Determination of hand surface area by sex and body shape using alginate

Hand surface area (HSA) has been utilized for burned skin area estimation in burn therapy, heat exchange in thermal physiology, exposure assessment in occupational toxicology, and the development of manual equipment/ protective gloves in ergonomics. The purpose of this study was to determine the hand surface area to the total body surface area (BSA) and derive a formula for estimating HSA. Thirty-four Korean males (20-60 years old; 158.5-187.5 cm in height; 48.5-103.1 kg in body weight) and thirty-one Korean females (20-63 years old; 140.6-173.1 cm; 36.8-106.1 kg) participated as subjects. The HSA and BSA of 65 subjects were directly measured using alginate. The measurements showed 1) the surface area of the hand had a mean of 448 (371-540) cm(2) for males, and 392 (297-482) cm(2) for females. 2) The hand as a percentage of the total body surface area for males and females was 2.5% and 2.4% respectively, showing no significant difference. 3) The hand as a percentage of BSA by body shape was 2.5% for the lean group and 2.3% for overweight people (p=0.001). 4) When estimating the surface area of a hand, formulae based on hand length or hand circumference were more valid than formulae based on height and body weight. We obtained the following formula for estimating HSA: Estimated HSA(cm(2))=1.219 Hand length(cm) x Hand circumference(cm).     

Improving the accuracy of burn-surface estimation

A user-friendly computer-assisted method of calculating total body surface area burned (TBSAB) has been developed. This method is more accurate, faster, and subject to less error than conventional methods. For comparison, the ability of 30 physicians to estimate TBSAB was tested. Parameters studied included the effect of prior burn care experience, the influence of burn size, the ability to accurately sketch the size of burns on standard burn charts, and the ability to estimate percent TBSAB from the sketches. Despite the ability for physicians of all levels of training to accurately sketch TBSAB, significant burn size over-estimation (p less than 0.01) and large interrater variability of potential consequence was noted. Direct benefits of a computerized system are many. These include the need for minimal user experience and the ability for wound-trend analysis, permanent record storage, calculation of fluid and caloric requirements, hemodynamic parameters, and the ability to compare meaningfully the different treatment protocols.     

