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PubMed1985

Dietary protein suppresses feedback control of glomerular filtration in rats.

We have examined the possibility that changes in glomerular filtration rate (GFR) after changes in dietary protein intake may depend on altered function of the tubuloglomerular (TG) feedback system. We studied male Sprague-Dawley rats after dietary pretreatment for 9.6 +/- 3.6 (SD) d with isocaloric diets containing either 6% or 40% casein. We found that GFR in rats fed the high protein diet was 24-29% higher than in rats fed the low protein diet. Simultaneous measurements of single nephron GFR (SNGFR) in the distal tubule were 6.3 nl/min or 21% higher in the rats fed the high protein diet whereas proximally measured SNGFR was not statistically different in the two groups. The higher distally measured SNGFR of rats receiving the high protein diet was associated with a 4.2 nl/min or 50% smaller suppression of SNGFR by TG feedback (-4.3 vs. -8.5 nl/min, P less than 0.001). Loop perfusion experiments demonstrated that in rats fed the high protein diet the TG feedback mechanism was less sensitive than in rats fed the low protein diet. The TG feedback response in rats fed the low protein diet, as assessed by reductions in stop-flow pressure and SNGFR, was half-maximal at flows of 14-15 nl/min. In contrast, the TG feedback response in rats fed the high protein diet was half-maximal at 22-24 nl/min. Maximal suppression of stop-flow pressure and SNGFR and the slope of the TG feedback response to increasing loop flow rates were not different in the two groups. We conclude that the sensing mechanism of the TG feedback system is rendered less responsive by a high protein intake, and that this change permits GFR to increase.

Animals↗
PubMed2004

Challenges and recent developments in hearing aids. Part II. Feedback and occlusion effect reduction strategies, laser shell manufacturing processes, and other signal processing technologies.

This is the second part of a review on the challenges and recent developments in hearing aids. Feedback and the occlusion effect pose great challenges in hearing aid design and usage. Yet, conventional solutions to feedback and the occlusion effect often create a dilemma: the solution to one often leads to the other. This review discusses the advanced signal processing strategies to reduce feedback and some new approaches to reduce the occlusion effect. Specifically, the causes of three types of feedback (acoustic, mechanical, and electromagnetic) are discussed. The strategies currently used to reduce acoustic feedback (i.e., adaptive feedback reduction algorithms using adaptive gain reduction, notch filtering, and phase cancellation strategies) and the design of new receivers that are built to reduce mechanical and electromagnetic feedback are explained. In addition, various new strategies (i.e., redesigned sound delivery devices and receiver-in-the-ear-canal hearing aid configuration) to reduce the occlusion effect are reviewed. Many manufacturers have recently adopted laser shell-manufacturing technologies to overcome problems associated with manufacturing custom hearing aid shells. The mechanisms of selected laser sintering and stereo lithographic apparatus and the properties of custom shells produced by these two processes are reviewed. Further, various new developments in hearing aid transducers, telecoils, channel-free amplification, open-platform programming options, rechargeable hearing aids, ear-level frequency modulated (FM) receivers, wireless Bluetooth FM systems, and wireless programming options are briefly explained and discussed. Finally, the applications of advanced hearing aid technologies to enhance other devices such as cochlear implants, hearing protectors, and cellular phones are discussed.

Acoustics↗
PubMed2005

Developing essential professional skills: a framework for teaching and learning about feedback.

BACKGROUND: The ability to give and receive feedback effectively is a key skill for doctors, aids learning between all levels of the medical hierarchy, and provides a basis for reflective practice and life-long learning. How best to teach this skill? DISCUSSION: We suggest that a single "teaching the skill of feedback" session provides superficial and ineffective learning in a medical culture that often uses feedback skills poorly or discourages feedback. Our experience suggests that both the skill and the underlying attitude informing its application must be addressed, and is best done so longitudinally and reiteratively using different forms of feedback delivery. These feedback learning opportunities include written and oral, peer to peer and cross-hierarchy, public and private, thereby addressing different cognitive processes and attitudinal difficulties. SUMMARY: We conclude by asking whether it is possible to build a consensus approach to a framework for teaching and learning feedback skills?

Assertiveness↗
PubMed1976

Feedback of client-relevant information and clinical practice.

