The Effect of Gluteus Medius Muscle Activation on Lower Limb Three-dimensional Kinematics and Kinetics in Male and Female Athletes During Three Drop Jump Heights PDF Download

Author: Stephanie Christine Nowak
Publisher:
ISBN:
Category : Anterior cruciate ligament
Languages : en
Pages :

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Book Description
Women are four to eight times more likely to injure their anterior cruciate ligament (ACL) compared to men. It is most commonly injured through a non-contact mechanism during game time situations. During landings, women display valgus collapse, where a less active gluteus medius muscle (GMed) may be unable to control the internal rotation of the thigh, causing an increase in knee joint abduction angle, augmenting the risk of ACL injury. This study's purpose was to determine the difference between 12 male and 12 female athletes in muscle activity, specifically the GMed, and the 3D kinematics and kinetics of the lower-limb during drop jump landings from three heights; maximum vertical jump height, tibial length, and a commonly used height of 40cm. Results showed that females had greater hip adduction and knee abduction angles compared to men. The GMed activity showed no significant differences between sexes at each drop jump height.

Author: Letha Y. Griffin
Publisher: Academy
ISBN:
Category : Medical
Languages : en
Pages : 140

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Book Description
This important work will help you understand: the epidemiology of noncontact ACL injuries; risk factors for injuries; the "at-risk" athlete; neuromuscular prevention programs; their influence on injury rates. Supported by the American Orthopaedic Society for Sports Medicine, the National Athletic Trainers Association Research and Education Foundation, the National Collegiate Athletic Association, and the Orthopaedic Research and Education Foundation.

Author: Cristine Agresta
Publisher:
ISBN:
Category :
Languages : en
Pages : 143

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Book Description
Running injuries have been linked to poor lower extremity dynamic alignment, increased whole body and joint loading, and insufficient modulation of stiffness throughout stance phase. Upper body muscle activity and movement have a relationship to lower body dynamics; however, the literature has largely neglected their role during running. To date, biomechanical gait analysis has primarily focused on lower extremity mechanics and muscle activation patterns with no studies investigating the role of functional muscle synergies on stability and loading during running. Therefore, the primary objective of this project is to determine the role of the Back Functional Line (BFL), via measure of latissimus dorsi (LD), gluteus maximus (GM), and vastus lateralis (VL) muscle activity, during running and to determine their influence on lower extremity kinematics and kinematic predictors of loading that are linked to running-related injuries (RRI). We used conditions of arm swing constraint to manipulate the action of the LD and investigate the response in GM and VL muscles. Our main variables of interest include: 1) BFL muscle activity, specifically mean and peak amplitude, onset, and co-activation of the LD and GM 2) frontal plane lower extremity kinematics, and 3) kinematic predictors of kinetics, specifically foot inclination angle at initial contact and vertical COM displacement. Twenty healthy recreational runners (10 M; 10 F) participated in this study. Male runners tended to be slighter older with a higher weekly running mileage and longer running history. All participants were between the ages of 18 and 55 years old and consistently ran at least once per week. Participants ran under three arm conditions - free arm swing, unilateral arm swing constraint, and bilateral arm swing constraint. During the running trials, surface EMG and lower extremity kinematics were collected over the gait cycle. We operationally defined the primary BFL as the muscle synergy composed of the non-dominant upper extremity (i.e., constrained side during unilateral condition) LD muscle, the dominant GM muscle, and the dominant VL muscle. The secondary BFL was defined as the dominant upper extremity (i.e., unconstrained during unilateral condition) LD muscle, the non-dominant GM muscle, and the non-dominant VL muscle. Primary and secondary BFL muscle synergy activity were analyzed during two specific phases of gait - the pre-activation (PA) phase and the loading response (LR) phase. In support of the hypothesis, the primary BFL LD mean amplitude decreased during both the PA and LR phases of gait. GM and VL muscle mean amplitude demonstrated a varied response. During the PA phase, both the GM and VL muscles increased during the unilateral condition and decreased during the bilateral condition. During LR phase, GM and VL muscles increased during both arm swing constraint conditions. The highest increase in amplitude was seen during the unilateral condition. Peak amplitudes for each muscle did not change dramatically across conditions for either the PA or LR phases of gait. Secondary BFL LD and GM mean and peak amplitude increased during both the PA and LR phases of gait, with changes during the LR phase reaching significance for both muscles. Secondary BFL VL also increased in mean and peak amplitude during the bilateral constraint condition. GM and VL mean and peak muscle amplitude were significantly correlated during the LR phase, but not for the PA phase. This indicates that the lower extremity muscles of the BFL (GM and VL) may not be preparing for impact similarly but are adjusting muscle activity in a similar fashion as the lower limb is loaded. The increase in muscle amplitude for secondary BFL muscles, particularly during the LR phase of gait, may have resulted from a difference between lower limb strength or lower extremity single leg stability. Onset of muscle activity during loading response did not significantly differ across conditions for the LD, GM, or VL muscles, however, analysis of co-activation demonstrated that LD and GM were in-phase throughout the gait cycle. This suggests that this portion of the BFL may be acting together to stabilize the lumbopelvic-hip complex (LPHC) during running. LD and GM appeared to be co-activated throughout the gait cycle regardless of arm swing variation. Instability, either from asymmetrical movement patterns or poor single leg stability may contribute to the activation of the BFL muscle synergy. GM increased during the unilateral arm swing constraint during both phase and for both BFL synergies, indicating that asymmetrical movement patterns may induce a potential instability or an unstable state requiring the need for greater stability around the LPHC. Knee frontal plane kinematics changed significantly across conditions. Knee abduction angle showed the greatest increase during the unilateral arm swing constraint condition suggesting that asymmetrical movement patterns effect lower extremity mechanics more so than symmetrical patterns (i.e., bilateral arm swing restriction or free arm swing). Hip adduction and contralateral pelvic drop angles did not differ significantly across conditions. Our study did not find a significant relationship between BFL muscle activity and knee abduction angles. Participants demonstrated larger knee abduction angles on their non-dominant limb at midstance. The corresponding (secondary) BFL LD and GM demonstrated a significant increase during the LR phase. This may indicate that BFL muscle activity is engaged when the need for lower limb stability is greater, either due to poor single leg dynamic control or abnormal frontal plane mechanics. Kinematic predictors of joint and whole-body loading differed across conditions. Vertical COM displacement was significantly decreased during the bilateral arm swing constraint condition. Foot inclination angle at initial contact did not significantly change with arm swing constraint. Differences were found between right and left lower extremity foot strikes (i.e., foot inclination angle) across all conditions; the non-dominant limb demonstrated greater plantarflexion during initial contact. Knee flexion angle at initial contact and peak knee flexion during stance did not demonstrate a significant change. Muscle activity was not significantly correlated to kinematic predictors. Spatiotemporal measures altered with arm swing suppression. Stride length decreased and step rate increased significantly. Taken together, these results suggest that runners alter spatiotemporal measures more so than sagittal plane kinematics when adjusting to arm swing suppression. The role of the BFL muscle synergy during running remains unclear. Asymmetrical movement patterns and arm swing restriction appear to influence BFL muscle activity and lower extremity kinematics. Single leg stability, particularly during the LR phase, may alter BFL muscle activity due to the need for increased stabilization of the loaded limb and the LPHC. Future research is needed to determine how these variables impact BFL muscle activation and whether injured runners respond differently to arm swing constraint during running.

