Fighter pilots who are frequently exposed to severe cold ambient temperatures experience neck pain disabilities and occupational disorders more often than those who are not so exposed. We hypothesized that a cold-induced increase in muscle strain might lead to in-flight neck injuries. The aims of this study were to measure the level of cooling before takeoff and to determine muscle strain under Gz loading (0 to +4 Gz) at different temperatures.
Test subjects' (n = 14) skin temperature (T(skin)) over the trapezoids was measured before the walk to the aircraft and again in the cockpit (air temperature -14 degrees C). The subjects then performed trampoline exercises in two different ambient temperatures (-2 degrees C and +21 degrees C) after a 30-min period at the respective temperatures. EMG activity of the sternocleidomastoid (SCM), cervical erector spinae (CES), trapezoid (TRA), thoracic erector spinae (TES) muscles, and Tskin of the SCM and TRA were measured.
Tskin over the trapezoids decreased from 30.1 +/- 1.7 degrees C to 27.8 +/- 2.6 degrees C (p
105 factory workers (38 females and 67 males) have been questioned about their frequency of back pain. 60% of the females and 61% of the males have previously experienced episodes of back pain. 21% of the females and 37% of the males have been absent from work due to back pain. The incidence of back pain is not related to age, height, sort of work, or isometric muscle strength of the back (IS). For the males the incidence rises with increasing weight, i.e. combination of height and obesity, but is not related to any two single factors. For the females there is no correlation between the incidence of pain and weight. IS is correlated to height and age in the males but not in the females. Standards for IS are presented and suggested as a guide to evaluation of the working capabilities of individual subjects with back pain.
In this cross-sectional population study with 78 healthy 0.5-5 years postmenopausal, 49-55 year old females a significant simple linear correlation between lumbar spine LII-LIV bone mineral density and adjacent back extensor and flexor isometric muscle strength was found. With the stepwise multiple linear regression analyses the most significant predictors for lumbar spine LII-LIV and femoral neck bone mineral density were weight (partial R2) (R2 = 0.197, p = 0.0001; R2 = 0.157, p = 0.0009) and age (R2 = 0.056, p = 0.0205; R2 = 0.036, p = 0.0708). Height and isometric muscle strength and endurance of muscles were not significant predictors. Weight and age were the most significant predictors also for isometric muscle strength. The mobility of spine, body fat content and anaerobic threshold had no correlation on bone mineral density.
BACKGROUND: The Danish Longitudinal Study of Alcoholism has identified a number of early biological indicators that predicted alcohol dependence 30 years later. In light of recent evidence linking deficits of the cerebellum to certain neuropsychiatric disorders often comorbid with alcoholism, we hypothesized that developmental deficits in the cerebellar vermis may also play a role in the initiation of adult alcohol dependence. The present study evaluated whether measures of motor development in the first year of life predict alcohol dependence three decades later. METHODS: A total of 241 subjects of the original 330 infants who were entered into this study completed the 30-year follow-up (12 had died). The subjects were men who were drawn from a large birth cohort born in Copenhagen, Denmark, from 1959 to 1961. A comprehensive series of measures were obtained on each subject before, during, and shortly after birth as well as at 1 year of age. Muscle tone at birth and day 5 as well as 1-year measures of motor coordination--age to sitting, standing, and walking--were examined. A DSM-III-R diagnosis of alcohol dependence and a measure of lifetime problem drinking served as the 30-year outcome variables. RESULTS: Several measures of childhood motor development significantly predicted alcohol dependence at 30 years of age. These included deficits in muscle tone 5 days after birth, delays in the age to sitting, and delays in the age to walking. CONCLUSIONS: Relationships found between adult alcoholism and early delays in motor development offer support for the theory that cerebellar deficits may play a causal role in the addiction process.
The effects of maternal bupivacaine paracervical block on neonatal neurobehavioural responses were studied at the ages of 3 h, 1 day, 2 days and 4-5 days. Subjects were healthy, term neonates born vaginally to 10 mothers with paracervical block and to 12 mothers without analgesia. No statistically significant differences were found in the responses between the groups. It is concluded that paracervical block with a small dose of bupivacaine, applied by experienced obstetricians to non-risk parturients with healthy foetuses, has no detrimental effects on newborn behaviour or neurological recovery.
Microgravity was used to study accelerometrically recorded microvibration (MV) and postural tremor (PT) at reduced muscle tone on one cosmonaut before, during, and after an 8-day space flight on the Russian Mir station. MV of the relaxed forearm in the 1 g environment showed the typical 7- to 13-Hz resonance oscillations triggered by the heart beat. In 0 g, these pulsations shifted to below 5 Hz and the waveform became similar to an ultralow frequency acceleration ballistocardiogram. PT of the arm stretched forward showed an irregular waveform in 1 g. In 0 g, the higher-frequency components were reduced and again an ultralow frequency ballistocardiogram emerged. As a control, hand force tremor was recorded as well; it was not affected by the gravity condition. A second-order analog with muscle stiffness (C) as parameter was used to evaluate the measurements. For MV it could be shown that cardiac impacts produce damped resonance oscillations when C is high enough (1 g). At low C (0 g), this resonance phenomenon is essentially filtered out. For PT both neuromuscular and cardiovascular forces produce an irregular output; when C is lowered (0 g) the higher-frequency content is strongly reduced. It is concluded that both MV and PT waveforms are sensitive to musculoskeletal stiffness, such that at the lowest stiffness achieved the cardiac impact dominates. In 1 g, the cosmonaut's data were not significantly different from the results in a control group (n = 6).