Maximum trunk tip force assessment related to trunk position and prehensile 'fingers' implication in African savannah elephants.

African elephants have a wide range of abilities using their trunk. As a muscular hydrostat, and thanks to the two finger-like processes at its tip, this proboscis can both precisely grasp and exert considerable force by wrapping. Yet few studies have attempted to quantify its distal grasping force. Thus, using a device equipped with force sensors and an automatic reward system, the trunk tip pinch force has been quantified in five captive female African savanna elephants. Results showed that the maximum pinch force of the trunk was 86.4 N, which may suggest that this part of the trunk is mainly dedicated to precision grasping. We also highlighted for the first time a difference in force between the two fingers of the trunk, with the dorsal finger predominantly stronger than the ventral finger. Finally, we showed that the position of the trunk, particularly the torsion, influences its force and distribution between the two trunk fingers. All these results are discussed in the light of the trunk's anatomy, and open up new avenues for evolutionary reflection and soft robot grippers.

2D/4D Finger Length Ratio in the Screening of Developmental Dysplasia of the Hip.

OBJECTIVE: To investigate whether there is a relationship between the 2nd finger and 4th finger length measurement ratios and developmental dysplasia of the Hip (DDH). STUDY DESIGN: Cross-sectional observational study. Place and Duration of the Study: Department of Orthopaedics and Traumatology, Meram Faculty of Medicine Hospital, Konya, Turkiye, from January 2020 to May 2023. METHODOLOGY: Infants were screened for DDH with Graff method for the ultrasounds of both hips. Lengths of the 2nd and 4th fingers of both hands were measured and recorded. Patients with additional risk factors for developmental dysplasia of the hip (breech birth, family history, oligohydramnios, swaddling) were excluded. RESULTS: Two hundred and fifty-six babies were screened including 55.1% (n = 141) girls and 44.9% (n = 115) boys. Their mean age was 2.51 ± 0.80 months. The average lengths were 31.73 ± 3.05 mm, for the left 2nd finger and 34.26 ± 3.48 mm for the left 4th finger. In the hip USG measurements, the mean alpha angles were 62.91 ± 3.12° for the right hip and, 63.20 ± 3.55° for the left hip. Eighteen (7%) of babies who underwent hip ultrasound (USG) had unilateral or bilateral DDH. Among these cases, 2.7% (n = 7) had right, 2.3% (n = 6) had left, and 2% (n = 5) had bilateral DDH. There was no statistically significant correlation between the ratios of right 2/4 finger lengths and the right alpha angle (rs = 0.051; p = 0.421). There was a statistically positive and statistically significant correlation between the ratios of left 2/4 finger lengths and the left alpha angle (rs = 0.154; p = 0.013). CONCLUSION: Only the left-hand finger ratio among the parameters in the model had a statistically significant effect on DDH. Therefore, the left hand 2D/4D finger length may be of value in screening for DDH. KEY WORDS: Developmental dysplasia of the hip, Second to fourth finger digit ratio, Ring finger, Digit ratios.

Is digit ratio (2D:4D) a biomarker for lactate? Evidence from a cardiopulmonary test on professional male footballers.

BACKGROUND: Lactate accumulation is associated with vigorous exercise, cardiovascular disease and a number of cancers. Digit ratio (2D:4D) has also been linked to oxygen metabolism, myocardial infarction and various cancers. Such similarities suggest the possibility that 2D:4D is a biomarker of lactate. Here, we consider the relationship between 2D:4D and lactate during an incremental cardiopulmonary exercise test. METHOD: The participants were male professional football players. The treadmill test began at a speed of 8 km/h when the first lactate measurement was taken. The speed was increased by 2 km/h every 3.15 min, with measurements at 10, 12, 14 and 16 km/h. RESULTS: There were 72 Caucasian and 7 Black participants, results are reported for the most numerous group. Lactate levels increased with running speed and were not correlated with age, body size or body composition. Median splits of digit ratios (right, left and right-left 2D:4D [Dr-l]) were calculated. In comparison to the Low ratio group, the High ratio group showed higher lactate levels across speeds. Effect sizes varied from very large to huge (right 2D:4D), large (left 2D:4D) and medium (Dr-l). At the individual level, positive correlations between digit ratios and lactate at the five different speeds varied from large (right 2D:4D), medium (left 2D:4D) and small (Dr-l). CONCLUSION: There were large positive associations between right 2D:4D and lactate at all running speeds. We discuss our findings in relation to oxygen metabolism and suggest that 2D:4D may be a biomarker for lactate in the wider context of the latter's importance in health and disease.

