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PubMed1999

Clinical validity and stability of active and passive cervical range of motion with regard to total and unilateral uniplanar motion.

STUDY DESIGN: A study of inter- and intra-examiner reliability and clinical validity using two instruments for assessment of spinal range of motion in healthy individuals. OBJECTIVE: To assess the clinical validity, stability, and normative values for active and passive cervical range of motion as measured by the CA-6000 (Orthopedic Systems Inc., Union City, CA), an electrogoniometer. SUMMARY OF BACKGROUND DATA: The authors' early trials with the electrogoniometer yielded values that differed substantially from those in other reports. The authors sought to resolve those discrepancies and understand their sources. METHODS: Axial rotations along the transverse, coronal, and frontal planes were measured as half-cycles (i.e., left-right or flexion-extension) that were repeated seven times per trial. Test-retest data were collected on the same healthy individuals for active and passive motion using men and women aged 20-39 years. For validity, simultaneous digital dual inclinometry and electrogoniometry were performed twice over a 1-week interval. In addition, a bench test was performed for validation of axial rotation. RESULTS: Clinical reliability of the CA-6000 was high for inter- and intra-examiner studies of total active motion, and validity was high when compared with that obtained with dual inclinometry. Total range of motion had less between-trial variability than half-cycles, axial rotation and lateral bending measurements had greater reliability than did flexion-extension measurements, and active motion was more reliable than passive motion. CONCLUSION: The CA-6000 provides valid and reliable measures of cervical range of motion. Discrepancies reported elsewhere appear to have arisen from several sources, as discussed in this article.

Adult↗
PubMed2003

A comparison of lumbar range of motion and functional ability scores in patients with low back pain: assessment for range of motion validity.

STUDY DESIGN: A clinical convenience sample of workers with low back problems was tested once for a variety of parameters. OBJECTIVES: To quantify the links between lumbar range of motion and scores obtained from functional evaluation tests. SUMMARY OF BACKGROUND DATA: Although lumbar range of motion traditionally has been the standard used to determine disability for the purposes of compensation, a concern arises from the fact that a discrete physical impairment associated with low back pain and diminished range of motion often is never found. METHODS: This study involved 18 workers with chronic low back pain referred to a rehabilitation center for determination of compensation and fitness for return to work. Lumbar range of motion was precisely and accurately measured with a three-dimensional lumbar motion instrument. In addition, typical functional tests were performed for each patient. Comparisons were made between all the lumbar range of motion values and each of the functional ability scores. RESULTS: The most notable finding was the lack of significant correlation between most of the lumbar range of motion values and the functional test scores. Only 9 of a possible 144 correlations were significant. CONCLUSIONS: The relation between lumbar range of motion measures and functional ability is weak or nonexistent. This has implications for clinical practice as it relates to disability determination for patients with chronic low back pain, and perhaps for the current impairment guidelines of the American Medical Association.

Hand Strength↗
PubMed2004

Visual mechanisms of motion analysis and motion perception.

Psychophysical experiments on feature tracking suggest that most of our sensitivity to chromatic motion and to second-order motion depends on feature tracking. There is no reason to suppose that the visual system contains motion sensors dedicated to the analysis of second-order motion. Current psychophysical and physiological data indicate that local motion sensors are selective for orientation and spatial frequency but they do not eliminate any of the three main models-the Reichardt detector, the motion-energy filter, and gradient-based sensors. Both psychophysical and physiological data suggest that both broadly oriented and narrowly oriented motion sensors are important in the early analysis of motion in two dimensions.

Humans↗
PubMed2006

The influence of biological motion perception on structure-from-motion interpretations at different speeds.

Nonrigid point-light representations of biological motion are ideal to test higher level influences on structure-from-motion (SFM) perception. Here, we investigated the influence of biological motion perception on 3D SFM interpretations at different speeds. We presented nonrigid biological motion and rigid structures rotating around the vertical axis. The familiarity of the stimuli was changed by presenting three walker types: normal, inverted, and phase scrambled. Subjects had to discriminate rotation in depth and rigidity. We found that at lower-than-natural gait speeds, subjects perceived nonrigid biological motion to be rotating in depth, especially when the walker type was less familiar. In contrast, the percept of rigidity was correct at all speeds. A second experiment, in which a constant fraction of the gait cycle was presented, confirmed the influence of speed and additionally showed that brief displays of a familiar form at a high speed facilitate biological motion interpretations. The more veridical percept of rotation toward higher speeds fits the idea of biological motion channels tuned to higher-more natural walking-speeds that overrule a default assumption to perceive trajectories in depth. We also speculate that the rotation-in-depth percept at lower speeds points toward the existence of low-speed-tuned object motion channels.

