5954 research outputs found
Sort by
A KINEMATIC COMPARISON OF CONVENTIONAL INSWING AND OUTSWING BOWLING IN CRICKET
Get PDFSwing bowling is an important facet of cricket, however, it has received little consideration from researchers. This study compared the bowling action and initial ball flight kinematics of inswing and outswing deliveries in 15 (male = 12, female = 3) pathway and high-performance medium and fast pace bowlers. Participants delivered the ball with their forearm, hand and the seam of the ball angled towards and away from the batter for inswing and outswing with an extended wrist flexing at ball release. Therefore, significant differences were found in forearm orientation (p \u3c 0.001), hand orientation (p \u3c 0.001), seam azimuth angle (p \u3c 0.001) and swing angle (p \u3c 0.001). By identifying similarities and differences of inswing and outswing, this study could benefit coaches to improve swing bowling performance in bowlers and provide a foundation for future research
JOINT- AND LOAD-SPECIFIC ASYMMETRIES DURING THREE LOWER EXTREMITY RESISTANCE TRAINING EXERCISES
Get PDFThe purpose of this study was characterize the consistency of limb symmetries at the knee and hip in the front squat, hexagonal barbell deadlift, and Romanian deadlift across three loads (40%, 60%, 80% of front squat one-repetition maximum). Eight female collegiate soccer players performed three repetitions at each aforementioned load and for each exercise while motion capture and ground reaction force data were recorded. Bilateral net joint moments were calculated and used to quantify joint-specific limb symmetry indices (LSI) for each exercise and loading condition. Correlation analyses revealed similarity in LSI at the knee and hip within all exercises and between the front squat and hexagonal barbell deadlift. At the joint level, greater biomechanical similarity between tasks seems to result in greater consistency of interlimb asymmetries
THREE DIMENSIONAL KINEMATIC DIFFERENCES BETWEEN MALE AND FEMALE SOCCER PLAYERS
Get PDFThis research describes a method of biomechanical analysis that allows for kinematic data to be captured in a game-like environment and key biomechanical differences between male and female soccer players to be identified. Male (n=3) players aged between 22 and 24 years and female players (n=3) aged between 19 and 23 years were recorded using a VICON motion capture system operating outdoors at an artificial grass venue. Biomechanical measurements of the lower limb such as inversion/eversion and flexion/extension of the ankle; the flexion/extension, varus/valgus and internal/external rotation of the knee; and the internal/external rotation and abduction/adduction of the hip, were recorded. Initial observations showed an increase in knee valgus and external tibial rotation in female players’ key activities performed during a soccer game
METHODOLOGICAL CONSIDERATIONS FOR COMPARISONS OF UPPER EXTREMITY EMG BETWEEN INDIVIDUALS WITH AND WITHOUT PARAPLEGIA
Get PDFThis study compared normalization methods for surface electromyography (sEMG) for comparing individuals with (Para) and without (AB) paraplegia. Participants (Para, n=7, AB, n=11) performed 4 minutes of arm-cycling at several submaximal intensities, and an incremental maximal test to exhaustion, while sEMG of the right biceps brachii was recorded. This study analyzed sEMG at two intensities: rate of perceived exertion (RPE) 13 and at 60 W, with four methods of normalization: non-normalized, against a maximal voluntary contraction (MVIC), against a rate of perceived exertion (RPE) 9, and against the max test. Using submaximal exercise intensity based on RPE or power output will affect the results when comparing sEMG of Para and AB groups, regardless of which normalization method is used to inspect the data
Students’ perception of a fully online introductory biomechanics class
Get PDFThe purpose of this study was to examine students’ perception of a fully online introductory biomechanics class delivered in both synchronous and asynchronous format within the same class. Twenty-five students completed a survey regarding the pedagogical approaches utilised for synchronous and asynchronous meetings. Students reported that the pre-recorded videos and pre-work assignments helped the most for asynchronous learning. During synchronous class time, the most helpful strategy was the thin-pair-share for questions to review the major concepts by answering several applied questions. Students had resistance to work in a small group (2-3 people) to complete assignments asynchronously. Recommendations for delivering biomechanics classes online should include sufficient time for the synchronous meeting promote student-to-student contact
