Heart rate variability in response to psychological test in hand-arm vibration syndrome patients assessed by frequency domain analysis.
To investigate heart rate variability in response to psychological tests (Japanese version of Stroop color word test and mirror drawing test) in 29 hand-arm vibration syndrome (HAVS) patients, 16 of them with vibration-induced white finger (VWF) and 13 without VWF, and 10 healthy controls of similar age, heart rate variability during spontaneous and deep (6 cycles a minute) breathing in supine position before and after exposure to the psychological tests was examined calculating frequency domain components such as low frequency (LF) power-index of both the sympathetic and parasympathetic activity, high frequency (HF) power-index of the parasympathetic activity and LF/HF-index of the sympathovagal balance. The group of all patients and the group without VWF indicated significant increase in LF/HF in the deep breathing measurement after exposure to the psychological tests. The result suggests that the sympathetic tone in the sympathovagal balance predominated in the HAVS patients which means that they had larger sensitivity of the sympathetic nervous system to the psychological tests. (+info)
A four-year follow-up study on subjective symptoms and functional capacities in workers using hand-held grinders.
Fifty-three grinders in the metal industry were re-examined 4 years after their first examination. Information about age, occupation, daily vibration exposure, drinking and smoking habits, and presence of subjective symptoms such as vibration-induced white finger (VWF), and numbness and pain in the fingers was collected during the first and second examination. Cold provocation test (10 degrees C/10 min) was also employed to evaluate disturbances in the peripheral circulatory and peripheral nerves in all subjects. The frequency-weighted vibration acceleration of various types of hand-held tools was measured. There was no subject with VWF at the first examination; however, during the course of follow-up, two cases (3.8%) of VWF with latent interval of more than 25 years were diagnosed. Prevalence of numbness in the fingers and shoulder stiffness was significantly higher at the second examination. When the prevalence of subjective symptoms was tested by the subjects' total operating time (TOT) during the 4-year follow-up period, those whose TOT was equal to or more than 2500 hours showed higher prevalence compared to the other subgroup. The paired values of recovery rate of finger skin temperature and vibration sensation threshold after the cold water immersion test were significantly different at the first and second examination. On average, the diminution of hand-grip force during the 4-year follow-up course was 7.4%; the difference being significant at 0.01 level. Significant differences in the paired data of pinching power and tapping ability could be detected. The frequency-weighted vibration acceleration of various tools was in the range of 1.1-4.6 m/s2. It was concluded that: (1) prolonged occupational exposure to the vibration of hand-held grinding tools should be considered as a risk factor causing disturbances in the hand-arm system of the operators; (2) the results of recovery rate of finger skin temperature and the vibration sensation threshold seemed to be appropriate indicators for the assessment of peripheral vascular and peripheral nerve disturbances in workers exposed to hand-arm vibration; and (3) to reduce the subjects' physical stress, attention should be paid to ergonomic factors. (+info)
A study on the effects of countermeasures for vibrating tool workers using an impact wrench.
The aims of this study were (1) to measure frequency-weighted vibration acceleration and (2) to study the effects of introducing a vibration-proof impact wrench on VWF in workers. The subject pool was 383 male workers who were regularly using an impact wrench and taking special medical examinations for vibration syndrome in a factory from 1982 to 1999. The prevalence of workers with VWF increased gradually after 1982, reached a peak value (4.8%) in 1986, gradually decreased after 1987, and disappeared in 1994. Sixteen subjects who had had VWF at least one time during the observation period were selected for this study. The stages of VWF were at stage I on the Stockholm Workshop scale in all subjects. After the vibration-proof impact wrench was introduced in 1986, the vibration acceleration of the impact wrench measured on the handle decreased from 8.6-11.1 m/s2 to 5.1-7.1 m/s2. The actual time per day that subjects were assumed to use the impact wrench was 108 minutes. The subjects actually used an impact wrench more than the occupational exposure limit allowed. However, VWF disappeared after the introduction of a vibration-proof impact wrench. This might have resulted from the combined effect of introducing the vibration-proof impact wrench and certain countermeasures that were taken against cold working environments. (+info)
Forced use of the upper extremity in chronic stroke patients: results from a single-blind randomized clinical trial.