Feedback refers to client-relevant information that is communicated directly to the client. A review of the literature suggests that how one reacts to feedback is influenced by the kind of feedback, the conditions under which feedback is presented, and a variety of relevant subject variables. The most frequent design has resulted in acceptance of false feedback by college students leading to derogation of instruments and assessors. Honest feedback has led to a variety of positive effects in both research studies and clinical examples. The beginnings of a human science rationale for honest feedback are presented.

Attitude↗
PubMed1991

The role of the hippocampus in feedback regulation of the hypothalamic-pituitary-adrenocortical axis.

There is considerable, although not entirely consistent, evidence that the hippocampus inhibits most aspects of HPA activity, including basal (circadian nadir) and circadian peak secretion as well as the onset and termination of responses to stress. Although much of the evidence for these effects rests only on the measurement of corticosteroids, recent lesion and implant studies indicate that the hippocampus regulates adrenocortical activity at the hypothalamic level, via the expression and secretion of ACTH secretagogues. Such inhibition results largely from the mediation of corticosteroid feedback, although more work is required to determine whether the hippocampus supplies a tonic inhibitory input in the absence of corticosteroids. It must be noted that the hippocampus is not the only feedback site in the adrenocortical system, since removal of its input only reduces, but does not abolish, the efficacy of corticosteroid inhibition, and since other elements of the axis appear eventually to compensate for deficits in feedback regulation. The importance of other feedback sites is further suggested not only by the presence of corticosteroid receptors in other parts of the brain and pituitary, but also by the improved prediction of CRF levels by combined hypothalamic and hippocampal receptor occupancy. The likelihood of feedback mediated by nonhippocampal sites underscores the need for future work to characterize hippocampal influence on HPA activity in the absence of changes in corticosteroid secretion. However, despite the fact that the hippocampus is not the only feedback site, it is distinguished from most potential feedback sites, including the hypothalamus and pituitary, by its high content of both type I and II corticosteroid receptors. The hippocampus is therefore capable of mediating inhibition over a wide range of steroid levels. The low end of this range is represented by corticosteroid inhibition of basal (circadian nadir) HPA activity. The apparent type I receptor specificity of this inhibition and the elevation of trough corticosteroid levels after hippocampal damage support a role for hippocampal type I receptors in regulating basal HPA activity. It is possible that basal activity is controlled in part through hippocampal inhibition of vasopressin, since the inhibition of portal blood vasopressin correlates with lower levels of hippocampal receptor occupancy, and the expression of vasopressin by some CRF neurons is sensitive to very low corticosteroid levels. At the high end of the physiological range, stress-induced or circadian peak corticosteroid secretion correlates strongly with occupancy of the lower affinity hippocampal type II receptors.(ABSTRACT TRUNCATED AT 400 WORDS)

Adrenal Cortex↗
PubMed2004

Contrasting negative-feedback control of endogenously driven and exercise-stimulated pulsatile growth hormone secretion in women and men.

GH represses its own secretion via rapid and reversible feedback exerted at key hypothalamic loci. The primary mechanisms include stimulation of somatostatin release and inhibition of GHRH outflow. Autoinhibition is prominent in the adult male rat but diminutive in the female animal. The sex contrast reflects important differences in central neuropeptide signaling in this species. No comparable insights into gender-specific control of GH autofeedback are available in the human. To examine this issue, we quantitated acute recombinant human (rh)GH-induced inhibition of baseline (resting) and aerobic exercise-stimulated GH secretion in healthy young men (n = 8) and early follicular-phase women (n = 6). Each subject underwent four fasting, morning inpatient infusion studies in a prospectively randomized, placebo-controlled, double-blind, within-subject cross-over design. The feedback paradigm comprised 6-min bolus iv infusion of saline or rhGH (10 microg/kg) followed in 120 min by rest or submaximal aerobic (individually calibrated) bicycle ergometry for 30 min. Concomitantly, blood was sampled every 10 min for 6 h, and sera were submitted to immunochemiluminometric GH assay (sensitivity 0.005 microg/liter). Biexponential deconvolution analysis was applied to estimate stimulated GH secretory-burst mass (microg/liter per 90 min after onset of exercise or rest). Women and men had statistically comparable serum estradiol but unequal testosterone concentrations. Repeated-measures ANOVA documented a significant three-way interaction among gender, stimulus type (rest or exercise), and feedback status (saline or rhGH injection) in determining GH secretory-burst mass (P = 0.008). There were prominent two-factor interactions among gender and exercise (P < 0.001); gender and rhGH-induced negative feedback (P = 0.002); and exercise and rhGH feedback (P = 0.006). Gender comparisons disclosed that women, compared with men, maintain 20-fold higher GH secretory-burst mass at rest (P < 0.001); 40-fold less stimulation of pulsatile GH release by exercise than rest (P < 0.001); and 20-fold greater inhibition of GH secretory-burst mass by rhGH than saline at rest (P < 0.05). Observed feedback contrasts by sex were specific, inasmuch as gender did not affect absolute estimates of exercise-stimulated GH secretion (microg/liter/90 min); nadir GH concentrations (microg/liter) enforced by rhGH infusion; and the time latency (min) to manifest maximal inhibition after rhGH injection. In summary, the present clinical investigation unmasks: 1) markedly greater fractional feedback inhibition of pulsatile GH secretion by rhGH in young women than men; and 2) partial resistance of the aerobic-exercise stimulus to GH autofeedback in both women and men. We postulate that sex-steroid-specific control of somatostatin and GHRH outflow may mediate the former gender contrasts, whereas unknown (gender-independent) factors may determine the capability of exercise to significantly antagonize GH autoinhibition.

