Disorders of finger flexion crease formation in various congenital anomalies of human development]

Deviations in finger flexion crease formation and ridge counts were analysed in normal and deformed (Down syndrome, arthrogriposis, diastrophic dysplasia) hands. Certain interrelation was found between decrease in the ridge count and the number of the finger flexion creases in Down syndrome. The changes observed agree with the hypothesis that intersegmental borders, and later, the joints and finger flexion creases are laid out on the basis of the positional information which is directed by morphogenetic gradients. This model enables us to interpret more or less unequivocally the changes in flexion creases in patients with arthrogriposis and diastrophic dysplasia (dwarfism).     

湖南侗族的手纹研究

报道了湖南通道侗族337例正常人的指纹型、总指纹嵴数（TFRC）、a-b纹嵴线（a-bRC)、atd角、轴三角百分距（tPD)、大鱼际纹、小鱼际纹、指间区纹、掌褶纹、掌纹主线横向指数（MLIT）等手纹参数正常值,并与侗族不同人群和湖南周边不同民族进行了比较,发现湖南侗族手掌真实花纹和掌褶纹分布频率与湖南周边其他已研究过的民族和侗族群体存在明显差异。     

Maternal effects on fingertip dermatoglyphics.

Significantly larger variation between sibships within families of male MZ twins than between sibships within families of female MZ twins, indicative of maternal influences, was found for 10 of 41 dermatoglyphic fingertip variables. Of these, five were thumb-related with the effect primarily on the thumb radial and ridge count (larger of radial and ulnar count). These same variables were previously found to have unequal variances in MZ twins of known placental type, and the results indicate maternal influences in singletons as well as twins for these variables. Although the total ridge count (TRC), previously shown to differ in MZ twins of known placental type (paralleling the thumb radial and ridge counts) did not reach significance, the trend indicated that the observed thumb changes may be reflected in the TRC as well. Little finger pattern type and ulnar counts also showed less variability in families of female MZ twins, but the interpretation is complicated by the concomitant differences in mean squares within-sibships for these little finger variables.     

Relationship between finger length and ridge count in patients with Marfan syndrome]

Palmar dermatoglyphs were studied in 38 patients with lens dislocation. The patients were distributed into three groups: Marfan syndrome, mild Marfan syndrome, isolated lens dislocation. Marked arachnodacytyly was observed in the first group. In these patients increase in finger length was positively correlated with the ridge count. Moderate increase in finger length and ridge count was observed in the second group. The relative finger length was lower in patients with isolated lens dislocation than in unaffected persons, though the ridge count did not differ from the control. The relations noted between the finger length and ridge count in Marfan syndrome are in agreement with the suggestion that these two parameters are determined by common cause, namely, the morphogenetic gradient in digital primordia.     

Fixed and random effects in the variation of the finger ridge count: a study of fragile-X families.

A maximum-likelihood scoring technique for analysis of pedigree data allows for the concurrent estimation of random and of fixed effects in a quantitative trait. We included both types of effects in genetic models, to study the sources of variation in finger ridge count in 54 large families affected with the fragile-X disorder. The fixed effects were represented by fragile X and sex, and the random effects by environmental and genetic variance. We found a significant effect of fragile X in the mean of the finger ridge count on the thumb (finger 1) and index finger (finger 2), which had the lowest heritability and a negligible nonadditive component of genetic variance. This was in contrast with ridge counts on fingers 3 and 4, which showed little fragile-X effect, but high heritability and a significant nonadditive component. A contrast in genetic properties for ridge counts on fingers 1 and 2, compared with these counts on the remaining three fingers, may be relevant to increased selection pressures on functions of the thumb and of the index finger in evolution of modern man. We have also demonstrated an important effect of fragile X in increasing the additive variance in covariance, especially between male pairs. These findings suggest that the effect of the fragile-X genotype in finger ridge count is additive and superimposed on the normal hereditary variations in this trait.     

Treatment of congenital upper extremity problems

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Describe the terminology and classification of congenital hand anomalies. 2. Describe the incidence and embryogenesis of some common congenital hand anomalies. 3. Discuss the general principles and goals for treatment of congenital hand anomalies. 4. Describe the management of five of the more common congenital hand anomalies (syndactyly, short digits, thumb duplication, hypoplastic thumb, and radial dysplasia). SUMMARY: Congenital hand anomalies can cause substantial emotional and functional problems. This article reviews the etiology, classification, and management of some of the more common hand anomalies. A general approach to the patient and the goals of treatment are reviewed, as is the approach to five specific congenital hand anomalies: syndactyly, short digits, thumb duplication, hypoplastic thumb, and radial dysplasia.     

