Sexual dimorphism of the posterior cervical spine muscle attachments.

Cervical spinal injury and neck pain are common disorders with wide physical implications. Neck pain and disability are reported to occur in females more often than in males, and chronic or persistent neck pain after whiplash is twice as common in females. Female athletes also sustain a higher percentage of concussions compared to male athletes. Still, while sexual differences in clinical presentation and outcome are well-established, the underlying etiology for the disparity remains less clear. It is well-established that the origin and insertion landmarks of posterior neck muscles are highly variable, but we do not know if these interindividual differences are associated with sex. Expanding our knowledge on sexual dimorphism in the anatomy of the cervical muscles is essential to our understanding of the possible biomechanical differences between the sexes and hence improves our understanding as to why females suffer from cervical pain more than males. It is also of paramount importance for accurate planning of posterior cervical spine surgery, which cuts through the posterior cervical musculature. Therefore, our main objective is to characterize the anatomy of posterior neck musculature and to explore possible sexual differences in the location of their attachment points. Meticulous posterior neck dissection was performed on 35 cadavers, 19 females, and 16 males. In each specimen, 8 muscle groups were examined bilaterally at 45 osseous anatomical landmarks. Muscles and their attachment sites were evaluated manually then photographed and recorded using Microscribe Digitizer technology built into 3D models. A comparison of attachment landmarks between males and females for each muscle was conducted. Out of the eight muscles that were measured, only two muscles demonstrated significant sex-related anatomical differences-Spinotranversales (splenius capitis and cervicis) and Multifidus. Male Spinotransversales muscle has more attachment points than female. It showed more cranial insertion points in the upper cervical attachments (superior nuchal line, C1 posterior tubercle, and mastoid process) and more caudal insertion points in the spinous processes and transverse processes of the lower cervical and upper thoracic vertebrae. Thus, the male subjects in this study exhibited a greater coverage of the posterior neck both cranially and caudally. Female Multifidus has more attachment points on the spinous processes and articular processes at middle and lower cervical vertebrae and at the transverse processes of the upper thoracic vertebrae. All remaining muscles exhibited no sexual differences. Our findings highlight, for the first time, a sexual dimorphism in attachment points of posterior cervical musculature. It reinforces the notion that the female neck is not a scaled version of the male neck. These differences in muscle attachment could partially explain differences in muscle torque production and range of motion and thus biomechanical differences in cervical spine stabilization between sexes. It sheds a much-needed light on the reason for higher whiplash rates, concussion, and chronic cervical pain among females. Surgeons should take these sexual morphological differences into consideration when deliberating the best surgical approach for posterior cervical surgery.

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.

The Neandertal vertebral column 2: The lumbar spine.

Here we provide the most extensive metric and morphological analysis performed to date on the Neandertal lumbar spine. Neandertal lumbar vertebrae show differences from modern humans in both the vertebral body and in the neural arch, although not all Neandertal lumbar vertebrae differ from modern humans in the same way. Differences in the vertebral foramen are restricted to the lowermost lumbar vertebrae (L4 and L5), differences in the orientation of the upper articular facets appear in the uppermost lumbar vertebrae (probably in L1 and L2-L3), and differences in the horizontal angle of the transverse process appear in L2-L4. Neandertals, when compared to modern humans, show a smaller degree of lumbar lordosis. Based on a still limited fossil sample, early hominins (australopiths and Homo erectus) had a lumbar lordosis that was similar to but below the mean of modern humans. Here, we hypothesize that from this ancestral degree of lumbar lordosis, the Neandertal lineage decreased their lumbar lordosis and Homo sapiens slightly increased theirs. From a postural point of view, the lower degree of lordosis is related to a more vertical position of the sacrum, which is also positioned more ventrally with respect to the dorsal end of the pelvis. This results in a spino-pelvic alignment that, though different from modern humans, maintained an economic postural equilibrium. Some features, such as a lower degree of lumbar lordosis, were already present in the middle Pleistocene populations ancestral to Neandertals. However, these middle Pleistocene populations do not show the full suite of Neandertal lumbar morphologies, which probably means that the characteristic features of the Neandertal lumbar spine did not arise all at once.

The role of allometry and posture in the evolution of the hominin subaxial cervical spine.

Cervical vertebrae not only protect the spinal cord but also are the insertion and origin points for muscles related to the movement of the head, upper limb, and trunk, among others, and are thus important elements in primate evolution. While previous work has been undertaken on the first two cervical vertebrae, there is a dearth of studies on the subaxial cervical spine in hominines. In this paper, we provide detailed morphological information on two important aspects of the subaxial cervical vertebrae (C3 - C7): mid-sagittal morphology and superior facet orientation. We studied large samples of African apes including modern humans and the most complete fossil hominin subaxial cervical vertebrae using both traditional and geometric morphometrics. There are significant differences between extant hominoids related to the relative length and orientation of the spinous process as well as to the orientation of the articular facets, which are related to size, locomotion, and neck posture. In fact, fossil hominins do not completely conform to any of the extant groups. Our assessment of mid-sagittal morphology and superior articular facet orientation shows that australopiths have more Homo-like upper subaxial cervical vertebrae coupled with more "primitive" lower cervical vertebrae. Based on these results, we hypothesize that those changes, maybe related to postural changes derived from bipedalism, did not affect the entire subaxial cervical spine at once. From a methodological point of view, the combination of traditional and geometric morphometric data provides a more integrative perspective of morphological change and evolution, which is certainly useful in human evolutionary studies.

Morphological and postural sexual dimorphism of the lumbar spine facilitates greater lordosis in females.

