Download or read book The Effects of Two Different Fatigue Protocols on Lower Extremity Kinematics and Kinetics During an Unanticipated Running Stop jump written by David L. Quammen and published by . This book was released on 2010 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of a Functional Fatigue Protocol on Landing Kinetics and Kinematics of the Lower Extremity written by Ashley S. Long and published by . This book was released on 2005 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discussion. Significant changes in time to peak GRF, time to peak of maximum knee flexion, muscle activation and temporal patterning may suggest a kinematic difference in landing form in a fatigued state.

Download or read book The Influence of Residual Fatigue on Lower Limb Stiffness During Jump Landing written by Lindsay Victoria Slater and published by . This book was released on 2010 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Background: Anterior cruciate ligament (ACL) injuries have become commonplace among female athletes in today's society. With more than 70% of injuries resulting from noncontact mechanisms such as jump landing, the relationship between fatigue and altered movements patterns has become an important topic of research. Purpose: The main purpose of this study was to investigate the influence of residual fatigue on lower extremity kinematics and vertical leg stiffness at landing as experienced by female athletes. Method: The participants in this study were 12 NCAA female intercollegiate soccer players. Participants completed five single-leg drop jumps on their dominant leg every day for 4 days. The first day was completed without intervention to obtain pre-fatigue data and drop jumps on days two through four were completed after a fatigue protocol. Results: A repeated measures MANOVA did not reveal significant differences in post-fatigue peak knee flexion angle, vertical ground reaction forces, or vertical leg stiffness. Despite lack of statistical significance, vertical leg stiffness was increased during post-fatigue testing when compared to pre-fatigue values. Implications: The increased vertical leg stiffness may indicate altered landing techniques in post-fatigue states. If fatigue results in compromised movement patterns, it may explain the increased number of ACL injuries during the end of soccer matches. Suggestions for Future Research: Future research with a larger sample size should include post-fatigue dominant and nondominant leg comparison due to previous conflicting findings regarding which limb is most often injured. Future researchers should also quantify the magnitude of fatigue induced by the fatiguing protocol to document the strength of the independent variable.

Download or read book Fatigue Related Gender Differences in the Biomechanics of Drop Jumps written by Pralhad S. Bide and published by . This book was released on 2008 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the present study was to determine the effects of gender and fatigue on knee kinematic and kinetic variables during the counter movement and drop jumps with specific interest on the progressive changes on knee kinematics and kinetics through out the fatigue protocol. Miami University students were recruited as study participants (n=52). Participants performed two baseline drop jumps and then were subjected to fatigue protocol for three different times. In between the fatigue protocols and at the end again they performed drop jumps. The kinetic and kinematic variables were recorded using force platform and the video cameras with SIMI motion analysis system respectively. Results indicated that with fatigue there were no changes in landing angles and in the force around the knee joint. They showed the decreased flexion at the knee joint with the progression of fatigue. Gender differences with the fatigue are also discussed.

Download or read book The Effects of Fatigue on Lower Extremity Kinetics and Kinematics in Subjects with Known Ankle Instability written by Lindsay Ellen Clayton and published by . This book was released on 2015 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this study was to evaluate biomechanical differences between healthy subjects and those with ankle instability during the gradual onset of lower extremity fatigue from a landing activity. An understanding of these differences is needed in order to prevent future injury to or further debilitation in individuals with ankle instability. A functional fatiguing activity was designed to focus fatigue on the quadriceps muscles, as those are the muscles most frequently fatigued during sport. Measures were taken throughout the progression of fatigue with a force plate and a motion tracking system and included vertical ground reaction force and lower extremity kinetics, kinematics, and energetics. The time required to reach self-reported fatigue and a balance assessment, the Star Excursion Balance Test, before and after the onset of fatigue was also recorded. Significant differences were observed between groups in peak ground reaction force, ground reaction force impulse, and frontal plane ankle joint impulse. Results indicated that subjects with ankle instability not only exhibited a different baseline for most measurements than normal subjects, but also managed the progression of fatigue differently. With this information and information from further studies, recommendations and/ or training schemes could be made and implemented to help those with ankle instability avoid recurrent injuries.

