Trauma systems and emergency preparedness: the hand bone's connected to the arm bone...
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Discriminant function analysis has been applied to numerous dimensions of the cranial and postcranial skeleton for sex determination of U.S. blacks and whites and is extended here to five measurements of the arm and wrist. These include maximum lengths of the long arm bones in addition to two measurements that reflect wrist breadth. Our results indicate that whites are more accurately classified than blacks, but seven of the 31 possible measurement combinations common to both groups yield functions with sex prediction accuracies comparable to most, but not all, functions based on other parts of the skeleton.
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The analysis of asymmetry of the arm long bones and of the cranial jugular foramen has been used to suggest handedness in humans. However, because of the unavailability of documented skeletal material, neither criterion has been systematically tested. If both criteria are associated with handedness, they should also be intercorrelated within individuals. Data were collected from skeletal material of 125 males and 57 females to test whether this intercorrelation exists. According to Chi-square analysis, no statistically significant association was identified. After examining several hypotheses, it was concluded that until further substantiation, neither criterion is related to handedness to a degree appropriate for forensic science identification from skeletal remains.
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Data from the Child Research Council (Denver, CO) were utilized to model longitudinal adolescent growth of the humerus, radius, femur, and tibia for 36 girls (10-16 years) and 33 boys (10-17 years). Multilevel modeling procedures were used to estimate variation, covariation, and the polynomial parameters necessary for generating growth curves. At age 10, long bone lengths for girls and boys are similar; by age 16, each of the boys' arm bones is about 20 mm longer and each of their leg bones is about 30 mm longer. Due to the earlier maturation of girls, the models show the length of each of their long bones exceeding that of boys to some degree during some period of adolescence. Peak velocities for leg bones are attained earlier than those for arm bones; in both sexes, age at humeral peak velocity coincides with age at peak height velocity (PHV). At age 13, correlations among lengths and among velocities of bones are strong to moderate, and girls consistently display higher variation than do boys for both long bone length and growth velocity. Considered relative to the average velocity of each bone's growth, the tibia is the most variable of the four long bones at age 13 years.
In 6 dogs the hip joint was experimentally replaced using a ceramic stepped-stem prosthetic device implanted in the thigh bone. In six other dogs V4A steel stepped-stem prosthetic devices inserted in the arm bone was used for replacing shoulder joint. The six devices replacing the shoulder joint healed up without complications and proved to be mechanically stable. From six devices replacing the hip joint only one was successful; the remaining five implants did not heal up due to fractures of the stem, loosening in the thigh bone and osteomyelitis. We suggest that these different results are based not on the different material, but on the different conditions characteristic for each implantation sites. The devices implanted in the arm bone of the dog, corresponding to the conditions in man, were stressed mainly by pressure and pull. In such conditions the newly formed bone tissue anchoring in the steps on the stem stabilized the device. On the other hand, the biomechanical load on the hip joint replacing device in the dog is represented mainly by rotation at stress, for which the devices are not conceived. The stepped profile of the stem can not work; it twists in the thigh bone and remains unstable causing consequences such as fractures, osteomyelitis and loosening. For experimental testing of bone and joint replacing prosthetic devices of cementless anchoring systems replacing human hip joint and thigh bone we recommend the shoulder joint of the dog instead of hip joint, because of the comparable biomechanics.
Arm muscle area (AMA, cm2) is currently calculated from triceps skinfold thickness (TSF, cm), and midarm circumference (MAC, cm). In assessing the accuracy of the current equation by comparison to AMA measured by computerized axial tomography, error in each of the four approximations made was found to result in a 20 to 25% overestimate of AMA. Two correctible error sources were: a 10 to 15% overestimation caused by assuming a circular midarm muscle compartment and a 5 to 10% overestimation due to inclusion of midarm cross-sectional bone area. Corrected AMA equations for men and women were respectively: [(MAC - pi x TSF)2/4 pi] - 10, and [MAC - pi x TSF)2/4 pip] - 6.5. With two additional study groups, the overall improved accuracy of the new equations was confirmed, although the average error for a given patient was 7 to 8%; the relationship between corrected AMA and total body muscle mass was established [muscle mass (kg) = (ht, cm2) (0.0264 + 0.0029 x corrected AMA)]; and the minimal range of corrected AMA values compatible with survival (9 to 11 cm2) was defined. Bedside estimates of undernutrition severity and prognosis can therefore be calculated from two simple measurements, TSF and MAC.
