activació a la part inferior del cos només va ser investigada en el concentrat d’isquiosurals en suspensió (estudi 1). La posició i el ritme d’execució (70 bpm) van ser determinants per la producció de força exercida sobre el tirant de suspensió a l’esquat búlgar (estudi 2). El dispositiu de suspensió a l’esquat búlgar va augmentar les forces verticals contra el terra (estudi 3). Sobre el dispositiu la producció de força va ser major quan el nivell d’inestabilitat era baix (estudi 3 i 4), però a nivell muscular el dispositiu va ser igual de demandant que l’exercici tradicional (estudi 3). Un augment de la pertorbació, va incrementar l’activació muscular (estudis 3, 4, 5) i la magnitud de la inestabilitat per l’esquat búlgar i el mig squat amb barra (estudis 4 i 5). Així, la vibració superposada en un dispositiu de suspensió esdevé un repte per incrementar el nivell de pertorbació i millorar la força, la resistència muscular i l’estabilització (estudi 6). A més, els sensors de força són una eina adequada i usable per valorar les forces exercides sobre els dispositius de suspensió, i l’ús de l’acceleròmetre permet determinar la magnitud de la pertorbació que ofereixen els diferents materials desestabilitzadors mesurant l’acceleració del centre de masses corporal.Actualmente, los dispositivos de suspensión son uno de los materiales más utilizados para producir perturbación y fortalecer globalmente la mayoría de los músculos. Aunque, faltan evidencias de sus efectos sobre la extremidad inferior. Así, el objetivo principal de esta tesis doctoral fue cuantificar la producción de fuerza, la actividad muscular y la magnitud de la perturbación en la sentadilla búlgara y otros ejercicios de la extremidad inferior en condiciones de inestabilidad. Se analizaron 18 estudios para llevar a cabo una revisión sistemática (estudio 1) y 75 participantes físicamente activos fueron reclutados para realizar los diferentes estudios transversales sobre los efectos de los dispositivos de suspensión, las superficies inestables y las vibraciones mecánicas (plataforma vibratoria y vibración superpuesta) en ejercicios de la extremidad inferior (estudios 2-6). Se confirmó que la activación en la parte inferior del cuerpo sólo fue investigada en el concentrado de isquiosurales en suspensión (estudio 1). La posición y el ritmo de ejecución (70 bpm) fueron determinantes para la producción de fuerza ejercida sobre el tirante de suspensión en la sentadilla búlgara (estudio 2). El dispositivo de suspensión en la sentadilla búlgara aumentó las fuerzas verticales contra el suelo (estudio 3). Sobre el dispositivo la producción de fuerza fue mayor cuando el nivel de inestabilidad era bajo (estudio 3 y 4), pero a nivel muscular el dispositivo fue igual de demandante que el ejercicio tradicional (estudio 3). Un aumento de la perturbación incrementó la activación muscular (estudios 3, 4, 5) y la magnitud de la inestabilidad en la sentadilla búlgara y la media sentadilla con barra (estudios 4 y 5). Así, la vibración superpuesta en un dispositivo de suspensión se convierte en un reto para incrementar el nivel de perturbación y mejorar la fuerza, la resistencia muscular y la estabilización (estudio 6). Además, los sensores de fuerza son una herramienta adecuada y usable para valorar las fuerzas ejercidas sobre los dispositivos de suspensión, y el uso del acelerómetro permite determinar la magnitud de la perturbación que ofrecen los diferentes materiales desestabilizadores midiendo la aceleración del centro de masas corporal.Nowadays, suspension devices are one of the most widely used pieces of equipment to produce perturbation and strengthen most muscle groups globally. However, there is a lack of evidence of their effects on the lower limb. Thus, the main objective of this doctoral thesis was to quantify force production, muscle activity and the magnitude of perturbation in the Bulgarian squat and other lower extremity exercises under unstable conditions. Eighteen studies were analysed for a systematic review (study 1) and 75 physically active participants were recruited to perform the different cross-sectional studies on the effects of suspension devices, unstable surfaces, and mechanical vibrations (vibration platform and superimposed vibration) on lower limb exercises (studies 2-6). It was confirmed that lower body activation had only been previously investigated in the suspended hamstring curl (study 1). Position and pace (70 bpm) were determinants for the force exerted on the suspension strap in the Bulgarian squat (study 2). The suspension device in the Bulgarian squat increased the vertical ground reaction forces (study 3). The force production was higher on the device when the level of instability was low (study 3 and 4), but for muscle activity the device was just as demanding as a traditional exercise (study 3). Increased perturbation enhanced muscle activation (studies 3, 4, 5) and the magnitude of instability in the Bulgarian squat and barbell half-squat (studies 4 and 5). Thus, superimposed vibration on a suspension device becomes a challenge to increase the level of perturbation and improve strength, muscular endurance, and stabilisation (study 6). In addition, load cells are a suitable and practical tool to assess the forces exerted on suspension devices, and the use of an accelerometer makes it possible to determine the magnitude of the perturbation offered by different equipment providing instability by measuring the acceleration of the body's centre of mass