Author: Neal A.J. Nettesheim
Publisher:
ISBN:
Category : Buttocks
Languages : en
Pages : 25

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Book Description
Alterations in the pattern of muscle activation during some movements have been shown to cause injusry or chronic pain. In an athelete, similar poor muscle activation patterns may lead to decreased performance during athletic movements. One specific adaptation in muscles is a delay between the onset of hip extension and activation of hte gluteus maximus, also known as gluteal latency. So far, no correlation has been drawn between gluteal latency and performance during an athletic hip extension movement such as jumping.

Author: T. Jeff Chandler
Publisher: Routledge
ISBN: 1315438437
Category : Sports & Recreation
Languages : en
Pages : 1767

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Book Description
Fully revised and updated, the third edition of Conditioning for Strength and Human Performance provides strength and conditioning students with the clearest and most accessible introduction to the scientific principles underpinning the discipline. Covering bioenergetics and nutrition, a systematic approach to physiological and endocrinological adaptations to training and the biomechanics of resistance training, no other book provides such a thorough grounding in the science of strength and conditioning or better prepares students for evidence-based practice.

Author: Ganesh R. Naik
Publisher: BoD – Books on Demand
ISBN: 9535108050
Category : Medical
Languages : en
Pages : 464

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Book Description
Electromyography (EMG) is a technique for evaluating and recording the electrical activity produced by skeletal muscles. EMG may be used clinically for the diagnosis of neuromuscular problems and for assessing biomechanical and motor control deficits and other functional disorders. Furthermore, it can be used as a control signal for interfacing with orthotic and/or prosthetic devices or other rehabilitation assists. This book presents an updated overview of signal processing applications and recent developments in EMG from a number of diverse aspects and various applications in clinical and experimental research. It will provide readers with a detailed introduction to EMG signal processing techniques and applications, while presenting several new results and explanation of existing algorithms. This book is organized into 18 chapters, covering the current theoretical and practical approaches of EMG research.

