1,721,039 research outputs found
Structuring a virtual environment for sport training: A case study on rowing technique
No full textThe advancements in technology and the possibility of their integration in the domain of virtual environments allow access to new application domains previously limited to highly expensive setups. This is specifically the case of sport training that can take advantage of the improved quality of measurement systems and computing techniques. Given this the challenge that emerges is related to the way training is performed and how it is possible to evaluate the transfer from the virtual setup to the real case. In this work we discuss the aspect of system architecture for a VE in sport training, taking as a case study a rowing training system. The paper will address in particular the challenges of training technique in rowing
Boat Dynamics and Force Rendering Models for the SPRINT System
No full textThe skills professional rowing indoor training (SPRINT) system is designed to support rowing training. The sys- tem includes a configurable instrumented rowing apparatus that supports sculling and sweep rowing and that is coupled with a vir- tual reality display and haptic feedback. Herein, the system has been updated with models that aim at improving force rendering and at simulating the rowing dynamics. These new models support the rendering of vertical and horizontal forces on the hands and they estimate the effects that actions performed on SPRINT would produce on an actual rowing shell. A proof of concept evaluation with one expert and one intermediate rower included a comparison of data gathered on an actual boat and with SPRINT. Outputs of the boat dynamics model showed to be consistent when compared both with the literature and on-boat data. Moreover, these prelimi- nary data suggest boat dynamics output to be useful to discriminate expertise. In addition, subjective ratings of kinematic features and force rendering by expert and intermediate rowers indicated that they find SPRINT suitable for training
Expert rowers’ motion analysis for synthesis and technique digitalization
No full textFour expert rowers’ gestures were gathered on the SPRINT rowing platform with the aid of an optic motion tracking system. Data were analyzed in order to get a digital representation of the features involved in rowing. Moreover, these data provide a dataset for developing digital models for rowing motion synthesis. Rowers were modeled as kinematic chains, data were processed in order to get position and orientation of upper body limbs. This representation was combined with SPRINT data in order to evaluate features found in the literature, to find new ones and to build models for the generation of rowing motion. The analysis shows the effectiveness of the motion reconstruction and two examples of technique features: stroke timing and upper limbs orientation during the finish phase
Preliminary evaluation of timing training accelerator for the SPRINT rowing system
Get PDFThis paper shows the selection and preliminary evaluation of rowing gesture timing training on the SPRINT platform. After the analysis of experts’ gestures and a literature review of rowing technique features, the selection of proper feedbacks and the development of the training protocol are investigated. The general problem discussed here is the learning of timing of complex motor pattern under the effect of load. Eight novice adults participated the experiment, half of them receiving vibrotactile feedback (VIB), both receiving knowledge of results (KR) after training blocks. Preliminary results show the difficulty people had to accomplish the task and to exploit feedback. There is in fact no evidence of feedback effectiveness when comparing VIB-KR and KR group. Some causes were hypothesized and a side effect of load condition arisen from data. Therefore timing training will be further investigated exploiting information gathered
Energy management using virtual reality improves 2000-m rowing performance
No full textElite-standard rowers tend to use a fast-start strategy followed by an inverted parabolic-shaped speed profile in 2000-m races. This strategy is probably the best to manage energy resources during the race and maximise performance. This study investigated the use of virtual reality (VR) with novice rowers as a means to learn about energy management. Participants from an avatar group (n = 7) were instructed to track a virtual boat on a screen, whose speed was set individually to follow the appropriate to-be-learned speed profile. A control group (n = 8) followed an indoor training programme. In spite of similar physiological characteristics in the groups, the avatar group learned and maintained the required profile, resulting in an improved performance (i.e. a decrease in race duration), whereas the control group did not. These results suggest that VR is a means to learn an energy-related skill and improve performance
(WMSDs issue) A novel wearable system for the online assessment of risk for biomechanical load in repetitive efforts