The re-education of upper limb movement post stroke using iterative learning control mediated by electrical stimulation

An inability to perform tasks involving reaching is a common problem following stroke. Evidence supports the use of robotic therapy and electrical stimulation (ES) to reduce upper limb impairments following stroke, but current systems may not encourage maximal voluntary contribution from the participant. This study developed and tested iterative learning control (ILC) algorithms mediated by ES, using a purpose designed robotic workstation, for upper limb rehabilitation post stroke. Surface electromyography (EMG) which may be related to impaired performance and function was used to investigate seven shoulder and elbow muscle activation patterns in eight neurologically intact and five chronic stroke participants during nine tracking tasks. The participants’ forearm was supported using a hinged arm-holder, which constrained their hand to move in a two dimensional horizontal plane.Outcome measures taken prior to and after an intervention consisted of the Fugl-Meyer Assessment (FMA) and the Action Research Arm Test (ARAT), isometric force and error tracking. The intervention for stroke participants consisted of eighteen sessions in which a similar range of tracking tasks were performed with the addition of responsive electrical stimulation to their triceps muscle. A question set was developed to understand participants’ perceptions of the ILC system. Statistically significant improvements were measured (p?0.05) in: FMA motor score, unassisted tracking, and in isometric force. Statistically significant differences in muscle activation patterns were observed between stroke and neurologically intact participants for timing, amplitude and coactivation patterns. After the intervention significant changes were observed in many of these towards neurologically intact ranges. The robot–assisted therapy was well accepted and tolerated by the stroke participants. This study has demonstrated the feasibility of using ILC mediated by ES for upper limb stroke rehabilitation in the treatment of stroke patients with upper limb hemiplegia

Neuromuscular Control Strategy during Object Transport while Walking: Adaptive Integration of Upper and Lower Limb Movements

When carrying an object while walking, a significant challenge for the central nervous system (CNS) is to preserve the object’s stability against the inter-segmental interaction torques and ground reaction forces. Studies documented several strategies used by the CNS: modulation of grip force (GF), alterations in upper limb kinematics, and gait adaptations. However, the question of how the CNS organizes the multi-segmental joint and muscle coordination patterns to deal with gait-induced perturbations remains poorly understood. This dissertation aimed to explore the neuromuscular control strategy utilized by the CNS to transport an object during walking successfully. Study 1 examined the inter-limb coordination patterns of the upper limbs when carrying a cylinder-shaped object while walking on a treadmill. It was predicted that transporting an object in one hand would affect the movement pattern of the contralateral arm to maintain the overall angular momentum. The results showed that transporting an object caused a decreased anti-phase coordination, but it did not induce significant kinematic and muscle activation changes in the unconstrained arm. Study 2 examined muscle synergy patterns for upper limb damping behavior by using non-negative matrix factorization (NNMF) method. Four synergies were identified, showing a proximal-to-distal pattern of activation preceding heel contacts. Study 3 examined the effect of different precision demands (carrying a cup with or without a ball) and altered visual information (looking forward vs. looking at an object) on the upper limb damping behavior and muscle synergies. Increasing precision demand induced stronger damping behavior and increased the electromyography (EMG) activation of wrist/hand flexors and extensors. The NNMF results replicated Study 2 in that the stabilization of proximal joints occurred before the distal joints. The results indicated that the damping incorporates tonic and phasic muscle activation to ensure object stabilization. Overall, three experiments showed that the CNS adopts a similar synergy pattern regardless of task constraint or altered gaze direction while modulating the amount of muscle activation for object stabilization. Kinematic changes can differ depending on the different levels of constraint, as shown in the smaller movement amplitude of the shoulder joint in the transverse plane during the task with higher precision demand

