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Integrative Movement Science Institute

@movementscience.bsky.social

An NSF Biology Integration Institute dedicated to advancing the understanding of muscular control of movement

41 Posts56 Follower14 Folgt
Integrative Movement Science Institute@movementscience.bsky.social · 2mo ago

How can wearable robots better support balance and reduce fall risk? New research by Kristen Jakubowski, Gregory Sawicki, PhD, and Lena Ting suggests that center-of-mass feedback may help inform balance-assistive control strategies for wearable robots. doi.org/10.1186/s129... #WearableRobotics

Center of mass feedback for joint torque control during perturbed standing: a potential generalizable control approach for balance augmentation in wearable robots - Journal of NeuroEngineering and Rehabilitation

Background Exoskeletons have the potential to augment balance and decrease fall risk. However, existing balance-augmenting wearable robotic controllers have only been tested in single planes of motion during either standing or walking. Thus, it is unclear whether a single control scheme can generalize across perturbations with varying spatial properties or from standing to walking. Inspired by the nervous system’s generalizable balance control strategy across perturbation types and conditions, we propose a novel torque control framework that modulates multi-joint reactive torques based on center of mass (CoM) deviation. We evaluated the generalizability of our delayed CoM feedback controller to predict multi-joint torque responses to perturbations of varying magnitudes, directions, and across movement contexts. Methods In nine healthy young adults, we tested the ability of a delayed CoM feedback scheme to predict multi-joint torque responses to (1) ramp-and-hold support surface perturbations at three magnitudes in 8 directions, (2) a continuous sinusoidal movement, resulting in a cyclical movement of the CoM with similar periodic features as walking, and (3) a sinusoidal motion with random perturbations superimposed to mimic perturbations during cyclic tasks. We trained the model on single ramp-and-hold conditions and evaluated its ability to generalize across directions, magnitudes, movement contexts, and subjects. Results The delayed CoM feedback controller trained on a single ramp-and-hold condition generalized to all ramp-and-hold perturbations for all joints, predicting the joint torques for perturbations of varying directions and magnitudes with high fidelity (average R2 > 0.84 and RMSE < 0.08 Nm/kg). However, generalization from standing to cyclic movement only occurred for hip and knee flexion. The CoM feedback parameters from ramp-and-hold perturbations generalized to the continuous sinusoidal movement (cyclic movement) and the sinusoidal movement with superimposed perturbations (unexpected perturbations) for hip flexion and knee flexion (average R²>0.70 and RMSE < 0.13 Nm/kg), but not for ankle plantarflexion and hip adduction (R²>0.20 and RMSE < 0.22 Nm/kg). Conclusion Our findings show that a physiologically-inspired CoM feedback controller can robustly predict balance-correcting torques appropriate for driving a hip or knee wearable robotic device during standing and movement, and an ankle device during standing only. The goodness-of-fit of joint torque is comparable to top machine learning algorithms, yet requires orders of magnitude less training data, enabling rapid implementation to reduce fall risk.

doi.org

Integrative Movement Science Institute@movementscience.bsky.social · 3mo ago

Mark your calendars 📅 Just one week until our next IMSI Research Seminar. Join us as Dr. Ridhi Sahani shares her work characterizing three-dimensional skeletal muscle properties.

Integrative Movement Science Institute@movementscience.bsky.social · 4mo ago

Join IMSI for a research seminar with Ridhi Sahani on in vivo skeletal muscle mechanics. Explore how muscle properties shape function and inform rehab design. 📅 May 11 🕘 9–10 AM PT Learn more: cims.uci.edu/event/resear... RSVP: CIMS@uci.edu #Biomechanics #MuscleMechanics #STEM #Science

Integrative Movement Science Institute@movementscience.bsky.social · 3mo ago

New research from Lena Ting (@lenating.bsky.social) and collaborators shows a primary central brain source drives balance-evoked N1 responses in younger adults, with other regions shaping timing. journals.physiology.org/doi/10.1152/...

A Primary Central Source Determines Perturbation-Evoked N1 Amplitudes in Younger Adults | Journal of Neurophysiology | American Physiological Society

The balance perturbation-evoked N1 potential is a reliable cortical response during reactive balance control that is correlated to a variety of cognitive and motor functions. Although the supplementary motor area (SMA) has been identified as the primary source of the N1, it is less understood whether other brain regions contribute to N1 recorded at the scalp. We used source localization on electroencephalography (EEG) data from 25 younger adults recorded during backward whole-body perturbations during stance. We identified the sources that contribute to channel-based N1 recordings and quantified their impact on N1 amplitude and latency. In younger adults, N1 amplitudes can be explained by one single source in a central midline cortical region covering the SMA. When reconstructing N1 signals using backprojections with one versus all independent components (IC) identified as brain sources there was no difference in peak amplitudes and a small but significant difference in N1 peak latencies. Parallel brain sources thus deflect the time course of the N1, but not its magnitude. Brain areas associated with IC’s contributing to the shift in N1 latency varied between participants. Our results emphasize the dominant influence of central cortical areas on the N1 response, informing hypothesizes regarding the nature of the signal and its functional role. Importantly, the extent and location of other cortical structures that influence N1 timing, such as parietal cortex areas and the anterior cingulate cortex, may further elucidate cortical contributions to balance. These markers could be crucial for the early detection of balance problems in clinical populations.

