The influence of wrist posture,grip type,and grip force on median nerve shape and cross‐sectional area

During grasping, the median nerve undergoes mechanical stress in the carpal tunnel which may contribute to carpal tunnel syndrome. This study investigated the effects of wrist posture, grip type, and grip force on the shape and cross‐sectional area of the median nerve. Ultrasound examination was used to obtain cross‐sectional images of the dominant wrist of 16 healthy subjects (8 male) at the proximal carpal tunnel during grasping. The cross‐sectional area, circularity, and axis lengths of the median nerve were assessed in 27 different conditions (3 postures × 3 grip types × 3 force levels). There were no significant changes in median nerve cross‐sectional area (P > 0.05). There were significant interactions across posture, grip type, and grip force affecting nerve circularity and axis lengths. When the wrist was flexed, increasing grip force caused the median nerve to shorten in the mediolateral direction and lengthen in the anteroposterior direction (P < 0.04), becoming more circular. These effects were significant during four finger pinch grip and chuck grip (P < 0.05) but not key grip (P > 0.07). With the wrist extended, the nerve became more flattened (less circular) as grip force increased during four finger pinch grip and chuck grip (P < 0.04) but not key grip (P > 0.3). Circularity was lower during the four finger pinch compared to chuck or key grip (P < 0.03). The findings suggest that grip type and wrist posture significantly alter the shape of the median nerve. Clin. Anat. 30:470–478, 2017. © 2017 Wiley Periodicals, Inc.     

Development of Cortical Bone Geometry in the Human Femoral and Tibial Diaphysis

Ontogenetic growth processes in human long bones are key elements, determining the variability of adult bone structure. This study seeks to identify and describe the interaction between ontogenetic growth periods and changes in femoral and tibial diaphyseal shape. Femora and tibiae (n = 46) ranging developmentally from neonate to skeletally mature were obtained from the Norris Farms No. 36 archeological skeletal series. High‐resolution X‐ray computed tomography scans were collected. Whole‐diaphysis cortical bone drift patterns and relative bone envelope modeling activity across ages were assessed in five cross‐sections per bone (total bone length: 20%, 35%, 50%, 65%, and 80%) by measuring the distance from the section centroid to the endosteal and periosteal margins in eight sectors using ImageJ. Pearson correlations were performed to document and interpret the relationship between the cross‐sectional shape (I_max/I_min), total subperiosteal area, cortical area, and medullary cavity area for each slice location and age for both the femur and the tibia. Differences in cross‐sectional shape between age groups at each cross‐sectional position were assessed using nonparametric Mann‐Whitney U tests. The data reveal that the femoral and tibial midshaft shape are relatively conserved throughout growth; yet, conversely, the proximal and distal femoral diaphysis and proximal tibial diaphysis appear more sensitive to developmentally induced changes in mechanical loading. Two time periods of accelerated change are identified: early childhood and prepuberty/adolescence. Anat Rec, 296:774–787, 2013. © 2013 Wiley Periodicals, Inc.     

The impact of obesity on skeletal muscle architecture in untrained young vs. old women