FOOTBOARD AND SEAT KINETIC CHANGES ASSOCIATED WITH STROKE RATE ON A KAYAK ERGOMETER
Get PDFThe purpose of this study was to determine if stroke rate effects anteroposterior, lateral, and vertical forces on the kayak’s footboard and seat. Participants (n=10), with a year or more of competitive kayaking experience, completed four 30-second trials on a kayak ergometer at different stroke rates (60 strokes per minute (spm), 80 spm, 100 spm, and maximum spm). Mean force, impulse, and impulse*stroke rate were identified for the footboards, and seat, separately within each trial (ten single strokes). Interestingly, both anteroposterior and lateral axes kinetic adaptations to stroke rate occurred on the left footboard whereas the right footboard presented only lateral adaptations
EFFECTS OF TRUNK POSTURE ON LOWER LIMB JOINTS: IMPLICATIONS FOR NON-CONTACT ANTERIOR CRUCIATE LIGAMENT INJURY
Get PDFNon-contact anterior cruciate ligament (ACL) injuries are common and trunk posture may be an important determinant of landing injury management. Seven university female athletes (age 19.570.79 y) volunteered and completed countermovement jumps (CMJ) using both single and double leg landings across three different trunk landing positions (lean forward, self-selected and upright). Lower limb joint angles and torques were calculated at peak vertical ground reaction force (vGRF). Repeated measure ANOVA 2-Way (p ≤ 0.05) was used to test the within-subject differences of landing biomechanical characteristics. Results indicated that trunk posture can influence joint displacement angles and reduce knee joint load in landing, potentially reducing the prevalence of non-contact ACL injury during the CMJ
Identification and Ecological Significance of Endoparasite Load in Martes americana of Michigan and Alaska
No full textThough the American marten (Martes americana) is considered an important indicator species of forest ecosystems, we know very little about its endoparasite ecology. In Michigan, marten populations have been nearly extirpated, in contrast to the relatively consistent populations throughout Interior Alaska. Contrasting these populations presents an opportunity to learn about the distribution of parasite diversity in recovering species of concern. This situation also offers an opportunity to make interesting observations of marten parasite-host interactions. Our goal was to understand the diversity, prevalence, and intensity of infections of gastrointestinal parasites in marten collected by trappers in Michigan and Alaska. We sampled 98 marten gastrointestinal tracts from Interior Alaska and 12 from Michigan’s Upper Peninsula. Preliminary data shows 45% prevalence of infection in Alaskan marten, while Michigan samples were at 8%. We plan to utilize DNA sequencing to confirm species identifications for collected parasites. We will use these data to evaluate the population structure of parasites in these marten populations. We also collected gut microbiome samples from each Alaskan marten, which will be used to study relationships between gut microbiome assemblages of marten and their helminth infections. This study will contribute to our understanding of the abundance and diversity of parasites in Michigan and Alaskan marten, a species of regulation concern and an economically valuable fur-bearer
THE BROWN BEAR GUT MICROBIOME: A NOVEL TOOL FOR CONSERVATION & MANAGEMENT
Get PDFGut 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 has yet to be realized fully. Here, I use brown bears (Ursus arctos) as an ecological model to investigate (1) how both extrinsic and intrinsic factors influence GMB community membership and structure; and (2) the correlation between GMB membership and brown bear health metrics. To achieve these aims, I subsampled archived brown bear fecal samples collected during United States National Park Service research activities at three National Parks and Preserves and extracted microbial DNA for 16S rRNA amplicon sequencing and microbial taxonomic classification. My results indicate that location and diet drive GMB variation and GMB composition reflects diverse foraging strategies while allowing brown bears to achieve similar body condition outcomes. Monitoring brown bear GMBs could enable managers to quickly detect and assess the impact of environmental perturbations on brown bear health