Author: Thomas Kevin Robinson
Publisher:
ISBN:
Category :
Languages : en
Pages : 106

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Purpose/Hypotheses: The knee is the most commonly injured major joint, with approximately 80,000 anterior cruciate ligament (ACL) injuries annually. Epidemiological studies of sporting events show that knee injury frequency increases during during the latter portion of the game, thus injury may be associated with biomechanical changes induced by fatigue. We investigated the bilateral effects of unilateral lower extremity (LE) extensor muscle fatigue on electromyographic (EMG) patterns, kinematics, and kinetics of the single-leg vertical jump. Subjects: 15 healthy males, 22-29 years old. Methods: Subjects performed 5 maximal single-leg vertical jumps with each leg. Bilateral EMG (gluteus medius, vastus medialis and lateralis, medial and lateral hamstrings, gastroc/soleus), 3D lower extremity motion and ground reaction forces (GRF) from the jumping/landing leg were collected simultaneously. Subjects exercised the dominant LE (plant leg when kicking a ball) on a leg press machine to fatigue (unable to perform a complete leg press against resistance of 30% of body weight), then single-leg vertical jumps were repeated. Data were exracted in relation to landing events - initial force plate contact and the peak vertical GRF. EMG data were averaged across 5 trials and normalized as a percentage of the pre-exercise value for each muscle. Data analysis used repeated measures ANOVA and MANOVA. Results: There were significant interactions between limb dominance and fatigue for frontal plane knee valgus/varus moment (p=.035; larger on the dominant knee after exercise) and peak vertical GRF (p=.013; lower on the dominant leg after exercise). There was also a main effect of fatigue on peak anterior shear ground reaction force (p=.008; greater for the dominant leg after exercise). The dominant leg had significantly greater EMG activity of the gluteus medius and medial hamstring muscle groups. Conclusion: Despite reduced vertical and anterior GRF following exercise, landing from a single-leg vertical jump produced greater knee valgus moments and more EMG activity in the gluteus medius ad medial hamstring muscle groups in the dominant (exercised) leg and greater lateral hamstring and gastroc/soleus EMG activity in the non-dominant leg. Clinical Relevance: The change in post-fatigue forces in the dominant limb, particularly increased knee valgus moments, may increase the risk of ACL injury. The post-fatigue increase in gluteus medius and medial hamstring activity may be compensatory strategies to counteract the potentially damaging forces.

Author: Ferber, Reed
Publisher: Human Kinetics
ISBN: 1450424392
Category : Education
Languages : en
Pages : 152

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Book Description
Running Mechanics and Gait Analysis With Online Video is the premier resource for running mechanics and injury prevention. Referencing over 250 peer-reviewed scientific manuscripts, this text is a comprehensive review of the research and clinical concepts related to gait and injury analysis.

Author: Eleanor Criswell
Publisher: Jones & Bartlett Learning
ISBN: 0763732745
Category : Medical
Languages : en
Pages : 436

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Book Description
This book provides an introduction to the basics of surface electromyography and a detailed atlas for electrode placement.

Author: Vladimir M. Zatsiorsky
Publisher: Human Kinetics
ISBN: 1492582107
Category : Science
Languages : en
Pages : 543

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Book Description
Richly illustrated and presented in clear, concise language, Biomechanics of Skeletal Muscles is an essential resource for those seeking advanced knowledge of muscle biomechanics. Written by leading experts Vladimir Zatsiorsky and Boris Prilutsky, the text is one of the few to look at muscle biomechanics in its entirety—from muscle fibers to muscle coordination—making it a unique contribution to the field. Using a blend of experimental evidence and mechanical models, Biomechanics of Skeletal Muscles provides an explanation of whole muscle biomechanics at work in the body in motion. The book first addresses the mechanical behavior of single muscles—from the sarcomere level up to the entire muscle. The architecture of human muscle, the mechanical properties of tendons and passive muscles, the biomechanics of active muscles, and the force transmission and shock absorption aspects of muscle are explored in detail. Next, the various issues of muscle functioning during human motion are addressed. The transformation from muscle force to joint movements, two-joint muscle function, eccentric muscle action, and muscle coordination are analyzed. This advanced text assumes some knowledge of algebra and calculus; however, the emphasis is on understanding physical concepts. Higher-level computational descriptions are placed in special sections in the later chapters of the book, allowing those with a strong mathematical background to explore this material in more detail. Readers who choose to skip over these sections will find that the book still provides a strong conceptual understanding of advanced topics. Biomechanics of Skeletal Muscles also contains numerous special features that facilitate readers’ comprehension of the topics presented. More than 300 illustrations and accompanying explanations provide an extensive visual representation of muscle biomechanics. Refresher sidebars offer brief reminders of mathematical and biomechanical concepts, and From the Literature sidebars present practical examples that illustrate the concepts under discussion. Chapter summaries and review questions provide an opportunity for reflection and self-testing, and reference lists at the end of each chapter provide a starting point for further study. Biomechanics of Skeletal Muscles offers a thorough explanation of whole muscle biomechanics, bridging the gap between foundational biomechanics texts and scientific literature. With the information found in this text, readers can prepare themselves to better understand the latest in cutting-edge research. Biomechanics of Skeletal Muscles is the third volume in the Biomechanics of Human Motion series. Advanced readers in human movement science gain a comprehensive understanding of the biomechanics of human motion as presented by one of the world’s foremost researchers on the subject, Dr. Vladimir Zatsiorsky. The series begins with Kinematics of Human Motion, which details human body positioning and movement in three dimensions; continues with Kinetics of Human Motion, which examines the forces that create body motion and their effects; and concludes with Biomechanics of Skeletal Muscles, which explains the action of the biological motors that exert force and produce mechanical work during human movement.