It is unknown whether loading of the lower limbs through additional storage of fat mass as evident in obesity would promote muscular adaptations similar to those seen with resistance exercise. It is also unclear whether ageing modulates any such adjustments. This study aimed to examine the relationships between adiposity, ageing and skeletal muscle size and architecture. A total of 100 untrained healthy women were categorised by age into young (Y) (mean ± SD: 26.7 ± 9.4 years) vs. old (O) (65.1 ± 7.2 years) and body mass index (BMI) classification (underweight, normal weight, overweight and obese). Participants were assessed for body fat using dual energy x‐ray absorptiometry, and for gastrocnemius medialis (GM) muscle architecture (skeletal muscle fascicle pennation angle and length) and size [GM muscle volume and physiological cross‐sectional area (PCSA)] using B‐mode ultrasonography. GM fascicle pennation angle (FPA) in the obese Y females was 25% greater than underweight (P = 0.001) and 25% greater than normal weight (P = 0.001) individuals, while O females had 32 and 22% greater FPA than their underweight (P = 0.008) and normal weight (P = 0.003) counterparts. Furthermore, FPA correlated with body mass in both Y and O females (Y r = 0.303; P < 0.001; O r = 0.223; P = 0.001), yet no age‐related differences in the slope or r‐values were observed (P > 0.05). Both GM muscle volume (P = 0.003) and PCSA (P = 0.004) exhibited significant age × BMI interactions. In addition, muscle volume and PCSA correlated with BMI, body mass and fat mass. Interestingly, ageing reduced both the degree of association in these correlations (P < 0.05) and the slope of the regressions (P < 0.05). Our findings partly support our hypotheses in that obesity‐associated changes in GM PCSA and volume differed between the young and old. The younger GM muscle adapted to the loading induced by high levels of body mass, adiposity and BMI by increasing its volume and increasing its pennation angle, ultimately enabling it to produce higher maximum torque. Such an adaptation to increased loading did not occur in the older GM muscle. Nonetheless, the older GM muscle FPA increased to a similar extent to that seen in young GM muscle, an effect which partly explains the relatively enhanced absolute maximum torque observed in obese older females.     

Ontogenetic changes of geometrical and mechanical characteristics of the avian femur: a comparison between precocial and altricial birds

The mechanical performance of limb bones is closely associated with an animal's locomotor capability and is thus important to our understanding of animal behaviour. This study combined a geometrical analysis and three‐point bending tests to address the question of how the mechanical performance of the femurs of Japanese quail (Coturnix coturnix japonica) and pigeon (Columba livia domestica) respond to changing functional demands during ontogeny. Results showed that hatchling quails had stiff bone tissues, and the femoral ultimate loads scaled negatively with body mass, corresponding to high functional demands during early growth. The hatchling pigeon femora had weak material properties but they showed a dramatic increase in Young's modulus during growth. Consequently, although femoral cross‐sectional geometry showed negative allometry, the ultimate loads scaled positively with body mass. Older pigeons had more circular bone cross‐sections than younger pigeons, probably due to load stimulation changes occurred shortly after the onset of locomotion. Negative allometry and isometry of the cross‐sectional geometry of hind limb bones were observed in flying birds and ground‐dwelling birds, respectively. The correspondence between geometrical change and locomotor pattern suggests that ontogenetic changes in cross‐sectional geometry may be an effective indicator of avian locomotor behaviour.     

Cardiac response to exercise in normal-weight and obese, Hispanic men and women: implications for exercise prescription

Aim: The effects of obesity on cardiac function during incremental exercise to peak oxygen consumption (VO_2peak) have not been previously described. The purpose of this study was to compare submaximal and maximal cardiac function during exercise in normal‐weight and obese adults. Methods: Normal‐weight (n = 20; means ± SE: age = 21.9 ± 0.5 years; BMI = 21.8 ± 0.4 kg m^?2) and obese (n = 15; means ± SE: age = 25.1 ± 5.2 years; BMI = 34.1 ± 01.0 kg m^?2) participants were assessed for body composition, VO_2peak and cardiac variables (thoracic bioimpedance analysis) at rest and at heart rates (HR) of 110, 130, 150 and 170 beats min^?1 and maximal HR during incremental cycling exercise to exhaustion. Differences between groups were assessed with mixed‐model ancova with repeated measures. Cardiac variables were statistically indexed for body surface area and resting HR. VO₂ and arteriovenous oxygen difference (a‐vO₂) were statistically indexed for fat‐free mass and resting HR. Results: Significant main effects for group indicated obese participants had higher cardiac output (Q) index and stroke volume (SV) index but lower ejection fraction (EF) and a‐vO₂ index during incremental exercise to exhaustion compared with their normal‐weight peers, despite similar submaximal and maximal VO₂ and absolute power outputs (P < 0.05). Conclusions: Our findings suggest that although Q index and SV index were higher in obese, young adults, EF and a‐vO₂ index were significantly lower when compared to matched, normal‐weight adults.     

