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LOWER BODY CONTRIBUTIONS TO PELVIS ENERGY FLOW AND PITCH VELOCITY IN COLLEGIATE BASEBALL PLAYERS
Get PDFThe aims of this study were to examine the generation, absorption, and transfer of energy through the pelvis at the drive hip, stride hip, and lumbosacral joints and to determine predictors of ball speed during baseball pitching. Motion capture and ground reaction force (GRF) data from 20 collegiate pitchers were analysed using energy flow and LASSO regression analyses. Energy was transferred from the drive leg to the pelvis during the stride phase while energy was transferred from the pelvis to the stride leg and trunk during arm-cocking. Drive leg GRF, impulse, and stride hip generation contribute to pitch velocity
OPTIMAL MOVEMENT FOR LOWER EXTREMITY INJURY PREVENTION; HOW TO CREATE AN OPTIMAL LEARNING ENVIRONMENT FOR YOUTH SOCCER GIRLS
Get PDFFor lower extremity injury prevention, it is crucial to decrease external loads to the joints in sport-specific situations. The purpose of this study was to examine how landing kinetics and psychological factors (i.e., motivation) change during a four-week laboratory training program. Ten talented soccer girls practiced three sport-specific tasks and received expert video instruction. Increased fun and competence in week 3 compared to week 1 was observed. No significant changes of effort and joint load (a discrete number to describe combined external frontal and transverse plane knee and ankle moments) were found. Results are promising and innovative as this is the first study testing the entire OPTIMAL model including retention and linking biomechanics with perceived motivation. More research is planned on additional instructions and feedback that may enhance the motor learning curve
The rapid stretch stimulus does not enhance muscle strength in active individuals following a 4-week proprioceptive neuromuscular strengthening protocol.
Get PDFProprioceptive neuromuscular facilitation (PNF) a technique widely used as a training modality among physically active individuals. PNF in the upper limb is combined with the rapid stretch stimulus at the beginning of every repetition of resistive diagonal PNF. The stretch stimulus is applied at the palm of the hand & fingers in the opposite direction to activate receptors. The aim of the study was to evaluate the effects of stretch stimulus with PNF exercises over 4-weeks for improvements in muscle strength. Eight participants were recruited & randomly divided into the CG, n=4 with no stretch stimulus & EG, n=4 with addition of stretch stimulus. Muscle strength of elbow flexors & maximum grip strength was measured. Mixed ANOVA showed that the rapid stretch stimulus is not sufficient in this small group to improve strength when combined with PNF diagonal strengthening (p\u3e0.05)
COORDNIATION OF CENTER OF MASS VELOCITY AND UPPER EXTREMITY KINEMATICS DURING BASKETBALL SHOTS FROM TWO DISTANCES
Get PDFThe purpose of this study was to analyze the coordination patterns for individual players when shooting from different distances. Seven experienced basketball players attempted at least 10 shots from 4.19 m and 6.02 m from the hoop. The coordination between the player’s center of mass vertical velocity, upper arm angular velocity, and forearm angular velocity were characterized using phase-plane analysis. Within player, coordination of center of mass vertical velocity and arm kinematics were found to be unique to each individual and comparable between shot distances, particularly during the shot preparation phase. Deviations in coordination patterns between shot distances were attributed to increases in center of mass vertical velocity at ground departure and ball release, consistent with the need for a greater ball velocity at release at further shot distances
TYPICAL RISK PATTERN FOR ANTERIOR CRUCIATE LIGAMENT INJURY IS LARGELY PRESENT IN COMPETITIVE ATHLETES: BIOMECHANICAL SCREENING THROUGH WEARABLE SENSORS
Get PDFThe purpose of this study was to investigate the presence of biomechanical risk patterns for Anterior Cruciate Ligament (ACL) injury in a healthy population during the execution of high-dynamics movements. Competitive athletes (n=34) performed a test battery, including single-leg landings, sprints, and cuts. Kinematics was assessed through wearable sensors, and movements exhibiting risk patterns were searched through multiple joint thresholds based on the current literature on ACL injury mechanism. A large portion of the athletes exhibited dangerous patterns in one (94%) or more movements (up to 11). The incidence was higher at initial foot contact and for the movement performed with the non-dominant limb. The early identification of at-risk athletes might support ACL professionals and promote preventative training strategies focused on the increase of movement quality
DIFFERENCES IN TORSO KINEMATICS BETWEEN ERGOMETER CYCLING AND OUTDOOR CYCLING IN TRIATHLETES – A PRELIMINARY STUDY