No full textWork-related Musculo Skeletal Disorders (WMSD) are considered the third main reason for disability and early retirement in the U.S. and are widespread in many occupations, involving both heavy and light biomechanical loads. In Italy, only taking into account the years 2009-2010, it is estimated an exponential increasing in the number of WMSD reports. In particular a 159.7% increment has been reported compared to the 2006 statistics. In this context, it is clear how important correctly diagnosing this kind of pathology is becoming. Traditional methods for WMDS assessment are based on observational techniques, in which experts manually segment, label and evaluate movements with the help of pro-forma sheets. Since these methods are currently based on visual inspection and subjective judgment, they could benefit from objective measurements in terms of both reliability and repeatability. Moreover an automatic tool for ergonomics assessment would vastly reduce the time that an expert needs to carry out the same assessment manually. In this context a novel wearable wireless system capable of assessing the muscular efforts and postures of the human upper limb for WMSDs diagnosis is proposed. The system, being non-obstructive, can be used to monitor workers in ecologic environment while they are carrying on their everyday tasks. A real-time assessment is obtained according to two of the most common indexes for the analysis of risk factors on workplaces: the Rapid Upper Limb Assessment (RULA) and the Strain Index (SI). The system exploits inertial measurement units (IMUs) to reconstruct the upper limb posture, modeled as a 7 degrees of freedom (DoF) kinematic chain. As far as muscular efforts are concerned, surface EMG sensors are used to assess forearm flexor muscles strain. As an example of the proposed system application the results of a first data collection campaign regarding super-market cashiers during everyday real-life operations is reported.Relevance to industry: The presented system has a high potential impact on industry as a timely intervention on the WMSD factors may reduce pathologies and reduce the recovery of expert workers. (C) 2015 Elsevier B.V. All rights reserved
Wearable solution for online assessment of biomechanical load risks
No full textWork-related Musculo Skeletal Disorders (WMSD) are considered the third
main reason for disability and early retirement in the U.S. and are
widespread in many occupations. In Italy, only taking into account the
years 2009-2010, it is estimated an exponential increasing in the number
of WMSD reports. In particular a 159.7 % increment has been reported
compared to the 2006 statistics. In this context, it is clear how
important correctly diagnosing this kind of pathology is becoming.
Traditional methods for WMDS assessment are based on observational
techniques, in which experts manually segment, label and evaluate
movements with the help of pro-forma sheets.
Since these methods are currently based on visual inspection and
subjective judgment, they could benefit from objective measurements in
terms of both reliability and repeatability. Moreover an automatic tool
for ergonomics assessment would vastly reduce the time that an expert
needs to carry out the same assessment manually.
In this context we propose a novel wearable wireless system capable of
assessing the muscular efforts and postures of the human upper limb for
WMSDs diagnosis. The system, being non-obstructive, can be used to
monitor workers in ecologic environment while they are carrying on their
everyday tasks.
Different methods assessing different factors lead to different risk
evaluations. For this reason using more than one method at the same time
can help prioritize interventions and ensure a more thorough evaluation
of risk factors. The proposed system provides real-time assessment
obtained according to two of the most common indexes for the analysis of
risk factors on workplaces: the Rapid Upper Limb Assessment (RULA) and
the Strain Index (SI). The manual assessment of multiple methods would
lead to an unacceptably high cost in terms of time and money for
practitioners.
The system exploits inertial measurement units (IMUs) to reconstruct the
upper limb posture, modeled as a 7 degrees of freedom (DoF) kinematic
chain. As far as muscular efforts are concerned, surface EMG sensors are
used to assess forearm flexor muscles strain.
A case study application of the system is presented showing the results
of a first data collection campaign regarding super-market cashiers
during everyday real-life operations. The system assessment has been
compared using two human evaluators as ground truth. The system RULA
score accuracy is 94.79%, while the SI score shows an accuracy of 50%.
Further investigation will be carried on taking also into account the
subjects' perceived effort using self-assessment sheets
Kinematic analysis of a novel pin-wheel joint
No full textIn this paper an innovative joint for the transmission of motion between parallel and incident axes is presented. It is made up of two frontal pin-wheels with cylindrical pins. The kinematics in case of parallel axes is discussed in detail. It is shown that, quite surprisingly, it may behave in many different ways, depending on the value of the center distance between the two axes. A systematic way to analyze the joint kinematics is provided. © 2007 Springer Science+Business Media B.V
Real-time error detection for a rowing training system
No full textThe use of coaches in training provides several advantages to the skill transfer process. However, their use is limited because of cost reasons. Automatic recognition processes, on the other hand, have a vastly lower cost ratio and can replace or integrate many of the functions otherwise performed by a human. The paper presents an effective design of a real-time error recognition system for rowing in a simulator. It was designed in order to be easy to develop, be computationally efficient and offer an excellent classification ability
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