Depth Perception↗
PubMed2004

An analysis of full range of motion vs. partial range of motion training in the development of strength in untrained men.

The purpose of this investigation was to compare partial range of motion versus full range of motion training in the development of maximal strength. The bench press was used as the criterion measurement. The study was conducted over a 10-week period with training sessions occurring twice per week. Subjects were divided into 3 groups. Group 1 (N = 11) trained with 3 full range of motion sets on the bench press. Group 2 (N = 15) trained with 3 partial range of motion sets. A partial repetition was defined as one that is beyond the sticking point 2 to 5 inches from full extension of the elbows. Group 3 (N = 30) trained with a combination of partial and full range of motion sets. All subjects were pre- and posttested on the bench press through a full range of motion using a 1 repetition maximum. Each of the 3 groups demonstrated statistically significant increases in strength from pre- to posttest. No differences were found between groups. These findings appear to suggest that partial range of motion training can positively influence the development of maximal strength. Therefore, those involved in the strength and conditioning profession can confidently including this method as an adjunct to their normal training protocols when working with individuals similar to those found in this investigation. It is suggested that additional research be conducted to further establish the effectiveness of partial range of motion training in developing maximal strength.

Adaptation, Physiological↗
PubMed1995

The effect of intercarpal joint motion on wrist motion: are there key joints? An in vitro study.

The contribution of each intercarpal joint individually and as a member of a regional group to total wrist motion was analyzed in 10 fresh, frozen cadaver specimens. Each intercarpal joint had an effect on the total wrist motion, but the contribution of each to the different planes of motion was not equal. The scaphoid-capitate joint had a governing effect on the motion of a region comprised of scaphoid-trapezium, scaphoid-trapezoid, and scaphoid-capitate. The lunate-capitate joint had a governing effect on the motion of a region comprised of the lunate-triquetrum, lunate-capitate, triquetrum-hamate, and hamate-capitate complex. Elimination of motion in either of the key governing joints affected total wrist motion the same as elimination of motion in all the joints in that region. Intercarpal fusion for treatment of ligament injury of the proximal intercarpal row may be limited to the scaphoid-capitate or lunate-capitate joint. There is no need to attempt fusion in all joints of either of the two regions.

Adolescent↗
PubMed2005

Vertical linear self-motion perception during visual and inertial motion: more than weighted summation of sensory inputs.

We evaluated visual and vestibular contributions to vertical self motion perception by exposing subjects to various combinations of 0.2 Hz vertical linear oscillation and visual scene motion. The visual stimuli presented via a head-mounted display consisted of video recordings of the test chamber from the perspective of the subject seated in the oscillator. In the dark, subjects accurately reported the amplitude of vertical linear oscillation with only a slight tendency to underestimate it. In the absence of inertial motion, even low amplitude oscillatory visual motion induced the perception of vertical self-oscillation. When visual and vestibular stimulation were combined, self-motion perception persisted in the presence of large visual-vestibular discordances. A dynamic visual input with magnitude discrepancies tended to dominate the resulting apparent self-motion, but vestibular effects were also evident. With visual and vestibular stimulation either spatially or temporally out-of-phase with one another, the input that dominated depended on their amplitudes. High amplitude visual scene motion was almost completely dominant for the levels tested. These findings are inconsistent with self-motion perception being determined by simple weighted summation of visual and vestibular inputs and constitute evidence against sensory conflict models. They indicate that when the presented visual scene is an accurate representation of the physical test environment, it dominates over vestibular inputs in determining apparent spatial position relative to external space.

Adolescent↗
PubMed2003

Novel prospective respiratory motion correction approach for free-breathing coronary MR angiography using a patient-adapted affine motion model.

A novel technique is presented which enables the calibration of a 3D affine respiratory motion model to the individual motion pattern of the patient. The concept of multiple navigators and precursory navigators is introduced to address nonlinear properties and hysteresis effects of the model parameters with respect to the conventional diaphragmatic navigator. The optimal combination and weighting of the navigators is determined on the basis of a principal component analysis (PCA). Thus, based on a given navigator measurement the current motion state of the object can be predicted by means of the calibrated motion model. The 3D motion model is applied in high-resolution coronary MR angiography examinations (CMRA) to prospectively correct for respiration-induced motion. The basic feasibility of the proposed calibration procedure was shown in 16 volunteers. Furthermore, the application of the calibrated motion model for CMRA examinations of the right coronary artery (RCA) was tested in 10 volunteers. The superiority of a calibrated 3D translation model over the conventional 1D translation model with a fixed correction factor and the potential of affine prospective motion correction for CMRA are demonstrated.