Outcome of patients with toxic epidermal necrolysis syndrome revisited

Toxic epidermal necrolysis syndrome is an uncommon, acute, life-threatening, medication-induced disorder with a reported mortality rate of 20 to 60 percent. Different variables have been identified as risk factors. The extent to which these variables, when combined, affect the mortality and outcome in toxic epidermal necrolysis syndrome patients has not yet been reliably defined. Because of the high mortality rate, the logistic analysis of studied variables was performed to see whether a prognostic algorithm could be developed to aid the management of these patients. Thus, a retrospective review of 56 consecutive toxic epidermal necrolysis syndrome patients treated over a period of 13 years was undertaken in the authors' burn center. The demographics included age, sex, race, and total body surface area involved. The other variables studied were comorbidities, sepsis, steroid administration, and the interval between onset of rash and burn center admission. Data were subjected to Fisher's exact test and logistic analysis. Thirty-six patients (64.3 percent) were alive and 20 (35.7 percent) died. Univariate analysis indicated that the male/female ratio was 12:24 for survivors and 9:11 for nonsurvivors (p = 0.4). The white/nonwhite ratio was 80 percent for survivors and 54 percent for nonsurvivors (p = 0.58). The median age was 48.4 +/- 22.8 years (survivors, 41.7 +/- 22.0; nonsurvivors, 60.5 +/- 19.5; p = 0.002). Total body surface area involvement for survivors was 56.9 +/- 32 and 77.7 +/- 21 for nonsurvivors (p = 0.005). The presence of one or more comorbidities between the two groups differed (53 percent survivors and 90 percent nonsurvivors, p = 0.007), indicating eight times higher odds of dying in their presence. The average time between the onset of symptoms and admission to the burn unit was 5.25 +/- 3.4 days for survivors and 7.15 +/- 4.5 days for nonsurvivors (p = 0.08). The presence of sepsis (19.4 percent survivors, 95 percent nonsurvivors, p < 0.001) decreased odds for survival by a factor of 79. Steroids given as a single dose or multiple doses before the patient's transfer to the burn unit were not significantly associated with death (44 percent survivors, 65 percent nonsurvivors, p = 0.14). A multivariate logistic regression model yielded odds ratios of 1.11 (95 percent confidence interval, 1.03 to 1.19) for age in years, 304 (95 percent confidence interval, 8.83 to 10,400) for the presence of sepsis, and 1.03 (95 percent confidence interval, 0.99 to 1.08) for body surface area in percent. All those entering the burn unit with sepsis died. Equivalently, no survivors had sepsis before admission to the burn unit, whereas 55 percent of nonsurvivors had sepsis before admission and 40 percent developed sepsis after admission. When investigating the effect of age and sepsis, no patients over age 60 ever having sepsis survived, whereas all those who were under 60 and without sepsis survived. Likewise, all patients whose age was over 60 and whose total body surface area involved was over 60 percent died. The main factors contributing to the mortality from toxic epidermal necrolysis syndrome, when considering covariates separately, are the presence of sepsis at any time (odds ratio, 79), the presence of comorbidities (odds ratio, 8.05), age, and total body surface area, whereas multivariate models suggested age (odds ratio per year of additional age, 1.11), total body surface area (odds ratio per additional percent of body surface area, 1.03), and the presence of sepsis (odds ratio, 304). By using the actual coefficients in the logistic model, the log odds that the patient will die as the result of his or her condition can be summarized in the following formula: -11.5 + (10 percent of the patient's age + 3 percent of total body surface area + 5.75 if sepsis is present). The awareness of the importance of these covariates, and their early recognition as risk factors, should offer a focused approach to the patients' management and improve their outcome.     

Evaluation of hand asymmetry in relation to hand preference

We evaluated the asymmetric hand measurements in right- and left-handed individuals. 343 men and 290 women aged 18-42 years (22.11 +/- 2.07) participated in the study. There were no statistically significant differences when right-left differences in hand length, third finger length, palmar length, and the digit index value were evaluated according to hand preference and sex. Statistically significant differences were found for right-left differences in hand width, hand-shape index, and the palmar length/width according to hand preference. The strong left-handers, weak left-handers, and ambidextrous individuals in the study group all exhibited asymmetry favoring the left and were considered together. Similarly, the strong and weak right-handers exhibited asymmetry favoring the right hand and were considered together. The difference between these two groups was significant. When the data were evaluated according to sex, significant differences were found between the subgroups. In particular, right-left differences in the hand-shape index and palmar length/width values of the strong left-handers, weak left-handers, and ambidextrous individuals were found to be statistically significant according to sex; in contrast, the strong and weak right-handers showed no significant differences according to sex. These results suggest a relation of hand asymmetry to hand preference in a Turkish population.     

Handgrip strength and hand dimensions in young handball and basketball players

In handball and basketball the longer the finger length the better the accuracy of the shot or throw. All shots and throws are finished with the wrist and fingers. It can be proposed that athletes with longer fingers and greater hand surface parameters also probably have greater grip strength. The aim of this study was to investigate the influence of general body and hand-specific anthropometric dimensions on handgrip strength in boys participating in handball and basketball training. In total, 193 boys aged 10-17 years participated in this study. They were divided into 6 groups: 10-, 11-, 12-, 13-, 14-15-, and 16-17-year-olds. The body height and body mass were measured and body mass index was calculated as general anthropometric parameters. The outlines of the hands of the boys were drawn on paper with a thin marker. Three groups of hand anthropometric parameters were measured: 5 finger spans, 5 finger lengths, and 5 perimeters of the hand. Handgrip strength was measured on the dominant hand with a Lafayette dynamometer. As a rule, general anthropometric parameters determined the maximal handgrip strength more accurately than did specific hand anthropometric parameters. From the specific hand anthropometric parameters, finger lengths and perimeters of the hand significantly correlated with the maximal handgrip strength. In summary, fingers are the smallest, lightest parts of the motor apparatus, and, therefore, they represent the parts most easily deflected by force from the ball, but at the same time, finger control is especially important for the accuracy of different shots, both in handball and basketball. Thus, it is especially necessary to measure finger length and perimeters of the hand for practical reasons.     

