To achieve good performance, athletes need to synchronize a series of movements in an optimal manner. One of the indicators used to monitor this is the order of occurrence of relevant events in the ...movement timeline. However, monitoring of this characteristic of rapid movement is practically limited to the laboratory settings, in which motion tracking systems can be used to acquire relevant data. Our motivation is to implement a simple-to-use and robust IMU-based solution suitable for everyday praxis. In this way, repetitive execution of technique can be constantly monitored. This provides augmented feedback to coaches and athletes and is relevant in the context of prevention of stabilization of errors, as well as monitoring for the effects of fatigue. In this research, acceleration and rotational speed signal acquired from a pair of IMUs (Inertial Measurement Unit) is used for detection of the time of occurrence of events. The research included 165 individual strikes performed by 14 elite and national-level karate competitors. All strikes were classified as slow, average, or fast based on the achieved maximal velocity of the hand. A Kruskal–Wallis test revealed significant general differences in the order of occurrence of hand acceleration start, maximal hand velocity, maximal body velocity, maximal hand acceleration, maximal body acceleration, and vertical movement onset between the groups. Partial differences were determined using a Mann–Whitney test. This paper determines the differences in the temporal structure of the reverse punch in relation to the achieved maximal velocity of the hand as a performance indicator. Detecting the time of occurrence of events using IMUs is a new method for measuring motion synchronization that provides a new insight into the coordination of articulated human movements. Such application of IMU can provide additional information about the studied structure of rapid discrete movements in various sporting activities that are otherwise imperceptible to human senses.
The influence of joint motion on punch efficiency before impact is still understudied. The same applies to the relationship between the kinematic and temporal parameters of a reverse punch (RP) that ...determines a score. Therefore, the aim of this study was to investigate if the exclusion or inclusion of body segments affects the acceleration, velocity, rotation angle, and timeline of execution, and to examine the correlation between these quantities. Seven elite male competitors—senior European and World Championship medalists—participated in the in-field testing. Quantities were acquired in the developmental phase of RP through three modalities of execution. Synchronized real-time data were obtained using combined multimodal sensors and camera fusion. The main findings of the study have highlighted the significant differences in the temporal and kinematic variables of RP that arise from the modality of execution. Large and medium correlation coefficients were obtained between the examined variables of body and hand. In conclusion, the results show that measured parameters are affected by segmental body activation. Moreover, their interdependence influences punch execution. The presented interdisciplinary approach provides insightful feedback for: (i) development of reliable and easy-to-use technical solutions in combat sports monitoring; and (ii) improvements in karate training.
Karate fighters are under constant pressure to find adequate scoring solutions in ever-changing combat conditions. Thus, technique improvement at high levels of mastery demands a novel approach to ...key data acquisition and in-depth analysis of more than just the impact phase in punch execution. With the aim of describing the kinematic and temporal structure of a reverse punch in the developmental phase, two wireless sensors were used for the acquisition of selected quantities in ten modalities performed by a continental and world medallist. The results show that the timeline of kinematic parameters may be a reliable factor regarding the efficiency of the reverse punch. The obtained hand results show a tendency towards maintaining greater levels of stability in comparison to the body. Additionally, the differences between parameters in relation to applied tests that replicated training and combat conditions were noted. The highest acceleration values were obtained in sliding motion preceding RP, with a partner holding chest punch pad, both static (7.35 ± 0.47 g0) and dynamic (6.99 ± 1.23 g0) tests. The same applies for velocity (8.39 ± 0.14 and 7.30 ± 1.28 m/s). The obtained results indicate the need for specific testing and an individual approach in the analysis of the techniques of elite competitors, along with the use of sensors in data acquisition. Such an approach may help improve the training and competition practice of karate fighters.
Tekst predstavlja i analizira knjigu Vinka Srhoja Crno na bijelo i vice versa, koja obuhvaća njegove izabrane napise o umjetnosti iz posljednjih četiriju desetljeća, i to iz nekoliko registara, od ...znanstvenih radova i izlaganja na znanstvenim skupovima, preko kritika u stručnim časopisima i dnevnim novinama, sve do polemika i političkih intervencija u javnoj sferi. Pristupa joj se iz rakursa transformacija umjetničkog polja i krize kritike koje su uokvirile i kritičarov „radni staž” da bi se u tom svjetlu sagledala važnost njegova zahvata. Srhoj je kritičar „staroga kova”, ali njegov kritičarski postupak nipošto nije modernistički distanciran, on utopijski aspekt kritike nužan za modernistički projekt spaja s postmodernom kritikom (modernističkih) stubova institucije umjetnosti. Zbirka skladno uvezuje autorove preokupacije, tematske, estetske i teorijske, te predstavlja i svojevrsni pregled domaćeg modernog i suvremenog kiparstva i slikarstva, u kontekstu umjetničkog razvoja na lokalnoj i međunarodnoj umjetničkoj sceni te u svojem društvenopolitičkom kontekstu.
