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PubMed2001

Incisor and mandibular condylar movements of young adult females during maximum protrusion and lateratrusion of the jaw.

This study evaluated the correlations between condylar translation and incisor movements during maximum protrusion and lateratrusion. The sample was 27 adult females (23--35 years old), selected for normal temporomandibular function, occlusion, and skeletal patterns. Condylar and mandibular central incisor movements [linear distances (LD) and curvilinear pathways (CP)] were recorded in three dimensions for 20 s with an optoelectric (Optotrak) jaw-tracking system while each participant performed multiple maximum protrusive and lateratrusive cycles. Masticatory analysis and multilevel statistical programs computed the three-dimensional movements of the incisors and condylar hinge axis during protrusion and lateratrusion. CP of the incisor point averaged 12.0 mm (9.3 mm LD) during protrusion, 13.0 mm (11.5 mm LD) during right excursion and 12.3 mm (11.0 mm LD) during left excursion. CP of the condyles averaged 11.9--12.9 (9.2--9.5 LD) mm during protrusion. During lateratrusion the contralateral condyles moved anteroinferiorly 11.6--14.1 mm (9.5--10.2 mm LD); the ipsilateral condyles moved posterolaterally 5.8-6.8 mm (2.3--2.5 mm LD). The left condyles demonstrated more movement than the right condyles during protrusion and than the contralateral condyles during laterotrusion. Relative variation, as measured by the coefficient of variation, was greater for the movements of the ipsilateral than contralateral condyles. Incisor movements were only moderately related to condylar movements between individuals and between replicates; LDs showed stronger correlations than CPs; and correlations were stronger for lateratrusion than protrusion. While incisor and condylar movements were not affected by repeated protrusion, incisor CP (approx. 0.2 mm/cycle) and LD (approx. 0.1 mm/cycle) increased significantly with repeated excursive movements to the left and right. It was concluded that (1) incisor protrusion and lateratrusion provide moderately reliable measures of condylar translation; (2) the linear distances that the incisors move during lateratrusion provide the best measure of contralateral condylar translation; and (3) condylar movements are not affected by repeated protrusion or lateratrusion.

Adult↗
PubMed1998

Ago-antagonist muscle spindle inputs contribute together to joint movement coding in man.

The proprioceptive feedback associated with the performance of even quite simple movements is always generated by the whole set of muscles subjected to mechanical deformation (lengthening, shortening, contraction, etc.) during that particular movement. The question was addressed here as to how muscle spindle feedbacks arising from agonist and antagonist muscles may contribute to the coding of movement parameters such as the direction and velocity. For this purpose, the activity of single muscle spindle afferents located in the lateral peroneal nerve was analysed using the microneurographic technique, in human subjects performing repetitive voluntary movements, i.e., plantar/dorsal flexions of the ankle, at three different velocities (3, 4.5 and 6 degrees/s). The data obtained suggest that in humans, the direction of a slow movement may be specified on the basis of the spindle discharge rate, which is greater in the stretched than in the shortened muscle, and that the velocity of this movement might be correlated with the difference between the spindle activity occurring in the agonist and antagonist muscles. These neurophysiological data are in agreement with the results of previous psychophysical studies showing for example that a sensation of illusory movement can be elicited only when there exists an imbalance between the agonist versus antagonist vibration-induced Ia inputs. In addition, the greater the difference between the vibration frequencies applied to the two antagonist muscles, the higher the perceived movement velocity was found to be. All in all, joint movement perception seems to result from the co-processing by the central nervous system of the multiple spindle feedbacks originating from the whole set of muscles involved in the performance of a movement.

Adult↗
PubMed2001

Perceiving affect from arm movement.