Cardiac mitochondrial damage and loss of ROS defense after burn injury: the beneficial effects of antioxidant therapy.

Mechanisms of burn-related cardiac dysfunction may involve defects in mitochondria. This study determined 1) whether burn injury alters myocardial mitochondrial integrity and function; and 2) whether an antioxidant vitamin therapy prevented changes in cardiac mitochondrial function after burn. Sprague-Dawley rats were given a 3 degrees burn over 40% total body surface area and fluid resuscitated. Antioxidant vitamins or vehicle were given to sham and burn rats. Mitochondrial and cytosolic fractions were prepared from heart tissues at several times postburn. In mitochondria, lipid peroxidation was measured to assess oxidative stress, mitochondrial outer membrane damage and cytochrome-c translocation were determined to estimate mitochondrial integrity, and activities of SOD and glutathione peroxidase were examined to evaluate mitochondrial antioxidant defense. Cardiac function was measured by Langendorff model in sham and burn rats given either vitamins or vehicle. Twenty-four hours postburn, mitochondrial outer membrane damage was progressively increased to approximately 50%, and cytosolic cytochrome-c gradually accumulated to approximately three times more than that measured in shams, indicating impaired mitochondrial integrity. Maximal decrease of mitochondrial SOD activity occurred 8 h postburn ( approximately 63.5% of shams), whereas maximal decrease in glutathione peroxidase activity persisted 2-24 h postburn ( approximately 60% of shams). In burn animals, lipid peroxidation in cardiac mitochondria increased 30-50%, suggesting burn-induced oxidative stress. Antioxidant vitamin therapy prevented burn-related loss of membrane integrity and antioxidant defense in myocardial mitochondria and prevented cardiac dysfunction. These data suggest that burn-mediated mitochondrial dysfunction and loss of reactive oxygen species defense may play a role in postburn cardiac dysfunction.     

Body surface area of Africans: a study based on direct measurements of Nigerian males

Direct measurement of body surface area (Ab) was made on 20 male adult Nigerians of African descent by coating and planimetry. The results were compared with estimated Ab values obtained using six widely accepted height and weight prediction equations. The results show that existing formulas do not predict surface areas of our subjects accurately. Measured Ab values of our subjects were 6-22% greater than predicted values obtained from non-African nomograms. Using these results, we computed new variables for height and weight formulas that accurately predict the surface area of Africans. The closest fit to measured values is given by the equation Ab(m2) = 0.001315 x Height 1.2139 (cm) x weight 0.2620 (kg) +/- 0.04815 (SEE). The new variables are significantly different from those of existing equations. Our height variable is several times greater than the weight variable and reflects a greater importance of height than weight in determining the surface area of Africans than is the case with Caucasians.     

Determination of body surface area in neonatal swine.

The body surface area of 30 neonatal pigs of both sexes, weighing 445--1,976 g, were determined by the direct skinning technique. The range of measured body surface area values was 635--1,400 cm2 (mean = 895.1 cm2). The regression line, fitted to a scatter diagram and calculated by the least square method, was found to be Y = 337.2 + 0.553X; where X was body weight expressed in grams and Y was body surface area expressed in square centimeters.     