Adult↗
PubMed2006

Advantages and limitations of prospective head motion compensation for MRI using an optical motion tracking device.

RATIONALE AND OBJECTIVES: Subject motion appears to be a limiting factor in numerous magnetic resonance (MR) imaging (MRI) applications. In particular, head tremor, which often accompanies stroke, may render certain high-resolution two- (2D) and three-dimensional (3D) techniques inapplicable. The reason for that is head movement during acquisition. The study objective is to achieve a method able to compensate for complete motion during data acquisition. The method should be usable for every sequence and easily implemented on different MR scanners. MATERIALS AND METHODS: The possibility of interfacing the MR scanner with an external optical motion-tracking system capable of determining the object's position with submillimeter accuracy and an update rate of 60 Hz is shown. Movement information on the object position (head) is used to compensate for motion in real time by updating the field of view (FOV) by recalculating the gradients and radiofrequency parameter of the MR scanner during acquisition of k-space data, based on tracking data. RESULTS: Results of rotation phantom, in vivo experiments, and implementation of three different MRI sequences, 2D spin echo, 3D gradient echo, and echo planar imaging, are presented. Finally, the proposed method is compared with the prospective motion correction software available on the scanner software. CONCLUSION: A prospective motion correction method that works in real time only by updating the FOV of the MR scanner is presented. Results show the feasibility of using an external optical motion-tracking system to compensate for strong and fast subject motion during acquisition.

Algorithms↗
PubMed1997

Validity and reliability of measures obtained from the OSI CA-6000 Spine Motion Analyzer for lumbar spinal motion.

SUMMARY. The aims of this investigation were firstly to determine the level of agreement between angular measures of lumbar spinal motion recorded by the OSI CA 6000 Spine Motion Analyzer (OSI SMA) and measures obtained from X-rays of subjects without lumbar symptoms, and secondly to determine the intra-rater reliability of measures of lumbar spinal range of motion using the OSI SMA on individuals with lumbar symptoms. To fulfill the first aim 13 asymptomatic subjects (mean age = 28.6 years; SD = 7.1) performed the motions of lumbar flexion, extension, side bending to the right, and side bending to the left twice while wearing the OSI SMA, and once for the exposure of the X-ray. The difference between the measures obtained by the two methods was plotted against the average of those measures for each subject to illustrate the level of agreement of the two methods. Differences between measures that were within one standard deviation of the mean were as follows: for flexion, 7 out of 10 showed less than 8 degrees difference; for extension, 7 out of 10 showed less than 7 degrees difference; for side bending to the right, 11 out of 13 showed less than 6 degrees difference; and for side bending to the left, 10 out of 13 showed less than 5 degrees difference. For asymptomatic subjects, measures obtained from the OSI SMA appear to provide good agreement with measures of lumbar spinal motion in the sagittal and frontal planes as determined by X-rays. To fulfil the second aim of the investigation thirty subjects with lumbar symptoms (mean age = 35.9 years; SD = 14.2) performed four trials of lumbar motion to their maximum for flexion, extension, side bending to the right and left, and rotation to the right and left. The OSI SMA hardware was then completely removed and replaced by the same examiner, and the trials were repeated. ICC values were 0.903 or higher for all motions. These results suggest that active range of motion measures obtained with the OSI SMA in subjects with lumbar symptoms are consistent over repeated trials. Copyright 1997 Harcourt Publishers Ltd.

Journal Article↗
PubMed1990

Motion analysis of the cervical spine in athetoid cerebral palsy. Extension-flexion motion.