We examined the visual perception of affect from point-light displays of arm movements. Two actors were instructed to perform drinking and knocking movements with ten different affects while the three-dimensional positions of their arms were recorded. Point-light animations of these natural movements and phase-scrambled, upside-down versions of the same knocking movements were shown to participants who were asked to categorize the affect of the display. In both cases the resulting confusion matrices were analyzed using multidimensional scaling. For the natural movements the resulting two-dimensional psychological space was similar to a circumplex with the first dimension appearing as activation and the second dimension as pleasantness. For the scrambled displays the first dimension was similar in structure to that obtained for the natural movements but the second dimension was not. With both natural and scrambled movements Dimension 1 of the psychological space was highly correlated to the kinematics of the movement. These results suggest that the corresponding activation of perceived affect is a formless cue that relates directly to the movement kinematics while the pleasantness of the movement appears to be carried in the phase relations between the different limb segments.

Affect↗
PubMed2000

Movement biomechanics goes upwards: from the leg to the arm.

The analysis of lower limb movements has been well established in biomechanics research and clinical applications for a long time. For these studies, powerful and very advanced tools have been developed to measure movement parameters and reaction forces. The main focus of interest aims towards gait movements while the understanding of the basic concepts is supported by numerous models. Definitions of physiological ranges and detection of pathological changes in movements open an increasingly valuable clinical field of application. If, however, the primary function of the upper extremities as highly variable and adaptive organ for manipulating tasks is the subject of interest, the situation becomes considerably more complex. The nature of free arm movements is completely different from being restricted, repeatable or cyclic as compared to gait. Therefore, the transfer of the knowledge and experience gained in lower extremity movement analysis to the analysis of upper extremities turns out to be difficult. A proposal for how to proceed in measurements, e.g. where to place the markers and how to calculate movements and angles of segments involved, will be discussed which results in the description of the joint movements of wrist, elbow and shoulder joint. The definition of the motion is a specific step in upper extremity motion analysis which is important in terms of repeatability and significance of the results. An example of assessing movement disorders in children with plexus lesion will illustrate the implications and the potential of upper extremity movement analysis in clinical applications.

Arm↗
PubMed1997

Dissociation in the neural control of single-joint and multi-joint movements in the thalamic ataxia syndrome.

We report a patient presenting with a right thalamic ataxia syndrome following a hemorrhage located in the left lateral and posterior thalamus. We investigated the fast goal-directed movements of the wrists (single-joint movements) and the fast pointing movements in the upper limbs (multi-joint movements). On the right side, single-joint movements were markedly hypermetric and characterized by an asymmetry in kinematics, an abnormality of ballistic movements which is considered to be a fundamental cerebellar disorder. By contrast, rapid multi-joint movements were only very slightly impaired. These results suggest that ballistic movements of the wrist are under the strong influence of the cerebello-thalamo-cortical pathway, while rapid pointing multi-joint movements in upper limb are mostly influenced by another pathway emerging from the lateral cerebellum, possibly the dentato-rubral or the dentato-reticular projections in the brainstem. The roles of these neuroanatomical pathways in the control of fast single-joint and multi-joint movements are discussed.

Ataxia↗
PubMed2002

A lesion of the posterior parietal cortex disrupts on-line adjustments during aiming movements.

It is long known that the posterior parietal cortex (PPC) is critically involved in goal-directed movements. Nevertheless, there are still some controversies about its specific functions. Although most published studies have emphasised the role of PPC in sensorimotor planning processes, it has been recently suggested that PPC can also participate to on-line movement control. We studied kinematics of hand movements in a patient with a bilateral PPC lesion who exhibited no deficit in planning of her grasping movements in central vision. She was instructed to reach and grasp a cylinder presented at different locations and her motor performance was compared to that of four healthy control subjects. To address on-line control specifically, the cylinder was quickly and unexpectedly jumped, on a few trials, at movement onset, to a new location some 10 degrees (of apparent visual angle) from the original location. The patient could easily grasp stationary objects seen in foveal vision, exhibiting the same kinematic pattern as controls. Therefore, she could plan movements accurately. In response to the object jump, unlike the controls, the patient was unable to amend her ongoing movement. In this situation, she completed two distinct movements, a first one toward the initial object location and a second one toward the final object location. These results support the hypothesis that beyond a role in movement planning, PPC plays a major role in the on-line control of reach-to-grasp movements.