Bone mineral density is higher in dominant vs. nondominant limbs, implying that the greater use of dominant limbs in everyday activities results in the deposition of more bone or that the dominant limb is genetically larger. The objective of the present study was to determine whether bone mineral density differences between dominant and nondominant arms were greater in older vs. younger women. To determine whether this was due to a greater lifetime of preferential loading of the dominant arm, differences between dominant and nondominant arms were compared to accumulated amounts of physical activities which emphasized use of the dominant arm. Bone mineral density of dominant and nondominant arms was assessed by dual-energy X-ray absorptiometry in groups of younger (n = 35; age = 20.9) and older (n = 53; age = 57.4) women. The difference between arms was greater in the older vs. the younger group (5.2% vs. 1.9%, respectively, P < 0.01). Within the older group, total lifetime energy expenditure during activities emphasizing loading of the dominant arm correlated with the bone mineral difference between dominant and nondominant arms (r = 0.47, P < 0.01). This implies that a greater lifetime of preferential loading of the dominant arm in the older group resulted in a greater difference between arms. Am. J. Hum. Biol. 12:633-637, 2000. Copyright 2000 Wiley-Liss, Inc.
Seventy-two postmenopausal osteoporotic women having more than one nontraumatic vertebral crush fracture were studied. Thirty-six of them, aged 68.8 +/- 1.2 years (18 +/- 4 YSM-years since menopause), were treated with 100 IU/day of salmon calcitonin i.m. plus 500 mg of elemental calcium for 10 days each month. The remaining 36 patients, aged 69.6 +/- 1.4 years (19 +/- 3 YSM), were given only 500 mg of elemental calcium for 10 days each month. All patients underwent clinical and analytical evaluation every 3 months. Radiological evaluation, assessment of vertebral deformities, and metacarpal radiogrammetry were done every 6 months. Densitometric measurements of total and regional bone mass were made every 12 months. At 24 months, the calcitonin group showed a 60% reduction in the number of new fractures and the group receiving only calcium had a 45% increase (P < 0.001). The incidence of vertebral fractures was 0.07 per patient-year in the group treated with calcitonin and 0.45 per patient-year in the group treated with calcium (P < 0.001). At 2 years, the calcitonin group showed a 12% increase in cortical bone mass on metacarpal radiogrammetry, a 16% increase in the axial skeleton on trunk densitometry, a 3.5% increase in total body bone mineral content, a 30.7% increase in pelvic bone mineral content, and a 6.2% increase in arm bone mineral content (all P < 0.001). In the group treated with calcium alone there was a loss of bone mass in every region. These findings suggest that salmon calcitonin is effective in the treatment of osteoporosis and show that it acts on cortical and trabecular bone.
The effect of thiazides on total body bone mineral content and axial (trunk) and peripheral (arms) bone mass was evaluated. First, dual-energy X-ray absorptiometry was used to study bone mass in 24 patients with idiopathic hypercalciuria and in 22 healthy subjects. Next, the patients were randomized into a group of 14 patients treated with chlorthalidone (50 mg/day) and a group of 10 untreated patients who served as controls; in these two groups biochemical and bone mass studies were repeated 1 year later. Compared with healthy controls, patients with idiopathic hypercalciuria had less bone mass in total body (p < 0.02), arms (p < 0.001), and trunk (p < 0.05). After 1 year, the group of patients treated with thiazides manifested an increase of bone mass in total body (p < 0.0045), arms, and trunk (p < 0.0001) and a decrease in 24-hour calciuria, urinary calcium/creatinine ratio, and serum tartrate resistant acid phosphatase concentration; the untreated group of patients lost bone mass in all three sites. Under baseline conditions, the groups of treated and untreated patients exhibited a negative linear regression between total body bone mass and both urinary calcium/creatinine (r2 = 0.234; p < 0.001) and serum tartrate resistant acid phosphatase concentration (r2 = 0.399; p < 0.0001). Our results confirm the favorable effect of thiazides on bone mass and provide evidence of enhanced bone remodeling in idiopathic hypercalciuria.
