Empirical Suitability of Scoring Systems of Observational Techniques for Repetitive Movements Based on Discomfort

This study empirically investigated the effects of repetitive movements of body parts through an experiment, and evaluated the suitability of the scoring systems of the existing observational methods for repetitive movements, based on the experimental results. Eighteen healthy college students participated in the experiment to assess discomfort, wherein joint movement, its repetition, and external load were used as independent variables. Postural loads for 16 postures used in the experiment were assessed using rapid upper limb assessment (RULA) and loading on the entire body assessment (LEBA). Three independent variables, joint motion, its repetition, and external load, as well as the interaction between motion repetition and external load, had significant effects on discomfort. Joint motion and external load significantly affected the RULA grand score, whereas all three independent variables affected the LEBA score. This finding may indicate that LEBA more accurately reflects the effect of repetitive body part movements. Additionally, the scoring systems for repetitive back motions by quick exposure check (QEC) and for repetitive wrist motions via a risk assessment and management tool for manual handling proactively II (RAMP II) may be reasonable based on the results of this study. The findings of this study can be used as reference information for better evaluation of postural loads assessed using the existing observational techniques, and as useful baseline data for the development of a new observational method to accurately assess stress caused by repetitive movements.

Comparison of auditory cueing in toe tapping and gait in persons with Parkinson's disease

Introduction

Much research has examined the relationship between bradykinesia and gait impairment in persons with Parkinson's disease (PD). Specifically, impairments in repetitive movements of the upper extremity have been associated with freezing of gait. Studies examining lower extremity repetitive movements are limited. Moreover, the use of external cueing has been a treatment strategy for both bradykinesia and gait, but information on how cues should be used is lacking. The purpose of this study was to compare the effects of auditory cueing on one side versus both sides for bilateral repetitive toe tapping and gait, and to determine if there was a relationship between toe tapping and gait. We hypothesize that there will be no difference between the cueing conditions, but that there will be a significant association between repetitive toe tapping performance and gait performance.

Methods

Twenty-seven persons with PD completed a toe tapping task in which the more affected side was cued at 70 beats per minute (BPM), the less affected side was cued at 70 BPM, and both sides were cued at 140 BPM. The same cueing conditions were completed for the gait task. Inter movement interval and amplitude data was collected and analyzed for the toe tapping task. Stance time, swing time, step length, and step width were collected and analyzed for the gait task.

Results

Results revealed a significant difference in movement performance between the single side cueing conditions and both sides cued condition for inter movement interval (toe tapping), stance time (gait), step length (gait), and step width (gait). Moreover, results revealed a significant association between inter movement interval and stance time and step length.

Discussion

These results would suggest that cueing both sides is better than only one side and that there is a relationship between toe tapping and gait performance when both sides are cued in persons with PD. This study adds to the literature exploring possible shared mechanisms between bradykinesia and gait in persons with PD.

A Rare Pathologic Collecting and Hoarding Behavior Following Left Middle Cerebral Artery Territory Infarction

BACKGROUND AND SIGNIFICANCE

Punding is the term used to describe complex, purposeless abnormal behaviors that are thought to be related to either excessive dopamine stimulation or inhibition. We report a case of punding after cerebral infarction at the caudate nucleus.

CASE

A 70-year-old man presented with acute-onset motor aphasia. Upon examination, he showed no other neurological deficit. The computed tomography scan and magnetic-resonance imaging scan taken during admission were consistent with acute infarctions of the left caudate nucleus and multiple scattered areas of multiple cortices. Six months after the episode, he gradually became disruptive and ill-tempered. He began to buy and collect assorted repair tools. In addition, he presented hoarding behavior by acquiring unnecessary goods and stacking them at his house.

CONCLUSION

To the best of our knowledge, this is the first case of punding following an ischemic stroke at the caudate nucleus. Our case strengthens the hypothetical pathophysiology of punding, which may involve not only direct dopaminergic stimulation but also the dysregulation of the dopamine system.

Expertise- and Tempo-Related Performance Differences in Unimanual Drumming

BACKGROUND

High-speed drumming requires precise control over the timing, velocity, and magnitude of striking movements.

AIM

To examine effects of tempo and expertise on unaccented repetitive drumming performance using 3D motion capture.

METHODS

Expert and amateur drummers performed unimanual, unaccented, repetitive drum strikes, using their dominant right hand, at five different tempi. Performance was examined with regard to timing variability, striking velocity variability, the ability to match the prescribed tempo, and additional variables.

RESULTS

Permutated multivariate analysis of variance (PERMANOVA) revealed significant main effects of tempo (p < .001) and expertise (p <.001) on timing variability and striking velocity variability; low timing variability and low striking velocity variability were associated with low/medium tempo as well as with increased expertise. Individually, improved precision appeared across an optimum tempo range. Precision was poorest at maximum tempo (400 hits per minute) for precision variables.

CONCLUSIONS

Expert drummers demonstrated greater precision and consistency than amateurs. Findings indicate an optimum tempo range that extends with increased expertise.

The Chd1 Chromatin Remodeler Shifts Nucleosomal DNA Bidirectionally as a Monomer

Chromatin remodelers catalyze dynamic packaging of the genome by carrying out nucleosome assembly/disassembly, histone exchange, and nucleosome repositioning. Remodeling results in evenly spaced nucleosomes, which requires probing both sides of the nucleosome, yet the way remodelers organize sliding activity to achieve this task is not understood. Here, we show that the monomeric Chd1 remodeler shifts DNA back and forth by dynamically alternating between different segments of the nucleosome. During sliding, Chd1 generates unstable remodeling intermediates that spontaneously relax to a pre-remodeled position. We demonstrate that nucleosome sliding is tightly controlled by two regulatory domains: the DNA-binding domain, which interferes with sliding when its range is limited by a truncated linking segment, and the chromodomains, which play a key role in substrate discrimination. We propose that active interplay of the ATPase motor with the regulatory domains may promote dynamic nucleosome structures uniquely suited for histone exchange and chromatin reorganization during transcription.

Effectiveness of the multidimensional ergonomic intervention model to reduce musculoskeletal discomfort among street sweepers in Chiang Rai Province, Thailand

The aim of this study was to evaluate the effectiveness of multidimensional ergonomic intervention (MEI) model to reduce musculoskeletal discomfort (MSD) among street sweepers. A quasi-experimental study was conducted in Chiang Rai Province. The MEI model was designed on the basis of four core components: cognitive behavior therapy, ergonomic education training, stretching exercise, and the foam sleeve broom handle grip. Seventy-five street sweepers volunteered for the screening process on MSD of having level score ≥4 by physiotherapist. Face to face interviews were used mainly in order to diagnose MSD. Physical examination was performed by physiotherapist and physical performance by sports scientist. The findings showed that the MEI model among the intervention group significantly reduced MSD compared with that among control group at exit model and follow-up (P<0.01). This research suggests that the MEI model was appropriate to reduce MSD associated with repetitive movement and awkward postures on task.