Adult↗
PubMed2003

The potato virus X TGBp2 protein association with the endoplasmic reticulum plays a role in but is not sufficient for viral cell-to-cell movement.

Potato virus X (PVX) TGBp1, TGBp2, TGBp3, and coat protein are required for virus cell-to-cell movement. Plasmids expressing GFP fused to TGBp2 were bombarded to leaf epidermal cells and GFP:TGBp2 moved cell to cell in Nicotiana benthamiana leaves but not in Nicotiana tabacum leaves. GFP:TGBp2 movement was observed in TGBp1-transgenic N. tabacum, indicating that TGBp2 requires TGBp1 to promote its movement in N. tabacum. In this study, GFP:TGBp2 was detected in a polygonal pattern that resembles the endoplasmic reticulum (ER) network. Amino acid sequence analysis revealed TGBp2 has two putative transmembrane domains. Two mutations separately introduced into the coding sequences encompassing the putative transmembrane domains within the GFP:TGBp2 plasmids and PVX genome, disrupted membrane binding of GFP:TGBp2, inhibited GFP:TGBp2 movement in N. benthamiana and TGBp1-expressing N. tabacum, and inhibited PVX movement. A third mutation, lying outside the transmembrane domains, had no effect on GFP:TGBp2 ER association or movement in N. benthamiana but inhibited GFP:TGBp2 movement in TGBp1-expressing N. tabacum and PVX movement in either Nicotiana species. Thus, ER association of TGBp2 may be required but not be sufficient for virus movement. TGBp2 likely provides an activity for PVX movement beyond ER association.

Amino Acid Sequence↗
PubMed1999

The role of ventrolateral striatal acetylcholine in the production of tacrine-induced jaw movements.

The anticholinesterase tacrine induces tremulous jaw movements in rats, and considerable evidence indicates that this response is dependent upon ventrolateral striatal mechanisms. Three experiments were conducted to study the relation between ventrolateral striatal acetylcholine and the production of tremulous jaw movements. In Experiment 1, intracranial microinjection of the acetylcholine synthesis inhibitor hemicholinium-3 into the ventrolateral neostriatum reduced tremulous jaw movements induced by 5.0 mg/kg tacrine. Microinjection of hemicholinium into a cortical site dorsal to striatum (Experiment 2) was without significant effect upon tacrine-induced tremulous jaw movements. In Experiment 3, rats were implanted with dialysis probes in the ventrolateral striatum to measure extracellular levels of acetylcholine during tacrine-induced jaw movements. Tacrine (2.5-5.0 mg/kg) increased both extracellular acetylcholine and tremulous jaw movements. The 5.0 mg/kg dose of tacrine produced a substantial increase in ventrolateral striatal acetylcholine levels (324% of baseline within 30 min). Across all tacrine-treated rats there was a significant linear correlation between tremulous jaw movements and acetylcholine levels (r = +0.56) during the first 30-min postinjection period. This correlation was largely due to the group that received 5.0 mg/kg tacrine; within this group, there was a very high correlation (r = +0.87) between tremulous jaw movements and acetylcholine levels in the first sample after injection. These data are consistent with the notion that tremulous jaw movements induced by tacrine are mediated by ventrolateral striatal acetylcholine. Moreover, these results suggest that dialysis methods could be used to monitor the relation between striatal acetylcholine and tremulous movements induced by a variety of different conditions.

Acetylcholine↗
PubMed2000

Effects of H1 antagonists on cholinomimetic-induced tremulous jaw movements: studies of diphenhydramine, doxepin, and mepyramine.

