Download or read book External ankle supports alter kinematics and kinetics during drop jump landing and forward jump landing tasks written by Hidefusa Okamatsu and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Ankle Bracing on Knee Joint Kinematics and Kinetics During Repeated Single Leg Hop and Drop Vertical Jump in High School Aged Girls written by Virginia Norene Christensen and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Background: Ankle bracing has not been studied for its effects of knee joint kinematics and kinetics in the adolescent female athlete. Hypothesis: A) A statistically significant mean increase of knee joint valgus and extensor moments and valgus angles would be found in the braced group during the drop vertical jump and the single log hop tests and B) A statistically significant mean decrease in knee joint varus and extensor moments and valgus angles will be found between pre- and post-test acclimation periods in the braced condition. Study Design: Randomized Controlled Trial. Methods: Fifteen adolescent female athletes performed Drop Vertical Jump (DVJ) and Single Leg Hop (SLH) tests without ankle bracing and with a lace-up style ankle brace. Subjects wore braces over a 1 week period and retested. Results: During the DVJ, bracing increased knee extensor moments during the first 50 ms of landing but had no affect on knee frontal plane moments. Bracing increased vertical ground reaction force (vGRF) within the first 50ms of landing, and peak vGRF with less time to achieve peak vGRF. During the SLH, bracing increased knee flexion at IC and decreased knee frontal plane displacement into valgus. Ankle bracing increased vGRF within the first 50ms of landing and decreased stance time. Conclusions: Ankle bracing increased vGRF and knee extensor moments during the first 50ms of landing. Clinical Relevance: The adolscent female athlete may be at risk for knee injury during the initial landing phse when wearing a lace-up style ankle brace.
Download or read book Ankle Kinetics During Landing Tasks in Participants with Chronic Ankle Instability and Uninjured Controls written by Alison Lorinda Bauer and published by . This book was released on 2006 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Author's abstract: Lateral ankle sprains are a common injury sustained by physically active individuals. Many of these individuals will incur repetitive episodes of lateral ankle sprain, resulting in chronic ankle instability (CAI). CAI has been heavily researched, but few conclusions have been drawn. Much of this research has focused on sagittal plane kinematics and kinetics. Therefore, the purpose of this study was to compare three-dimensional ankle joint kinetics during functional landing tasks in participants with CAI and uninjured controls. Participants performed single-leg vertical drop landings and single-leg cross-over landings. There were no significant diffferences between the two groups for ankle net joint moments (plantarflexion/dorsiflexion, inversion/eversion, internal/external rotation) and ankle net joint forces (axial, anterior/posterior, medial/lateral) at any time point from ground contact to 150 ms after. We conclude that those with CAI do not suffer from an alteration in motor programming, and are able to absorb forces upon landing similar to uninjured individuals.
Download or read book Ankle Bracing as a Mediator of the Influence of Attentional Foci on Landing Mechanics in Healthy Females written by Mackenzie Haines and published by . This book was released on 2018 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Context: Biomechanics risk factors observed during landing task have been identified such as decreased hip and knee flexion, increased knee valgus, hip adduction and hip external rotation. These patterns have been related to the increase risk for ACL injury and could also be observed with decreased ankle range of motion (ROM). The effects of different forms of attentional focused instruction has been studied and is thought to optimize landing mechanics; decreasing risk for ACL injury. This has not yet been explored in a population with an external mechanical restriction such as an ankle brace. Objective: To determine the effects of lace-up ankle bracing and attentional focused instruction on lower extremity kinematics and kinetics during a landing task in healthy females Design: Crossover. Setting: Laboratory. Participants: 19 healthy females. Inclusion: aged 18-35, physically active with minimal familiarity of drop vertical jump task (DVJ). Exclusion: lower extremity musculoskeletal injury within last 6 months, history of lower extremity injury, vestibular, balance or connective tissue disorders, or history of ankle sprains. Interventions: Independent variables included condition (brace vs. no brace) and mode of attentional focus (external focus (EF) , internal focus (IF), neutral). All participants completed five DVJ trails for each different modes of attentional focus instruction for both bracing conditions. Main Outcome Measures: 3D trunk and lower extremity kinematics and kinetics were analyzed during landing phase of DVJ from initial contact to peak knee flexion Results: Bracing decreased peak ankle dorsiflexion (19.6°± 6.4° vs 25.9°± 5.3°) compared to non-braced. In the bracing vs. nonbraced condition, EF increased peak hip abduction (-3.8°±5.0° vs. -1.7°±4.2°), hip flexion (83.6°±14.3° vs. 79.0°±16.1°), and decreased knee valgus (-13.8°±6.6° vs. - 14.9°± 6.9°). Conclusion: EF instruction can aid in optimizing landing mechanics in healthy female population with mechanical restriction at the ankle is in place.