Unveiling intra-person fingerprint similarity via deep contrastive learning.

Fingerprint biometrics are integral to digital authentication and forensic science. However, they are based on the unproven assumption that no two fingerprints, even from different fingers of the same person, are alike. This renders them useless in scenarios where the presented fingerprints are from different fingers than those on record. Contrary to this prevailing assumption, we show above 99.99% confidence that fingerprints from different fingers of the same person share very strong similarities. Using deep twin neural networks to extract fingerprint representation vectors, we find that these similarities hold across all pairs of fingers within the same person, even when controlling for spurious factors like sensor modality. We also find evidence that ridge orientation, especially near the fingerprint center, explains a substantial part of this similarity, whereas minutiae used in traditional methods are almost nonpredictive. Our experiments suggest that, in some situations, this relationship can increase forensic investigation efficiency by almost two orders of magnitude.

Understanding Covid-19: Digit ratios and duration of oxygen therapy in hospitalized Covid-19 patients.

BACKGROUND: Covid-19 severity shows a sex difference (males>females) and progressive hypoxia among the most seriously affected. Digit ratios are sexually dimorphic and may be negatively-related to prenatal (2nd-to-4th digits' ratio; 2D:4D) and pubertal (3rd-to-5th digits' ratio; 3D:5D) testosterone. Oxygen therapy is important in Covid-19 treatment and low 2D:4D is linked to efficient oxygen metabolism. We consider relationships between digit ratios and duration of oxygen treatment in hospitalized Covid-19 patients. METHODS: Digit lengths were measured from photographs of the patient's hands. Age, Sex, BMI, vaccination status and number of days of O2 treatment, were recorded. RESULTS: There were 100 (58 women) patients. Sex differences (males

Digit Ratio (2D:4D; Right-Left 2D:4D) and Multiple Phenotypes for Same-Sex Attraction: The BBC Internet Study Revisited.

Same-sex attraction may be linked to low prenatal androgen (in men) and high prenatal androgen (in women). Digit ratio (2D:4D) is thought to be a negative correlate of prenatal androgen and right-left 2D:4D (Dr-l) to reflect lateralized differences in sensitivity to prenatal androgen. Lower 2D:4D has been reported for lesbians compared to heterosexuals, but links to high 2D:4D in gay men are less clear. The largest study thus far (the BBC Internet study) found no significant difference between the 2D:4D of lesbians and heterosexual women but a higher 2D:4D in gay men compared to heterosexual men. Here we consider the possibility that low and high prenatal androgen is associated with same-sex attraction in men (n = 108,779) and women (n = 87,742), resulting in more than two phenotypes. We examined the associations between 2D:4D, Dr-l, and same-sex attraction scores in the BBC Internet study. In contrast to the earlier report, which considered sexual orientation in categories, there were positive linear associations in men (right and left 2D:4D, but not Dr-l) and negative linear associations in women (right 2D:4D and Dr-l, but not left 2D:4D). There were no curvilinear relationships for right and left 2D:4D. However, Dr-l showed a U-shaped association with same-sex attraction in men. Thus, (1) high prenatal androgen may be implicated in female homosexuality, while both low and high prenatal androgen may be implicated in male homosexuality, and (2) large side differences in sensitivity to androgen may be associated with elevated same-sex attraction in men.

Identification of the length and location of the A1 pulley combining palpation technique with palm landmarks: a cadaveric study.

