Vibration sensation associated with motor function has specific frequency characteristics in community-dwelling older Japanese adults / 体力科学

Vibration sensation is related to motor function. However, it is unclear which vibration frequencies are associated with motor function. Therefore, in this cross-sectional study, we investigated whether a specific frequency of vibration sensation could explain motor functions. Thirty-two community-dwelling Japanese healthy older adults aged 70 years or older participated in the present study. Grip strength, one-leg standing time, and 10-m walking time were evaluated as indicators of motor function. Vibratory (40, 128, and 256 Hz) and tactile sensory tests were examined as sensory functions. Grip strength per body weight was significantly correlated with sex, body mass index, falls efficacy scale, vibration sensation with 40 and 128 Hz, and 10-m walking time (P < 0.05). Furthermore, one-leg standing time showed a correlation between vibration sensation (128 and 256 Hz) and fall history (P < 0.05). However, 10-m walking time was significantly correlated with only the grip strength to body weight ratio. Multiple regression analysis showed that vibration sensation with 128 Hz (β = 0.427) and sex (β = -0.335) (P < 0.05) were significant independent variables associated with grip strength to body weight ratio. Vibration sensation with 256 Hz (β = 0.465) and age (β = -0.343) (P < 0.05) were significant independent variable associated with one-leg standing time. No significant variables were identified for the 10-m walking time. Vibration sensation associated with motor function shows specific frequency characteristics in community-dwelling older Japanese adults.

A Frequency Weighting Contour for Chinese Young Males / 航天医学与医学工程

Objective To obtain the frequency weighting contour for seated Chinese young males in z axis.Method 10 male volunteers served as the subjects.They were exposed to standard vibration stimulus (a sinusoidal vibration of 1.0 m/s2 at 8 Hz) and 14 kinds of sinusoidal experimental vibration stimuli at frequencies from 4 Hz to 80 Hz.The magnitude of the experimental vibration stimulus was changed by the subject through a signal condition and switching device made by ourselves to obtain an equal vibration sensation to the standard vibration.The data were fitted to the same form of the frequency weighting Wk of ISO 2631-1 with the least square method and optimization of parameters.Result Compared with ISO 2631-1,the frequencies weightings of Chinese young males at 16～80 Hz are significantly higher than those of ISO 2631-1(P<0.005),but there are no significant difference between two frequency weighting contours at other frequencies. Conclusion Chinese young males are more sensitive to vibration at 16～80 Hz in Z axis.

Quantitative Sensory Test in Normal Adult

OBJECTIVE: To obtain normal data of quantitative sensory test (QST) in Korean adult. METHOD: The subjects were 85 normal adults aging from 30 to 69 years old, who had no abnormal sensory and neurologic problem. We performed following three QSTs on dominant side and one verbal questionnaire. 1) Semmes-Weinstein monofilament wire system (0.05 G, 0.2 G, 2 G, 4 G, 10 G, 300 G) for touch sensation, 2) Rydel-Seiffer Tuning Fork for vibration sensation, 3) TSA-2001 Thermal sensory analyser for thermal sensation, 4)University of Texas Subjective Peripheral Neuropathy verbal questionnaire. RESULTS: 1) Touch perception score measured with Semmes-Weinstein monofilament wire system, declined with age (p<0.01). 2) Vibration perception score measured with the tuning fork, declined with age in foot (p<0.01). 3) Warm sense and heat pain threshold measured with TSA-2001 thermal sensory analyser increased with age, and cold sense and cold pain threshold declined with age. 4) Weight showed negative correlation with vibration perception score in man's foot. CONCLUSION: Normal data of three sensory test obtained from this study could be used for the early detection of peripheral neuropathy or loss of "protective sensation".

Quantitative Sensory Test for the Detection of Diabetic Peripheral Neuropathy / 대한정형외과학회잡지

The aim of this study was to compare widely used quantitative sensory tests to evaluate the diabetic neuropathy(DN). We tested plantar sensation of 40 patients with diabetes mellitus(Group I: 20 with neuropathic symtom, Group II: 20 without symptom) using Semmes-Weinstein monofilament(touch sensation), Biothesiometer(vibration sensation) and EMG. This result was also compared with that of the control group. Eighty percent of Group I and thirty percent of Group II had abnormal EMG findings. Group I had decreased vibration and touch sensation. Comparison of vibration perception threshold(Biothesiometer) with touch pressure sensation(Semmes-Weinstein monofilament) showed that the test with Biothesiometer was relatively accurate, however it was complicated, time consuming and that the test with monofilament was simple and easily performed in the field even though it was relatively crude. 5.07 monofilament could be very effective in the eearly detection of diabetic neumpathy. In conclusion, we recommend 5.07 monofilament as a screening method of diabetic neuropathy and biothesiometer as its follow-up method.