Adult↗
PubMed2004

Age and testosterone feedback jointly control the dose-dependent actions of gonadotropin-releasing hormone in healthy men.

Healthy older men manifest combined declines in testosterone concentrations, LH secretory burst mass (amount of LH released per pulse), and feedback-sensitive regularity of unknown cause. To test a unifying hypothesis of simultaneous reductions in GnRH outflow, gonadotrope responsiveness to GnRH, and androgenic negative feedback, we monitored LH secretion 1) after bolus iv injection of a 1000-fold range of randomly ordered individual doses of GnRH on separate mornings, 2) during unmodified (eugonadal) or testosterone-withdrawn (hypoandrogenemic) negative feedback, and 3) in 16 young (age, 18-35 yr) and 15 older (age, 60-85 yr) healthy men. LH secretory burst mass and pattern regularity were quantitated by intensive blood sampling, high specificity LH beta-subunit-directed immunoradiometric assay, deconvolution analysis, and approximate entropy. GnRH dose responsiveness was assessed by four-parameter nonlinear regression analysis. We demonstrated that older men exhibit 1) delayed attainment of GnRH-evoked maximal LH secretion; 2) enhanced potency of GnRH stimulation in both the feedback-intact and feedback-withdrawn states; 3) elevated gonadotrope sensitivity to GnRH, unmasked by experimental testosterone depletion; 4) comparable young adult-like GnRH efficacy, independent of testosterone feedback milieu; and 5) diminished regularity of GnRH-induced LH release evident only during unmodified androgenic feedback. We conclude that a 3-fold interaction among GnRH dose, testosterone concentration, and age governs GnRH action, and age determines both testosterone-modulated and testosterone-independent actions of GnRH.

Adolescent↗
PubMed1978

Prolonged negative feedback suppression after estradiol administration: proposed mechanism of eugonadal secondary amenorrhea.

The finding of normal gonadotropin and estradiol levels in eugonadal women with secondary amenorrhea suggests a disordered feedback relationship of the hypothalamic-pituitary-ovarian axis. To identify possible defects in negative and positive feedback, we compared the effects of five daily injections of 17 beta-estradiol (E2) in 13 normal women and 11 eugonadal patients with absent cyclic menses. The suppression phase of negative feedback was normal, as LH and FSH were similarly lowered in both groups on day 3. Continued LH (P less than 0.01) and FSH (P less than 0.02) inhibition on day 10 of the protocol, 5 days after the last E2 injection, indicated a defect in the recovery phase of negative feedback in the 11 amenorrheic women. In the 4 patients studied gonadotropin suppression persisted for 3 weeks, E2 did not blunt pituitary responsiveness to GnRH in the amenorrheic women, suggesting a central nervous system site for prolonged gonadotropin inhibition. Nine normal but only 2 amenorrheic women X2 = 4.15; P less than 0.05) exhibited a positive feedback increase in LH on days 4-6. We propose that a defect in the recovery phase of negative feedback to E2 rather than absent positive feedback may be the dominant physiological abnormality which causes secondary amenorrhea by preventing early follicular phase gonadotropin increments and follicular maturation.