We previously reported that calcium intake enhanced the leg bone response to physical activity of preschool children in a 12-month randomized trial of calcium supplementation and physical activity. To determine whether the intervention-induced changes in leg bone mineral content and size were maintained through the subsequent 12-month follow-up period, total body bone measurements by DXA and 20% distal tibia pQCT bone measurements were obtained at 24 months (12 months post-intervention). Children also were measured for height and weight, and accelerometer readings were obtained in a subset of children at 18 and 24 months (6 and 12 months post-intervention). Regression analyses were performed controlling for covariates and indicated that increases from 12 to 24 months were greater in the gross motor (GM) activity group (bone loading, large muscle exercises) vs. fine motor (FM) activity group (arts and crafts program) for arm bone area (BA) (P <0.01), total body (P=0.04) and arm (P <0.01) bone mineral content (BMC). There were no differences in BA or BMC changes from 12 to 24 months by calcium supplementation. Differences in tibia periosteal circumference by pQCT persisted at 24 months (GM 51.4 +/- 0.4 mm vs. FM 50.2 +/- 0.4 mm, P=0.03) with a trend for greater endosteal circumferences in the children in the GM vs. FM groups at both 12 and 24 months (both, P=0.08). There were no significant differences in cortical area or thickness by activity or supplement group at 24 months. Children in the GM group had greater accelerometer counts/day (P=0.04) and more time in vigorous activity (P=0.05) at 18 months compared to FM group. No differences in accelerometer readings were noted at 24 months. In conclusion, we found higher activity levels in children randomized to gross motor vs. fine motor activities 6 months after the intervention program ceased. Whether the greater periosteal circumference that was observed 12 months post-intervention was a persistent biological bone effect or due to persistently higher activity levels is not known.
Arm muscle plus bone (M + B) cross-sectional area of the arm estimated from area circumference and skinfold thickness was compared with that estimated from CAT scans. The anthropometric technique overestimated M + B area, and the degree of overestimation varied directly with arm adiposity.
Right-left differences in the maximum length of the humerus and radius, and the femur and tibia of the leg in an archaic population were investigated. The materials consisted of skeletons dated to the Neolithic Jomon period excavated in eastern Japan. The results obtained in this study were compared with those of four other populations. Dominant side in the arm and leg bones were found to be dissimilar based on the mean right-left differences. The arm bones of right side were significantly longer than those of left. The leg bones of the left side were longer than those of the right. Mean right-left differences of female arm bones were usually greater than those of males. Obvious sex-differences could not be seen for leg bones. The mean right-left differences of the humerus seemed to be more variable than those of the other three bones.
Our purpose was to determine the effects of creatine supplementation combined with resistance training on bone mineral content and density in older men. Twenty-nine older men (age 71 y) were randomized (double blind) to receive creatine (0.3 g/kg creatine for 5 d and 0.07 g/kg thereafter) or placebo while participating in resistance training (12 weeks). Bone mineral content and density were determined by dual energy X-ray absorptiometry before and after training. There was a time main effect for whole-body and leg bone mineral density (p < or = 0.05) with these measures increasing by approximately 0.5%, and 1%, respectively in the combined groups. There was a group by time interaction for arms bone mineral content, with the group receiving creatine increasing by 3.2% (p < 0.01) and the group receiving placebo decreasing by 1.0% (not significant). Changes in lean tissue mass of the arms correlated with changes in bone mineral content of the arms (r = 0.67; p < 0.01). Resistance training of 12 weeks increases bone mineral density in older men and creatine supplementation may provide an additional benefit for increasing regional bone mineral content. The increase in bone mineral content may be due to an enhanced muscle mass with creatine, with potentially greater tension on bone at sites of muscle attachment.
