skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: ARrow: A Real-Time AR Rowing Coach
Rowing requires physical strength and endurance in athletes as well as a precise rowing technique. The ideal rowing stroke is based on biomechanical principles and typically takes years to master. Except for time-consuming video analysis after practice, coaches currently have no means to quantitatively analyze a rower’s stroke sequence and body movement. We propose ARrow, an AR application for coaches and athletes that provides real-time and situated feedback on a rower’s body position and stroke. We use computer vision techniques to extract the rower’s 3D skeleton and to detect the rower’s stroke cycle. ARrow provides visual feedback on three levels: Tracking of basic performance metrics over time, visual feedback and guidance on a rower’s stroke sequence, and a rowing ghost view that helps synchronize the body movement of two rowers. We developed ARrow in close collaboration with international rowing coaches and demonstrated its usefulness in a user study with athletes and coaches.  more » « less
Award ID(s):
2107328
PAR ID:
10435030
Author(s) / Creator(s):
; ; ; ; ;
Date Published:
Journal Name:
EuroVis - Short Papers
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; (, Integrative and Comparative Biology)
    null (Ed.)
    Synopsis Numerous aquatic invertebrates use drag-based metachronal rowing for swimming, in which closely spaced appendages are oscillated starting from the posterior, with each appendage phase-shifted in time relative to its neighbor. Continuously swimming species such as Antarctic krill generally use “pure metachronal rowing” consisting of a metachronal power stroke and a metachronal recovery stroke, while burst swimming species such as many copepods and mantis shrimp typically use “hybrid metachronal rowing” consisting of a metachronal power stroke followed by a synchronous or nearly synchronous recovery stroke. Burst swimming organisms need to rapidly accelerate in order to capture prey and/or escape predation, and it is unknown whether hybrid metachronal rowing can augment acceleration and swimming speed compared to pure metachronal rowing. Simulations of rigid paddles undergoing simple harmonic motion showed that collisions between adjacent paddles restrict the maximum stroke amplitude for pure metachronal rowing. Hybrid metachronal rowing similar to that observed in mantis shrimp (Neogonodactylus bredini) permits oscillation at larger stroke amplitude while avoiding these collisions. We comparatively examined swimming speed, acceleration, and wake structure of pure and hybrid metachronal rowing strategies by using a self-propelling robot. Both swimming speed and peak acceleration of the robot increased with increasing stroke amplitude. Hybrid metachronal rowing permitted operation at larger stroke amplitude without collision of adjacent paddles on the robot, augmenting swimming speed and peak acceleration. Hybrid metachronal rowing generated a dispersed wake unlike narrower, downward-angled jets generated by pure metachronal rowing. Our findings suggest that burst swimming animals with small appendage spacing, such as copepods and mantis shrimp, can use hybrid metachronal rowing to generate large accelerations via increasing stroke amplitude without concern of appendage collision. 
    more » « less
  2. ; ; ; ; (, International Journal of Sports Science & Coaching)
    Wearables are a multi-billion-dollar business with more growth expected. Wearable technology is fully entrenched at multiple levels of athletic competition, especially at the National Collegiate Athletic Association (NCAA) and professional levels where these solutions are used to gain competitive advantages by assessing health and performance of elite athletes. However, through the National Science Foundation (NSF) Innovation Corps (I-Corps) training experience, a different story emerged based on pilot interviews from coaches and trainers regarding the lack of trust in wearables, and how the technology falls short of measuring what practitioners need. An NSF I-Corps project was funded to interview over 100 strength and conditioning coaches (S&CCs) and athletic trainers (ATs) regarding the current state of wearables at the NCAA and professional levels. Through 113 unstructured interviews, a conceptual map of relationships amongst themes and sub-themes regarding wearable technology emerged through the grouping of responses into meaning units (MUs). Interview findings revealed that discussions by S&CCs and ATs regarding wearables could be grouped into themes tied to (a) the organizational environment, (b) the athlete, and (c) the analyst or data scientist. Through this project, key findings and lessons learned were aggregated into sub-themes including: the sports ecosystem and organizational structure, brand development, recruiting, compliance and gamification of athletes, baselining movement and injury mitigation, internal and external loads, “return tos,” and quantifying performance. These findings can be used by practitioners to understand general technology practices and where to close the gap between what is available versus what is needed. 
