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THE MUSCLE ACTIVATION AND LANDING KINEMATICS OF CAI ATHLETES IN SINGLE-LEG LANDING AND LATERAL JUMPS
Get PDFThis study investigated the motor control of chronic ankle instability (CAI) athletes in different landings. 16 athletes participated (8 CAI and 8 control) and performed single-leg landing, inward lateral jump, and outward lateral jump. Electromyography of tibialis anterior, peroneus longus, medial gastrocnemius and lateral gastrocnemius (LG), ankle angle, and time to peak vertical ground reaction force were analysed. Statistics using two-way ANOVA with people and motion as independent variables. The data showed that CAI had different feedforward and feedback strategies with larger inversion angle pre and post initial contact (IC), larger plantarflexion pre and at IC, and lower LG activation pre IC. The large inversion ankle angle post IC could be the risk factor for reinjury. Injury prevention programs of CAI should pay attention to the activation of LG muscle in the landing
COMPRESSION ENGINEERING OF SPORTS GARMENTS USING ATHLETES\u27 ANTHROPOMETRIC DATA/3D SCANNING TECHNOLOGIES
Get PDFThis research aims to develop sport compression garments (SCGs) for athletes and with the required compression. Graduated compression thigh-high socks were designed for the Alva-40 mannequin, and compression was measured using picopress instrument. The anthropometry of the mannequin and six male scans were analysed using 3D scanning size stream software. The compression results were modelled for six scans through fabric stress to strain (found through tensile testing) on the body using its dimensions and compared to mannequins with scans of similar dimensions at the ankle. Results found dimension variation randomly at different points for scans, leading to compression that was not progressive for modelled results. It concludes that wearing compression garments designed for one body has varying compression on other bodies
SEX DIFFERENCES IN SUPPORT LEG DYNAMICS IN SOCCER INSTEP KICKING
Get PDFThe present study aimed to demonstrate differences in the support leg knee joint dynamics during soccer instep kicking between female and male players. Three-dimensional lower body motion (500 Hz) and ground reaction force underneath the support leg (1000 Hz) during the instep kicking of twenty female and twenty male players, were captured to calculate knee joint torque and joint power of the support leg using inverse dynamics. Statistical Parametric Mapping (SPM) was conducted to compare these time-series changes. Female players exhibited significantly smaller knee extension joint torque (58~100%, p\u3c0.001) and joint power (82~100%, p=0.001) than male players. Our findings suggested a possible strategy for achieving a better instep kicking of female players by enhancing the knee extensor’s strength of the support leg
BIOMECHANICAL ANALYSIS OF THE BURPEE PUSH-UP USING PREDICTED GROUND REACTION FORCES
Get PDFThe Burpee is a dynamic full-body workout integrating strength, cardiovascular, and plyometric elements. Despite its widespread use, scientific literature on its biomechanics and physiological effects is limited. The present study aimed to comprehensively define the Burpee exercise and its biomechanics, focusing on the joint contributions and reaction forces. For this purpose, an original approach to predict ground reaction forces at feet and hands was exploited, combined with motion capture data. Results highlighted the knees as the most affected joints, especially during landing reaching 3.5 body weight. In conclusion, this work established the groundwork for future studies aiming to evaluate proper execution for safety and training progression of the Burpee
UTILIZING THE LEAF-QUESTIONNAIRE TO DETERMINE THE RISK OF LOW ENERGY AVAILABILITY IN COLLEGE FEMALE WRESTLERS
Get PDFThe challenge of maintaining a specific weight class alongside rigorous practices and competitions, within the college lifestyle of female wrestlers, can potentially induce unhealthy eating habits and overtraining. This can ultimately lead to Low Energy Availability (LEA). Purpose: The primary purpose of this study was to examine the number of National Collegiate Athletic Association Division II female college wrestlers at risk for LEA during in-season training. The secondary purpose was to explore additional characteristics that may be related to the “at risk” group. Methods: To examine the risk of LEA in Division II female wrestlers, an online survey utilizing the Low Energy Availability in Females Questionnaire (LEAF-Q) was administered. In addition to the LEAF-Q, supplementary questions were asked to help