The incidence of osteoporotic fractures rises exponentially with age and is increasing faster than the demographic increase in the aging population. Physical activity has great potential to reduce the risk for osteoporotic fractures. Three independent but interactive factors contribute to the risk of fractures: bone strength, the risk of falling, and the effectiveness of neuromuscular response that protects the skeleton from injury. Exercise can reduce fracture risk not only by preventing bone loss, but by decreasing the risk of falling and the force of impact by improving strength, flexibility, balance, and reaction time. Extreme inactivity causes rapid bone loss of up to 40%, while athletic activity results in bone hypertrophy of up to 40%. Exercise intervention programs have reduced bone loss or increased bone mass in both men and women of various ages and initial bone status. These benefits have been shown for arm bone mineral content, total body calcium, spine, calcium bone index, tibia, and calcaneus. In both middle-aged and elderly women, physical activity intervention reduced bone loss or increased bone mass. The mechanisms for maintenance of skeletal integrity rely on a cellular response to hormonal and mechanical load stimuli. Studies in animal models show that training affects cellular activity. In osteoporotics, cellular erosion is increased and mineral apposition rate (MAR) decreased compared with normal age-matched controls. In contrast to this, sows trained on a treadmill 20 min per day for 20 weeks had greater active periosteal surface, periosteal MAR, and osteonal MAR than untrained sows.
Spinal cord injury (SCI) results in a dramatic loss of bone mineral and a marked increase in fracture incidence in the femur; however, its effect on the femur's geometric structure and strength is poorly studied. The primary purpose of the present study was to assess the geometric structure, composition, and strength of the midfemur in men with long-term (>2 years), complete SCI (C6-L1 level; n=7) relative to men without SCI (n=8). T1-weighted axial images of the thigh were collected on a GE 1.5-T magnetic resonance imager and geometric, structure, composition, and strength measurements of the midfemur and skeletal muscle volume of the midthigh were determined. Areal bone mineral density (aBMD), bone mineral content (BMC), and bone area of the midthird of the femur and arms were determined using dual-energy X-ray absorptiometry. There were no differences in age, height, weight, femur length, arm BMC, arm aBMD, or arm bone area between the SCI group and controls. While the volume of the midfemur was not different in the two groups, the medullary cavity had 53% more volume and was 21-25% wider in the SCI group (P<0.05). In contrast, the cortical wall in the SCI group had a 24% lower volume and was 27-47% thinner (P<0.05). The cortical wall was particularly thin in the posterior section of the bone. The SCI group also had lower BMC and aBMD in the midfemur (21% and 25%, respectively, P<0.05). Calculated cross-sectional moment of inertia (CSMI), section modulus (Z), and polar moment of inertia (J) were lower in the SCI group (13-19%, P<0.05). A higher ratio of cortical bone volume to muscle volume and BMC to muscle volume in the SCI group (P<0.05) suggests that there was a greater loss of muscle than cortical bone after SCI; however, muscle volume was strongly correlated with cortical bone volume and BMC in the SCI and control groups (r=0.71 to 0.90, P<0.05). Muscle volume was also moderately to strongly correlated with CSMI and Z in the anterior-posterior direction and J. Muscle volume was weakly correlated or not correlated with bone strength measures in the control group (P>0.05). These findings suggest that after SCI, the midfemur erodes on the endosteal surface, resulting in a decreased resistance to bending and torsion. Although midthigh muscle volume appears to decline to a greater degree than midfemur cortical bone volume and BMC, their relationships remain strong.