Search results for "Juoksu"
showing 10 items of 119 documents
Continuous Analysis of Running Mechanics by Means of an Integrated INS/GPS Device
2019
This paper describes a single body-mounted sensor that integrates accelerometers, gyroscopes, compasses, barometers, a GPS receiver, and a methodology to process the data for biomechanical studies. The sensor and its data processing system can accurately compute the speed, acceleration, angular velocity, and angular orientation at an output rate of 400 Hz and has the ability to collect large volumes of ecologically-valid data. The system also segments steps and computes metrics for each step. We analyzed the sensitivity of these metrics to changing the start time of the gait cycle. Along with traditional metrics, such as cadence, speed, step length, and vertical oscillation, this system est…
Markerless 2D kinematic analysis of underwater running : A deep learning approach
2018
Kinematic analysis is often performed with a camera system combined with reflective markers placed over bony landmarks. This method is restrictive (and often expensive), and limits the ability to perform analyses outside of the lab. In the present study, we used a markerless deep learning-based method to perform 2D kinematic analysis of deep water running, a task that poses several challenges to image processing methods. A single GoPro camera recorded sagittal plane lower limb motion. A deep neural network was trained using data from 17 individuals, and then used to predict the locations of markers that approximated joint centres. We found that 300–400 labelled images were sufficient to tra…
Deep learning approach for prediction of impact peak appearance at ground reaction force signal of running activity
2020
Protruding impact peak is one of the features of vertical ground reaction force (GRF) that is related to injury risk while running. The present research is dedicated to predicting GRF impact peak appearance by setting a binary classification problem. Kinematic data, namely a number of raw signals in the sagittal plane, collected by the Vicon motion capture system (Oxford Metrics Group, UK) were employed as predictors. Therefore, the input data for the predictive model are presented as a multi-channel time series. Deep learning techniques, namely five convolutional neural network (CNN) models were applied to the binary classification analysis, based on a Multi-Layer Perceptron (MLP) classifi…
A Kinematic Analysis of Three Best 100 m Performances Ever
2013
The purpose of this investigation was to compare and determine the relevance of the morphological characteristics and variability of running speed parameters (stride length and stride frequency) between Usain Bolt’s three best 100 m performances. Based on this, an attempt was made to define which factors determine the performance of Usain Bolt's sprint and, therefore, distinguish him from other sprinters. We analyzed the previous world record of 9.69 s set in the 2008 Beijing Olympics, the current record of 9.58 s set in the 2009 Berlin World Championships in Athletics and the O lympic record of 9.63 s set in 2012 London Olympics Games by Usain Bolt. The application of VirtualDub Programme …
Neuromuscular, hormonal and oxidative stress responses to endurance running exercises in well-trained runners
2007
The aim of this study was to investigate to which type of running exercises well trained endurance runners respond more favourably with regard to acute neuromuscular and endocrinological responses and exercise-induced oxidative stress. It was hypothesized that these responses depend on the type of running exercise and relate to the physical characteristics. Altogether nine different running exercises and a long walking exercise were performed by a total of 88 male athletes. An intermittent exercise consisting of progressive 20 s runs decreased vertical jump performance in middle distance runners (MID), but improved it in marathon runners (MAR). An 18 – 24 min exhaustive test run, a 40 min i…
Maaston ja juoksunopeuden vaikutukset askelmuuttujiin suunnistusjuoksusuorituksessa
2014
Johdanto. Suunnistuksessa sekä fyysinen että taidollinen elementti vaikuttavat lopputulokseen. Suunnistusjuoksusuorituksessa taas edetään maastoon viitoitettua reittiä pitkin. Suunnistusjuoksu eroaa tasamaan juoksusta maaston jatkuvan vaihtelun, maastopohjan esteiden sekä korkeuserojen myötä. Nämä tekijät vaikuttavat myös suunnistusjuoksutekniikkaan. Tässä tutkimuksessa selvitettiin suunnistusjuoksun askelmuuttujien vaihtelua maastonosien sekä juoksunopeuden mukaan. Menetelmät. Tutkimukseen osallistui 10 miessuunnistajaa. Tutkimukset suoritettiin kahtena päivänä siten, että ensimmäinen päivä sisälsi antropometrisia mittauksia sekä suoran hapenottokykytestin juoksumatolla (VO2max -testi). Yh…
Alustan kovuuden vaikutukset juoksun muuttujiin 30 metrillä
2004
Olli Tikkanen. 2004. Alustan kovuuden vaikutukset juoksun muuttujiin 30 metrillä. Liikuntabiologian laitos. Jyväskylän yliopisto. s. 35 Tämän tutkimuksen tarkoituksena oli selvittää juoksualustan kovuuden vaikutuksia juoksunopeuksiin, juoksun muuttujiin sekä juoksijalta vaadittaviin ominaisuuksiin. Koehenkilöinä tutkimuksessa oli 8 nuorta miesurheilijaa, jotka suorittivat 30 metrin nopeustestit kandella erikovuisella alustalla sekä voimatestit. Nopeustesteissä mitattiin juoksuajat 10, 20 ja 30 metriltä sekä kontakti- ja heilandusajat, joiden perusteella laskettlin myös askelpituudet ja —frekvenssit Kaikilla koehenkilöillä, yhtä lukuun ottamatta, juoksuajat olivat huonompia hiekkatekonurmell…
Specific distribution of cross-sectional area in each hamstring muscle of sprint runners and relationship between those and sprint performance
2018
The purpose of the present study was to examine characteristics of muscle anatomical cross-sectional area (CSA) for different regions from proximal to distal parts of each muscle of the hamstring muscles in high-level sprinters, and to examine the relationship with those and the sprint performance. The CSA of the semitendinosus (ST), semimembranosus (SM), biceps femoris long head (BFL) and biceps femoris short head (BFS) at the four different region of hamstring muscles for twenty sprinters (SPRINT) and twenty healthy male control subjects (CTRL) were measured by using B-mode ultrasonography. The measured regions were divided into four parts from proximal to distal parts (PRO1, PRO2, DIS2, …
Self-selected running gait modifications reduce acute impact loading, awkwardness, and effort
2021
Impact loading has been associated with running-related injuries, and gait retraining has been suggested as a means of reducing impact loading and lowering the risk of injury. However, gait retraining can lead to increased perceived awkwardness and effort. The influence of specifically trained and self-selected running gait modifications on acute impact loading, perceived awkwardness and effort is currently unclear. Sixteen habitual rearfoot/midfoot runners performed forefoot strike pattern, increased step rate, anterior trunk lean and self-selected running gait modifications on an instrumented treadmill based on real-time biofeedback. Impact loading, perceived awkwardness and effort scores…
Factors related to excessive patellofemoral loading in rearfoot running
2015
Running is recognized as one of the most popular exercise methods. Furthermore, running related injuries have been under the scope for the last few decades. Synchronous function between the segments of the lower limbs is necessary for efficient locomotion. Patellofemoral pain syndrome is a common exercise related syndrome and multifactorial in nature. The purpose of this study was to measure contact forces and frontal plane moments to detect the factors that are associated with atypically high patellofemoral joint loading in rearfoot striking (RFS) running pattern, and moreover, which could possibly contribute to development of the patellofemoral pain syndrome. 39 team sport female athletes…