Morphological profile of atypical femoral fractures: age‐related changes to the cross‐sectional geometry of the diaphysis

The use of bisphosphonates for osteoporosis patients has markedly decreased the incidence of femoral neck or trochanteric fractures. However, anti‐osteoporosis drugs have been reported to increase the incidence of atypical femoral fractures, which involve stress fractures in the subtrochanteric region or the proximal diaphysis. In this study, the morphological characteristics of the cortical bone in human femoral diaphysis samples were analyzed from individuals who lived before bisphosphonate drugs were available in Japan. A total of 90 right femoral bones were arbitrarily selected (46 males and 44 females) from modern Japanese skeletal specimens. Full‐length images of these femurs were acquired using a computed tomography scanner. An image processing method for binarization was used to calculate the threshold values of individual bones for determining their contours. The range between the lower end of the lesser trochanter and the adductor tubercle of each femur was divided at regular intervals to obtain 10 planes. The mean value of cortical bone thickness, periosteal border length, and the cortical cross‐sectional area was evaluated for all planes. Moreover, the ratio of the area of the cortical bone to the total area of cross‐section at the mid‐diaphysis was calculated. A comparison between males and females demonstrated that most females had lower cortical bone area ratios at the mid‐diaphysis. The femoral outer shape did not differ markedly according to age or sex; however, substantial individual differences were observed in the shape of the inner surface of the cortical bone. The cortical bone thickness and the cross‐sectional area decreased with age in the femoral diaphysis; furthermore, in females, the decrease was higher for the former than for the latter. This may be due to a compensatory increase in the circumference of the femoral diaphysis. In addition, in about half of the subjects there was a discrepancy between the region with maximal value of the cortical bone thickness and that of the total cross‐sectional area. Biological responses to mechanical stresses to the femoral diaphysis are thought not to be uniform. Bisphosphonates inhibit bone resorption and may promote non‐physiological bone remodeling. Thus, a nonhomogeneous decrease in cortical thickness may be related to the fracture occurrence in the femoral diaphysis in some cases. Thus, long‐term administration of bisphosphonates in patients with morphological vulnerability in the femoral cortical bones may increase the occurrence of atypical femoral fractures.     

Anthropometric measurements of Australian Aboriginal adults living in remote areas: Comparison with nationally representative findings

To compare body size measurements in Australian Aboriginals living in three remote communities in the Northern Territory of Australia with those of the general Australian population. Height, weight, waist and hip circumferences and derivative values of body mass index (BMI), waist‐hip ratio (WHR), waist‐height ratio (WHT), and waist‐weight ratios (WWT) of adult Aboriginal volunteers (n = 814), aged 25 to 74 years were compared with participants in the nationally representative ‘AusDiab’ survey (n = 10,434). The Aboriginal body habitus profiles differed considerably from the Australian profile. When compared to Australian females, Aboriginal females were taller and had lower hip circumference but had higher WC, WHR, WHT, and WWT (P < 0.01 for all). When compared with their Australian counterparts, Aboriginal males were shorter, had lower body weight, WC, hip circumference, BMI, and WHT but had higher WHR and WWT (P < 0.001 for all). Significantly more Aboriginal females were classified as overweight and or obese using cutoffs defined by WC and by WHR than by BMI. Aboriginal males were less often overweight and/or obese by BMI than their counterparts, but were significantly more often overweight or obese by WHR. There were significant variations in body size profiles between Aboriginal communities. However, the theme of excess waist measurements relative to their weight was uniform. Aboriginal people had preferential central fat deposition in relation to their overall weight. BMI significantly underestimated overweight and obesity as assessed by waist measurements among Aboriginals. This relationship of preferential central fat deposition to the current epidemic of chronic diseases needs to be explored further. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.     