Adult↗
PubMed2006

A comparison of visual and haltere-mediated feedback in the control of body saccades in Drosophila melanogaster.

The flight trajectories of fruit flies consist of straight flight segments interspersed with rapid turns called body saccades. Although the saccades are stereotyped, it is not known whether their brief time course is due to a feed-forward (predetermined) motor program or due to feedback from sensory systems that are reflexively activated by the rapid rotation. Two sensory modalities, the visual system and the mechanosensory halteres, are likely sources of such feedback because they are sensitive to angular velocities within the range experienced during saccades. Utilizing a magnetic tether in which flies are fixed in space but free to rotate about their yaw axis, we systematically manipulated the feedback from the visual and haltere systems to test their role in determining the time course of body saccades. We found that altering visual feedback had no significant effect on the dynamics of saccades, whereas increasing and decreasing the amount of haltere-mediated feedback decreased and increased saccade amplitude, respectively. In other experiments, we altered the aerodynamic surface of the wings such that the flies had to actively modify their wing-stroke kinematics to maintain straight flight on the magnetic tether. Flies exhibit such modification, but the control is compromised in the dark, indicating that the visual system does provide feedback for flight stability at lower angular velocities, to which the haltere system is less sensitive. Cutting the wing surface disrupted the time course of the saccades, indicating that although flies employ sensory feedback to modulate saccade dynamics, it is not precise or fast enough to compensate for large changes in wing efficacy.

Animals↗
PubMed2005

Effect of distance feedback on pacing strategy and perceived exertion during cycling.

PURPOSE: The aim of this study was to investigate whether providing incorrect distance feedback would alter pacing strategies, perceived exertion, and heart rate during 20-km cycling time trials (TT). METHODS: Well-trained cyclists (N=15) performed a peak power output (PPO) test, familiarization trial, and four 20-km cycling TT during which they were provided with only distance feedback using 1-km distance splits. For the control trial, subjects received accurate feedback at each kilometer split. In the increase trial, they received inaccurate feedback at 0.775 km for the first kilometer split with the distance increasing by 25 m each subsequent split up to 1.25 km in the final kilometer split. For the decrease trial, inaccurate feedback was provided at 1.25 km for the first kilometer split with the distance decreasing by 25 m each subsequent split up to 0.775 km in the final split. For the random trial, distance splits were randomized. RESULTS: No significant differences were found in the finishing times between trials. Pacing strategies were unaltered as suggested by similar power output profiles during all trials. RPE scores were also similar for all trials. However, average heart rate varied significantly between trials (P<0.05). CONCLUSIONS: These results suggest that exercise performance, pacing strategy, and RPE during a 20-km cycling TT are not altered by incorrect distance feedback. The data supported the existence of a pacing strategy that is set before exercise and that is unaffected by external distance feedback.

Adaptation, Physiological↗
PubMed2005

Double dissociation of exteroceptive and interoceptive feedback systems in the orbital and ventromedial prefrontal cortex of humans.

The primate ventral prefrontal cortex contains two densely interconnected subregions: a lateral/orbital cortex processing primarily sensory/exteroceptive information, and a ventromedial cortex processing primarily visceroappetitive/interoceptive information. These regions have major afferents from and efferents to other associative cortices. The organization of these structures leads to an hypothesized role in feedback processing. We use neuroimaging to test this model, defined so far mostly through anatomical studies. Healthy volunteers were trained operantly on a transitive inference task (A>B, B>C ==> A>C) requiring flexible manipulation of feedback to solve. Two groups of subjects learned an arbitrary face hierarchy, one adjacent face pair at a time; each group received either visual/exteroceptive ("XXXX") or visceroappetitive/interoceptive (fruit juice) feedback for correct responses to adjacent face pairs. After task acquisition, the subjects were tested on novel stimulus pairs (i.e., nonadjacent, TEST) derived from the acquired hierarchy. The TEST condition required transitive inference. No feedback was provided during TEST. Brain activity during TEST in the group trained with visual/exteroceptive feedback increased in the orbital prefrontal cortex and decreased in the ventromedial prefrontal cortex. In contrast, brain activity during TEST in the group trained with visceroappetitive/interoceptive feedback decreased in the orbital prefrontal cortex and increased in the ventromedial prefrontal cortex. These results provide functional evidence, consistent with previous anatomical studies, for two major feedback systems in human ventral prefrontal cortex: a lateral system specialized for exteroceptive information and a medial system specialized for interoceptive information. Although highly interconnected, there is a double dissociation of function between these networks in healthy humans.