Background/Aim. Reactive thrombocytosis, as a paraneoplastic syndrome, is often observed in cancer patients. A variety of tumor-related humoral factors and cytokines con-tribute to tumor-stimulated ...thrombopoiesis. However, the exact role of these cytokines in the pathogenesis of thrombocytosis remains unclear. The aim of this study was to analyze systemic values of cytokines and clinical-pathological characteristics in colorectal carcinoma (CRC) patients with and without thrombocytosis. Methods. Fifty nine CRC patients were involved in this study and divided into two groups according to the number of platelets. We recorded and analyzed the data about: age, gender, size of the cancer, localization, metastasis, vascular or lymph vessel invasion, nuclear grade, histological differentiation rate, tumor, nodus, metastasis (TNM) stage and concentration of cytokines interleukin (IL)-1, IL-33, IL-12, IL-17 and interferon (IFN)-? in both groups. Results. CRC patients with thrombocytosis had significantly higher nuclear grade of the cancer (p = 0.002); higher percentage of detectable metastatic lesions in the liver (p = 0.002), lung (p = 0.001), peritoneal carcinomatosis (p = 0.001), detectable invasion of blood (p = 0.012) and lymph vessels (p = 0.010). Concentrations of tumor markers alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA19-9) and se-rum values of IL-1 a nd I L-33 were significantly higher in CRC patients with thrombocytosis. IL-1/IL-12 (p = 0.016), IL-1/IFN-? (p = 0.007), IL-1/IL-17 (p = 0.006), IL-33/IL- 12 (p = 0.001), IL-33/IFN-? (p = 0.001), IL-33/IL-17 (p = 0.002), and IL-33/IL-1 (p = 0.006) ratios were significantly higher in CRC patients with thrombocytosis in comparison to CRC patients without thrombocytosis. Analysis of Receiver Operating Characteristic (ROC) curves showed that values of IL-1 area under curve (AUC) = 0.718; 95% confidence interval (CI): 0.567?0.868; sensitivity 69.2%, specificity 62.9% and IL-33 (AUC = 0.763; 95% CI: 0.614? 0.911; sensitivity 84.6%, specificity 65.7%), could be serve as possible markers for paraneoplastic thrombocytosis in CRC patients. Conclusion. IL-1 a nd I L-33 significantly correlated to high thrombocyte number in patients with more aggressive CRC.
•Assessment and reliability of affordable devices in objectification of performance.•Sophisticated measuring tool overcoming combat sports constraints.•Understanding maximum acceleration and time ...patterns in specific tasks.•Data acquired in realistic conditions enhance the athlete’s professional training.
In order to understand the complexity of punches, measurement under realistic conditions in a training environment is necessary. A crucial element to achieving valid results is a reliable instrument. The aim of the study was to evaluate the metrical characteristics and reliability of kinematic sensors (KS) in specific karate testing as a novel method in the training process. Fourteen male competitors, members of a Serbian national senior and cadet karate team, participated in the study. Segmental acceleration in the different modalities of reverse punch (Gyako tsuki) were measured using KS placed on the hand and body. In relation to the qualitative criterion of the intraclass correlation coefficient (ICC) significance, good reliability (ICC = 0.75–0.90) was observed for eight kinematic variables, while excellent reliability (ICC > 0.90) was confirmed for ten kinematic variables. KS can be considered sophisticated measuring tools providing a reliable base of information for the objectification of assessment as the primary approach to top-level athletes.
We investigated circulating levels of inflammatory biomarkers pentraxin-3 (PTX3), cyclophilin A (CypA), and heparin-binding epidermal growth factor-like growth factor (HB-EGF); oxidative stress; and ...antioxidant status markers in the patients with ST-segment elevation acute myocardial infarction (STEMI) to better understand a relationship between inflammation and oxidative stress. We examined the impact of oxidative stress on high values of inflammatory parameters. The study included 87 patients with STEMI and 193 controls. We observed a positive correlation between PTX3 and HB-EGF (ρ = 0.24, P = .027), CyPA, and sulfhydryl (SH) groups (ρ = 0.25, P = .026), and a negative correlation between PTX3 and SH groups (ρ = −0.35, P = .001) in patients with STEMI. To better understand the effect of the examined parameters on the occurrence of high concentrations of inflammatory parameters, we grouped them using principal component analysis. This analysis identified the 4 most contributing factors. Optimal cutoff values for discrimination of patients with STEMI from controls were calculated for PTX3 and HB-EGF. An independent predictor for PTX3 above the cutoff value was a “metabolic-oxidative stress factor” comprised of glucose and oxidative stress marker prooxidant-antioxidant balance (odds ratio = 4.449, P = .030). The results show that higher PTX3 values will occur in patients having STEMI with greater metabolic and oxidative stress status values.
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