Determination of body surface area and formulas to estimate body surface area using the alginate method

The purpose of this study was to determine the body surface area (BSA) based on the alginate method, to derive formulae for estimating BSA, and to compare the error of the present formula to previous formulas obtained from other countries. We directly measured the entire body surface area of 34 males (20-60 years old, 158.5-187.5 cm in height, 48.5-103.1 kg in body weight) and 31 females (20-63 years old, 140.6-173.1 cm, 36.8-106.1 kg) using alginate. The measurements showed that the BSA had a mean of 18,339 cm(2) (15,416-22,753 cm(2)) for males, and 16,452 cm(2) (12,825-22,025 cm(2)) for females. Based on these measurements, a regression model to estimate BSA was derived: Estimated BSA (cm(2))=73.31 Height (cm)(0.725) x Weight (kg)(0.425) (r(2)=0.999). The mean error of the formula was -0.1%, and did not show any significant difference by gender or body shape. When applied to the datasets (n=506) composed of various races (Caucasians, Africans, and Asians), the mean error of the formula was 0.4% and was smaller than that of DuBois & DuBois's, Gehan & George's, and Mosteller's formulas when applied to the same datasets. The errors of the three previous formulas were also within 2%. Overall, formulas based on the DuBois exponent (Weight(0.425) Height (0.725)) did not show any tendency of overestimation or underestimation by body shape, but other BSA-formulae showed differences by body shape. The present BSA formula has shown good accuracy in Korean adults of all weight categories compared to traditional formulas.     

Fist position for skin grafting on the dorsal hand: I. Analysis of length of the dorsal hand surgery in hand positions.

In skin grafting for reconstruction of burns and contracture deformities of the dorsal hand, the hand is kept in a proper position to provide the greatest amount of skin and to avoid the secondary functional deformity. The safe position has been commonly used for immobilizing the hand, but this is to protect the hand function rather than to provide maximal surface for skin grafting. Split-thickness skin graft contracts up to 30 to 50 percent of the original size owing to secondary contraction. If insufficient skin is grafted, contracture deformity of the dorsal hand may occur. To graft the greatest amount of skin on the dorsal hand, the hand should be kept preoperatively in a position flexing all joints of the wrist, metacarpophalangeal joints, and interphalangeal joints and maximally stretching the dorsal hand (a fist position). We studied the surface length of the dorsal hand between the wrist, the metacarpophalangeal joint, and the eponychium in the anatomic, safe, and fist positions of the right hand in 60 adults. Difference of total length between the anatomic and safe positions was not statistically significant (p > 0.05). The total length in a fist position was significantly increased in comparison with the other two positions (p < 0.05). In a fist position compared with the safe position, the increase in length of the dorsal surface of the proximal hand was 11 to 20 percent except in the thumb, and the increase in length of the dorsal surface of the finger was 12 to 17 percent. The increase in total length of a fist position was about 9 mm (7 to 8 percent) in the thumb and 20 to 32 mm (14 to 18 percent) in the index to little fingers. It suggests that the safe position fails to provide an increased dorsal hand surface area for skin grafting compared with the anatomic position. The greatest amount of skin can be grafted in a fist position. Hand immobilization in a fist position for 7 to 9 days after skin grafting has not resulted in irrevocable joint stiffness in our experience. If injury of the deep structures is not present, the hand should be immobilized in a fist position before skin grafting on the dorsal hand.     

Normal values for total hand length, palm length and middle finger length in Malaysian newborns from 34-42 weeks of gestation.

Early identification of a syndrome at birth is of paramount importance for genetic counselling and possible prevention. Often malformation of the hands and fingers are cardinal manifestations of recognizable syndromes. As there are no published standards for hand and finger size for Malay newborn infants, this study was undertaken to establish normal values for hand, middle finger and palmar lengths, and their indices. A cross-sectional study was done on 509 consecutive newborn Malay babies between 34 and 42 weeks of gestation. Measurements were made on the right hand according to the recommended guidelines of Bergsma & Feingold (1975). The mean values for the measurements did not differ significantly between boys and girls, or change with gestation. For the whole group the mean value for total hand length was 64.4 +/- 3.42 mm, middle finger length 37.1 +/- 2.91 mm, palmar length 27.4 +/- 2.15 mm, finger index 0.425 +/- 0.03 and palmar index 0.58 +/- 0.03. A comparison with published measurements for newborns of different racial origin shows significant differences for the total hand length, middle finger length and palm length from Indian and Jewish infants, but not from Japanese infants. The indices were similar in Malay, Indian, Jewish and Japanese newborn infants.     