Download or read book Learned Biomechanics Through Feedback written by Laura Young and published by . This book was released on 2013 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a critical need to develop cost and time-effective prophylactic interventions to decrease the risk of anterior cruciate ligament (ACL) injury. Currently, jumplanding feedback interventions have demonstrated the ability to alter movements that increase the risk of ACL injury during landing. Unfortunately, it remains unknown if jump-landing interventions, which demonstrate the ability to alter movements during a jump-landing task, can alter similar movements in a different task, such as a cutting maneuver. The specific aims of this randomized control trial was to determine the effects of a jump landing feedback intervention on 1) the kinetics and 2) the kinematics performed during an anticipated cutting maneuver and a jump-landing task compared to a control group. Our central hypothesis was that biomechanical alterations known to occur during a jump-landing task, following a jump landing feedback intervention, will also be altered during a cutting maneuver. We used separate repeated measures ANOVAs to evaluate differences in kinetics and kinematics between feedback and control groups overtime. The results of this study revealed a significant decrease in peak vertical ground reaction force (VGRF) in the feedback group during the jump landing task but not the cutting task. Neither group improved knee flexion angles during the jump landing task, while the feedback group became more extended at the knee joint compared to the control during the cutting task. Both groups demonstrated an improvement in hip flexion over time in the jump landing task, but not the cutting task. Lastly, neither group demonstrated a change in knee abduction angles during either of the tasks. The findings of the study do not entirely support our hypotheses, but we would expect to find more differences with more participants added to the sample size. While the results were not what we expected, they have provided us with insight into the limitations of a feedback intervention and in order to improve future prevention programs, it is imperative to understand the limitations of the feedback intervention.
Download or read book Sex Specific Neuromuscular and Kinematic Analysis of Unanticipated Single leg Landings In Young Athletes written by Nicholas Romanchuk and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the higher incidence of anterior cruciate ligament injuries in pediatric female populations, limited research has investigated sex-differences in youth biomechanics. Furthermore, research involving jump mechanics typically requires participant to follow a set protocol, such as sticking the landing. To reduce variability and improve reliability, trails where participants fail to meet the required protocol are discarded; however, significant clinical findings may be elucidated from these trials. The purpose of this thesis was to provide a complete biomechanical analysis of unanticipated single-leg drop-jump landings in youth athletes. Thirty-two healthy youth athletes completed unanticipated single-leg drop-jump landings on their dominant limb. Trials where participants shifted foot position or touched the ground with the contralateral leg were categorized as failed. Drop-jump landings were time-normalized using landmarks within the drop-jump task. Statistical parametric mapping (SPM) determined time-varying sex-differences in muscle onset time, co-activation, kinematics and kinetics. Wilcoxon signed-rank tests and paired sample t-tests compared lower-limb kinematics, centre-of-mass excursion and muscle activation amplitudes during the successful and failed landings. A logistic regression model was also fit to predict the likelihood of a successful landing. SPM identified significantly greater trunk flexion angle in males during the deceleration, flight, and landing phase of the drop-jump. Greater quadriceps-gastrocnemius co-activation was identified during the flight phase in female participants and independent sample t-test identified longer muscle onset time in the vastus lateralis of male participants. When comparing failed and successful landings greater hip abduction and less external rotation angles were observed during the successful trials. In addition, greater preparatory muscle activation was observed in the rectus femoris and semitendinosus during the flight phase of the failed landings. A logistic regression model, which included eight kinematic and neuromuscular variables, offered a training classification accuracy of 70% and a leave-one-out cross-validation accuracy of 65%. In conclusion, females land in a more erect posture and may be less effective at dissipating landing forces. In addition, greater co-activation and shorter pre-activations of the lower limb musculature may indicate a less effective muscle activation strategy in females. Furthermore, hip kinematics and the surrounding musculature play an important role in controlling successful and failed unanticipated landings. The variables included in the logistic regression model indicate which key factors are linked to landing a jump successfully. Training modalities aimed at improving landing mechanics should therefore focus on modifying these variables.