Frequently instability and premature onset of spondylosis of the cervical spine are found in athetoid cerebral palsy (CP) patients. These structural abnormalities appear to be related to athetoid motion of the neck in CP. Through motion analysis, the authors aimed to clarify the abnormalities of cervical motion that could precipitate structural abnormalities. The gross characteristic feature of cervical motion in athetoid CP is "whip movement." Both velocity and acceleration during extension-flexion motion were greater than in normal subjects, especially at the upper cervical levels. Also, a sudden increase in velocity and acceleration occurred during rapid motions at certain levels, followed by a larger range of motion of the cervical spine. Such kinematic abnormalities were thought to generate a greater shearing force and bending moment exerted on the corresponding cervical articulations-discs and facets. Olisthetic instability often accompanied disc degeneration at the upper cervical levels. A large range of extension--flexion motion of the cervical spine, analogous to a cantilever, caused a repeated bending moment of extraordinary magnitude and was regarded as a precipitative factor for disc degeneration and osteophytosis common at the middle and lower levels of the disc.

Adult↗
PubMed2004

Human cortical auditory motion areas are not motion selective.

The existence of a specialized mechanism supporting auditory motion processing in humans is a matter of debate in the psychophysical literature. Recent functional neuroimaging data appear to have resolved the debate in favor of a specialized motion system in that several studies have found cortical regions that seem to be motion selective. While all these studies contrast some form of moving auditory stimulation with a stationary stimulus, none have adequately controlled for the possibility that these areas are simply computing sound-source location and not motion per se: a moving stimulus varies in spatial location as well as motion, and so a system computing spatial location (and not motion) would be activated in response to both a moving and stationary sound source. To control for this possibility, ten subjects were scanned while listening to moving stimuli and while listening to stationary stimuli that varied randomly in spatial location. Consistent with previous imaging studies, we found that a motion stimulus when contrasted with rest (scanner noise) activated STG/planum temporale (bilaterally) and right parietal lobe. However, stationary stimuli presented at varying locations activated these regions equally well, arguing against the existence of specialized motion-processing areas in human cortex.

Acoustic Stimulation↗
PubMed1986

Motion detection in the presence and absence of background motion in an Anolis lizard.

Anolis lizards respond to a moving object viewed in the periphery of their visual field by turning their eye to fixate the object with their central fovea. This paper describes the relative effectiveness of different patterns of motion of a small black lure in eliciting these eye movements and the way motion of a backdrop of vegetation affects the response. The stimulus was positioned 45 degrees from the animal's line of gaze and oscillated in the vertical axis at different frequencies between 0.5 and 10 Hz. At each frequency, the amplitude of the oscillation was increased until the lizard flicked its eye towards the stimulus. The minimum amplitude needed for response (0.22 degrees of visual angle) was independent of frequency and waveform. The probability of any response occurring was, however, lower at higher frequencies (7 and 10 Hz) and a 1.5 Hz square wave evoked the greatest proportion of responses. Sinusoidal oscillation of a background of vegetation at 1.6 Hz during or before motion of the stimulus lure reduced the probability of an eye flick but did not raise the minimum amplitude needed for a response. The suppressive effect was greatest when the lure was oscillated at frequencies close to that of the background. It is concluded that Anolis, which rely upon motion to detect objects in the periphery of the visual field, filter out irrelevant motion such as that of windblown vegetation by responding preferentially to particular patterns of motion and short term habituation to commonly present patterns of motion.

Acceleration↗
PubMed1990

Comparison of various motion stimuli on motion sickness and acquisition of adaptation in Suncus Murinus.

Effects of various types of motion stimuli were compared to investigate optimum method to elicit motion sickness and adaptation in Suncus murinus (suncus). Three different direction of shaking in the horizontal plane, back and forth, right and left and revolving, induced emetic response to the similar extent. However, vertical shaking was far less effective in inducing motion sickness. Mild and severe horizontal shaking (15 min per day) was continued for 14 days and emetic response to standard motion stimulus was compared before and after the training. The severe daily acceleration strongly depressed the susceptibility to motion stimulus. The mild acceleration which was not emetic stimulus in itself also remarkably attenuated the vomiting response to standard motion stimulus. These results indicate that 1) the emetic responsiveness of the suncus does not depend on the modes of shaking as long as the direction is in the horizontal plane, 2) the suncus is relatively refractory to the vertical linear acceleration and 3) the adaptation to motion stimulus does not develop on the latest peripheral steps of the vomiting reflex pathways.

Adaptation, Physiological↗
PubMed2003

Retinotopic pathways providing motion-selective information to the lobula from peripheral elementary motion-detecting circuits.