In several previous studies, tremulous jaw movements in rats have been used to assess the effects of antiparkinsonian drugs and atypical antipsychotics. Because antihistamines such as diphenhydramine are used as antiparkinsonian agents, and atypical antipsychotic drugs such as clozapine and olanzapine have high affinity for histamine H1 receptors, the present study investigated the effects of H1 antagonists on cholinomimetic-induced jaw movements. Diphenhydramine, doxepin, and mepyramine (all injected IP 2.5-20.0 mg/kg) were assessed for their ability to block the jaw movements induced by 5.0 mg/kg of the anticholinesterase tacrine. Within this dose range, only diphenhydramine produced a robust and significant reduction in jaw movement activity. Thus, diphenhydramine was subjected to further testing, which employed procedures previously used to assess the effects of other antitremorogenic drugs, such as clozapine. Diphenhydramine did not induce jaw movement activity. In addition to suppressing jaw movement activity after acute injections, diphenhydramine also suppressed tacrine-induced jaw movements after repeated (14-day) administration. In summary, the present results show that diphenhydramine suppresses cholinomimetic-induced jaw movements, an effect that is similar to other antiparkinsonian or antitremor drugs such as anticholinergics, L-DOPA, DA antagonists, and clozapine. Nevertheless, doxepin produced only mild effects, and mepyramine, which has a higher affinity and selectivity than diphenhydramine for H1 receptors, failed to suppress cholinomimetic-induced jaw movements. These results suggest that diphenhydramine suppresses tremulous movements through a mechanism that does not depend upon antagonism of histamine H1 receptors.

Animals↗
PubMed1992

An evaluation of the importance of formal, maternal fetal movement counting as a measure of fetal well-being.

Maternal perception of fetal movements has, over the years, become recognised as a valuable tool for early detection of fetal compromise. Several studies published in the mid-1970s have demonstrated that a reduction or cessation in maternally perceived fetal movements may precede antepartum late fetal death by a day or longer. From these findings formal fetal movement counting emerged as a valuable, non-invasive method of assessing fetal well-being; the belief being that clinical actions taken on the basis of reduced fetal movement counting may prevent antepartum death or morbidity. Conversely, more recent studies have failed to demonstrate that there is a beneficial effect of a formal, fetal movement counting policy on antepartum death. It is not disputed that fetal movements are of clinical importance but it seems that routine daily counting of fetal movements by women followed by appropriate action when movements are reduced offers no advantages over formal inquiry about fetal movements during standard antenatal care. Thus, the application of formal, maternal fetal movement counting as a method of fetal surveillance to reduce late antepartum death must be questioned.

Female↗
PubMed2000

The DopFet system: a new ultrasonic Doppler system for monitoring and characterization of fetal movement.

To enable the investigation of fetal movement in a manner similar to fetal heart rate (FHR) monitoring we have developed an apparatus (the DopFet system) that consists of a pair of miniature sensors, a 2-MHz continuous-wave directional Doppler electronic module and a laptop personal computer. One of the sensors is aimed at the fetal limbs and the other at the thorax to detect heart and upper body movements. The signals are analyzed, presented in real-time and postprocessed by software developed by us. The postprocessing software computes a number of parameters (the DopFet parameters) describing fetal movement. These parameters can be divided into two categories: parameters that describe the quantity of fetal movement (i.e., number of movements) and parameters that describe qualitative aspects of fetal movement (i.e., average movement duration). Future studies using the DopFet system will be aimed at discovering which of these parameters or combination of parameters is the best indicator of fetal well-being. We present an example of a 0.5 h recording and the results of testing on 23 volunteer mothers. These results show good sensitivity of the system compared to real-time ultrasound (US). The system detects 96% of rolling movements, 100% of flexion movements and 97% of leg movements.

Female↗
PubMed1996

Reverse learning and the physiological basis of eye movement desensitization.

Eye movement desensitization is a new and effective procedure for post-traumatic stress disorder that requires explanation. Reverse learning is a model developed in artificial neural networks as a theoretical explanation of rapid-eye-movement sleep. It demonstrates that an overloaded node within a network can be consolidated with a series of non-specific activations. Rapid-eye-movement sleep is suspected to have a memory consolidation function. Ponto-geniculo-occipital spikes, which occur in rapid-eye-movement sleep, are a candidate for such activations in the real brain. In cats, the phasic functions of rapid-eye-movement sleep are driven by ponto-geniculo-occipital spikes, which are non-specific, at highest amplitude in the visual system but present in other parts of the cortex. Such spikes can be evoked by sensory events such as eye movements. There is evidence of similar events in the human brain. Induced eye movements could generate ponto-geniculo-occipital equivalent spikes and eye movement desensitization/reprocessing could be explained as a focused and artificial exploitation of the rapid-eye-movement sleep mechanism. This theory of eye movement desensitization/reprocessing enables some explanation of current results and may be relevant to other problems, such as stereotyped behaviour.