journals.physiology.org

Integrative Movement Science Institute@movementscience.bsky.social · 4mo ago

Mark your calendars 📅 Just one week until our next IMSI Research Seminar. Join us for a conversation with Prof. Gregory Sawicki on wearable robotics and advancing human mobility.

Integrative Movement Science Institute@movementscience.bsky.social · 5mo ago

Join IMSI and Prof. Gregory S. Sawicki (Georgia Tech) for Pushing Exoskeletons Out of the Lab and Into the Wild: Smart-Apparel to Support Resilient Mobility Across the Healthspan and Lifespan. 📅 April 21 | 12–1 PM PT 🔗 cims.uci.edu/event/resear... #Biomechanics #WearableRobotics

Monica Daley@birdbiomech.bsky.social · 4mo ago

A new paper on guinea fowl gait biomechanics for National Biomechanics Day! 
 How do bipedal animals adjust movement to avoid falls in slippery terrain? We found that guinea fowl slow down, take shorter steps and adjust posture to reduce fall risk in slippery terrain, just like humans. 
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Integrative Movement Science Institute@movementscience.bsky.social · 4mo ago

New research in The Journal of Experimental Biology (@jexpbiol.bsky.social) by Hannah Goldsmith, Jade Hall, and Monica A. Daley: Turning in guinea fowl on low-friction terrain reveals a trade-off between speed and stability. Article: doi.org/10.1242/jeb.... Dataset: doi.org/10.5061/drya...

Faster fowl fall frequently: speed and force regulation during turning maneuvers by guinea fowl on high and low friction terrains

Summary: Birds run slower and modulate limb–substrate reaction forces when executing turns on slippery terrain, but individual speed preferences persist even with practice and experience of higher sli...

doi.org

Christian Hubicki@chubicki.bsky.social · 5mo ago

It was a blast teaching these students to code simulation models in Python. Catch the replay video here! www.youtube.com/live/LYwOEOJ...

You Can Code with Dr. Christian Hubicki

YouTube video by Christian Hubicki

youtube.com

Integrative Movement Science Institute@movementscience.bsky.social · 5mo ago

During the second session of IMSI's Prepare to Play Workshop, students used their own data to build Python simulations and explore the physics of basketball shots—bringing biomechanics, computation, and hands-on STEM to life. Led by Dr. Christian Hubicki @chubicki.bsky.social. #MovementScience

Integrative Movement Science Institute@movementscience.bsky.social · 5mo ago

New research by Daisey Vega and IMSI affiliate Christopher J. Arellano in the Journal of Experimental Biology @jexpbiol.bsky.social examines how muscle pre-activation shapes lateral gastrocnemius mechanics during locomotion. Read the paper: journals.biologists.com/jeb/article/... #Biomechanics

In situ muscle pre-activation shifts the lateral gastrocnemius muscle–tendon unit to rely on active fascicle lengthening to absorb peak power input

Summary: A muscle pre-activation strategy during in situ stretch experiments reveals how a muscle–tendon unit deals with high rates of energy-absorbing demands.

journals.biologists.com

Integrative Movement Science Institute@movementscience.bsky.social · 5mo ago

Reminder: IMSI Research Seminar tomorrow How do animals produce sound, and what can that teach us about the human voice? Join Prof. Coen Elemans for Embodied Motor Control of the Animal Voice. Stream live Mar 11, 1–2 PM PT, or watch the recording afterwards: www.youtube.com/live/FKPTMpb...

IMSI Research Seminar | Coen P. H. Elemans — Embodied Motor Control of the Animal Voice

YouTube video by IMSI - Integrative Movement Sciences Institute

youtube.com

Monica Daley@birdbiomech.bsky.social · 5mo ago

The death of Alan Wilson is an enormous loss to comparative biomechanics. He was a visionary who pushed the envelope of technology to enable rigorous measures of movement and physiology of wild animals. He lifted the entire field by pushing us to address big, integrative questions.

Professor John R. Hutchinson@johnrhutchinson.bsky.social · 5mo ago

At the RVC we are grieving the death of the Structure & Motion Lab's creator, and stalwart comrade, Professor Alan Wilson FRS, from a plane crash in Namibia on Wednesday. He was a giant in comparative biomechanics and an amazing scientist. I'm still reeling. It is utterly shocking and deeply sad.