Ontogeny of hallucal metatarsal rigidity and shape in the rhesus monkey (Macaca mulatta) and chimpanzee (Pan troglodytes)

Life history variables including the timing of locomotor independence, along with changes in preferred locomotor behaviors and substrate use during development, influence how primates use their feet throughout ontogeny. Changes in foot function during development, in particular the nature of how the hallux is used in grasping, can lead to different structural changes in foot bones. To test this hypothesis, metatarsal midshaft rigidity [estimated from the polar second moment of area (J) scaled to bone length] and cross‐sectional shape (calculated from the ratio of maximum and minimum second moments of area, I_max/I_min) were examined in a cross‐sectional ontogenetic sample of rhesus macaques (Macaca mulatta; n = 73) and common chimpanzees (Pan troglodytes; n = 79). Results show the hallucal metatarsal (Mt1) is relatively more rigid (with higher scaled J‐values) in younger chimpanzees and macaques, with significant decreases in relative rigidity in both taxa until the age of achieving locomotor independence. Within each age group, Mt1 rigidity is always significantly higher in chimpanzees than macaques. When compared with the lateral metatarsals (Mt2–5), the Mt1 is relatively more rigid in both taxa and across all ages; however, this difference is significantly greater in chimpanzees. Length and J scale with negative allometry in all metatarsals and in both species (except the Mt2 of chimpanzees, which scales with positive allometry). Only in macaques does Mt1 midshaft shape significantly change across ontogeny, with older individuals having more elliptical cross‐sections. Different patterns of development in metatarsal diaphyseal rigidity and shape likely reflect the different ways in which the foot, and in particular the hallux, functions across ontogeny in apes and monkeys.     

The effect of menarcheal age on anthropometric,limb length,and bone measures in Hutterite and non‐Hutterite women

The age women reach menarche may affect bone length and mass. Some studies show an earlier menarcheal age (MA) results in a shorter stature and increased body fat. We hypothesized that Hutterite women have a shorter height and limb length, but greater bone mass and areal bone mineral density (aBMD) than non‐Hutterites. Results are from a secondary analysis of 344 (198 Hutterite) healthy, pre‐menopausal women aged 20?40 years who participated in the South Dakota Rural Bone Health Study. Bone measures were obtained by DXA (spine, hip and total body) and pQCT (4 and 20% distal radius). MA correlated with year of birth (r = ?0.10, P = 0.08) indicating a trend toward a younger MA for women born in more recent years. MA was inversely associated with current weight (r = ?0.11, P < 0.05), percent body fat (r = ?0.16, P < 0.01), femoral neck BMC (r = ?0.18, P = 0.003), femoral neck aBMD (r = ?0.21, P < 0.001), hip aBMD (r = ?0.22, P < 0.001) and trabecular volumetric BMD (vBMD) (r = ?0.14, P = 0.03). Hutterite women had a younger MA than non‐Hutterite women (12.3 ± 1.3 vs. 13.0 ± 1.3 yr, P < 0.001). In final regression models controlling for diet and activity patterns, Hutterite compared to non‐Hutterite women had shorter standing height (162 ± 0.4 vs. 166 ± 0.4 cm, P < 0.001), forearm length (258 ± 0.8 vs. 261 ± 0.9 mm, P = 0.04); and leg length (76 ± 0.2 vs. 77 ± 0.3 cm, P < 0.01) as hypothesized, but MA did not predict these outcomes. In conclusion, younger MA in Hutterite women did not explain their shorter standing height and limb lengths, but total hip aBMD was inversely associated with MA and greater in Hutterite than non‐Hutterite women. Am. J. Hum. Biol., 2008. © 2008 Wiley‐Liss, Inc.     

Evidence of a hypermineralised calcified fibrocartilage on the human femoral neck and lesser trochanter