The estimation of the cross-sectional area of the ulna and radius

Postero-anterior radiographs of 20 clean, dry ulnae were taken. The width of each bone was measured on its radiograph at 30 sites along the length of the bone. The ulnae were then sectioned at these sites and the cross-sectional areas of the sections were determined. For each measurement site, a regression equation, together with its associated standard error of estimate and correlation coefficient, was derived for the estimation of the cross-sectional area of the bone from its width. A set of 20 clean, dry radii was examined in the same way. The relevance of the results to the assessment of osteoporosis from densitometric scan information is discussed.     

新疆维吾尔族手掌侧投影面积测定

应用WT-2型数字图像处理仪测定了123名维吾尔族青年手的掌侧投影面积。各指掌侧投影面积的平均值,以中指最大(15.32平方厘米),食指(13.72平方厘米)及环指(13.16平方厘米)次之,拇指再次(12.11平方厘米),小指最小(9.36平方厘米)。全手掌侧投影总面积平均156.97平方厘米。指掌侧投影总面积平均63.67平方厘米,占全手掌侧投影总面积的40.67％。手掌投影面积平均93.30平方厘米,占全手掌侧投影总面积的59.33％。按照Stevenson(1937)公式,根据身高和体重,计算出体表面积的估计值,进而求得全手掌侧投影面积占身体表面积的1.008％。经计算机处理,求得手长、手宽、身高、体重与手面积的相关系数,并建立了由手长和手宽推算手掌侧投影面积的多元回归方程。     

Arches of the hand in reach to grasp

Topographically, the hand is described by its anterior (palmar) and posterior (dorsal) surfaces that encompass a hollow cavity that changes its shape during hand preshaping and grasping according to the object to be grasped. The hollow cavity has been described as consisting of three arches that run in different directions: transverse, longitudinal and oblique, spanning the anterior surface of the hand. Although described anatomically, the modulation in the palmar arches has not been investigated kinematically during actual grasping. In this study, we describe and compare biomechanical formulations of the palmar arch, specifically, the distal transverse and the oblique arches. In addition, we introduce another biomechanical formulation of the palmar arch, called the kinematic transverse arch that takes account of the thenar and hypothenar involvement in arch formation. Hand shape modulation during two natural power-grasping tasks was studied in eight healthy adults. Results showed a significant influence of the overall contribution of thenar and hypothenar movement during hand shape modulation. While there was relatively more thenar contribution during transport shaping, more hypothenar contribution was evident during preshaping and contact shaping-the two phases of grasping during which the hand establishes contact with the object. The advantage of the new formulation is that it better described the contributions from thenar and hypothenar movement to palmar arch formation which may be a more accurate depiction of hand preshaping during grasping.     

A conductive polymer sensor for measuring external finger forces.

This paper describes the construction and use of a durable and thin force sensor that can be attached to the palmar surface of the fingers and hands for studying the biomechanics of grasp and for use in hand injury rehabilitation. These force sensors were constructed using a modified commercially available conductive polymer pressure sensing element and installing an epoxy dome for directing applied forces through a 12 mm diameter active sensing area. The installation of an epoxy dome was effective for making the sensors insensitive to contact surfaces varying from 25 to 1100 mm2 and a 16 mm radius surface curved convex towards the finger. The completed sensors were only 1.8 mm thick and capable of being taped to the distal phalangeal finger pads. They were calibrated on the hand by pinching a strain gage dynamometer. The useful range was between 0 and 30 N with an accuracy of 1 N for both static loading and normal dynamic grasp activities. The sensor time constant was 0.54 ms for a step force input. Because of varying offset voltages every time the sensors were attached, these sensors should be calibrated on the hand before each use. The sensors were used for measuring finger forces during controlled pinching and lifting tasks, and during ordinary grasping activities, such as picking up a book or a box, where the useful force range and response for these sensors were adequate.     