Animals↗
PubMed2000

A comparison of ventilatory prostate movement in four treatment positions.

PURPOSE: To ensure target coverage during radiotherapy, all sources of geometric uncertainty in target position must be considered. Movement of the prostate due to breathing has not traditionally been considered in prostate radiotherapy. The purpose of this study is to report the influence of patient orientation and immobilization on prostate movement due to breathing. METHODS AND MATERIALS: Four patients had radiopaque markers implanted in the prostate. Fluoroscopy was performed in four different positions: prone in alpha cradle, prone with an aquaplast mold, supine on a flat table, and supine with a false table under the buttocks. Fluoroscopic movies were videotaped and digitized. Frames were analyzed using 2D-alignment software to determine the extent of movement of the prostate markers and the skeleton for each position during normal and deep breathing. RESULTS: During normal breathing, maximal movement of the prostate markers was seen in the prone position (cranial-caudal [CC] range: 0.9-5.1 mm; anterior-posterior [AP] range: up to 3.5 mm). In the supine position, prostate movement during normal breathing was less than 1 mm in all directions. Deep breathing resulted in CC movements of 3.8-10.5 mm in the prone position (with and without an aquaplast mold). This range was reduced to 2.0-7.3 mm in the supine position and 0.5-2.1 mm with the use of the false table top. Deep breathing resulted in AP skeletal movements of 2.7-13.1 mm in the prone position, whereas AP skeletal movements in the supine position were negligible. CONCLUSION: Ventilatory movement of the prostate is substantial in the prone position and is reduced in the supine position. The potential for breathing to influence prostate movement, and thus the dose delivered to the prostate and normal tissues, should be considered when positioning and planning patients for conformal irradiation.

Adenocarcinoma↗
PubMed1986

Graphical analysis of two-dimensional eye movements.

Horizontal and vertical monocular movements were recorded by electronystagmography using silver plate electrodes or by the magnetic search coil system. Both horizontal and vertical monocular movements were simultaneously measured with the use of a computer-controlled testing system. The data was composed by the computer and presented as a two-dimensional graphical plot of the actual eye movement trajectories. There are three factors in eye movements, that is, slow component of eye movements--pursuit; quick component--saccades; and fixation. The two-dimensional plot of pursuit monocular movements in normal subjects indicated that the eye did not move in a perfectly straight horizontal or vertical line. The plot appeared to be a series of smooth and snaky movements. Saccades showed quick jumping movement to reach a target and fixation. During fixation, eye position was not restricted to the point of a target and the eye moved around the target. Disturbance of pursuit is known as saccadic or ataxic. A two-dimensional plot of pathological pursuit showed a series of smaller saccades and fixation. Disturbance of saccades is shown as overshoot or undershoot. Also, a two-dimensional plot of pathological saccades was made of smaller saccades and of fixation. Failure of fixation showed larger and more irregular movements around the target. Thus, the two-dimensional plot of monocular movements clearly showed normal or pathological pursuit, saccades, and fixation.

Brain Diseases↗
PubMed1998

Event-related beta synchronization after wrist, finger and thumb movement.

Pre-movement event-related desynchronization (ERD) and post-movement event-related synchronization (ERS) were studied in a group of normal subjects during voluntary thumb, index finger and wrist movement. The band power time courses were computed for the upper alpha band (10-12 Hz) and for two frequency bands in the range of beta (16-20 Hz and 20-24 Hz). While a similar mu ERD was found during motor preparation for the 3 movement tasks, significant differences concerning beta synchronization were observed after movement off set. The contralateral percentage beta increase (ERS) was significantly larger in gross movements of the wrist as compared to index finger and thumb movements, which is discussed under the assumption of a cumulative effect. Summarizing, pre-movement desynchronization seems relatively independent of the forthcoming type of movement, whereas the post-movement beta synchronization might depend on the activated muscle mass.