Femoral neck fractures are a major cause of morbidity and mortality in elderly humans. In addition to the age‐related loss of cancellous bone, changes to the microstructure and morphology of the metaphyseal cortex may be a contributing factor in osteoporotic hip fractures. Recent investigations have identified a hypermineralised tissue on the neck of the femur and trochanteric region that increases in fractional area with advancing age in both males (Boyce & Bloebaum, 1993) and females (Vajda & Bloebaum, 1999). The aim of this study was to determine if the hypermineralised tissue previously observed on the proximal femur is calcified fibrocartilage. Regional variations in the fractional area of hypermineralised tissue, cortical bone, and porosity of the cortical bone along the neck of the femur and lesser trochanter were also quantified. Comparison of back scattered electron and light microscope images of the same area show that regions of hypermineralised tissue correlate with the regions of calcified fibrocartilage from tendon and capsular insertions. The hypermineralised tissue and calcified fibrocartilage had similar morphological features such as the interdigitations of the calcified fibrocartilage into the bone, lacunar spaces, and distinctly shaped pores adjacent to the 2 tissues. Regions of the neck that did not contain insertions were covered with periosteum. There were no regional differences (P > 0.05) on the superior and inferior femoral neck in terms of the percentage area of hypermineralised calcified fibrocartilage, cortical bone, or cortical bone porosity. The lesser trochanter exhibited regional differences in the fractional area of hypermineralised calcified fibrocartilage (P = 0.007) and cortical bone (P = 0.007) but not porosity of the cortical bone (P > 0.05). The effects of calcified fibrocartilage on femoral neck periosteal expansion, repair, and mechanics are unknown, but may play a role in osteoporotic fractures and intracapsular fracture healing.     

Body mass index,overweight and obesity in married and never married men and women in Poland

The study examined the relationship between marital status and the body mass index (BMI) and the prevalence of overweight and obesity in the Polish population. The sample included 2,266 men and 4,122 women, 25–60 years of age, who were occupationally active inhabitants of Wroclaw, in southwestern Poland. Marital status was defined by two categories: never married and presently married, and two groups in each category were established on the basis of educational level: well‐educated (12 or more years in school) and poorly educated (less than 12 years in school). The subjects were also divided into four age groups: 25–30, 31–40, 41–50, and 51–60 years. Height and weight were measured and the BMI was calculated. Three categories of the BMI were established: normal, BMI < 25.0 kg/m², overweight, BMI ≥ 25 < 30 kg/m², and obese, BMI ≥ 30 kg/m². In each age and educational group, married individuals had a higher BMI than those who were never married. With the exception of well‐educated males 51–60 years, differences in the BMI between married and never married individuals increased with age. In general, married men and women were more likely to be overweight and obese than never married individuals. The results indicated a significant association (P < 0.001) between marital status and the BMI in both sexes. After age, marital status was the most important predictor of overweight/obesity among men (P < 0.001), whereas educational level did not have a significant role. Among women, age, marital status, and education were significantly (P < 0.001) related to the BMI. Am. J. Hum. Biol. 14:468–475, 2002.© 2002 Wiley‐Liss, Inc.     

Associations between sleep quality with cardiorespiratory fitness and BMI among adolescent girls

The main goal of this study was to examine the association between sleeping quality with cardiorespiratory fitness (CRF) and obesity status (BMI) This was a cross‐sectional study of 1,726 adolescent girls, aged 10 to 18 years. CRF was predicted by maximal multistage 20 m shuttle‐run test according to procedures described from FITNESSGRAM. Children's BMI was classified according to International Obesity Task Force and sleeping quality was assessed by questionnaire. The prevalence of overweight and obesity was 21.2% and 5.7%, respectively. Sleeping quality was significantly associated with CRF (Rho = 0.17; P < 0.05), but not with BMI. Girls who were classified as fit were more likely (OR: 2.25; P < 0.05) to report better sleep quality compared to their unfit peers. Poor sleep quality was associated with lower CRF although no associations have been shown with BMI. Am. J. Hum. Biol. 2010. © 2009 Wiley‐Liss, Inc.     