BACKGROUND AND PURPOSE: Of all stroke survivors, 30% to 66% are unable to use their affected arm in performing activities of daily living. Although forced use therapy appears to improve arm function in chronic stroke patients, there is no conclusive evidence. This study evaluates the effectiveness of forced use therapy. METHODS: In an observer-blinded randomized clinical trial, 66 chronic stroke patients were allocated to either forced use therapy (immobilization of the unaffected arm combined with intensive training) or a reference therapy of equally intensive bimanual training, based on Neuro-Developmental Treatment, for a period of 2 weeks. Outcomes were evaluated on the basis of the Rehabilitation Activities Profile (activities), the Action Research Arm (ARA) test (dexterity), the upper extremity section of the Fugl-Meyer Assessment scale, the Motor Activity Log (MAL), and a Problem Score. The minimal clinically important difference (MCID) was determined at the onset of the study. RESULTS: One week after the last treatment session, a significant difference in effectiveness in favor of the forced use group compared with the bimanual group (corrected for baseline differences) was found for the ARA score (3.0 points; 95% CI, 1.3 to 4.8; MCID, 5.7 points) and the MAL amount of use score (0.52 points; 95% CI, 0.11 to 0.93; MCID, 0.50). The other parameters revealed no significant differential effects. One-year follow-up effects were observed only for the ARA. The differences in treatment effect for the ARA and the MAL amount of use scores were clinically relevant for patients with sensory disorders and hemineglect, respectively. CONCLUSIONS: The present study showed a small but lasting effect of forced use therapy on the dexterity of the affected arm (ARA) and a temporary clinically relevant effect on the amount of use of the affected arm during activities of daily living (MAL amount of use). The effect of forced use therapy was clinically relevant in the subgroups of patients with sensory disorders and hemineglect, respectively. (+info)
Sensory impairment: a feature of chronic venous insufficiency.
OBJECTIVE: Clinical and microscopic evidence suggests the existence of sensory neuropathy in patients with severe chronic venous insufficiency (CVI). A clinical evaluation was conducted to determine whether a sensory neuropathy was present and, if so, to determine its extent and distribution. METHODS: The study was performed in a university-affiliated Veterans Affairs Medical Center. Twenty-three limbs were studied in 14 male veterans with mild or moderate CVI. The exclusions included diabetes, previous ipsilateral extremity surgery, or other diseases associated with neuropathy. Sensory thresholds in the limbs with CEAP class 2 disease (n = 11) were compared with the thresholds in the limbs with CEAP class 5 disease (n = 12) at nine different sites on the foot, ankle, calf, thigh, and palm. Thenar and hypothenar thresholds were measured as internal controls. Thresholds were determined by a pressure aesthesiometer consisting of 20 graduated filaments that ranged from 1.65 to 6.65 (log(10)mg)(10) of pressure. A complete, sensory motor assessment of the limb was performed by an experienced neurosurgeon who specialized in peripheral nerve evaluation. The clinical variables assessed were deep tendon reflexes, vibration, proprioception, and light touch. Venous reflux was determined with duplex ultrasound scanning and air plethysmography. RESULTS: Sensory thresholds at the most common site of venous ulceration-just proximal to the medial malleolus--were significantly (P <.05) different between mild (class 2) and severe (class 5) CVI. Sensory abnormalities coincided with the extent of trophic changes and did not reflect specific dermatomal or cutaneous nerve distributions. In addition to light touch or pinprick, vibration sense and deep tendon reflexes were also significantly worse in those with severe CVI. CONCLUSION: Sensory neuropathy is a feature of severe CVI, and its distribution is coincident with trophic changes. Because this is often unappreciated by the patient, it probably contributes to the propensity for deterioration from minor trauma. (+info)
Surgical management of superior sulcus tumors.
