5954 research outputs found
Sort by
BIOMECHANICAL ANALYSIS OF ELITE JAVELIN THROWER OF PAKISTAN
No full textThis study investigated the biomechanical factors influencing javelin throwing performance among elite Pakistani athletes. Eight national-level male throwers were analyzed using 3D motion capture during the 2024 National Athletics Championships. Key variables included release velocity components, approach run velocity, pull distance, and phase durations. Results showed that vertical release velocity and approach run velocity at right foot touchdown (R-on) were significantly correlated with throwing distance (r = 0.672, p \u3c .05 and r = 0.596, p \u3c .05, respectively). No significant correlations were observed for pull distance, step length, or phase durations. Findings suggest that elite performance relies on maximizing vertical release while maintaining sufficient horizontal speed, emphasizing the importance of individualized technical training in Pakistan’s javelin development programs
ON THE CURVED SKATE PATH TECHNIQUE OF SPEED SKATING
No full textThe classical model of speed skating assumes that the skate travels in a straight line at a constant forward velocity while the sideward push-offs generate motion of the skater\u27s centre of mass (CoM) perpendicular to the skate. However, experimental data suggest that the CoM also gains forward velocity during each stroke. This study explores the impact of the skate\u27s curved trajectory on a skater\u27s velocity. We hypothesized that as a skater leans inward while the skate follows a curved path, the CoM gains forward velocity. To test this, we developed a simplified model using an inverted, extendable pendulum, where the CoM maintains constant height while the leg extends and tilts inward. When the skate is constrained to a circular arc, the model shows an increase in forward CoM velocity during a stroke, a result not observed under the straight-line assumption. This refined model offers a more accurate representation of the mechanics of speed skating strokes
THE EFFECTS OF THE FOOTBALL+ WARMUP PROGRAM ON ISOKINETIC STRENGTH AMONG YOUTH AMATEUR MALE FOOTBALL PLAYERS
No full textThis study evaluated the effects of the Football+, a newly developed injury prevention program (IPP) on muscle strength, an established injury risk factor, among Iranian youth amateur football players. Two U18teams competing in Tehran division two participated in this study, underwent a baseline isokinetic dynamometry, and were assigned to either the Football+ (N=16, 17.31±0.12 age, 70.16±2.09 weight, 1.77±0.12 height) or control (N=16, 17.12±.09 age, 67.99±2.03 weight, 1.78±0.03 height) groups based on their respected teams. The intervention group performed the Football+ for 8 weeks while the control group followed its traditional warmup. The same strength assessment was performed after the intervention and differences were analysed to determine effects of the IPP. Significant time-group interactions were observed for hamstring eccentric strength at 60 and 180 degrees for both dominant and non-dominant legs while the changes in strength of the quadriceps were not significant. The Football+ therefore appears to have significant potential for reducing essential risk factors for muscle injuries in young football players
AN ASSESSMENT OF SUBADULT SKELETAL GROWTH AND DEVELOPMENT BASED ON A MICHIGAN MEDICAL EXAMINER SAMPLE
No full textWhen there is a high rate of subadults going through the medical examiner’s office (MEO), it is important to determine if there is a common underlying reason. The role of the MEO is to conduct forensic investigations, but also to assist with public health surveillance. Because these roles go hand-in-hand, the MEO often detects epidemics before any public health entity does. By evaluating the decedent’s length and weight-at-death and comparing them to expected values, based on their sex and age as published by the World Health Organization and the Centers for Disease Control, it can provide insight into their lives. When subadults are unidentified and go through the MEO, methods based on dental development or long bone measurements can be used to estimate age-at-death. Because the methods available for age estimation from long bone measurements are not based on data from modern populations, it is important to validate them. This study involved the evaluation of the length and weight measurements (collected at autopsy from decedents whose deaths were investigated by one Michigan MEO), and upper arm measurements (measured from radiographs, also collected at autopsy). The weight and length (measured crown to heel) were used to see if the decedents align with expected values; long bone measurements were used to estimate the skeletal age of the decedents. Overall, the decedents in this sample weigh more and have shorter lengths than expected, based on published standards, and the estimated ages of the full sample are not significantly different from their known ages-at-death
Investigating the Role of msBDNF – TrkB Signaling in the Maintenance of Mitochondrial Populations Through the BNIP3 Mitophagy Pathway
No full textMaintenance of mitochondrial transport and clearance at the pre- and post-synaptic terminal is an essential function of neuromuscular junctions to meet their high energy demands. Damaged or dysfunctional mitochondria can put stress on these synaptic junctions, ultimately leading to the degradation of the synapse and subsequent cell death. Dysfunctional mitochondria are also often present in neuromuscular diseases such as ALS. One possible mechanism by which neurons may eliminate dysfunctional mitochondria is through the muscle-synthesized BDNF (msBDNF) /TrkB-mediated Bcl-2 nineteen-kD interacting protein (BNIP3) mitophagy pathway, although the relationship is not well-defined. BNIP3 localizes to the mitochondria and triggers a loss of membrane potential leading to mitochondrial destruction. Using a murine model, functional and dysfunctional mitochondrial populations were labelled in the gastrocnemius of control, heterozygous and homozygous muscle-synthesized BDNF knockout mice. Injections of the mitochondria-labeling dye MitoTracker were performed on 52-day-old and 87-day-old mice in order to determine if abnormalities in mitochondrial clearance are a cause of the pathophysiology observed in this model, or possibly a byproduct of it. A BNIP3-specific antibody was used to specifically label dysfunctional mitochondria at the post-synapse of these mice. The goal was to assess the relationship between the lack of msBDNF-TrkB signaling in mice and the presence of BNIP3. Finally, BNIP3 expression and the ratio of functional and dysfunctional mitochondria in gastrocnemius muscle of both control and msBDNF knockout mice was measured to determine if there is a relationship between msBDNF expression and the number of dysfunctional mitochondria at the post-synapse of the neuromuscular junction
