Reweighting Sensory Signals to Maintain Head Stability: Adaptive Properties of the Cervicocollic Reflex

A major goal of this study was to characterize the cervicocollic reflexes (CCRs) in awake squirrel monkeys and compare it to observations in cat. This was carried out by stabilizing the head in space while rotating the lower body. The magnitude and phase of the torque produced between the head and the restraint system was used as an indicator of the CCR. Many properties of the squirrel monkey's CCR were found to be similar to those of the cat. The torque decreased as a function of frequency and amplitude. In addition, the static level of torque increased with head eccentricity. One difference was that the torque was 90× smaller in squirrel monkeys. Biomechanical differences, such as differences in head inertia, could account for these differences. The second goal was to determine if the CCR was sensitive to increases in the head's inertia. To test this, we increased the head's inertia by a factor of 36 and allowed the reflexes to adapt by rotating the whole body while the head was free to move. The CCR was rapidly assessed by periodically stabilizing the head in space during whole-body rotations. The magnitude of the torque increased by nearly 60%, suggesting that the CCR may adapt when changes in the head's inertia are imposed. Changes in the torque were also consistent with changes in head-movement kinematics during whole-body rotation. This suggests that the collic reflexes may dynamically adapt to maintain the performance and kinematics of reflexive head movement.

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Head Movements Produced During Whole Body Rotations and Their Sensitivity to Changes in Head Inertia in Squirrel Monkeys

Journal of Neurophysiology ◽

10.1152/jn.00320.2007 ◽

2008 ◽

Vol 99 (5) ◽

pp. 2369-2382 ◽

Cited By ~ 9

Author(s):

J. S. Reynolds ◽

G. T. Gdowski

Keyword(s):

Head Movement ◽

Muscle Activation ◽

Human Subjects ◽

Squirrel Monkeys ◽

The Body ◽

Head Movements ◽

Whole Body ◽

Movement Kinematics ◽

Behavioral Studies ◽

Wide Range

The head's inertia produces forces on the neck when the body moves. One collective function of the vestibulocollic and cervicocollic reflexes (VCR and CCR) is thought to be to stabilize the head with respect to the trunk during whole body movements. Little is known as to whether their head-movement kinematics produced by squirrel monkeys during whole body rotations are similar to those of cats and humans. Prior experiments with cats and human subjects have shown that yaw head-movement kinematics are unaffected by changes in the head's inertia when the whole body is rotated. These observations have led to the hypothesis that the combined actions of the VCR and CCR accommodate for changes in the head's inertia. To test this hypothesis in squirrel monkeys, it was imperative to first characterize the behavior of head movements produced during whole body rotation and then investigate their sensitivity to changes in the head's inertia. Our behavioral studies show that squirrel monkeys produce only small head movements with respect to the trunk during whole body rotations over a wide range of stimulus frequencies and velocities (0.5–4.0 Hz; 0–100°/s). Similar head movements were produced when only small additional changes in the head's inertia occurred. Electromyographic recordings from the splenius muscle revealed that an active process was utilized such that increases in muscle activation occurred when the inertia of the head was increased. These results are consistent with prior cat and human studies, suggesting that squirrel monkeys have a similar horizontal VCR and CCR.

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Sex-Specific Hip Movement Is Correlated With Pelvis and Upper Body Rotation During Running

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.657357 ◽

2021 ◽

Vol 9 ◽

Author(s):

Maurice Mohr ◽

Robin Pieper ◽

Sina Löffler ◽

Andreas R. Schmidt ◽

Peter A. Federolf

Keyword(s):

Principal Component ◽

Waveform Analysis ◽

Upper Body ◽

Whole Body ◽

Lower Body ◽

Body Rotation ◽

Running Injuries ◽

Hip Kinematics ◽

Transverse Rotation ◽

K 12

There is a sex bias for common overuse running injuries that are associated with sex-specific hip kinematics. Gait retraining programs aimed at altering hip kinematics may be more efficient if they incorporated an understanding of how hip kinematics are correlated with the movement of the remaining body segments. We applied a principal component analysis to structure the whole-body running kinematics of 23 runners (12 ♀) into k = 12 principal movements (PMk), describing correlated patterns of upper and lower body movements. We compared the time-dependent movement amplitudes with respect to each PMk between males and females using a waveform analysis and interpreted our findings according to stick figure animations. The movement amplitudes of two PMs (PM6 and PM8) showed statistically significant effects of “sex,” which were independent of running speed. According to PM8, females showed more hip adduction, which correlated with increased transverse rotation of the pelvis and upper body compared to men. We propose that increased hip adduction and upper body rotation in female runners may be a strategy to compensate for a less efficient arm and upper body swing compared to men. Gait interventions aimed at reducing hip adduction and running-related injuries in female runners should consider instructions for both upper and lower body to maximize training efficacy.