Through anatomical morphology, to accumulate the relevant parameters of the A1 pulley of each adult finger. A total of 100 fingers were selected, dissected layer by layer, and the A1 pulley and neurovascular of each finger were observed. Measure the length of the A1 pulley, the distance between the needle knife insertion point and the proximal edge of A1 pulley, and the nerves and blood vessels on both sides. (1) The length of A1 pulleys of each finger is 6.18 ± 0.33 mm, 6.58 ± 0.73 mm, 5.98 ± 0.67 mm, 5.36 ± 1.08 mm, 5.63 ± 1.09 mm. (2) The distances between the needle knife entry point of each finger and the volar proper nerve of the ulnar finger are 7.00 ± 1.55 mm, 8.29 ± 1.46 mm, 5.10 ± 0.25 mm, 5.30 ± 0.24 mm, 0 mm; the distances from the volar proper nerve of the radial finger are 9.08 ± 0.87 mm, 4.70 ± 1.10 mm, 7.03 ± 0.72 mm, 6.81 ± 0.22 mm, 7.81 ± 0.57 mm. (3) The distances between the needle knife entry point of each finger and the proper volar artery of the ulnar finger are 10.40 ± 0.75 mm, 8.89 ± 0.53 mm, 6.35 ± 0.44 mm, 7.26 ± 0.16 mm, 0 mm, respectively; The distances from the volar proper artery of the radial finger are 8.75 ± 1.07 mm, 6.10 ± 0.35 mm, 11.44 ± 0.41 mm, 8.19 ± 0.60 mm, 9.78 ± 0.68 mm, respectively. The landmarks of the needle entry points are located at the position corresponding to the highest point of the metacarpal heads, except the tail finger. From the needle knife entry point to distal, cut the proximal edge of the A1 pulley longitudinally along the midline until the patient can flex autonomously, and pay attention to the distance between the two sides of 3.60-11.85 mm neurovascular bundle.

Multi-region minutiae depth value-based efficient forged finger print analysis.

The application of biometrics has expanded the wings to many domains of application. However, various biometric features are being used in different security systems; the fingerprints have their own merits as it is more distinct. A different algorithm has been discussed earlier to improve the security and analysis of fingerprints to find forged ones, but it has a deficiency in expected performance. A multi-region minutiae depth value (MRMDV) based finger analysis algorithm has been presented to solve this issue. The image that is considered as input has been can be converted into noisy free with the help of median and Gabor filters. Further, the quality of the image is improved by sharpening the image. Second, the preprocessed image has been divided into many tiny images representing various regions. From the regional images, the features of ridge ends, ridge bifurcation, ridge enclosure, ridge dot, and ridge island. The multi-region minutiae depth value (MRMDV) has been computed based on the features which are extracted. The test image which has a similarity to the test image is estimated around MRMDV value towards forgery detection. The MRMDV approach produced noticeable results on forged fingerprint detection accuracy up to 98% with the least time complexity of 12 seconds.

Rehabilitation of Annular Pulley Injuries of the Fingers in Climbers: A Clinical Commentary.

ABSTRACT: The annular pulley ligaments of the fingers are one of the most injured anatomical structures in those who participate in climbing. Despite this, there is a paucity of guidance clearly describing the rehabilitation and physical preparation parameters to return to sport following such injuries. The foundation of effective rehabilitation is the judicious application of progressive loading to increase the morphological and material properties of the damaged tissues. We maintain the optimal management of the climbing athlete after a traumatic annular flexor pulley system rupture should be grounded in the principles of strength and conditioning.

Sex differences in radioulnar contrasts of the finger ridge counts across 21 human population samples.

Aim: The aim of the present study was to demonstrate the existence of uniform sexual dimorphism in some radioulnar contrasts between different finger ridge counts within the same hand in a large set of populations, thus confirming the universal nature of this dimorphism in humans.Subjects and methods: We analysed individual finger ridge counts (10 values on each hand) of both hands from archival sources (mainly the Brehme-Jantz database). In total, these included 4412 adults from 21 population samples covering all permanently inhabited continents and encompassing very different and geographically distant human populations. We calculated the contrasts (differences) of all pairs of ridge counts (45 per hand) and used diverse methods to assess the direction and degree of dimorphism of them across all population samples.Results: The highest sexual dimorphism was observed for nine contrasts involving the ridge count of the dermatoglyphic pattern on the radial side of the second finger of the right hand (R2r). Among these contrasts, we then found four that had the same direction of dimorphism in all 21 populations. The most dimorphic was the contrast R1rR2r - the difference between the ridge count of the radial side of the thumb and the radial side of the index finger.Discussion: Thus, these dermatoglyphic traits can be further investigated as potential markers of prenatal sex differentiation from ca. 10th week of intrauterine development. However, it will be useful to address the detailed factors and mechanisms for differences in the degree of dimorphism of these traits in different populations.