describe characteristics of the sample and to assess factors that may have also contributed to those at risk for LEA. Results: Twenty nine percent (n=20) of the total participants met the criteria for LEAF-Q and therefore were placed in the “at risk” group. The “at risk” group reported that 90% (n=18) had ≥ 3 years of wrestling experience, and 85% (n=17) were currently exercising outside the assigned practice and workouts. Additionally, 65% (n=13) indicated that they always concern themselves with overeating. Conclusion: LEAF-Q identified 29% (n=20) of the Division II female wrestlers at risk for LEA. The supplementary questions revealed that the “at risk” group exhibited excessive exercising alongside concerns regarding overeating
Patterns in Gray Wolf Pup Survival and Recruitment in Northern Minnesota
Get PDFKnowledge of how and why the vital rates of wildlife populations change through and over time is crucial for understanding wildlife population dynamics. Because estimating gray wolf pup survival is challenging, our understanding of pup survival and the factors influencing survival and recruitment is limited. I used a combination of litter counts and video observations from a large remote camera array to estimate annual wolf pup survival and recruitment and to evaluate intra-annual patterns in pup survival and recruitment within the Greater Voyageurs Ecosystem, MN, USA. Mean annual pup survival during 2019–2023 was 0.24, and the mean annual recruitment rate was 1.31 pups per pack. Annual wolf pup survival and recruitment rates were highly variable among years and packs, while intra-annual pup survival and recruitment followed a clear pattern. Intra-annual patterns of decline coincided with periods of reduced prey availability and increased energetic demands of dependent wolf pups. This indicates that starvation due to reduced prey availability is likely a primary cause of mortality among wolf pups and the driving force behind intra-annual patterns of change in survival and recruitment. Prey abundance appears to be the primary driver of variations in annual pup survival and recruitment rates and may influence the rate of decline of intra-annual survival and recruitment. The findings, that prey abundance and availability are the primary factors limiting wolf pup survival, and therefore wolf population growth, may have implications for future research and wolf management strategies
Michigan\u27s Upper Peninsula Is the Cradle of Paul Bunyan\u27s Beehives
Get PDFOne of the Michigan Upper Peninsula’s earliest industries was iron production. Iron furnaces (smelters) were part of that industry; these were primarily fueled by charcoal, produced in hundreds of charcoal kilns scattered across the Upper Peninsula. The four basic kiln designs (rectangular, round, conical, and beehive) were all used in the region, with the beehive design becoming the predominant form. James C. Cameron, Jr. is credited with developing the beehive charcoal kiln design while employed by Upper Peninsula iron furnaces. This design was first introduced to the Upper Peninsula, and then to Northeastern Wisconsin, Northern New York, and the Far West. Cameron relocated to Northeastern Wisconsin where his invention became the standard charcoal kiln design along the Fox River where Lake Superior ores were smelted. Later, he relocated to Utah, where again his design became the charcoal burning industry standard. The beehive charcoal kiln has at least part of its origin story set in the Upper Peninsula. There is a large charcoal kiln on U.S. Highway 41 South welcoming tourists to Marquette. When Yoopers explain to tourists what that is, they can add, “You know, that thing was invented here.
TARGETED CHANGES IN FOOTWEAR UPPER STRETCH IMPROVES RUNNING PERFORMANCE AND FOOTWEAR FIT
Get PDFThe feet are completely enclosed by shoes when performing athletic activities. However, footwear uppers are often overlooked when studying running performance. We sought to understand how targeted changes in the upper stiffness can influence running centre-of-mass (COM) work and footwear fit, via plantar pressure, with ten participants running at 3 m/s. We also investigated the relationship between peak toe pressure and COM work. We found that having a stretchy material over the cuneiforms with a stiffer material across the metatarsals and talus improved running performance by reducing the amount of COM work to run at a set speed. This configuration also improved qualitative fit and reduced peak toe pressure, a quantitative measure of fit. Finally, we found peak toe pressure is associated with COM work. This metric can be used outside-the-lab to understand fit and performance