Quantitative finger dermatoglyphics in a Spanish population (Tierra de Campos)

This study deals with the finger ridge counts and the distribution of their frequencies drawn from a Spanish sample consisting of 833 school-children (417 males and 416 females), which has been collected from the geographical area of Tierra de Campos. Paired t-test and Student-t-test were used to explore bimanual and sexual differences, respectively. The results showed: a bimanual asymmetry marked by significantly higher right hand ridge count for thumb and index pairs in both males and females, ridge counts of males are always higher than the corresponding values of females; the differences being significant excepting for right and left index and for left ring-finger. The frequency distribution of TFRC was slightly, but significantly, different from normality only in males, as Kolmogorov test showed. A great homogeneity between values for TFRC of males and females from Tierra de Campos and those of the available Spanish and Portuguese populations has been found, the values being high not only in the variation ranges of the Spanish and Portuguese populations, but also in the ranges reported for other European populations.     

The effect of a pattern in palmar interdigital II on a-b ridge count in black and white Down syndrome cases and controls

An unconfirmed study by Fang (Ph.D. thesis, Univ. of London, 1950) in Britain showed that individuals with Down syndrome had lower total a-b ridge counts in palmar Interdigital area II (ID II) than a group of controls. This study compares 603 white Down syndrome cases and 93 black Down syndrome cases with 668 white and 402 black controls. Our results confirm those of Fang in that the Down syndrome cases in both racial groups had lower total a-b ridge counts than their respective controls. In addition, the black controls and Down syndrome cases had lower a-b ridge counts than their white counterparts. The mean a-b ridge count was significantly lower in individuals with a pattern in ID II compared to individuals without a pattern in ID II in both the Down syndrome and control groups. Some of the lower a-b ridge counts in the Down syndrome samples can be accounted for by the fact that there is an increased frequency of a pattern in ID II in Down syndrome cases. Both Down syndrome and normal individuals who had a pattern unilaterally had a lower than expected a-b ridge count on the contralateral hand that did not have a pattern. There was a tendency also for increased asymmetry in Down syndrome cases with a pattern in ID II.     

Measuring 3D Hand and Finger Kinematics—A Comparison between Inertial Sensing and an Opto-Electronic Marker System

Objective analysis of hand and finger kinematics is important to increase understanding of hand function and to quantify motor symptoms for clinical diagnosis. The aim of this paper is to compare a new 3D measurement system containing multiple miniature inertial sensors (PowerGlove) with an opto-electronic marker system during specific finger tasks in three healthy subjects. Various finger movements tasks were performed: flexion, fast flexion, tapping, hand open/closing, ab/adduction and circular pointing. 3D joint angles of the index finger joints and position of the thumb and index were compared between systems. Median root mean square differences of the main joint angles of interest ranged between 3.3 and 8.4deg. Largest differences were found in fast and circular pointing tasks, mainly in range of motion. Smallest differences for all 3D joint angles were observed in the flexion tasks. For fast finger tapping, the thumb/index amplitude showed a median difference of 15.8mm. Differences could be explained by skin movement artifacts caused by relative marker movements of the marker system, particularly during fast tasks; large movement accelerations and angular velocities which exceeded the range of the inertial sensors; and by differences in segment calibrations between systems. The PowerGlove is a system that can be of value to measure 3D hand and finger kinematics and positions in an ambulatory setting. The reported differences need to be taken into account when applying the system in studies understanding the hand function and quantifying hand motor symptoms in clinical practice.     

Asymmetry of finger ridge countsamong four tribal populations of Andhra Pradesh, India

The asymmetry among the four tribal populations Dulia, Kotia, Manne Dora and Manzai Mali is reported. The mean directional asymmetry (MDA) and mean absolute asymmetry (MAA) were measured for homologous fingers. The asymmetry follows a decreasing trend in radio-ulnar direction with higher mean values in thumb and index finger. The individual variation is also higher in these fingers. Neither sexual nor population differences are consistent. Jantz's Square root of A2 (another measure to assess asymmetry) for total finger ridge count and absolute finger ridge count does not indicate any significant sexual or ethnic differences. The results suggest that the underlying mechanisms influencing the level of asymmetry may be similar for all groups, and that certain dermatoglyphic areas like the thumb are more vulnerable to developmental/environmental stress, that cause asymmetry at the developmental stage.     

Coordination of thumb joints during opposition

Thumb opposition plays a vital role in hand function. Kinematically, thumb opposition results from composite movements from multiple joints moving in multiple directions. The purpose of this study was to examine the coordination of thumb joints during opposition tasks. A total of 15 female subjects with asymptomatic hands were studied. Three-dimensional angular kinematics of the carpometacarpal (CMC), metacarpophalangeal (MCP) and interphalangeal (IP) joints were obtained by a marker-based motion analysis system. Thumb opposition revealed coordination among joints in a specific direction (inter-joint coordination) and among different directions within a joint (intra-joint coordination). In particular, linear couplings existed between the flexion and pronation at the CMC joint, and between the flexion of the CMC joint and flexion of the MCP joint. Principal component analysis showed that only two principal components adequately represented the thumb opposition data of seven movement directions. A term functional degrees of freedom by virtue of principal component analysis was proposed to uncover the extent of movement coordination in functional tasks.     