Can the Second and Fourth Finger (2D: 4D) Ratio Guide Physicians in Choosing Internal Medicine or Surgical Branch? / ¿Puede la proporción del Segundo y Cuarto Dedo (2D: 4D) Guiar a los Médicos en la Elección de Medicina Interna o Rama Quirúrgica?

SUMMARY: This study investigates the relationship between the second and fourth finger ratio (2D:4D), physicians' propensity to choose an internal or surgical branch, and sex differences. On a voluntary basis, 177 physicians working in Elazig, 122 men and 55 women were enrolled in the study. Their hands were measured for 2D and 4D lengths, and the 2D:4D ratio was computed. In female doctors, the left hand's 2D:4D ratio is 1.01, compared to the right hand's 1.00. Male doctors' right 2D:4D ratio is 0.99, while their left 2D:4D ratio is 1.00. Male physicians' 2D:4D ratios were different from those of men in the general population, whereas female physicians' 2D:4D ratios were comparable to those of women in the general population. As a result, this study was the first to examine the relationship between the ratio of the second and fourth fingers (2D:4D), physicians' tendency to choose an internal medicine or surgical branch, and sex differences. While the 2D:4D ratio was higher than 0.98 in all physicians, it was low in women who disliked their profession and branch. Since there aren't many studies on this subject, data from in-depth studies that will be conducted in the future will help physicians who choose internal medicine and surgery make more informed decisions.

Este estudio investiga la relación entre la proporción de los dedos segundo y cuarto (2D:4D), la propensión de los médicos a elegir una rama interna o quirúrgica y las diferencias de género. De forma voluntaria, se inscribieron en el estudio 177 médicos que trabajaban en Elazig, 122 hombres y 55 mujeres. Sus manos se midieron en longitudes 2D y 4D, y se calculó la relación 2D:4D. En las médicos mujeres, la relación 2D:4D de la mano izquierda es 1,01, en comparación con 1,00 de la mano derecha. La relación 2D:4D derecha de los médicos hombres fue 0,99, mientras que la relación 2D:4D izquierda fye 1,00. Las proporciones 2D:4D de los médicos hombres fueron diferentes de las de los hombres en la población general, mientras que las proporciones 2D:4D de las mujeres médicas fueron comparables a las de las mujeres en la población general. Como resultado, este estudio fue el primero en examinar la relación entre la proporción del segundo y cuarto dedo (2D:4D), la tendencia de los médicos a elegir una rama de medicina interna o quirúrgica y las diferencias de sexo. Mientras que la relación 2D:4D fue superior a 0,98 en todos los médicos, fue baja en las mujeres que no les gustaba su profesión y rama. Dado que no hay muchos estudios sobre este tema, los datos de estudios en profundidad que se realizarán en el futuro ayudarán a los médicos que eligen medicina interna y cirugía a tomar decisiones más informadas.

Is 2D:4D digit ratio related to avowed religion? A study among Mongolian young males from Ulaanbaatar.

BACKGROUND: The ratio of the second- (2D) to fourth (4D) digit lengths of hand (2D:4D) is a proxy marker of the relative testosterone and estrogen concentration during a relatively narrow period of fetal development that might affect behavioral and personality characteristics. AIM: To estimate the differences in 2D:4D between different religious groups among a sample of young adult males in Mongolia. METHODS: Two hundred and sixty-five Mongolian male students with mean age of 20.5 (SD = 1.7) years from different universities in Ulan Bator, were included in the study. Information on age, religious affiliation, marital status and parental education were obtained directly from each study participant. Digit lengths were measured from scanned images by using the ImageJ software 1.53 K. One-way analysis of variance was employed to evaluate whether they were significant differences in 2D:4D ratio between groups, along with Scheffe's post hoc comparison. RESULTS: Study participants significantly differed in 2D:4D across religion. Left 2D:4D, but not the right, showed a significant difference between religions, with Muslims exhibiting the highest 2D:4D mean and the lowest DR-L . CONCLUSION: Our study suggests that the 2D:4D ratio is related to the participants' religion. However, the distinctiveness of the Muslim students from study participants belonging to other religious groups in this study could also be related to ethnic differences, given that the students were Kazakhs. This is, to our knowledge, the only study looking at the relationship between the 2D:4D ratio and religious affiliation and, thus, further research is needed to confirm its results.