Adult↗
PubMed2005

Retinotopic axis specificity and selective clustering of feedback projections from V2 to V1 in the owl monkey.

Cortical maps and feedback connections are ubiquitous features of the visual cerebral cortex. The role of the feedback connections, however, is unclear. This study was aimed at revealing possible organizational relationships between the feedback projections from area V2 and the functional maps of orientation and retinotopy in area V1. Optical imaging of intrinsic signals was combined with cytochrome oxidase histochemistry and connectional anatomy in owl monkeys. Tracer injections were administered at orientation-selective domains in regions of pale and thick cytochrome oxidase stripes adjacent to the border between these stripes. The feedback projections from V2 were found to be more diffuse than the intrinsic horizontal connections within V1, but they nevertheless demonstrated clustering. The clusters of feedback axons projected preferentially to interblob cytochrome oxidase regions. The distribution of preferred orientations of the recipient domains in V1 was broad but appeared biased toward values similar to the preferred orientation of the projecting cells in V2. The global spatial distribution of the feedback projections in V1 was anisotropic. The major axis of anisotropy was systematically parallel to a retinotopic axis in V1 corresponding to the preferred orientation of the cells of origin in V2. We conclude that the feedback connections from V2 to V1 might play a role in enhancing the response in V1 to collinear contour elements.

Animals↗
PubMed2006

Models of IP3 and Ca2+ oscillations: frequency encoding and identification of underlying feedbacks.

Hormones that act through the calcium-releasing messenger, inositol 1,4,5-trisphosphate (IP3), cause intracellular calcium oscillations, which have been ascribed to calcium feedbacks on the IP3 receptor. Recent studies have shown that IP3 levels oscillate together with the cytoplasmic calcium concentration. To investigate the functional significance of this phenomenon, we have developed mathematical models of the interaction of both second messengers. The models account for both positive and negative feedbacks of calcium on IP3 metabolism, mediated by calcium activation of phospholipase C and IP3 3-kinase, respectively. The coupled IP3 and calcium oscillations have a greatly expanded frequency range compared to calcium fluctuations obtained with clamped IP3. Therefore the feedbacks can be physiologically important in supporting the efficient frequency encoding of hormone concentration observed in many cell types. This action of the feedbacks depends on the turnover rate of IP3. To shape the oscillations, positive feedback requires fast IP3 turnover, whereas negative feedback requires slow IP3 turnover. The ectopic expression of an IP3 binding protein has been used to decrease the rate of IP3 turnover experimentally, resulting in a dose-dependent slowing and eventual quenching of the Ca2+ oscillations. These results are consistent with a model based on positive feedback of Ca2+ on IP3 production.

Animals↗
PubMed1976

Age, sex, and delay time as factors affecting reaction to delayed auditory feedback.

Five groups of 10 males and 10 females each, aged 5, 7, 9, 11, and 13 yr., recited a nursery rhyme under normal delay and 113, 226, 306-m 403-, and 520-msec, delayed auditory-feedback conditions. Speaking rate and disfluency count changes from normal delay to each delayed auditory feedback condition were calculated as indicators of reaction to delayed auditory feedback. Analyses of variance and post hoc comparisons indicated that 5-yr.-olds reacted with greater change in rate at 520-msec. delayed auditory feedback than did older subjects. Five- and 7-yr.-olds were more disfluent at 413-and 520-msec. delayed auditory feedback than were older subjects. Sex differences were found in the 7-, 11-, and 13-yr.-old groups, using speaking rate as a measure of delayed auditory-feedback reaction. No significant sex differences were noted when disfluencies were used as indicators of delayed auditory-feedback reaction.

Adolescent↗
PubMed1976

Effects of intermittency of feedback on a compensatory tracking task.