Computed tomography‐guided in vivo cardiac orientation and correlation with ECG in individuals without structural heart disease and in age‐matched obese and older individuals

The cardiac axis in a structurally normal heart is influenced by a number of factors. We investigated the anatomical and electrical cardiac axes in middle‐aged individuals without structural heart disease and compared this with age‐matched obese and older individuals without structural heart disease. A retrospective study of controls included those between 30 and 60 years old with a normal body mass index (BMI), who were then compared with obese individuals between 30 and 60 years old and with individuals more than 60 years old with a normal BMI. The anatomical cardiac axis was determined along the long axis by cardiac computed tomography (CT) and correlated with the electrical cardiac axis on a surface electrocardiogram (ECG) in the frontal plane. A total of 124 patients were included. In the controls (n = 59), the mean CT axis was 38.1° ± 7.8° whilst the mean ECG axis was 51.8° ± 26.6°, Pearson r value 0.12 (P = 0.365). In the obese (n = 36), the mean CT axis was 25.1° ± 6.2° whilst the mean ECG axis was 20.1° ± 23.9°, Pearson r value 0.05 (P = 0.808). In the older group (n = 29), the mean CT axis was 34.4° ± 9.1° whilst the mean ECG axis was 34.4° ± 30.3°, Pearson r value 0.26 (P = 0.209). Obese individuals have a more leftward rotation of both axes than age‐matched normals (P <0.0001), which could be secondary to elevation of the diaphragm. Older individuals have a more leftward rotation only of their electrical cardiac axis (P = 0.01), which could be a normal variant or reflect underlying conduction disturbances in this age group. Clin. Anat. 28:487–493, 2015. © 2015 Wiley Periodicals, Inc.     

Effects of a mixed‐subsistence diet on the growth of Hadza children

Introduction: We investigated the preliminary effects of dietary changes on the anthropometric measurements of child and adolescent Hadza foragers. Methods: We conducted a cross‐sectional study comparing height and weight of participants (aged 0‐17 years) at two time points, 2005 (n = 195) and 2017 (n = 52), from two locations: semi‐nomadic “bush camps” and sedentary “village camps”. World Health Organization (WHO) calculators were used to generate standardized z‐scores for weight‐for‐height (WHZ), weight‐for‐age (WAZ), height‐for‐age (HAZ), and BMI‐for‐age (BMIFAZ). Cross tabulations were constructed for each measurement variable as a function of z‐score categories and the variables year, location, and sex. Results: Residency in a village, and associated mixed‐subsistence diet, was associated with favorable growth, including greater WAZ (P < .001), HAZ (P < .001), and BMIFAZ (P = .004), but not WHZ (P = .717). Regardless of residency location, participants showed an improved WAZ (P = .021) and HAZ (P < .001) in the 2017 study year. We found no sex differences. Discussion and Conclusion: These preliminary findings suggest that a mixed‐subsistence diet may confer advantages over an exclusive wild food diet, a trend also reported among other transitioning foragers.     

Cross‐sectional area of lumbar spinal muscles and vertebral endplates: a secondary analysis of 91 computed tomography images of children aged 2–20

Spinal muscle cross‐sectional area has been highly associated with spinal pathology. Despite the medium‐high prevalence of spinal pathology in children, there is very limited knowledge regarding muscle size and growth pattern in individuals younger than 20 years of age. The aim of this study is to analyze the change in size and symmetry of spinal muscles (erector spinae, multifidus, psoas and quadratus lumborum) in children 2–20 years of age. We studied reformatted images from 91 abdominal computed tomographic scans of children aged 2–20 years, from an existing imaging dataset. The cross‐sectional area of the muscles was bilaterally measured parallel to the upper endplate of the lumbar vertebrae L3–L5 and at true horizontal for S1. The cross‐sectional area of the upper vertebral endplate was measured at spinal levels L3–L5. Results were analyzed according to six groups based on children's age: 2–4 years (group 1), 5–7 years (group 2), 8–10 years (group 3), 11–13 years (group 4), 14–16 years (group 5) and 17–20 years (group 6). Vertebral endplate and spinal muscles cross‐sectional area increased with age. Two patterns were observed: Endplate, psoas and quadratus lumborum increased up to our 6th oldest age group (17–20), and multifidus and erector spinae reached their largest size in the 5th age group (14–16). The epaxial muscles (erector spinae and multifidus) reached their maximal cross‐sectional area before skeletal maturity (18–21 years of age). The hypaxial muscles (psoas and quadratus lumborum) continued to increase in size at least until spinal maturity. Contributing factors for the differences in developmental pattern between the epaxial and hypaxial muscles might include functional, embryological and innervation factors. In conclusion, this research is the first to describe the cross‐sectional area of spinal muscles in children. Future longitudinal studies are needed for further understanding of muscle development during childhood and adolescence. Level of evidence: level 2b, Retrospective cohort study.     