Direct and radiographic digit ratio (2D:4D) measurements of Tuvan children and adolescents from Southern Siberia: Sex differences and skeletal maturation.

BACKGROUND: In Mongolian-origin ethnic groups digit ratio (2D:4D; a proxy for prenatal sex-steroids) is sexually dimorphic (males < females), as reported for other ethnicities. Most studies measured 2D:4D from soft tissue (directly from the digits, or indirectly from hand scans), or from radiographs. Evidence on the correspondence of 2D:4D measurements from soft tissue with measurements from radiographic images is scarce and has not been reported for a Mongolian-origin sample. In addition, previous research has not considered relationships between 2D:4D and measures of skeletal maturity. AIM: To examine (i) associations between 2D:4D measured directly from the palms with those obtained from radiographic images of the same individuals in a sample of children and adolescents from the Tuvan population in Siberia (Russian Federation), and ii) associations between 2D:4D measurements with chronological and skeletal age. SUBJECTS AND METHODS: Participants were Tuvan boys and girls aged 7 to 18 years. 2D:4D of the right and left hand was measured from soft tissue (directly from the palm) and compared with radiographic images (left hand only). In addition to finger length 2D:4D, we examined 2D:4D of the phalanges from measurements of radiographs. Skeletal age was assessed using the Tanner-Whitehouse method. RESULTS: Sex differences (boys < girls) in measurements of 2D:4D from soft tissue and radiographs were found for total finger length and phalanges. In addition, 2D:4D measurements from radiographs correlated positively and significantly with those obtained from soft tissue. Sex predicted 2D:4D measurements from soft tissue and radiographs, but no effects of chronological/skeletal age and body height were detected. In girls (but not in boys), earlier skeletal maturity (relative to chronological age) was associated with higher 2D:4D in soft tissue measurements of both hands, radiographic 2D:4D, and 2D:4D of the proximal phalanges. CONCLUSION: Consistent with reports from other ethnic groups, 2D:4D in young Tuvans was sexually dimorphic, with boys having lower 2D:4D than girls. For girls, higher 2D:4D was found for participants whose skeletal age was more advanced than chronological age. This finding was obtained from direct soft tissue and indirect radiographic measurements. Age and body height were not associated with 2D:4D, which suggests differences in hormone developmental trajectories for 2D:4D and height.

Relationship of digit ratio with sexual steroid hormone receptor related genes - single nucleotide polymorphisms in a sample from Northern China.

BACKGROUND: Digit ratio, especially 2D:4D, is hypothesised as a potential biological marker of exposure to intrauterine sex hormones. The aim of this study was to investigate the association between 10 SNPs of sex steroid hormone receptor (SSHR) related genes and 2D:4D. SUBJECTS AND METHODS: 814 college students were randomly selected as research participants. After taking pictures of both hands of the participants, Image Pro Plus (IPP) software was used to measure 2D:4D. ESR1 (rs2228480 and rs3798758), ESR2 (rs944459, rs8006145, rs928554, and rs8018687), GPER1 (rs10269151 and rs12702047), and PGR (rs1042839 and rs500760) were genotyped using multiplex PCR. RESULTS: Females had significantly higher 2D:4D in both hands than male students (p < 0.05), and the R2D:4D of the Han population was significantly higher than that of the Hui population (p < 0.05). The number of females carrying the GPER1 G allele of rs12702047 was significantly higher than that of males (p < 0.05). The L2D:4D in males was significantly different in rs1042839, and the R2D:4D in the Han ethnicity was significantly different in rs3798758. Logistic regression analysis showed that rs12702047 was significantly associated with 2D:4D in both hands (p < 0.05). CONCLUSIONS: GPER1 rs12702047 may be involved in the formation of digit ratio by affecting phalanx development in the Chinese population.

