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EFFECTS OF RUNNING SHOE STACK HEIGHT ON MOVEMENT VARIABILITY - A SHARED BIOMECHANICAL AND MOTOR CONTROL PERSPECTIVE
Get PDFUnderstanding how shoe features affect motor control processes is crucial for designing targeted running shoes. The purpose of this study was to investigate adaptations of coupled movement components, i.e. kinematic synergies (kSYNs), when running with different shoe stack heights (19 mm, 35 mm, and 50 mm). The applied analysis combined a principal component analysis, support vector machine classifiers, and stride-to-stride variability (SSV) calculations. The results showed classification rates ranging from 82.9% to 94.4% across different stack heights. Notably, only the 50 mm stack height demonstrated increased SSV for the kSYNs that highly contribute to separating the two stack heights when compared to the 19 mm condition. The findings suggest that the motor control system adjusts to variations in stack height within certain limits by regulating task-relevant kSYNs
HOW DOES THE NEUROMUSCULAR SYSTEM UTILIZE SENSORY FEEDBACK FOR THE CONTROL OF SKILLED MOVEMENTS IN SPORT? A PERSPECTIVE
Get PDFThis perspective article explores concepts for how sensory information is utilized by the neuromuscular system for the correction of ongoing movements within the sports domain, highlighting its significance for movement stability, accuracy, precision, injury prevention, and performance enhancement. This paper aims to introduce a simplified model for feedback control and discusses implications of this model and approaches for experimental corroboration
EFFECTS OF FOREST SUCCESSION ON RAM\u27S HEAD LADY\u27S SLIPPER (CYPRIPEDIUM ARIETINUM) POPULATIONS IN THE GRAND SABLE DUNES, MI
Get PDFRam’s head lady slipper (Cypripedium arietinum) is rare across its range, but the Grand Sable Dunes (GSD) on the southern shore of Lake Superior harbors the largest known population in North America. It thrives in jack pine (Pinus banksiana) islands throughout the dunes. In this study, I updated the population status of ram’s head lady’s slipper at GSD and tracked changes in its distribution and reproductive health after a 14- year period since Bozic (2015) first surveyed GSD. I counted orchids, flowers, and fruit set in 741 1-m radius plots using stratified random sampling across 44 islands. I also resurveyed three 4 x 4-m permanent plots established by Bozic. The estimated C . ari e t i n u mpopulation declined by 65% in the random plot survey (from 3,596,000 951,000 (95% CI) in 2009, to 1,1777,000 257,000 in 2023). Orchids in three permanent plots declined by 42% (n=366). I mapped forest cover expansion at GSD using historical aerial photography (1939-2022) to analyze the effects of forest age on ram’s head densities and distribution. Orchid densities declined the most in the oldest and largest forest islands that established pre-1964 and pre-1939. In contrast, orchid densities remained stable in younger stands. Additionally, ram’s head spread from 26 islands in 2009 to 42 islands in 2023. Changes in the orchid population are tied to forest succession and Lake Superior dune formation and stabilization cycles. These findings will contribute to the conservation of rare orchids in this diversity hotspot
The Endings
No full textEssays and fictions concerning syntactical, physical, and metaphysical endings
KNEE AND TRUNK COORDINATION PATTERNS IN THE SNATCH: A PILOT STUDY ON THE INFLUENCE OF LOAD AND PHASE
Get PDFThe purpose of this study was to investigate the effect of load on trunk and knee coordination during different phases of the snatch. Four elite weightlifters performed the snatch from submaximal to maximal loads (~85-100%), while video data were collected with eight cameras. The video data were processed with markerless motion capture software, and trunk and knee joint angles were calculated. Trunk-knee coupling angles were calculated via vector coding analysis. During the pull phase, an increase in the frequency count of trunk-knee coordination patterns in response to an increase in load, indicated that the pull phase lengthened as the loads increased. Each weightlifter, however, made load-specific adjustments in their trunk-knee coordination pattern across the different phases, which may suggest the need for individualized technique training
ASSOCIATION BETWEEN JUMP PERFORMANCE AND ACL INJURY KINEMATIC RISK FACTORS