Differential strain patterns of the human gastrocnemius aponeurosis and free tendon,in vivo

Aim: The mechanical characteristics of the human free tendon and aponeurosis, in vivo, remains largely unknown. The present study evaluated the longitudinal displacement of the separate free Achilles tendon and distal (deep) aponeurosis of the medial gastrocnemius muscle during voluntary isometric contraction. Methods: Ultrasonography‐obtained displacement of the free tendon and tendon–aponeurosis complex, electromyography of the gastrocnemius, soleus, and dorsiflexor muscles, and joint angular rotation were recorded during isometric plantarflexion (n = 5). Tendon cross‐sectional area, moment arm and segment lengths (L_o) were measured using magnetic resonance imaging. Tendon force was calculated from joint moments and tendon moment arm, and stress was obtained by dividing force by cross‐sectional area. The difference between the free tendon and tendon–aponeurosis complex deformation yielded separate distal aponeurosis deformation. Longitudinal aponeurosis and tendon strain were obtained from the deformations normalized to segment lengths. Results: At a common tendon force of 2641 ± 306 N, the respective deformation and L_o were 5.85 ± 0.85 and 74 ± 0.8 mm for the free tendon and 2.12 ± 0.64 and 145 ± 1.3 mm for the distal aponeurosis, P < 0.05. Longitudinal strain was 8.0 ± 1.2% for the tendon and 1.4 ± 0.4% for the aponeurosis, P < 0.01. Stiffness and stored energy was 759 ± 132 N mm^?1 and 6.14 ± 1.89 J, respectively, for the free tendon. Cross‐sectional area of the Achilles tendon was 73 ± 4 mm², yielding a stress of 36.5 ± 4.6 MPa and Young's modulus of 788 ± 181 MPa. Conclusion: The free Achilles tendon demonstrates greater strain compared with that of the distal (deep) aponeurosis during voluntary isometric contraction, which suggests that separate functional roles may exist during in vivo force transmission.     

Pilot Study for Reconstruction of Soft Tissues: Muscle Cross‐Sectional Area of the Forearm Estimated from Cortical Bone for a Neolithic Sample

On a basis of a method for muscle cross‐sectional area estimation from cortical bone area that was previously developed (Slizewski et al. Anat Rec 2013; 296:1695–1707), we reconstructed muscle cross‐sectional area at 65% of radius length for a sample of Neolithic human remains from the Linear Pottery Culture (ca. 5,700–4,900 years BC). Muscle cross‐sectional area estimations for the Neolithic sample were compared to in vivo measurements from a recent human sample. Results demonstrate that the Neolithic individuals had larger muscle cross‐sectional area relative to radius length than the contemporary humans and that their forearms were more muscular and robust. We also found significant differences in relative muscle cross‐sectional area between Neolithic and recent children that indicate different levels of physical stress and isometric activities. Our results fit into the framework of studies previously published about the sample and the Linear Pottery Culture. Therefore, the new approach was successfully applied to an archaeological sample for the first time here. Results of our pilot study indicate that muscle cross‐sectional area estimation could in the future supplement other anthropological methods currently in use for the analysis of postcranial remains. Anat Rec, 297:1103–1114, 2014. © 2014 Wiley Periodicals, Inc.     