Adult↗
PubMed1999

[Event-related desynchronization and synchronization. Reactivity of electrocortical rhythms in relation to the planning and execution of voluntary movement].

Cortical electroencephalographic rhythms reactivity may be quantified using event-related desynchronization (ERD) and synchronization (ERS) methods. We therefore studied cortical activation occurring during programming and performance of voluntary movement in healthy subjects. EEG power evolution within the reactive frequency bands (mu and beta central rhythms) was averaged before, during and after a minimum of 50 self-paced flexions of the thumb. Recordings in 18 normal adults showed that ERD (decrease in power) of mu rhythm started 2,000 ms before movement onset, while ERD of beta rhythm started 1,500 ms before movement onset. Early ERD of mu and beta rhythms were located over the contralateral central region covering primary motor cortex. They were followed by bilateral ERD occurring over ipsilateral and contralateral central regions during performance of the movement. At the end of the movement, an ERS (increase in power) of beta rhythm occurred. These results suggest that programming of voluntary movement induces early activation in contralateral sensorimotor areas, while performance of the movement induces bilateral activation in sensorimotor areas. ERS of beta rhythm occurring at the end of the movement could correspond to inactivation of motor areas activated by movement. Based on EEG activity, ERD and ERS prove to be useful methods to analyze cortical activation during programming and performance of voluntary movements with good spatial and temporal resolution.

Adult↗
PubMed1998

Analysis of voluntary finger movements during hand tasks by a motion analyzer.

Finger movements have primarily been classified by the final position of the hand and finger during deliberate hand activities, rather than as a description of the movement process. In addition, as of yet there have been no reports based upon objective data from the analysis of the motion of three finger joints during movement, and no reports exist that describe the relationship of the three joints' motion during these movements. This paper describes the relationship of the three finger joints during simple finger movements and hand tasks using measurements and analysis from a two-dimensional motion analyzer. Two prehensile movements were examined in 15 healthy volunteers: pure finger extension from finger flex position in different wrist positions (dorsi-flexion position, neutral position and palmar-flexion position of the wrist joint) and the grasping of discs of different diameter (10, 11, 12 and 13 cm). In the sequence of pure finger extension, where the grasping task was not requested, results showed that the movement was started from the proximal joint and extended to the distal joint of the finger, and full finger extension accomplished from distal to proximal, one after another, in any wrist position in most subjects. With the grasping of a disc, however, joint movement was initiated from distal to proximal and the final motion for grasping was carried to completion from the proximal to distal joints of the finger in most subjects. In addition, it was recognized that the proportion of the angular change in each of the three joints was different, as were the time duration of the joint motion and the pattern of the angular change. From these results, it is suggested that deliberate activities of the finger and sophisticated joint movements provided delicate adjustments to fit the fingers to the size of the object, as compared to the simple finger extension movement.

Adult↗
PubMed2000

Sub-movement cueing and motor sequence execution in patients with Huntington's disease.

OBJECTIVES: We investigated whether the type of sub-movement cueing during the execution of motor sequences influences the movement time in patients with Huntington's disease. METHODS: The kinematic variables of rapid sequential free arm movements executed with different types of sub-movement cueing - externally-triggered (ET) and self-initiated (SI) tasks - were analyzed in 7 patients and 7 healthy controls. The ET task required subjects to initiate movements in response to consecutive visual go signals; the SI task allowed them to start at will. RESULTS: HD patients performed ET and SI tasks slower than normal subjects. Both groups executed ET sequences slower than SI, but movement times for the two tasks differed less in patients than in controls. Patients paused normally between sub-movements during the SI task, but they had slower reaction times for all the sub-movements of the ET task. CONCLUSIONS: Slower execution of both motor tasks indicates that HD patients are bradykinetic in performing sequential free arm movements. Our finding that total movement times for SI and ET tasks differ less in patients than in controls suggests that HD impairs internal more than external cueing mechanisms.

Adult↗