Get PDFMany triathletes cycle indoors when impacted by inclement road and weather conditions. In these situations, using a magnetic cycle ergometer (a turbo trainer) provides an alternative training solution. The purpose of this preliminary study was to investigate the biomechanical differences of torso kinematics during cycling on a magnetic turbo trainer compared with overground cycling. Triathletes (n=5) performed a varied 21 minute cycling cadence protocol in their familiar aerodynamic position on a magnetic resistance turbo trainer and a 21 minute overground cycle in their natural training environment whilst wearing a sacrum mounted triaxial accelerometer. Overground cycling significantly impacted anteroposterior torso kinematics (f = 7.92, p0.9) compared to turbo cycling. Despite no significant difference in cumulative triaxial acceleration magnitudes (p\u3e0.05), post-hoc analysis revealed significant variations when observed at each cadence change and epoch with increases to root mean square (RMS) values in overground cycling. Triathletes may need to consider torso position when cycling using different apparatus
EFFECTS OF MOVIE OBSERVATION AND MOTOR IMAGERY ON PERFORMANCE AND JOINT KINETICS DURING TAKE-OFF IN DROP JUMP
Get PDFThe aim of this study was to investigate the effects of movie observation and motor imagery intervention during the pre-set phase (prior to jumping off the platform), on drop jump (DJ) performance and the variables of lower leg kinetics. Three male jumpers performed the DJ under three different conditions (Normal, Movie, and Imagery) from a drop height of 0.3 m. The performance variables and joint kinetics were measured. The DJ performance tended to improve with the intervention of movie and imagery condition. Moreover, the negative ankle joint and positive hip joint kinetics variables (power and work) tended to improve with the intervention of movie and imagery condition. Therefore, it was suggested that movie observation and motor imagery intervention could improve DJ performance and the force exerted by lower leg, which affects performance
THREE-DIMENSIONAL INVERSE DYNAMICS LINKED SEGMENT MODEL IN SWIMMING
Get PDFThis study aimed to produce a three-dimensional (3-D) inverse dynamics linked segment model capable of utilising kinematic data of a subject simulating front crawl to determine joint rotations and moments. This model is intended to address the current gap in swimming performance literature concerning the measurement of dynamic loads acting on an athlete during swimming. Joint moments derived from this model are to be used to specify actuator requirements for a biomimetic robotic system which will then be used to replicate human swimming techniqu
Variation of activity patterns of American beaver, North American porcupine, and muskrat
No full textAnimals who are morphologically similar and therefore require similar resources have a high probability of interaction throughout the day. The American beaver (Castor canadensis), North American porcupine (Erethizon dorsatum), and muskrat (Ondatra zibethicus) all reside within the same ecosystem and compete for similar resources including trees and water space. My goal was to observe how the potential overlap in daily activity patterns effect interactions among these three species, thus I predicted that the American beaver and the North American porcupine will have little to no overlap between their activity patterns while the muskrat will overlap with both as a result of crepuscular activity. Using data from the Snapshot USA camera trapping project, I performed a Chi Square analysis determining that each species demonstrated a nocturnal activity pattern with the majority of activity between 11:09 pm and 6:06 am. The results of this study can help to preserve an American keystone species, the American beaver, who is known for increasing biodiversity and acting as an ecosystem engineer throughout much of North America
Brown Bear Gut Microbiomes: A Micro-Approach to Wildlife Management
No full textGut microbiomes (GMBs), complex communities of microorganisms inhabiting the gastrointestinal tracts of their hosts, perform countless micro-ecosystem services such as facilitating energy uptake and modulating immune responses. While scientists increasingly recognize the role GMBs play in host health, the role of GMBs in wildlife ecology and conservation have yet to be realized fully. Using brown bears (Ursus arctos) as an ecological model, we aim to a) assess variation in brown bear GMBs across three protected areas in Alaska and b) evaluate the role that extrinsic factors (e.g., location, diet, and season) play in brown bear GMBs. To achieve these aims, we subsampled brown bear fecal samples collected during previous United States Geological Survey and National Park Service research activities at Gates of the Arctic National Park and Preserve, Lake Clark National Park and Preserve, and Katmai National Park and Preserve. From these fecal samples, we extracted microbial DNA for 16S rRNA amplicon sequencing and conducted bioinformatic analysis to identify factors driving variation in brown bear GMBs. Our preliminary results indicate that location drives GMB variation across the study area. However, alpha diversity indices, Faith’s Phylogenetic and Shannon, are not significantly different between parks. By integrating macro and micro-ecological perspectives, we hope to identify characteristics of brown bear-associated GMBs that can serve as biomarkers for population-level health, thus informing local and landscape-level management decisions to promote long-term conservation and management