Recordings from afferent channels from the medulla supplying deep neuropils of the fly's optic lobes reveal different filter properties among the three classes of afferent neurons: transmedullary cells, T2 neurons, and Y cells. Whereas transmedullary cells respond to local flicker stimuli without discriminating these from directional or oriented motion, the T2 afferent neurons show clear motion orientation selectivity, which corresponds closely with a morphological bias in the orientation of their dendrites and could also be influenced by systems of local recurrent neurons in the medulla. A Y cell having a clearly defined terminal in the lobula, but having dendrite-like processes in the medulla and, possibly, the lobula plate, discriminates the direction of motion and its orientation. These results demonstrate unambiguously that the lobula receives information about motion and that the channels carrying it are distinct from those supplying wide-field motion-selective neurons in the lobula plate. Furthermore, recordings from a newly identified recurrent neuron linking the lobula back to the inner medulla demonstrate that the lobula discriminates nondirectional edge motion from flicker, thereby reflecting a property of this neuropil that is comparable with that of primary visual cortex in cats. The present findings support the proposal that elementary motion detecting circuits supply several parallel channels through the medulla, which segregate to, but are not shared by, the lobula and the lobula plate. The results are discussed in the context of other intracellular recordings from retinotopic neurons and with analogous findings from mammalian visual systems.

Afferent Pathways↗
PubMed1994

Modelling human motion perception. II. Beyond Fourier motion stimuli.

In the first part of this review a basic mechanism of motion perception was illustrated. The elementary motion detector (EMD) of the correlation type can account for the detection of "Fourier" motion stimuli in which the spatial intensity distribution on the retina is shifted over time. In recent years, novel classes of stimuli such as "drift-balanced" or "theta" motion (in which the picture elements carrying luminance contrast do not move, or move in the opposite direction to the traveling object defined by such element motion) were introduced into psychophysics. Such stimuli may play an important role in the understanding of "higher" visual processing which goes beyond the pure detection of motion. Thus, in the second part of the review, the question will be addressed as to what further processing steps, or more sophisticated mechanisms than the EMD, have to be assumed in order to understand more complex aspects of human motion perception.

Fourier Analysis↗
PubMed1995

Modulation of motion aftereffect by surround motion and its dependence on stimulus size and eccentricity.

As a mechanism to detect differential motion, we have proposed a model of 'a motion contrast detector' and have shown that it can explain the perceptual change from motion capture to induced motion with increasing stimulus size and decreasing eccentricity. To further test the feasibility of the model, we examined the effect of surround motion on the motion aftereffect (MAE) elicited in the center. Using a drifting grating surrounded by another drifting grating, the duration of MAE in the center after adaptation was measured for various surround velocities (Expt 1). MAE was stronger when the surround moved oppositely to, than together with, the center. This finding was consistent with some previous reports. Using similar stimuli, MAE was measured at various stimulus sizes and eccentricities by the cancellation technique (Expt 2). The effect of surround modulation turned out to vary with both size and eccentricity. We examined if the apparent dependence on eccentricity could reflect a simpler effect of cortical size when the data were rescaled according to a linear scaling factor. We interpret our results in terms of motion contrast detectors, possibly located in the area MT.

Adaptation, Ocular↗
PubMed2006

Sagittal plane motion in the human lumbar spine: comparison of the in vitro quasistatic neutral zone and dynamic motion parameters.

BACKGROUND: Disabling low back pain is often attributed to clinical instability but defining instability is problematic. The most common parameter used to characterize instability in the lab is the neutral zone which is measured with a quasi-static technique. But, it cannot be measured from continuous motion data. Our goal was to describe the relationship between the quasi-static neutral zone and dynamic motion parameters that might reflect laxity about the neutral position. We also sought to determine if dynamic parameters were correlated with disc degeneration. METHODS: Fifteen cadaveric lumbar motion segments were tested with both quasi-static and dynamic (continuous load) methods. Quasi-static range of motion and neutral zone were compared with dynamic range of motion, hysteresis loop width, and two parameters derived from the hysteresis data: transitional zone size and slope. Degeneration was graded macroscopically. FINDINGS: Neutral zone size was moderately correlated with hysteresis loop width (r=0.69) and strongly correlated with the transitional zone slope (r=-0.80). Degenerative grade had a significant effect on dynamic range of motion and transitional zone size and slope with differences found between grade 1 (normal) discs and higher grades. Only transitional zone slope was different between grades 1 and 2. INTERPRETATION: The transitional zone slope (representing the neutral region stiffness) had the strongest correlation with neutral zone and could best detect lower grades of degeneration. The transitional zone slope might be a useful parameter in dynamic studies investigating the association between degeneration and motion segment behavior.

Adult↗