The dermatoglyphic and clinical features of the 9p trisomy and partial 9p monosomy syndromes

Summary The physical and dermatoglyphic features obtained from published reports of 128 patients with the trisomy 9p syndrome and 27 patients with the partial 9p monosomy syndrome are tabulated. This information is also provided on two new individuals with each of these chromosomal disorders. The dermal ridge patterns and palmar creases of trisomy 9p which are most helpful from a diagnostic standpoint are zygodactylous or absent palmar digital triradii, brachymesophalangy, reduced total finger ridge count, complex thenar/ID I patterns, transverse palmar ridge alignment, simian creases, distal axial triradii, and great toe and hallucal arch patterns. The characteristic features in partial 9p monosomy include dolichomesophalangy with accessory finger flexion creases, digital whorl patterns and elevated total finger ridge count, distal axial triradii, simian creases, and palmar dermal ridge dissociation.     

The thumb of Miocene apes: new insights from Castell de Barberà (Catalonia, Spain)

Primate hands display a major selective compromise between locomotion and manipulation. The thumb may or may not participate in locomotion, but it plays a central role in most manipulative activities. Understanding whether or not the last common ancestor of humans and Pan displayed extant-ape-like hand proportions (i.e., relatively long fingers and a short thumb) can be clarified by the analysis of Miocene ape hand remains. Here we describe new pollical remains-a complete proximal phalanx and a partial distal phalanx-from the middle/late Miocene site of Castell de Barberà (ca., 11.2-10.5 Ma, Vallès-Penedès Basin), and provide morphometric and qualitative comparisons with other available Miocene specimens as well as extant catarrhines (including humans). Our results show that all available Miocene taxa (Proconsul, Nacholapithecus, Afropithecus, Sivapithecus, Hispanopithecus, Oreopithecus, and the hominoid from Castell de Barberà) share a similar phalangeal thumb morphology: the phalanges are relatively long, and the proximal phalanges have a high degree of curvature, marked insertions for the flexor muscles, a palmarly bent trochlea and a low basal height. All these features suggest that these Miocene apes used their thumb with an emphasis on flexion, most of them to powerfully assist the fingers during above-branch, grasping arboreal locomotion. Moreover, in terms of relative proximal phalangeal length, the thumb of Miocene taxa is intermediate between the long-thumbed humans and the short-thumbed extant apes. Together with previous evidence, this suggests that a moderate-length hand with relatively long thumb-involved in locomotion-is the original hand morphotype for the Hominidae.     

桂西壮族手皮纹的分析

本文对广西西部500例健康壮族大、中学生的手皮纹进行了观察分析,计算出各型指纹频率、指纹脊线总数、指纹频度指数、atd角度、a-b脊线数、τ距比、主线横向指数、皮纹花样出现率、掌褶纹出现率共九项基本参数,并将这些数值与汉族作了比较,桂西壮族的手纹与汉族既有相似之处,又有本民族的特点。     

中国十一个少数民族的皮纹研究 Ⅱ.掌纹

研究了中国11个少数民族(其中回族两个群体)5013人的掌纹样本,计算出了a—b脊线数、atd角、掌褶纹类型、掌纹真实花样、掌纹主线各个项目的基本参数,比较了不同民族、性别、左右侧以及人种间的差异。各民族的掌纹各具特点而又显示出蒙古人种的一般特征。     

Detection of renal anomalies by abdominal palpation in newborn infants.

In a new technique of palpation for renal anomalies in the newborn one hand supports the infant while the fingers of the other hand support the loin and the thumb explores the abdomen. In a series of 11 000 otherwise normal newborn children superficial palpation detected 11 renal anomalies, and deep palpation led to the discovery of another 42 anomalies. One of two other series in which palpation was performed bimanually gave a similar incidence of renal anomalies (0-5%). Early discovery of an asymptomatic anomaly enables early treatment of the complications that are often found in patients with congenital renal anomalies detected in later life.     