Download or read book Effects of Exercise Induced Muscular Fatigue on the Kinetics and Electromyographic Activity of a Single leg Vertical Jump in Healthy Men written by Thomas Kevin Robinson and published by . This book was released on 2004 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Lower Extremity Strategies During Different Fatigue Protocols written by Jodi Lynn Hagenbaugh and published by . This book was released on 1998 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Two Types of Fatigue on an Unanticipated Side step Cutting Task as Measured by Kinematic and Kinetic Variables written by Shawn E. Lucci and published by . This book was released on 2010 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Moderating Effect of Tibialis Anterior Fatigue Protocol on the Relationships Between Rearfoot Eversion Thigh Muscle Activation and Knee Internal Rotation During a Single Leg Forward Jump Stop Task written by Yohei Shimokochi and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Objective: To examine the moderating effect of tibialis anterior muscle fatigue protocol on the relationships between rearfoot eversion, thigh muscle activation, and knee internal rotation during a single leg forward jump stop task. Subjects: 72 recreationally active healthy individuals (age = 23.8, ht = 168.9cm, and mass = 70.9kg) Methods: Subjects performed a single leg forward jump stop task before and after a tibialis anterior muscle (TA) fatiguing protocol. TA fatigue was induced through dorsiflexion exercise by lifting 5% of subject's body weight using a pulley system. During the jump stop task, kinematic and thigh muscle activation data were obtained using an electromagnetic tracking system and surface electromyography (sEMG). Knee internal rotation excursion (KIRexc), rearfoot eversion excursion at peak knee internal rotation (EVKIRexc), and sEMG percent RMS amplitudes of vastus lateraris (%VL), biceps femoris (%BF), and semitendinosus (%ST) 150ms before touch down were obtained during the jump stop task before and after the fatiguing protocol. Path analyses examined the extent to which EVKIRexc and thigh muscle activations predicted KIRexc in pre- and post-fatigue conditions. A paired sample t-test examined if TA fatigue would increase total rearfoot eversion (EVexc) and KIRexc in the post-fatigue condition as compared to the pre-fatigue condition. Results: TA fatigue did not increase EVexc or KIRexc. Path analyses revealed that although no relationships were found between EVKIRexc, %VL, BF, or ST and KIRexc in the pre-fatigue condition, %VL was significantly related with KIRexc in post-fatigue condition. Conclusions: The primary results revealed that TA fatigue did not change either rearfoot eversion or knee internal rotation motion, and the only association found was between post-fatigue quadriceps muscle activation and knee internal rotation motion. Considering the ACL injury mechanism, these findings support the importance of preventing excessive quadriceps contraction to prevent excessive knee internal rotation, but calls into question the theoretical connection between excessive rearfoot eversion, increased knee internal rotation, and ACL injury risk. However, these findings are limited to a single leg forward jump stop task, and the theoretical connections between rearfoot eversion, knee internal rotation and ACL injury risk during other functionally relevant dynamic tasks should be evaluated."--Abstract from author supplied metadata.

Download or read book Recovery stress Questionnaire for Athletes written by Michael Kellmann and published by Human Kinetics. This book was released on 2001 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides athletic specialists, trainers, and coaches with resources for monitoring athletes to avoid over-training, burnout, and decreased performance. The questionnaire is based on the hypothesis that an accumulation of stress in different areas of life, with insufficient opportunity for recovery, leads to a compromised psychophysical state. Stress states are based on 12 nonspecific and seven sports-specific scales. The questionnaire package offers tools to measure and track an athlete's recovery, including two complete questionnaires (72- and 56-item forms), manual scoring keys, profile sheets, and a user manual that describes questionnaire development and data and profile interpretation.c. Book News Inc.

Download or read book Effects of a Raised Surface on Lower Extremity Kinematics Kinetics and Muscle Activation During a Sidecut in Recreational Female Softball Players written by Lauren Elizabeth Schroeder and published by . This book was released on 2017 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Noncontact anterior cruciate ligament (ACL) injury is a common sports-related injury. "High-risk" dynamic movements, such as a sidecut, have been associated with increasing the risk of noncontact ACL injury. Certain biomechanical abnormalities, specifically at the hip and knee, and neuromuscular abnormalities, such as unbalanced quadriceps-to-hamstrings activation ratios and certain activation patterns prior to initial contact and after initial contact, have also been associated with an increased likelihood of noncontact ACL injuries occurring. Approximately 78% of all NCAA Division I softball game-day injuries are classified as noncontact where there is no direct contact to a player. Internal derangement of the knee accounted for 221 game day injuries, and 31% of these injuries were noncontact ACL injuries. The base runner was at the greatest risk of injury, with 28.8% of athletes base running at the time of injury. Additionally, 9% of base runners, or 187 athletes, were injured while contacting the base. The purpose of this study was to determine the effects of a raised surface on lower extremity kinematics, kinetics, and muscle activation patterns during a sidecut, simulating rounding first base. Participants completed two base conditions - with a base present (WB) and no base (NB) present with a controlled entrance and exit speed. Results indicated the only biomechanical difference between base conditions was greater peak knee adduction moments in the NB condition compared to the WB condition. These findings suggest that the body may be in a better position when a raised surface is present during a sidecut and decrease the risk of noncontact ACL injury. Therefore, examining movement patterns at the ankle may provide a better explanation for noncontact ACL injuries that occur during this time. Regarding muscle activation, there was significantly greater quadriceps activation post-contact compared to pre-contact. Significantly greater quadriceps activation creates a large anterior shear force on the ACL, increasing risk of injury.