Target intermittence in tracking has been studied as frequency of target presentation at various time intervals. Task efficiency increased as a function of increased frequency of target display in open-loop tracking tasks, where the steady state of presentation resulted in the best performance. The present study examined effects of feedback intermittency in compensatory tracking as a major source of disruption of the motor-sensory feedback process in the closed-loop tracking system. Feedback intermittency is defined as the feedback of momentary sampling of the difference between target movements and the operator's control motion for specified time lengths before being displayed to him in a continuous tracking task. With a random wave pattern of 9.76 cpm, 7 magnitudes of 0.0, 0.2, 0.4, 0.6, 0.8, 1.0, and 1.5 sec. were used to represent various levels of feedback intermittency. Task efficiency decreased as a function of increased magnitudes of intermittency. Results are discussed relative to the difference between target intermittence and feedback intermittency and their effects on different tracking tasks. The findings also establish the concept of feedback intermittency as a disturbing factor in compensatory tracking in degrading the operator's performance.

Eye Movements↗
PubMed1980

Pursuit rotor learning of mildly retarded children under supplementary feedback conditions.

A rotary pursuit task employing a supplementary feedback paradigm was used to study the effects of augmenting, task-inherent information (feedback) in enhancing motor acquisition of mildly retarded children. 119 subjects were trained on the task under control and six differential applications of supplementary visual, tactile or auditory feedback. Task acquisition was facilitated by supplementary feedback in specific treatments. Also, task acquisition was favored under conditions where the locus of the supplementary feedback was juxtaposed with the "correct" response behavior. Those feedback treatments which were juxtaposed with incorrect or "error" behavior did not serve to facilitate acquisition of the pursuit task with mildly retarded subjects. A tenable explanation for the consistency of the difference between treatments could be an increase in habit state, created by the locus of the feedback which served to reinforce the elicited response.

Adolescent↗
PubMed1998

Feedback, test anxiety and performance in a college course.

The effects of three forms of test feedback and text anxiety on test performance were examined within the context of a self-paced, criterion-based course in educational psychology. 73 undergraduate students completed seven units of work and were evaluated by computer-administered unit tests. Students were randomly assigned to one of three test feedback forms: (1) item-by-item knowledge of responses, (2) answer-until-correct, and (3) delayed feedback. Students received their assigned feedback during the first two units, after which they were allowed to choose. Test anxiety was measured prior to testing on Sarason's Test Anxiety Scale and during testing on an item administered by the computer program. Students who reported high test anxiety on the Test Anxiety Scale experienced more anxiety during testing than students reporting low test anxiety. Anxiety during testing was not related to type of feedback, and the two variables were not related to course performance on the second unit. Data collected at the conclusion of the semester indicated that students who reported higher test anxiety required more attempts to pass unit tests than those reporting lower test anxiety. Given a choice, students preferred answer-until-correct feedback. This preference was not related to Test Anxiety Scale scores. Anxiety during testing was not related to being allowed to choose forms of feedback.

Achievement↗
PubMed2004

Measures of accuracy for active shoulder movements at 3 different speeds with kinesthetic and visual feedback.

STUDY DESIGN: Repeated-measures experiment. OBJECTIVE: To compare measures of end point accuracy (EPA) for 2 feedback conditions: (1) visual and kinesthetic feedback and (2) kinesthetic feedback alone, during shoulder movements, at 3 different speeds. BACKGROUND: Shoulder joint kinesthesia is typically reported with EPA measures, such as constant error. Reporting multiple measures of EPA, such as variable error and absolute error, could provide a more detailed description of performance. METHODS AND MEASURES: Subjects were seated with the shoulder abducted 90 degrees in the scapular plane and externally rotated 75 degrees, with the forearm placed in a custom shoulder wheel. Subjects internally rotated the shoulder 27 degrees to a target position at 48 degrees of shoulder external rotation for both conditions. Motion analysis was used to determine peak angular velocity and 3 EPA measures for shoulder movements. Each EPA measure was compared between the 2 feedback conditions and among the 3 speeds with a separate 2-way analysis of variance. RESULTS: Movements performed with kinesthetic feedback alone, measured by constant error (P<.01), variable error (P<.01), and absolute error (P<.01), were less accurate than movements performed with visual and kinesthetic feedback. Faster movements were less accurate when measured by constant error (P = .01) and absolute error (P<.01) than slower movements. Subjects tended to overshoot the target in the absence of visual feedback; however, movement speed played minimal role in the overshooting. CONCLUSIONS: Multiple measures of EPA, such as constant, variable, and absolute error during simple restricted shoulder movements may provide additional information regarding the evaluation of a motor performance or identify different central nervous system control mechanisms for joint kinesthesia.

Adult↗