Superior sulcus tumor refers to any primary lung cancer presenting with constant pain in the nerve distribution of the eighth cervical, first and second thoracic nerve roots and Horner's syndrome caused by invasion of the stellate ganglion. The pain is steady, severe, and unrelenting, involving the shoulder, the vertebral margin of the scapula and ulnar distribution of the arm to the elbow and finally to the ulnar surface of the forearm, and the small and ring fingers of the hand (Pancoast-Tobias syndrome). Weakness and atrophy of the hand muscles can also occur as the lesions spreads to involve the first and second ribs and vertebrae. Radiologically, there is a small shadow at the extreme apex of the lung with rib and possible vertebral body invasion. Pulmonary symptoms are less frequent because of the peripheral location of the lesions. Since Shaw and Paulson approached superior sulcus tumors in 1961 by using preoperative radiation-therapy (30 to 45 Gy in four weeks including the primary tumor, mediastinum and supraclavicular region) followed by surgical resection, this radiosurgical approach shortly became the standard treatment yielding better disease control and survival than that offered by other treatment modalities. It has now become evident that en bloc resection of the chest wall, involved adjacent structures as well as lobectomy must be considered the standard surgical approach for superior sulcus tumors combined with external radiation (preoperative, postoperative, or both). The goal of the operation is the complete and en bloc resection of the upper lobe in continuity with the invaded ribs, transverse processes, subclavian vessels, T1 nerve root, upper dorsal sympathetic chain and prevertebral muscles. (+info)
A radiographic method of quantifying protein-calorie undernutrition.
Estimation of midarm adipose tissue and muscle by the anthropometric technique is based on the idealized assumption that the arm and its muscle compartments are circular, and that fat is distributed evenly around the arm. We examined the validity of these assumptions by computerized axial tomography of the midarm in 21 subjects ranging from 65 to 255% of ideal body weight. Computerized axial tomography identified three errors inherent in the anthropometric method: 1) The arm and its muscle compartment were rarely circular, but resembled instead an ellipse and "cloverleaf", respectively; 2) fat was distributed asymmetrically around the arm, and furthermore when triceps skinfold was less than 5 mm, no fat was radiographically detectable, and 3) muscle are calculated by the anthropometric method includes bone area. Since bone area was not influenced by nutritional status, anthropometric "muscle area" underestimated the degree of muscle atrophy in undernutrition. Despite these limitations, in subjects 60 to 120% of ideal body weight anthropometric estimates of midarm muscle area (MAMA) and fat area did not differ greatly from the radiographic values. Anthropometric MAMA was consistently greater than the radiographic value by 15 to 25%, while midarm fat area agreed within +/- 10%. The error in the anthropometric MAMA could be nearly eliminated by two types of correction: expressing MAMA as a percentage of normal, and correcting for bone content by subtracting midarm bone area (6.3 and 4.7 cm2 for men and women). In subjects greater than 150% ideal body weight, however, anthropometric estimates of MAMA and midarm fat area differed from the radiographic values by greater than 50% even after the above two types of correction. Midarm computerized axial tomography scan provides an accurate alternative to the anthropometric method for estimating midarm muscle and fat in these obese individuals. (+info)
Catchlike-inducing train activation of human muscle during isotonic contractions: burst modulation.
Stimulation trains that exploit the catchlike property [catchlike-inducing trains (CITs)] produce greater forces and rates of rise of force than do constant-frequency trains (CFTs) during isometric contractions and isovelocity movements. This study examined the effect of CITs during isotonic contractions in healthy subjects. Knee extension was electrically elicited against a load of 10% of maximum voluntary isometric contraction. The stimulation intensity was set to produce 20% of maximum voluntary isometric contraction. The muscle was tested before and after fatigue with a 6-pulse CFT and 6-pulse CITs that contained an initial doublet, triplet, or quadruplet. For prefatigue responses, the greatest isotonic performance was produced by CITs with initial doublets. When the muscles were fatigued, triplet CITs were best. CITs produce greater excursion, work, peak power, and average power than do CFTs, because CITs produced more rapid rates of rise of force. Faster rates of rise of force enabled the preload on the muscle to be exceeded earlier during the stimulation train. (+info)