Scanning plane comparison of ultrasound‐derived morphological characteristics of the vastus lateralis

Muscle morphological characteristics obtained via ultrasonography have been used to quantify the size, architecture, and quality of skeletal muscle. Previous research has utilized varying ultrasonographic techniques, however there is little information comparing these different techniques. Muscle morphological characteristics, including cross‐sectional area (CSA), muscle thickness (MT), echo intensity (EI), and subcutaneous adipose tissue thickness (SubQ) were assessed in 24 males (20.2 ± 1.6 y) via three panoramic‐images captured in the transverse plane (PTI) and three still‐images captured in the longitudinal plane (SLI). Cross‐sectional area of PTI was significantly greater than CSA of SLI (P < 0.001), however positive correlations existed between the two measurements (r = 0.752, P < 0.001). Echo intensity of PTI was significantly lower than EI of SLI (P = 0.002), however, positive correlations existed between the two measurements (r = 0.681, P < 0.001). MT of PTI was significantly greater than MT of SLI (P = 0.003), but positive correlations existed between measurements (r = 0.809, P < 0.001). However, SubQ of PTI was significantly lower than SubQ of SLI (P < 0.001), but positive correlations existed between measurements (r = 0.915, P < 0.001). In conclusions, PTI and SLI yield significantly different CSA, EI, MT, and SubQ measurements but these values are highly correlated. Still longitudinal images require less time, cost, and expertise, and therefore may be preferred over PTI in future studies. Clin. Anat. 30:533–542, 2017. © 2016 Wiley Periodicals, Inc.     

A three‐dimensional axis for the study of femoral neck orientation

A common problem in the quantification of the orientation of the femoral neck is the difficulty to determine its true axis; however, this axis is typically estimated visually only. Moreover, the orientation of the femoral neck is commonly analysed using angles that are dependent on anatomical planes of reference and only quantify the orientation in two dimensions. The purpose of this study is to establish a method to determine the three‐dimensional orientation of the femoral neck using a three‐dimensional model. An accurate determination of the femoral neck axis requires a reconsideration of the complex architecture of the proximal femur. The morphology of the femoral neck results from both the medial and arcuate trabecular systems, and the asymmetry of the cortical bone. Given these considerations, two alternative models, in addition to the cylindrical one frequently assumed, were tested. The surface geometry of the femoral neck was subsequently used to fit one cylinder, two cylinders and successive cross‐sectional ellipses. The model based on successive ellipses provided a significantly smaller average deviation than the two other models (P < 0.001) and reduced the observer‐induced measurement error. Comparisons with traditional measurements and analyses on a sample of 91 femora were also performed to assess the validity of the model based on successive ellipses. This study provides a semi‐automatic and accurate method for the determination of the functional three‐dimensional femoral neck orientation avoiding the use of a reference plane. This innovative method has important implications for future studies that aim to document and understand the change in the orientation of the femoral neck associated with the acquisition of a bipedal gait in humans. Moreover, the precise determination of the three‐dimensional orientation has implications in current research involved in developing clinical applications in diagnosis, hip surgery and rehabilitation.     

Three‐dimensional orientation of the acetabulum

This study was designed specifically to determine the normal acetabular orientation and femoral head covering, and whether these are affected by age or sex. Computed tomographic images of normal Japanese hip joints were used (males 60, females 60; mean age 48.3 years, range 15–79 years). Male and female age profiles were matched. The reconstructed 3‐D pelvic images were aligned in the anatomical pelvic coordinate system. The acetabular orientation angles and femoral covering angles were measured in the sagittal, coronal, and horizontal planes. In the sagittal plane, the acetabular orientation angle was operative anteversion (O‐av), and the femoral covering angles were the anterior and posterior center‐edge angles (ACE and PCE). In the coronal plane, they were the Sharp angle (SA) and the lateral center‐edge angle (LCE). In the horizontal plane, they were anatomical anteversion (A‐av) and the anterior and posterior sector angles (ASA and PSA). The O‐av, SA, and A‐av were smaller in the male than the female acetabulum (P < 0.01). SA in both males and females was inversely correlated with age (P < 0.01). Both male PCE and PSA were significantly smaller than those of females, while male ASA was larger than female ASA (P < 0.05). The male acetabulum is directed further outward and downward than the female one. However, this does not indicate that the male acetabulum covers the femoral head more, because there is no significant sex difference in the LCE. Femoral coverage is more posteriorly biased in females than in males owing to pelvic inclination. Clin. Anat. 30:753–760, 2017. © 2017Wiley Periodicals, Inc.