Estimation of breast burn size

It is the authors' opinion that the size of chest burns on large-breasted women can be significantly underestimated, especially if the methods of calculation rely on burn charts, such as the Lund and Browder burns chart. This latter chart is based on data derived from only three women and eight men. The surface area of the torsos of 60 volunteers (20 men, 20 small-breasted women, and 20 large-breasted women) was measured using two well-established techniques. The torso surface area was divided into two parts: the anterior trunk and the posterior trunk (i.e., torso surface area = posterior trunk + anterior trunk). The anterior trunk was subdivided and the area above the costal margins defined as the pectoral region. These areas were measured separately for each individual. The volunteers' total body surface area was calculated using normograms, based on their weight and height. The area of each torso section was recorded as a percentage of the total body surface area and torso surface area. Whereas the torso surface area/total body surface area ratio did not vary significantly between the groups, the proportion of anterior to posterior trunk size did depend on the sex and on breast size. There was a direct correlation between the woman's bra cup size and the ratio of anterior-to-posterior trunk surface area. A simple chart was therefore derived that estimates the relative size of a woman's torso surface area once her bra cup size is known. Such a chart can be used to improve accuracy in adult female chest burn estimation, when used in conjunction with a burns chart. Breast burns in larger breasted women are underestimated when calculated using current burn charts. We recommend that a correction be made when estimating chest burns in women to account for the increased surface area of the breasts. A chart, such as the one we have developed, could be used in conjunction with a burn chart (e.g., Lund and Browder) to make this correction.     

A critical examination of four methods of estimating the surface area of stone substrate from streams in relation to sampling Simuliidae (Diptera)

Four methods of calculating stone surface area are examined for their value in estimating simuliid larval density. All methods produced area estimates highly correlated with each other. Stone surface area poorly correlated with simuliid abundance, which we concluded was the result of a highly variable microhabitat and the inability to estimate the surface area actually occupied by larvae. Therefore, if an estimate of stone surface area is required, the simplest methods are sufficient (e.g., maximum length × 90° maximum width).     

A reverse ulnar hypothenar flap for finger reconstruction

A reverse-flow island flap from the hypothenar eminence of the hand was applied in 11 patients to treat palmar skin defects, amputation injuries, or flexion contractures of the little finger. There were three female and eight male patients, and their ages at the time of surgery averaged 46 years. A 3 x 1.5 to 5 X 2 cm fasciocutaneous flap from the ulnar aspect of the hypothenar eminence, which was located over the abductor digiti minimi muscle, was designed and transferred in a retrograde fashion to cover the skin and soft-tissue defects of the little finger. The flap was based on the ulnar palmar digital artery of the little finger and in three patients was sensated by the dorsal branch of the ulnar nerve or by branches of the ulnar palmar digital nerve of the little finger. Follow-up periods averaged 42 months. The postoperative course was uneventful for all patients, and all of the flaps survived without complications. The donor site was closed primarily in all cases, and no patient complained of significant donor-site problems. Satisfactory sensory reinnervation was achieved in patients who underwent sensory flap transfer, as indicated by 5 mm of moving two-point discrimination. A reverse island flap from the hypothenar eminence is easily elevated, contains durable fasciocutaneous structures, and has a good color and texture match to the finger pulp. This flap is a good alternative for reconstruction of palmar skin and soft-tissue defects of the little finger.     

The surface area of mudfish

The surface area of two closely related mudfish species have been determined by coating the animals with masking tape. The results indicate that Labeo capensis specimens above 95 g body weight have a larger surface area than corresponding L. umbratus animals. The same is true for the fin surface area above 50 g body weight. Below these weights L. umbratus specimens have higher surface areas. The body surface area of L. capensis is always lower than that of L. umbratus in the range studied.