Get PDFThis study aimed to provide further insights into unclear aspects in the existing literature concerning the association between ACL injury kinematic risk factors and jump performance, as they might conflict. Fifty-four physically active females executed drop jumps with a maximal CMJ. A motion capture system provided knee and hip kinematics. Jump height, contact time, reactive strength index, initial speed, and power were obtained using a contact platform. Spearman’s correlations between first and second landing kinematics and jump indicators were evaluated. The results showed how highly performing participants were also able to land safely, plausibly reducing ACL injury risk factors. These findings regarding the relationship between ACL injury risk factors and performance, may help the development of preventive training programs without compromising performance
INFLUENCE OF MOTOR-COGNITIVE PERFORMANCE ON LANDING BIOMECHANICS IN DIFFERENT CONDITIONS: PRELIMINARY RESULTS
Get PDFThis pilot study examines the impact of varied cognitive loads on lower limb biomechanics during landing tasks. Ten male athletes performed a novel motor-cognitive assessment and then a landing task in three conditions with different cognitive loads. Findings suggest cognitive conditions may affect GRF, joint kinematics, and kinetics. Specifically, unanticipated tasks may elevate GRF, while altered hip abduction indicates adjustments in base support. Hip and knee moments vary based on cognitive conditions, emphasizing their influence on load absorption. Additionally, divided attention correlates with increased knee abduction moment, underscoring its relevance in managing potentially harmful sports movements. These results reinforce prior research, emphasizing the pivotal role of cognitive factors in screening and mitigating injury risks during athletic performances
EFFECTS OF STACK HEIGHT ON RUNNING BIOMECHANICS DURING LEVEL, UPHILL, AND DOWNHILL RUNNING AT DIFFERENT SPEEDS
Get PDFThis study aimed to investigate the effects of shoe stack height on comfort assessment, step frequency and lower limb joint range of motions (ROMs) during level, downhill and uphill running with different running speeds since stack height is one of the highly discussed key features of running shoes and was not intensively investigated for sloped running conditions. Seventeen male experienced runners completed the running protocol by wearing three running shoes with different stack heights. The kinematics were collected with a 3D motion capturing system. A comfort questionnaire was asked for each shoe. The lowest stack height resulted in the highest perceived stability and the lowest cushioning. Decrease in stack height resulted in increased step frequency and sagittal ROM in lower body joints (up to 10% change due to different stack heights) particularly in sloped running conditions. The results of this study can help to understand the effects of footwear technologies on running biomechanics and ultimately to improve running shoes to maximize their benefits in terms of running performance as well as injury risk
EFFECTS OF COMPREHENSIVE EXERCISE THERAPY ON KNEE JOINT FUNCTION AMONG OLDER ADULTS WITH KNEE OSTEOARTHRITIS
Get PDFThis study investigated the effects of comprehensive exercise therapy on knee joint function for older adults with knee osteoarthritis (KOA). Sixty-six older adults with KOA were randomly assigned to either the exercise group (EG), the heat and electrotherapy group (HG), or the control group (CG) to receive an 8-week intervention. Two-way repeated measures ANOVA was used to analyze the data of knee pain, proprioception, angle, moment, and strength. At week8, the EG had decreased pain scores, proprioception threshold, and knee abduction moment, increased flexion angle and extensor strength; the EG showed lower pain scores and greater strength than the HG and CG, and lower proprioception threshold and greater flexion angle than the CG. Comprehensive exercise therapy is indicated for older adults with KOA to improve knee joint function
DIFFERENCES IN RUGBY PLACE KICKING TECHNIQUE AND PERFORMANCE BETWEEN YOUTH AND SENIOR PLAYERS
Get PDFThe purpose of this study was to present normative place kicking data for youth players and compare them to senior players. Ten male players (seven youth, three senior) performed supra-maximal range place kicks on an outdoor, grass pitch. Ball trajectory was tracked to determine performance, and lower-body and torso kinematic data were analysed using XSens IMUs for each kicker’s three longest attempts. Youth and senior kickers achieved comparable kick distances. No differences were seen in kicking leg kinematics between groups, however, youth kickers demonstrated greater stance knee extension and greater centre of mass deceleration (mean differences: 4.8° and 0.51 m/s respectively) between support foot contact and ball contact, allowing them to maximise the transfer of linear momentum from body to ball during the kicking phase