Download or read book Ankle Bracing Alters Knee and Ankle Kinematics But Not Ground Reaction Forces During a Jump landing written by Lindsay J. Strickland and published by . This book was released on 2005 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Prophylactic Ankle Bracing on Knee and Hip Mechanics in Basketball Players During Jump Landing written by Riann K. Thayer and published by . This book was released on 2018 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Background: Many athletes of various sports have been required to wear ankle braces for prophylactic uses. Ankle braces have been shown to decrease range of motion in all directions, which means the main force absorption mechanism of the ankle may be inhibited. This decrease in force absorption at the ankle may increase the mechanical demands at the more proximal knee and hip joints. In this study, the change in knee, hip and lower back mechanics will be investigated to gain understanding as to whether bracing the ankle could create a higher injury potential. Methods: In this study, 12 intercollegiate basketball players (6 female, 6 male) participated during one session, in which each subject tested for each taping condition (self-adherent, adhesive cloth, and no tape). For each trial, the participants performed three maximum vertical jump trials and three depth drop trials, a 15-minute bout of exercise, and subsequently three more maximum vertical jumps and three more depth drops. The participants' lower body kinematics and kinetics were measured using 3D motion capture and force plates. Results: Analysis of ankle bracing pre- and post-exercise on lower extremity kinematics and kinetics through a two-way MANOVA yielded results that were not significant for any of the variables, including their interaction effect. There was no effect of the three different types of ankle bracing (control, adhesive, and self-adhesive), exercise (pre-and post-), or the interaction of those variables on peak hip flexion, peak knee flexion, peak knee moment, peak hip moment, and peak lumbosacral moment. Conclusion: Ankle bracing had no effect on selected lower body kinematics and kinetics. More research should be done to better understand whether ankle bracing has the potential to increase injury at other joints.
Download or read book Effects of Decision Making on Landing Neuromechanics as a Function of Task and Sex written by Melissa A. Mache and published by . This book was released on 2010 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although the incidence of non-contact anterior cruciate ligament (ACL) injuries is greater among women than men athletes, the factors that contribute to this greater risk of injury are not well understood. One relevant question is whether decision making during landing influences the biomechanical and neuromuscular factors thought to contribute to ACL injury, and whether these effects differ as a function of task and sex. The purpose of this study was thus to examine the effects of decision making on the neuromechanics of two-footed landing tasks in women and men. Twenty-nine healthy young adults (13 women; 16 men) completed a series of two-footed drop landing and drop-jump tasks under preplanned and decision-making conditions. Biomechanical and electromyographic data were collected. Repeated measures ANOVA was used to determine the effect of decision making on hip, knee, and ankle kinematics and kinetics, and on proactive and reactive muscle activity, as a function of task and sex. Multiple linear regression was used to assess the relationship between select knee biomechanical variables and proactive muscle activity. Decision making had numerous effects on lower extremity kinematics, kinetics, and neuromuscular control, many of which were task-specific. Under decision-making conditions, individuals exhibited similar joint postures at initial ground contact and similar amounts of reactive muscle activity across tasks. The majority of the observed modifications in neuromechanics suggested a default towards the preplanned drop landing strategy under decision-making conditions. Some effects of decision making on joint mechanics and reactive muscle activity varied with sex, although the extent to which these dissimilar effects modified relative ACL loading is not known. Knee flexion at initial contact, peak knee abduction, and peak knee adduction moment were significantly related to the proactive activity of several, primarily lateral, muscles of the lower extremity, independent of task and decision-making condition. These results indicate that decision making influences landing mechanics and neuromuscular control and that these effects are generally task-dependent and, in some cases, sex-dependent. The results also suggest that, in both women and men, drop landings and drop-jumps performed under decision-making conditions are no more dangerous, with respect to ACL loading, than preplanned drop landings.
