No abstract

No abstract

[Purpose] The fingernails allow for increased sensory perception at the finger pulp, and contribute to the accurate picking up of small objects. The purpose of the present study was to clarify the effect of fingernail length on hand dexterity using subjects’ own fingernails. [Subjects and Methods] The hand sizes and fingernail configurations of 38 young healthy volunteers (eighteen males and twenty females) were measured. The effect of fingernail length (0 and 2 mm) on hand dexterity also was investigated using the simple test for evaluating hand function. [Results] The hand and finger sizes as well as fingernail widths were significantly larger in males than in females. The time taken for each subtest of the simple test for evaluating hand function was generally shorter at a fingernail length of 2 mm than at 0 mm, and it was significantly shorter for a number of subtests. There was little significant difference in the time taken for the subtests between genders. [Conclusion] It was clear that a fingernail length of 2 mm had an advantageous effect on hand dexterity, with little gender difference observed. These findings suggest that the fingernail lengths of the subjects should be standardized when evaluating changes in their hand dexterity with time.

No abstract

Objective: The purpose of this study was to quantify the effects of prolonged vibratory stimulus on the maximal voluntary contraction (MVC) force and muscle activity of the triceps brachii and to clarify the effective stimulus time. Methods: Twenty-five healthy volunteers with a mean age of 21.4 years participated. A vibratory stimulus at 86 Hz was applied to the triceps brachii tendon for 5 and 10 minutes. Before and after these stimuli, the elbow extension MVC force was measured using a handheld dynamometer. Muscle activities of the lateral, long, and medial heads of the triceps brachii were also recorded by surface electromyography. Results: The median MVC force significantly decreased to 82.7% after 5 minutes of vibratory stimulus and to 83.3% after 10 minutes of vibratory stimulus (P b .001). The median percentage of integrated electromyography of the triceps also significantly decreased to 78.2 (lateral head), 83.8 (long head), and 81.5 (medial head) after 5 minutes of vibratory stimulus and to 77.7, 81.4, and 77.2, respectively, after 10 minutes of vibratory stimulus (P b .001). There were no differences in the decrease in the MVC force and median percentage of integrated electromyography between 5 and 10 minutes of vibratory stimulus (P N .05). Conclusion: Prolonged vibratory stimulus (5 minutes) to the triceps brachii tendon appeared to have an inhibitory effect on MVC force and muscle activity. The present results suggest that prolonged vibratory stimulus could be an effective treatment capable of reducing muscle tonus of the triceps brachii.