Digit ratio (2D:4D) and its relationship to foetal and maternal sex steroids: A mini-review.

The challenges of terrestrial existence may mean that the early development of tetrapod limb traits is linked to the development of the urogenital system and sex steroids. One such limb trait is the sex-dependent ratio of the lengths of the 2nd and 4th digits (2D:4D). Direct evidence for the association between early sex steroids and offspring 2D:4D can be obtained by manipulating foetal sex hormones. However, this is not ethically permissible in humans. It is widely accepted that 2D:4D is a biomarker for early foetal sex hormones in tetrapods but the link in humans remains controversial. Here we review the evidence that (i) manipulation of sex steroids in early development leads to sex-dependent changes in 2D:4D throughout the tetrapods, and (ii) maternal sex steroids cross the placenta and thus are associated with offspring 2D:4D in both non-human and human animals. We suggest a research focus on associations between human maternal sex steroids and offspring 2D:4D to clarify the link between 2D:4D and early sex steroids. A protocol is proposed to examine the correlation between 1st-trimester maternal sex steroids and offspring 2D:4D. Such an association may explain the existence and medium effect size of the human sex difference in 2D:4D.

Digit ratio (2D:4D), laryngeal cancer and vocal fold leukoplakia.

BACKGROUND: To date, there are no studies that have analyzed the possible influence of exposure to prenatal sex hormones on the risk of laryngeal cancer (LC) and premalignant laryngeal lesion-vocal fold leukoplakia (VFL). Digit ratio (2D:4D) is suggested to be a proxy of prenatal sex hormone exposure. OBJECTIVE: To examine 2D:4D in patients with LC and clarify if it could add to the verified risk factors in estimating the overall risk of LC. METHODS: 511 subjects participated in the study. The study group included 269 patients: with LC (N = 114, 64 men) and VFL (N = 155, 116 men). Controls included 242 healthy individuals (66.40 ± 4.50 years (106 men)). RESULTS: Predictive models estimating the risk of VFL and LC in women, based solely on predictors like smoking and alcohol consumption had a lower area under the ROC curve (AUC) than the model with left 2D:4D. AUC for the model estimating the likelihood of VFL increased from 0.83 to 0.85, and for LC from 0.76 to 0.79. CONCLUSIONS: Low left 2D:4D may be associated with an increased risk of developing leukoplakia and laryngeal cancer in women. In the case of laryngeal cancer, left 2D:4D may serve as additional variable (to other known risk factors, such as smoking and/or alcohol consumption), which can improve cancer risk prediction.

[Sports-related injuries of the thumb and fingers]. / Sportverletzungen des Daumens und der Finger.

Finger and thumb injuries are common in established and trend sports. Imaging plays an important role in acute trauma care, further therapy planning, and ultimately for a rapid return to play. Sound knowledge of the complex anatomy of the fingers and thumb is indispensable for accurate diagnosis. This article presents the ligament anatomy of the metacarpophalangeal and interphalangeal joints of the finger and the thumb, the extensor and flexor tendon apparatus, and the diagnosis of typical sports injuries using x­rays and magnetic resonance imaging. Furthermore, imaging findings of typical sports-associated injuries are illustrated.

The association of prenatal amniotic sex hormones and digit ratio (2D:4D) in children aged 5 to 70 months: A longitudinal study.