Download or read book Joint Kinematics and Kinetics During Drop Landings Under Braced and Taped Conditions in Persons with Functional Ankle Instability written by Hayley McKelle Ulm and published by . This book was released on 2005 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sex Differences in Kinematics and Kinetics During a Rotational Jump Landing and Unanticipated Cutting Maneuver written by Joshua L. Baker and published by . This book was released on 2009 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Jump Landing Impact Absorption Kinematics and Kinetics written by Dong-Min Shin and published by . This book was released on 1992 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Differences in Lateral Drop jumps from an Unknown Height Among Individuals with Ankle Instability written by Adam B. Rosen and published by ProQuest. This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ankle sprains are one of the most frequent athletic injuries. Ankle instability (AI) is a serious and debilitating condition that occurs after 20-50% of all sprains. Previous studies have documented many of the differences that occur between those with AI and normal ankles during various activities. Landing from a jump is one of the main causes of ankle injury and has been examined in-depth. However, literature is lacking on lateral jumping maneuvers, the role of visual cues and anticipatory muscle contractions, which may influence dynamic restraint and functional stability at the ankle. The purpose of this study was to examine electromyographic (EMG) activity of the tibialis anterior (TA), peroneus longus (PL) and lateral gastrocnemius (LG) muscles in unstable versus stable ankles during lateral drop-jumps from unknown heights. Subjects were placed on a platform lift, and instructed to perform a lateral drop-jump from a height of 35 cm or 50 cm with their eyes open or closed. MANOVAs were used to establish mean differences between EMG activity (area, peak, and time to peak) from a period 150 ms prior to ground contact until 250 ms after landing. The alpha level was set to 0.05. Results showed no significant differences between heights, but significant decreases during eyes closed conditions compared to eyes open conditions in EMG activity were observed in the TA, PL and LG in area, peak and time to peak variables, as well as decreased muscle activity in the AI subjects versus stable ankles in the TA area and time to peak variables. The inhibitory strategy observed in AI subjects diminishes dynamic restraint capabilities and may predispose subjects to subsequent injury. Future studies should focus on different types of interventions while assessing performance through similar functional perturbations.
Download or read book Neuromuscular Fatigue written by A. J. Sargeant and published by Royal Netherlands Academy of. This book was released on 1993-01-01 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paperback. Neuromuscular fatigue is a phenomenon of great importance in everyday life as well as being of theoretical and clinical significance. Eleven years ago there was a seminal symposium on muscle fatigue held in London. The published proceedings (Ciba Foundation Symposium 82 - Human muscle fatigue: physiological mechanisms, Pitman, London, 1981) served as an important 'state-of-the-art' reference. In the intervening period there have been many developments with respect to our understanding of fatigue of the motor output, including processes located in the skeletal muscle fibres themselves as well as problems related to various aspects of (moto) neural muscle control. However, there are still uncertainties and important questions which remain unanswered. It was felt that the time was ripe to attempt a renewed synthesis by bringing together international experts from a range of complementary research areas. In this way it was hoped that attention co
Download or read book Differences in Lower Limb Kinematics Between Female Athletes and Non athletes During Bilateral Landing Tasks and Single Leg Step downs written by Tamara Emeline Tompkins and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction: Specific movement patterns at the hip, knee and ankle during dynamic landing tasks have been associated with an increased risk of lower extremity injury. Training strategies have shown to be favourable in decreasing the risk of injury through addressing movement patterns that have been associated with increased injury risk. Objective: To determine differences in lower limb kinematics during three separate bilateral landing tasks (Drop Jump, Drop Landing, Slow Step Down) between female athletes and non-athletes. Methods: Lower extremity kinematic data were obtained using the Xsens MVN motion capture system for 12 university athletes, and 14 university non-athletes. Three-dimensional joint angles were determined for the hip, knee, and ankle at the instant of landing, and peak angles were determined throughout both landings. Peak angular velocities of the hip, knee and ankle joints, and minimum distance between the knees were found during landing. Jumping variables including jump height, ground contact time, flight time, reactive strength index, landing knee distance, minimum knee distance, and landing ankle distance were also analyzed. Results: The athletes, in general, landed with less plantarflexion at the ankle (p
Download or read book 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 written by Stephanie Christine Nowak and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book The Effects of Chronic Ankle Instability and Change in Visual Focus on Sensorimotor Control in the Lower Extremity During a Drop landing written by Lindsay M. Baic and published by . This book was released on 2013 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: Objective: To examine the effects of the combination of chronic ankle instability (CAI) and modified visual focus on lower extremity sagittal-plane kinematics and dynamic stability during a drop-jump task. Design: A case-control design. Participants: 15 participants with self-reported CAI and 15 healthy participants. Methods: Participants performed a drop-jump task in both looking-up and looking-down conditions. Main Outcome Measures: Pre-landing and post-landing sagittal-plane kinematics in the hip, knee, and ankle were analyzed. Time-to-stabilization (TTS) was calculated to assess dynamic stability. Statistical Analysis: A 2 x 2 repeated-measures analysis of variance was used for each dependent variable. Significance was set a priori at p