Applications of EMG in Clinical and Sports Medicine

This second of two volumes on EMG (Electromyography) covers a wide range of clinical applications, as a complement to the methods discussed in volume 1. Topics range from gait and vibration analysis, through posture and falls prevention, to biofeedback in the treatment of neurologic swallowing impairment. The volume includes sections on back care, sports and performance medicine, gynecology/urology and orofacial function. Authors describe the procedures for their experimental studies with detailed and clear illustrations and references to the literature. The limitations of SEMG measures and methods for careful analysis are discussed. This broad compilation of articles discussing the use of EMG in both clinical and research applications demonstrates the utility of the method as a tool in a wide variety of disciplines and clinical fields

Evaluation of Concavity Compression Mechanism as a Possible Predictor of Shoulder Muscle Fatigue

This study examined the lived experiences of American Muslim principals who serve in public schools post-9/11 to determine whether global events, political discourse, and the media coverage of Islam and Muslims have affected their leadership and spirituality. The aim of the study was to allow researchers and educators to gain an understanding of the adversities that American Muslims principals have experienced post-9/11 and to determine how to address these adversities, particularly through decisions about educational policy and district leadership. A total of 14 American Muslim school leaders who work in public schools post-9/11 across the United States participated in the study, and a phenomenological methodology was used to direct the data collection and coding. Edelman\u27s political spectacle theory served as the theoretical framework for the research. The findings yielded six themes of political climate, role of the media, inferior and foreign: being seen as the other, unconscious fear, spirituality, and education and communication over spectacle. Further, collective guilt and social responsibility emerged as two additional findings. The research suggests that political spectacle and its effects have a large impact on the lives of American Muslim principals, particularly in regard to their leadership and spirituality

Investigation of the feasibility of using focal vibratory stimulation with robotic aided therapy for spasticity rehabilitation in spinal cord injury

The occurrence of a traumatic spinal cord injury is in hundreds of thousands of people every year. Survivors are left with loss of many bodily functions, loss of sensation below the point of injury and many more painful and uncomfortable repercussions which interfere with activities of daily living. Over 70% of people with SCI develop spasticity: abnormally increased muscle tone and connected joint stiffness that interfere with residual volitional control of the limbs. Treatments for spasticity include many pharmacological and non-pharmacological techniques, however many of them have severe sideeffects. Evidence suggest the use of vibratory stimulation to relieve repercussions of spasticity, despite not agreeing on the most advantageous protocol. This thesis evaluated effects that focal vibratory stimulation have on the muscle performance. Within two studies, focal muscle vibration is compared against different application conditions such as timing and location. The results suggests that if focal vibrations are applied to the relaxed muscle, the increase in muscle's force is observed. Analysis of the cortical waves indicates minimal cortical involvement in vibratory stimulation modulation. On the other hand, FV applied of the connected tendon/bone imposed to a contraction seems to have a potential to increase muscle's activation. There is evidence that motor cortex is responding to this stimulation to stabilise the muscle in order to perform the contraction. Within clinical trial, focal muscle vibratory stimulation is employed in total of 6 interventional sessions while a joint's spastic exor and extensor muscles were relaxed. Spasticity appears to be reduced as a consequence of the stimulation. Moreover, engaging the joint into robotic-aided therapy increase volitional control of the wrist, according to the analysis of the active range of motion, joint stiffness and kinematic parameters associated to the movement. The measurement and movement facilitation device used in the clinical trial was designed and developed in accordance to the spasticity and spinal cord injury repercussions consideration. The studies conducted for this thesis demonstrated feasibility and potential for the use of focal muscle vibratory stimulation to enhance muscle power in healthy muscles but also relieve consequences of spasticity. Vibrations combined with movement robotic-aided therapy have a prospects to enhance motor control