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Impact of Kinanthropometric Differences According to Non-Professional Sports Activity Practiced

Applied Sciences ◽

10.3390/app11115063 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5063

Author(s):

Daniel J. Navas Harrison ◽

Ana María Pérez Pico ◽

Raquel Mayordomo

Keyword(s):

Physical Activity ◽

Body Composition ◽

Professional Sports ◽

Whole Body ◽

Lower Body ◽

Basketball Players ◽

Sports Activity ◽

Sedentary Population ◽

Activity Performance ◽

Amateur Athlete

Kinanthropometry allows us to analyze variations in physical dimensions and body composition. This study’s objective was to evaluate the kinanthropometric differences based on physical activity performance, depending on whether the lower body or the whole body is more or less potent and the differences with a sedentary population. We analyzed 131 individuals (74 men and 57 women), with an average age of 22.68 ± 2.98 years. We differentiated three populations: sedentary (n = 63), runners (n = 20), and basketball players (n = 48). Measurements and indices were obtained following the international protocol of the International Society for the Advancement of Kinanthropometry (ISAK). The results show differences between the populations regarding weight, height, wingspan, and certain perimeters, diameters, and morphotypes depending on the predominant training type and the sedentary population. These anthropometric measurements will allow the amateur athlete to compare between seasons or other moments of training, pay attention to their evolution, and assess the possibility of changes in training.

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Therapy-Resistant Atypical Downbeat Nystagmus with Vertigo Confined to Specific Head-Hanging Positions: Mapping to the Gravity Vector on a Multi-Axis Turntable

Case Reports in Neurology ◽

10.1159/000517840 ◽

2021 ◽

pp. 464-469

Author(s):

Dominik Péus ◽

Dominik Straumann ◽

Alexander Huber ◽

Christopher J. Bockisch ◽

Vincent Wettstein

Keyword(s):

Hair Cells ◽

Whole Body ◽

Downbeat Nystagmus ◽

Two Dimensional ◽

Body Rotation ◽

Therapeutic Approaches ◽

Atypical Case ◽

Anterior Semicircular Canal ◽

Head Positions ◽

Peripheral Origin

Downbeat nystagmus (DBN) observed in head-hanging positions, may be of central or peripheral origin. Central DBN in head-hanging positions is mostly due to a disorder of the vestibulo-cerebellum, whereas peripheral DBN is usually attributed to canalolithiasis of an anterior semicircular canal. Here, we describe an atypical case of a patient who, after head trauma, experienced severe and stereotypic vertigo attacks after being placed in various head-hanging positions. Vertigo lasted 10–15 s and was always associated with a robust DBN. The provocation of transient vertigo and DBN, which both showed no decrease upon repetition of maneuvers, depended on the yaw orientation relative to the trunk and the angle of backward pitch. On a motorized, multi-axis turntable, we identified the two-dimensional Helmholtz coordinates of head positions at which vertigo and DBN occurred (y-axis: horizontal, space-fixed; z-axis: vertical, and head-fixed; x-axis: torsional, head-fixed, and unchanged). This two-dimensional area of DBN-associated head positions did not change when whole-body rotations took different paths (e.g., by forwarding pitch) or were executed with different velocities. Moreover, the intensity of DBN was also independent of whole-body rotation paths and velocities. So far, therapeutic approaches with repeated liberation maneuvers and cranial vibrations were not successful. We speculate that vertigo and DBN in this patient are due to macular damage, possibly an unstable otolithic membrane that, in specific orientations relative to gravity, slips into a position causing paroxysmal stimulation or inhibition of macular hair cells.

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Antihysteresis of perceived longitudinal body axis during continuous quasi-static whole-body rotation in the earth-vertical roll plane

Experimental Brain Research ◽

10.1007/s00221-011-2572-8 ◽

2011 ◽

Vol 209 (3) ◽

pp. 443-454

Author(s):

M. Tatalias ◽

C. J. Bockisch ◽

G. Bertolini ◽

D. Straumann ◽

A. Palla

Keyword(s):

Body Axis ◽

Whole Body ◽

Body Rotation ◽

Longitudinal Body Axis ◽

Vertical Roll ◽

The Earth

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Recognition and prediction of driver’s whole body posture model

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/09544070211068676 ◽

2022 ◽

pp. 095440702110686

Author(s):

Jun Wu ◽

Jian Liu ◽

Xiuyuan Li ◽

Lingbo Yan ◽

Libo Cao ◽

...

Keyword(s):

Regression Model ◽

Body Posture ◽

Upper Body ◽

Whole Body ◽

Lower Body ◽

Key Factor ◽

Upper Body Posture ◽

Spatial Coordinates ◽

Posture Prediction ◽

Connection Length

The driver’s whole-body posture at the time of a collision is a key factor in determining the magnitude of injury to the driver. However, current researchs on driver posture models only consider the upper body posture of the driver, and the lower body area which is not perceived by sensors is not studied. This paper investigates the driver’s posture and establishes a 3D posture model of the driver’s whole body through the application of machine vision algorithms and regression model statistics. This study proposes an improved Kinect-OpenPose algorithm for identifying the 3D spatial coordinates of nine keypoints of the driver’s upper body. The posture prediction regression model of four keypoints of the lower body is established by conducting volunteer posture acquisition experiments on the developed simulated driving seat and analyzing the volunteer posture data through using the principal components of the upper body keypoints and the seat parameters. The experiments proved that the error of the regression model in this paper is minor than that of current studies, and the accuracy of the keypoint location and the keypoint connection length of the established driver whole body posture model is high, which provides implications for future studies.