    more » « less
  3. ; (, Integrative and Comparative Biology)
    Abstract Mantis shrimp swim via metachronal rowing, a pattern in which the pleopods (swimming limbs) stroke sequentially, starting with the last pair and followed by anterior neighbors. A similar swimming pattern is used at various sizes, Reynolds numbers, and advance ratios by diverse organisms including ciliates, ctenophores, copepods, krill, and lobsters. Understanding this type of locomotion is important because it is widespread and may inspire the design of underwater vehicles where efficiency, robustness, and maneuverability are desired. However, detailed measurements of the flow around free-swimming, metachronally rowing organisms are scarce, especially for organisms swimming in a high Reynolds number regime (Re ≥ 104). In this study, we present time-resolved, planar PIV measurements of a swimming peacock mantis shrimp (Odontodactylus scyllarus). Simultaneous kinematics measurements of the animal, which had body and pleopod lengths of 114 and 20 mm, respectively, reveal mean swimming speeds of 0.2–1.9 m s−1 and pleopod beat frequencies of 3.6–13 Hz, corresponding to advance ratios of 0.75–1.84 and body-based Reynolds numbers of 23,000–217,000. Further, the animal’s stroke is not purely metachronal, with a long phase lag between initiation of the first and fifth pleopod power strokes. Flow measurements in the sagittal plane show that each stroking pleopod pair creates a posteriorly moving tip vortex which evades destruction by the recovery strokes of other pleopod pairs. The vortex created by the anteriormost pleopod pair is the strongest and, owing to the animal’s high advance ratio, is intercepted by the power stroke of the posteriormost pleopod pair. The vortex strength increases as a result of this interaction, which may increase swimming speed or efficiency. A relationship for vortex interception by the posterior pleopod is proposed that relates the phase lag between the interacting pleopods to the beat frequency, distance between those pleopods, and speed of the vortex relative to the animal. We describe this interaction with a novel parameter called the interpleopod vortex phase matching Strouhal number StIVPM which is equal to the phase lag between interacting pleopods. This new nondimensional parameter may be useful in predicting the conditions where a constructive interaction may occur in other species or in physical models. Finally, we relate the advance ratio to the Reynolds number ratio, the ratio between the body-based Reynolds number and the pleopod-based Reynolds number. The importance of these parameters in promoting the interpleopod vortex interactions identified here, in dynamically scaled experiments, and in wake signatures behind schooling metachronal swimmers is discussed. 
    more » « less
  4. ; ; ; (, eLife)
    null (Ed.)
    It is thought that the brain does not simply react to sensory feedback, but rather uses an internal model of the body to predict the consequences of motor commands before sensory feedback arrives. Time-delayed sensory feedback can then be used to correct for the unexpected—perturbations, motor noise, or a moving target. The cerebellum has been implicated in this predictive control process. Here, we show that the feedback gain in patients with cerebellar ataxia matches that of healthy subjects, but that patients exhibit substantially more phase lag. This difference is captured by a computational model incorporating a Smith predictor in healthy subjects that is missing in patients, supporting the predictive role of the cerebellum in feedback control. Lastly, we improve cerebellar patients’ movement control by altering (phase advancing) the visual feedback they receive from their own self movement in a simplified virtual reality setup. 
    more » « less
  5. ; (, Journal of Science Teacher Education)
    While youth derive much of their science learning and appreciation outside of the formal science classroom, educators in afterschool and other out-of-school time (OST) settings have received relatively little investment in their professional learning. One exception is ACRES, a program that provides professional learning modules for OST educators in STEM facilitation skills, including Asking Purposeful Questions. Educators who participate in these facilitation modules exchange feedback with one another in response to the evidence of practice they bring to the professional learning setting. Due to the diverse nature of OST settings and the unique demands OST educators experience in their work, the type of evidence of practice participants bring to these sessions varies. Using a framework of teacher noticing, we explore how peer feedback in Asking Purposeful Questions modules differentiates across these diverse forms of evidence, as well as how differential feedback aligns with outcomes the coaches of Asking Purposeful Questions modules hope to see realized. We explore common forms of evidence educators experience in these cohorts, including video of contrived practice; authentic video with youth; professionally produced videos the coaches provide; and lesson descriptions. We find that, while all forms of evidence elicit noticing and associated feedback exchange supporting the module’s desired outcomes, each may be expected to exhibit specific strengths and limitations. We suggest that coaches may build upon these features to direct educators’ noticing to aspects of the evidence that may be particularly fruitful for learning. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email