The sex difference of the 2D:4D digit ratio (female > male)-a proposed marker for prenatal testosterone exposure-is well established. Studies suggest it already exists in utero and is of moderate effect size in adulthood. However, evidence for the claim that 2D:4D reflects prenatal androgen action is limited, and the sex difference may exhibit lability during childhood. In the present study, 244 mothers were recruited in the course of an amniocentesis examination (performed between gestational weeks 14 and 18). Prenatal testosterone (T) and estradiol (E) levels were determined from amniotic fluid for boys and girls. The majority (97.4%, n = 114) of available female T levels (n = 117) were found below the level of quantification. Therefore, only male amniotic fluid data (n = 117) could be included for the analysis of associations between amniotic sex hormones (T levels and T to E ratio (T/E)) and 2D:4D. The families were then invited to each of the five consecutive follow-ups (ages: 5, 9, 20, 40, and 70 months) where children's 2D:4D was measured for both hands. The alternative marker D[r-l] reflects the directional asymmetry of 2D:4D (right subtracted by left 2D:4D) and was subsequently calculated as an additional measure for prenatal T exposure. No significant correlations between amniotic T or the T/E ratio (measured between week 14 and 18 of gestation) with 2D:4D respectively D[r-l] were observed for any time point. There was a significant sex difference (females > males) and a significant age effect with moderate correlations of 2D:4D between time points. 2D:4D increased between 20 and 40 months and between 40 and 70 months of age. The findings raise questions regarding the applicability of 2D:4D as a marker for prenatal androgen action and are discussed in terms of the reliability of obtained digit ratio data as well as in terms of the developmental timing of amniocentesis.

Intramuscular aponeuroses and fiber bundle morphology of the five bellies of flexor digitorum superficialis: A three-dimensional modeling study.

Restoring balanced function of the five bellies of flexor digitorum superficialis (FDS) following injury requires knowledge of the muscle architecture and the arrangement of the contractile and connective tissue elements. No three-dimensional (3D) studies of FDS architecture were found in the literature. The purpose was to (1) digitize/model in 3D the contractile/connective tissue elements of FDS, (2) quantify/compare architectural parameters of the bellies and (3) assess functional implications. The fiber bundles (FBs)/aponeuroses of the bellies of FDS were dissected and digitized (MicroScribe® Digitizer) in 10 embalmed specimens. Data were used to construct 3D models of FDS to determine/compare the morphology of each digital belly and quantify architectural parameters to assess functional implications. FDS consists of five morphologically and architecturally distinct bellies, a proximal belly, and four digital bellies. FBs of each belly have unique attachment sites to one or more of the three aponeuroses (proximal/distal/median). The proximal belly is connected through the median aponeurosis to the bellies of the second and fifth digits. The third belly exhibited the longest mean FB length (72.84 ± 16.26 mm) and the proximal belly the shortest (30.49 ± 6.45 mm). The third belly also had the greatest mean physiological cross-sectional area, followed by proximal/second/fourth/fifth. Each belly was found to have distinct excursion and force-generating capabilities based on their 3D morphology and architectural parameters. Results of this study provide the basis for the development of in vivo ultrasound protocols to study activation patterns of FDS during functional activities in normal and pathologic states.

High digit ratio (2D:4D) is associated with attack frequency and severity in hereditary angioedema patients.

BACKGROUND: Hereditary angioedema (HAE) caused by a deficiency or dysfunction of the plasma protease C1-inhibitor is a rare autosomal-dominant disorder. We explored a possible correlation between the ratio of the second and fourth finger lengths (2D:4D) and the frequency of HEA attacks, and whether the ratio might predict laryngeal attack. METHOD: We evaluated 35 HEA patients aged 19 to 66 years; 3 were subsequently excluded. The 2D:4D ratio was calculated by dividing the length of the second finger by that of the fourth finger of both hands. A structured clinical questionnaire exploring HAE course and treatment over the prior year was administered. RESULTS: Of the 32 participants, 56.25 % (n = 18) were female. Of them, those with high 2D:4D ratios suffered significantly more laryngeal attacks than others; 93.3% of patients with high 2D:4D ratios experienced ≥5 attacks annually, significantly more than those with low ratios. Among type 2 HEA patients, 75 % of those experiencing ≥5 attacks annually had high 2D:4D ratios; all patients with low 2D:4D ratios reported <5 attacks annually. These significant effects were found for right-hand 2D:4D ratios and not left-hand 2D:4D ratios. CONCLUSION: The data suggest that intrauterine sex hormone exposure, which affects the 2D:4D ratio, is significantly associated with HEA attack frequency and severity, and laryngeal edema.