Palmar and plantar pads and flexion creases of genetic polydactyly mice (Pdn)

Attempts to gain a better understanding of the relationship between the epidermal ridge patterns (dermatoglyphics) and flexion creases on the volar aspects of human hands and feet and specific medical disorders led to a search for a suitable animal model, allowing studies of the fetal development of the pertinent structures. A common experimental animal, the rat (Rattus norvegicus), was found to be an excellent candidate, owing to the strong resemblance of the volar pads and flexion creases on its palmar and plantar surfaces to those of human subjects. A hereditary preaxial polydactyly mouse (Pdn) provides an opportunity to study the effects of this malformation on the surrounding morphological structures and, specifically, on the volar pads, i.e., the sites over which the dermatoglyphic patterns develop. The hands and feet of the wild‐type (+/+) mice show no anomalies, and their major pad and flexion crease configurations correspond to those of normal rats. The heterozygous (Pdn/+) mice, in spite of having a thumb/big toe with a duplicated distal phalanx on their hands/feet, did not display any alterations in palmar/plantar pads. The homozygous (Pdn/Pdn) mice have a protrusion in the thenar area and one to three supernumerary digits on the preaxial portion of both the hands and feet. The effect of these anomalies was found to be limited to the pad and flexion crease configurations in the preaxial areas; the postaxial sites were not affected. The original number of pads on the thenar/first interdigital areas of Pdn/Pdn mice was apparently identical to that of the +/+ and Pdn/+ mice. The preaxial protrusion, however, affected the number, size, and location of the pads observed in the newborn mice, resulting in varying pad configurations, such as fused and scattered pads or a pad cluster formed by gathering the neighboring pads. These pad modifications were induced by the preaxial plantar/palmar protrusion only and were not affected by the presence of supernumerary preaxial digits. In view of the similarities in the morphology and fetal development of human and mouse distal limbs, the present study is relevant to human subjects, particularly to the understanding of the significance of dermatoglyphic variations in individuals with specific medical disorders. Future studies of naturally occurring or experimentally induced limb malformations in mice or rats should provide valuable insights into the development of human hands and feet and into factors contributing to their congenital anomalies. J. Morphol. 239:87–96, 1999. © 1999 Wiley‐Liss, Inc.     

Thumb motor performance varies with thumb and wrist posture during single-handed mobile phone use

Design features of mobile computing technology such as device size and key location may affect thumb motor performance during single-handed use. Since single-handed use requires the thumb posture to vary with key location, we hypothesize that motor performance is associated with thumb and wrist joint postures. A repeated measures laboratory experiment of 10 right-handed participants measured thumb and wrist joint postures during reciprocal tapping tasks between two keys for different key pairs among 12 emulated keys. Fitts' effective index of performance and joint postures at contact with each key were averaged across trials for each key. Thumb motor performance varied for different keys, with poorest performances being associated with excessive thumb flexion such as when tapping on keys closest to the base of the thumb in the bottom right corner of the phone. Motor performance was greatest when the thumb was in a typical resting posture, neither significantly flexed nor fully extended with slight CMC joint abduction and supination, such as when tapping on keys located in the top right and middle left areas on the phone. Grip was also significantly affected by key location, with the most extreme differences being between the top left and bottom right corners of the phone. These results suggest that keypad designs aimed at promoting performance for single-handed use should avoid placing frequently used functions and keys close to the base of the thumb and instead should consider key locations that require a thumb posture away from its limits in flexion/extension, as these postures promote motor performance.     

The relationship between total ridge count and pattern intensity index of digital dermatoglyphics

A mathematical relationship between total ridge count (TRC) and pattern intensity index (PII) is explored using data from a sample of 180 males and 213 females of Negroid origin from southwestern Haiti, West Indies. Linear regression of total ridge count on pattern intensity index gave good fit to data in males. In females the linear and quadratic regression models were less satisfactory probably due to the considerable overlap of ridge count distribution between loops and whorls. Two other measures which compare better than total ridge count are absolute ridge count and weighted total ridge count. Predictions of TRC from PII on the basis of regression estimates from Haitian data gave satisfactory results for Negroid and some Caucasoid populations but less satisfactory results for Mongoloid groups suggesting that the relationship might be different in different ethnic groups.     

Manipulabilities of the index finger and thumb in three tip-pinch postures

Tip-pinch, in which the tips of the index finger and thumb pick up and hold a very fine object, plays an important role in the function of the hand. The objective of this study was to investigate how human subjects affect manipulabilities of the tips of the index finger and thumb within the flexion/extension plane of the finger in three different tip-pinch postures. The index finger and thumb of twenty male subjects, were modeled as linkages, based on measurement results obtained using two three-dimensional position measurement devices. The manipulabilities of the index finger and thumb were investigated in three tip-pinch postures, using three criteria indicating the form and posture of the manipulability ellipse of the linkage model. There were no significant differences (p > 0.05, ANOVA) in each criterion of each digit across the subjects, except for two criteria of the thumb. The manipulabilities of the index finger and thumb were separately similar across all subjects in tip-pinch postures. It was found that the manipulability for the cooperation of the index finger and thumb of all the subjects in tip-pinch depended on the posture of the index finger, but not on the posture of the thumb. In two-dimensional tip-pinch, it was possible that the index finger worked actively while the thumb worked passively to support the manipulation of the index finger.