UGA Anatomy and Physiology 1 Lab Manual, 3rd Edition

This lab manual was created for Anatomy and Physiology I at the University of Georgia under a Textbook Transformation Grant and revised through a Scaling Up OER Pilot Grant. The manual contains the following labs: Introduction to Anatomy & Physiology Cells Histology – Epithelial & Connective Tissues Histology – Muscle & Nervous Tissues The Integumentary System Introduction to the Skeletal System Introduction Joints The Lower Limb – Bones The Lower Limb – Muscles The Lower Limb – Joints The Lower Limb – Nerves The Lower Limb – Movement The Upper Limb – Bones The Upper Limb – Muscles The Upper Limb – Joints The Upper Limb – Nerves The Upper Limb – Movement Muscle Physiology Axial Skeleton Axial Musculature Intervertebral Discs Central Nervous System – The Spinal Cord Central Nervous System – The Brain Motor Control The Senses – Vision The Senses - Hearing Accessible files with optical character recognition (OCR) and auto-tagging provided by the Center for Inclusive Design and Innovation.https://oer.galileo.usg.edu/biology-textbooks/1013/thumbnail.jp

The Effects Of Various Warm-Up Devices on Bat Velocity and Trajectory in Collegiate Baseball Players

Purpose: The purpose of this study was to examine the effects of various weighted warm-up devices on standard baseball bat velocity and trajectory in collegiate baseball players. Methods: Three, right-handed hitters (mean age= 19.3yrs ±1.5yrs; height= 1.74m±.13m; mass=81kg ±20.4kg; baseball experience=14.2 ±1.3) volunteered for this study. Maximal bat velocity was obtained by swinging the 30oz standard bat for the control condition. Participants were then instructed to perform a general and specific warm-up with each of the weighted bats (standard bat with 16oz donut ring (46oz total) and standard bat with 24oz power sleeve (54oz total)) on separate days. Following the warm-up procedures, participants were instructed to swing 3 times with the 30oz standard bat for maximal velocity while impacting the ball resting on the tee located belt-high and in the middle of home plate.Results: No significant differences were revealed by Shewart Chart method for baseball bat velocity or trajectory. Also, it was observed that all participants swung the bat at its lowest point in its trajectory for all conditions. Conclusion: Based upon no changes in the dependent variables in the population tested, Division II collegiate athletes can choose any of the warm-up devices investigated because no deleterious effects were observed

The Effects Of Various Warm-Up Devices on Bat Velocity and Trajectory in Collegiate Baseball Players

Purpose: The purpose of this study was to examine the effects of various weighted warm-up devices on standard baseball bat velocity and trajectory in collegiate baseball players. Methods: Three, right-handed hitters (mean age= 19.3yrs ±1.5yrs; height= 1.74m±.13m; mass=81kg ±20.4kg; baseball experience=14.2 ±1.3) volunteered for this study. Maximal bat velocity was obtained by swinging the 30oz standard bat for the control condition. Participants were then instructed to perform a general and specific warm-up with each of the weighted bats (standard bat with 16oz donut ring (46oz total) and standard bat with 24oz power sleeve (54oz total)) on separate days. Following the warm-up procedures, participants were instructed to swing 3 times with the 30oz standard bat for maximal velocity while impacting the ball resting on the tee located belt-high and in the middle of home plate.Results: No significant differences were revealed by Shewart Chart method for baseball bat velocity or trajectory. Also, it was observed that all participants swung the bat at its lowest point in its trajectory for all conditions. Conclusion: Based upon no changes in the dependent variables in the population tested, Division II collegiate athletes can choose any of the warm-up devices investigated because no deleterious effects were observed