Download or read book Effects of Squatting Speed on Lower Extremity Kinematics and Kinetics During Stable and Unstable Squat written by Mohammad Bader Hasan and published by . This book was released on 2018 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the study was to investigate the effects of surface instability and movement speed on key kinematic and kinetic factors (ground reaction force, moment arm [MA], resultant joint moments) in the lower extremity joints (ankles, knees, and hips) during squat. A total of 30 healthy college students (8 males and 22 females) performed six different squat conditions based on 2 surfaces (stable and unstable) and 3 speeds (slow, moderate, and fast). Normalized peak resultant joint moments (RJM) of the lower extremity joints (i.e., hips, knees, and ankles) were extracted from each trial. Two two-way repeated-measure MANOVAs (2 x 3) were performed. The first MANOVA test was to compare resultant joint moment variables, whereas, the second MANOVA test was conducted to compare ground reaction force and moment arm variables with the speed and surface condition being the factors in both. The first MANOVA with RJM variables revealed a significant speed * surface interaction (p

Download or read book The Effect of Load on the Kinetics and Kinematics of the Lower Extremity During Landing written by Michael Sullivan and published by . This book was released on 2021 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Purpose: To understand the differences in the lower extremity kinetics and kinematics as load increases during jump landings. Methods: Ten male participants (20.4 years ℗ł 2.41 years, 108.8kg ℗ł 14.02kg) took part in two testing sessions. The first testing session involved testing each participant's 1-repetition max in the hexagonal barbell deadlift. The second testing session involved the data collection of the jumping trials for each participant. Participants performed their countermovement jumps under seven randomized conditions. Six of the conditions involved the hex bar using loads equivalent to 10, 20, 30, 40, 50, and 60% estimated 1-repetition max of the hexagonal barbell deadlift. The seventh condition was an unloaded (bodyweight or 0%) countermovement jump. Peak values for joint powers, moments, angles, and velocities were recorded for the ankle, knee, and hip for all participants and conditions. A repeated measures ANOVA was used to compare differences among results. Results: Significant differences (p

Download or read book The Effects of an Unanticipated Directional Stimulus on Lower Extremity Kinematics and Ground Reaction Forces During a Drop landing and Sublateral Cut written by Tane A. Owens and published by . This book was released on 2013 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Fatigue on Lower Extremity Mechanics During the Unanticipated Cutting Maneuver written by Kaitlyn J. Weiss and published by . This book was released on 2013 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Functional Vs Isokinetic Fatigue Protocol written by Erik A. Wikstrom and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT (con't) : Two way repeated measures ANOVA revealed no significant differences when comparing isokinetic to functional fatigue values for vertical TTS [F(1,19)= 3.93, p=.538], medial/lateral TTS[F(1,19)= .287, p=.598], anterior/posterior TTS [F(1,19)= .001, p=.978], toe touch GRF [F(1, 19)=.121, p=.286], and heel strike GRF (F=3.673, p=.070). Also, no significant differences were revealed when comparing the fatigue protocols for ankle Dorsiflexion [F(1,19)= .06, p=.803], knee flexion [F(1,19)= .21, p=.652], and knee valgum [F(1,19)= .79, p=.386]. The results of this investigation suggest that the specific fatigue protocol used did not impair dynamic stability and that future research should focus on fatigue that occurs during athletic competition and the correctness of the measure of time to stabilization.

Download or read book Effects of Dual Tasking on Anticipated and Unanticipated Cutting Maneuvers on Knee Biomechanics in Collegiate Male Athletes written by Taylor Frendt and published by . This book was released on 2017 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: An athlete is required to adapt to different situations throughout participation such as not knowing which direction they will be running, judging the actions of their opponents, catching or throwing a ball, and listening to the people around them. We investigated the effects of anticipation and dual tasking on trunk and lower extremity kinematics during a side step cutting maneuver in 32 healthy active males. Participants were directed with a green light to cut to the right or left either before they started running, anticipated cut, or right before they made the cut, unanticipated cut. While making the cut the participant also had to focus on possibly catching a ball meaning the ball was either faked or thrown to the participant. Our results did not indicate there was a significant effect of anticipation on a task. However, when the ball was either faked or thrown regardless of anticipation there was a decrease in lateral trunk flexion towards the stance leg at peak knee flexion and toe off. There was also an increase in trunk rotation at initial contact, peak knee flexion, and toe off when the ball was thrown. Overall, anticipation or dual tasking did not affect lower extremity kinematics.