How Can Coalitions Positively Impact Michigan’s Rural Communities and Influence Local Policies: A Comparative Case Study
Full text linkThis research explores the impact of coalitions on communities and their influence on local and state policies in rural agricultural communities in Michigan. Nonprofit organizations often utilize coalitions to strengthen their outreach efforts and impact, and in this paper, the author focuses on Farm-to-Power (FTP), a new nonprofit organization in Michigan. FTP advocates for landowners’ rights regarding renewable energy, specifically wind and solar, on a utility scale. This paper explores the best practices concerning effective coalition-building that have the capability to impact policy changes that benefit farming communities through improved economic stability. Access to renewable energy leases for Michigan farmers contributes to economic stability for farmers and their communities through direct payments to individual landowners, tax revenue for townships and counties, improved roads and land access, and money for local schools. Nonprofit organizations and coalitions can aid communities through advocacy work, combatting misinformation, educating stakeholders, and empowering individuals and organizations. FTP empowers individuals and organizations through outreach and uses a storytelling-journalism style to engage people and their communities. By sharing the direct experiences of farmers, some of the most trusted voices in America, FTP challenges misconceptions and misinformation about renewable energy on agricultural land and engages people, communities, and organizations to advocate for their own rights and challenges poor policies that negatively impact people and communities
I Gave Them a Voice: Reflections From a First-Time Author
Full text linkMichigan\u27s Upper Peninsula, an undergarment factory, and a women\u27s study club may seem unlikely ingredients for a book, but they led to my book about women in northern Michigan and two ladies\u27 undergarment factories where they worked. I never intended to publish a book. I did, however, want to shine a light on the largely untold story of hundreds of remarkable women to give them a voice and to preserve their stories
Life, Liberty and Property: Property as a Weapon Utilized Against Native Peoples and as a Tool to Strengthen Native Sovereignty in the Upper Midwest
Full text linkWhile many Americans today recognize the continuing paternalism of the federal government towards Tribal governments, much still remains unknown to the public regarding the specific laws, policies and treaties that have provided the continuing legal authority for this paternalism. Throughout American history, the relationship between the federal government and Native American tribes can be seen through the use of violence both in law, and outside of it. Treaties, the basis for removal, have been used by both the federal government and subsequently tribal governments to assert their authority over land. In the Upper Midwest, various Anishinaabe tribes signed several treaties ceding large portions of land under the threat of, or in addition to, violence, while still retaining unique tribal rights. This project will examine the always present, but only sometimes explicit violence that is inherent in Tribal-Federal relations. Further, it will examine how various laws, treaties, and policies that were designed to harm the Anishinaabe were co-opted by the Anishinaabe, and how they are used today to strengthen tribal sovereignty both on and off reservations
CHARACTERIZATION OF SHOULDER MOMENTS AND FORCE APPLICATION IN STATIC AND DYNAMIC CAMPUS EXERCISES
No full textThis study aimed to characterize shoulder joint moments and force application patterns in static and dynamic campus exercises. Campus exercises are upper-body plyometric movements performed on a ladder-like training board, where climbers ascend using only their arms, without foot support. Twenty advanced/elite climbers performed five trials of each exercise on an instrumented two-rung campus board. Shoulder joint moments on the 3 planes of motion and vertical forces for each limb were computed across the exercise cycles and time series were compared. Results showed that dynamic campus exercises elicited higher shoulder joint moments in the sagittal and frontal planes, particularly during the mid-cycle transition. In contrast, static campus required sustained force production, leading to higher joint moments in the supporting limb at the moment the reaching hand held the next rung. These findings suggest that static campus emphasizes steady body-control stabilization, whereas dynamic campus relies on power production and coordination
COMPARISON OF SHOULDER KINEMATICS AND KINETICS DURING RUNNING THROWS WITH WHIP-LIKE AND CIRCULAR WIND UP IN ELITE HANDBALL PLAYERS
No full textThe purpose of the current study was to compare shoulder kinematics and kinetics between the whip-like and circular wind-ups in running throws in handball. Thirteen elite handball players performed running throws with a circular and whip-like wind up. The main findings were that peak ball velocity and maximal shoulder distraction force were higher with the circular wind up together with lower maximal external shoulder rotation angle and higher angular external rotation velocity compared with the whip-like wind up. It was concluded that the higher distraction force was due to the combination of higher maximal angular horizontal flexion and internal rotation at ball release. While no significant different torques were found between the two wind up, this was probably caused by the variability in throwing technique experience due to the different playing positions included in the present study