Brent Raiteri

Biomechanics postdoc who moved halfway around the world to keep imaging muscle for a living

[Daniel Hahn @neuromecHAHNics]

📢 The Faculty of Sport Science @ruhrunibochum is hiring - two open professorship positions available!🚨

1) Training & Exercise Physiology
https://t.co/xgBmowucH4

2) Sports & Exercise Medicine
https://t.co/zcpDr53BnS

We strongly encourage highly qualified women to apply!

🙏RT

[Brent Raiteri @BrentRaiteri]

@BasVanHooren @Tim_vd_Zee @neuromecHAHNics At the moment the TimTrack parameters are optimised for MG, so to track soleus they will need some tuning and we haven't implemented two-region tracking yet. The code is open access so you could try yourself or if there's enough interest we could implement it

[Brent Raiteri @BrentRaiteri]

Do you use ultrasound imaging to look at muscle architecture changes during movement?
Then UltraTimTrack is for you! We leveraged the benefits of its predecessors, UltraTrack+TimTrack, to enable automatic, objective, and accurate fascicle tracking - https://t.co/XrTI8NCaJM 💪🦵🦶

[Brent Raiteri @BrentRaiteri]

We were very interested in the first in vivo human data supporting in-series sarcomere addition in the biceps femoris following eccentric exercise. However, upon closer inspection, the story is not that simple: https://t.co/UKTU5YfhiZ

[Daniel Hahn @neuromecHAHNics]

For anyone interested in doing a PhD in #biomechanics, do not miss this exciting opportunity!

[Greg Pearcey @gregorypearcey]

Together with @JSkarabot & @SimonAvrillon, we are happy to share a new postdoc opportunity. We are looking for someone to lead and support an international collaboration to decode motor pools during dynamic motor tasks. See link for more information:
https://t.co/LOIzm7bqP5

[Brent Raiteri @BrentRaiteri]

@neuromecHAHNics @Tim_vd_Zee @thePeerJ Disclaimer: It even outperforms manual tracking because it is repeatable, way less time consuming, less noisy and more objective. It should track fascicles during locomotion well, but it was only tested on medial gastroc in controlled conditions. OA so others can use & improve it

[Brent Raiteri @BrentRaiteri]

@Geoff_A_Power Because muscles can produce up to 3 times the peak power output of concentric contractions, which makes muscles better brakes than motors. This enhanced braking function comes at a cost though as muscles are more likely to tear, which might increase the rate of adaptation...

[Brent Raiteri @BrentRaiteri]

@BasVanHooren @TonyBlazevich @neuromecHAHNics @SimpliFaster No problem and thanks for the discussion, which is necessary for science to progress :)

[Brent Raiteri @BrentRaiteri]

@TonyBlazevich @BasVanHooren @neuromecHAHNics @SimpliFaster If you're interested, the code for the tracking method I used is available here (please let me know if you run into problems): https://t.co/dXWoGURlh4

[Brent Raiteri @BrentRaiteri]

@BasVanHooren @TonyBlazevich @neuromecHAHNics @SimpliFaster I think "removing incorrect snippets" is much more subjective than an automated tracking method

[Brent Raiteri @BrentRaiteri]

@BasVanHooren @TonyBlazevich @neuromecHAHNics @SimpliFaster I don't see your point as I did not correct the tracking at all (the tracking is completely automated) so being blinded or not will not affect the tracking outcome

[Brent Raiteri @BrentRaiteri]

@BasVanHooren @neuromecHAHNics @TonyBlazevich @SimpliFaster I'm very confused about why you mention apo tracking at all because I didn't track the apo and you can clearly see the distal fascicle endpoint more closely intersects with the deep apo than with the red diagonal line that you highlighted

[Brent Raiteri @BrentRaiteri]

@BasVanHooren @neuromecHAHNics @TonyBlazevich @SimpliFaster We disagree here as I see clear fascicle lengthening. Maybe you could reshare your video without any tracking and start a poll to see what people think 😅

[Brent Raiteri @BrentRaiteri]

@BasVanHooren @neuromecHAHNics @TonyBlazevich @SimpliFaster Of course the Hough-transform method is impacted by noise in this situation, you can see the outlined fascicle jumping to new lengths frame to frame - could you please provide a raw (unfiltered) fascicle length time-trace using your method?

[Brent Raiteri @BrentRaiteri]

@BasVanHooren @neuromecHAHNics @TonyBlazevich @SimpliFaster But in this case, isn't prior information more important for tracking a movement rather than assuming each (noisy) image is independent?

[Brent Raiteri @BrentRaiteri]

@BasVanHooren @neuromecHAHNics @TonyBlazevich @SimpliFaster Aponeurosis tracking is not important or needed for optic-flow-based estimates of fascicle length. The fascicle endpoints are updated based on the optic flow, and the fascicle does not need to be extrapolated to the aponeuroses to get a fascicle length via trigonometry

[Brent Raiteri @BrentRaiteri]

@BasVanHooren @neuromecHAHNics @TonyBlazevich @SimpliFaster ...which results in a lot of frame-to-frame noise and incorrect tracking of the underlying movement. Optic flow methods can even detect blood vessel pulsation and although the tracking drifts over time, this will not affect the overall conclusions for this short video.

[Brent Raiteri @BrentRaiteri]

@BasVanHooren @neuromecHAHNics @TonyBlazevich @SimpliFaster Here, I trust the optic flow results more because the tracking considers what happens between two consecutive frames and the same fascicle is tracked, whereas the Hough-transform method treats each image independently and takes the average orientation of all line-like structures