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Effects of repeated snowboard exercise in virtual reality with time lags of visual scene behind body rotation on head stability and subjective slalom run performance in healthy young subjects

Acta Oto-Laryngologica ◽

10.1080/00016489.2016.1193890 ◽

2016 ◽

Vol 136 (11) ◽

pp. 1121-1124 ◽

Cited By ~ 2

Author(s):

Yoshiro Wada ◽

Suetaka Nishiike ◽

Tadashi Kitahara ◽

Toshiaki Yamanaka ◽

Takao Imai ◽

...

Keyword(s):

Virtual Reality ◽

Visual Scene ◽

Time Lags ◽

Body Rotation ◽

Head Stability ◽

Young Subjects

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The perception threshold of the vestibular Coriolis illusion

Journal of Vestibular Research ◽

10.3233/ves-210073 ◽

2021 ◽

pp. 1-8

Author(s):

Mark M.J. Houben ◽

Arjan J.H. Meskers ◽

Eric L. Groen

Keyword(s):

Head Movement ◽

Generalized Linear Model ◽

Peak Velocity ◽

Head Rotation ◽

Velocity Model ◽

Whole Body ◽

Laboratory Studies ◽

Perception Threshold ◽

Spatial Disorientation ◽

S Peak

BACKGROUND: The vestibular Coriolis illusion is a disorienting sensation that results from a transient head rotation about one axis during sustained body rotation about another axis. Although often used in spatial disorientation training for pilots and laboratory studies on motion sickness, little is known about the minimum required rotation rate to produce the illusion. OBJECTIVE: This study determined the perception threshold associated with the Coriolis illusion. METHODS: Nineteen participants performed a standardized pitching head movement during continuous whole-body yaw rotation at rates varying between 5 to 50 deg/s. The participants reported their motion sensation in relation to three hypothesized perception thresholds: 1) any sense of motion, 2) a sense of rotation, and 3) a sense of rotation and its direction (i.e., the factual Coriolis illusion). The corresponding thresholds were estimated from curves fitted by a generalized linear model. RESULTS: On average threshold 1 was significantly lower (8 deg/s) than thresholds 2 and 3. The latter thresholds did not differ from each other and their pooled value was 10 deg/s. CONCLUSIONS: The Coriolis illusion is perceived at yaw rates exceeding 10 deg/s using a pitching head movement with 40 deg amplitude and 55 deg/s peak velocity. Model analysis shows that this corresponds to an internal rotation vector of 6 deg/s. With this vector the Coriolis perception threshold can be predicted for any other head movement.

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Activity of Ventroposterior Thalamus Neurons During Rotation and Translation in the Horizontal Plane in the Alert Squirrel Monkey

Journal of Neurophysiology ◽

10.1152/jn.00761.2007 ◽

2008 ◽

Vol 99 (5) ◽

pp. 2533-2545 ◽

Cited By ~ 32

Author(s):

Vladimir Marlinski ◽

Robert A. McCrea

Keyword(s):

Horizontal Plane ◽

Peak Velocity ◽

Discharge Rate ◽

Stimulus Frequency ◽

Squirrel Monkeys ◽

Response Amplitude ◽

Whole Body ◽

Power Functions ◽

Stimulus Velocity ◽

Rotational Response

The firing behavior of 107 vestibular-sensitive neurons in the ventroposterior thalamus was studied in two alert squirrel monkeys during whole body rotation and translation in the horizontal plane. Vestibular-sensitive neurons were distributed primarily along the anterior and posterior borders of ventroposterior nuclei; three clusters of these neurons could be distinguished based on their location and inputs. Eighty-four neurons responded to rotation; 66 (78%) of them responded to rotation only and 18 (22%) to both rotation and translation. Forty-one neurons were sensitive to linear translation; 23 (56%) of them responded to translation only. The population rotational response to 0.5-Hz sinusoids with a peak velocity of 40°/s showed a gain of 0.23 ± 0.15 spike·s−1·deg−1·s−1 and phase lagging behind the angular velocity by −9.3 ± 34.1°. Although rotational response amplitude increased with the stimulus velocity across the range 4–100°/s, the rotational sensitivity decreased with and was inversely proportional to the stimulus velocity. The rotational response amplitude and sensitivity increased with the stimulus frequency across the range 0.2–4.0 Hz. The population response to sinusoidal translation at 0.5 Hz and 0.1 g amplitude had a gain of 111.3 ± 53.7 spikes·s−1· g−1 and lagged behind stimulus acceleration by −71.9 ± 42.6°. Translational sensitivity decreased as acceleration increased and this was inversely proportional to the square root of the acceleration. Results of this study imply that changes in the discharge rate of vestibular-sensitive thalamic neurons can be approximated using power functions of the angular and linear velocity of spatial motion.

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