Previous work suggests females are evolutionarily adapted to have greater lumbar lordosis than males to aid in pregnancy load-bearing, but no consensus exists. To explore further sex-differences in the lumbar spine, and to understand contradictions in the literature, we conducted a cross-sectional retrospective study of sex-differences in lumbar spine morphology and sacral orientation. In addition, our sample includes data for separate standing and supine samples of males and females to examine potential sex-differences in postural loading on lumbosacral morphology. We measured sagittal lumbosacral morphology on 200 radiographs. Measurements include: lumbar angle (L1-S1), lumbar vertebral body and disc wedging angles, sacral slope and pelvic incidence. Lumbar angle, representative of lordotic curvature between L1 and S1, was 7.3° greater in females than males, when standing. There were no significant sex-differences in lumbar angle when supine. This difference in standing lumbar angle can be explained by greater lordotic wedging of the lumbar vertebrae (L1-L5) in females. Additionally, sacral slope was greater in females than males, when standing. There were no significant sex-differences in pelvic incidence. Our results support that females have greater lumbar lordosis than males when standing, but not when supine - suggesting a potentially greater range of motion in the female spine. Furthermore, sex-differences in the lumbar spine appear to be supported by postural differences in sacral-orientation and morphological differences in the vertebral body wedging. A better understanding of sex-differences in lumbosacral morphology may explain sex-differences in spinal conditions, as well as promote necessary sex-specific treatments.

Brief communication: Lumbar lordosis in extinct hominins: implications of the pelvic incidence.

Recently, interest has peaked regarding the posture of extinct hominins. Here, we present a new method of reconstructing lordosis angles of extinct hominin specimens based on pelvic morphology, more specifically the orientation of the sacrum in relation to the acetabulum (pelvic incidence). Two regression models based on the correlation between pelvic incidence and lordosis angle in living hominoids have been developed. The mean values of the calculated lordosis angles based on these models are 36°-45° for australopithecines, 45°-47° for Homo erectus, 27°-34° for the Neandertals and the Sima de los Huesos hominins, and 49°-51° for fossil H. sapiens. The newly calculated lordosis values are consistent with previously published values of extinct hominins (Been et al.: Am J Phys Anthropol 147 (2012) 64-77). If the mean values of the present nonhuman hominoids are representative of the pelvic and lumbar morphology of the last common ancestor between humans and nonhuman hominoids, then both pelvic incidence and lordosis angle dramatically increased during hominin evolution from 27° ± 5 to 22° ± 3 (respectively) in nonhuman hominoids to 54° ± 10 and 51° ± 11 in modern humans. This change to a more human-like configuration appeared early in the hominin evolution as the pelvis and spines of both australopithecines and H. erectus show a higher pelvic incidence and lordosis angle than nonhuman hominoids. The Sima de los Huesos hominins and Neandertals show a derived configuration with a low pelvic incidence and lordosis angle.

The Neandertal vertebral column 1: the cervical spine.

This paper provides a metric analysis of the Neandertal cervical spine in relation to modern human variation. All seven cervical vertebrae have been analysed. Metric data from eight Neandertal individuals are compared with a large sample of modern humans. The significance of morphometric differences is tested using both z-scores and two-tailed Wilcoxon signed rank tests. The results identify significant metric and morphological differences between Neandertals and modern humans in all seven cervical vertebrae. Neandertal vertebrae are mediolaterally wider and dorsoventrally longer than modern humans, due in part to longer and more horizontally oriented spinous processes. This suggests that Neandertal cervical morphology was more stable in both mid-sagittal and coronal planes. It is hypothesized that the differences in cranial size and shape in the Neandertal and modern human lineages from their Middle Pleistocene ancestors could account for some of the differences in the neck anatomy between these species.

Lumbar lordosis of extinct hominins.

The lordotic curvature of the lumbar spine (lumbar lordosis) in humans is a critical component in the ability to achieve upright posture and bipedal gait. Only general estimates of the lordotic angle (LA) of extinct hominins are currently available, most of which are based on the wedging of the vertebral bodies. Recently, a new method for calculating the LA in skeletal material has become available. This method is based on the relationship between the lordotic curvature and the orientation of the inferior articular processes relative to vertebral bodies in the lumbar spines of living primates. Using this relationship, we developed new regression models in order to calculate the LAs in hominins. The new models are based on primate group-means and were used to calculate the LAs in the spines of eight extinct hominins. The results were also compared with the LAs of modern humans and modern nonhuman apes. The lordotic angles of australopithecines (41° ± 4), H. erectus (45°) and fossil H. sapiens (54° ± 14) are similar to those of modern humans (51° ± 11). This analysis confirms the assumption that human-like lordotic curvature was a morphological change that took place during the acquisition of erect posture and bipedalism as the habitual form of locomotion. Neandertals have smaller lordotic angles (LA = 29° ± 4) than modern humans, but higher angles than nonhuman apes (22° ± 3). This suggests possible subtle differences in Neandertal posture and locomotion from that of modern humans.

The significance of right ear auditory processing to balance.

Although the association between balance and hearing thresholds at different frequencies in the right/left ear is crucial, it has received scant empirical attention. Balance is widely ignored when evaluating hearing in adults. This study examined the relative contribution of left versus right ear hearing at different frequencies to balance, and the mediating role of suprathreshold speech perception on age-balance associations. Pure tone hearing thresholds (500-4000 Hz), suprathreshold speech perception, balance, and risk of falling were evaluated in 295 adults. The results indicate that the right ear contributes more to balance than the left ear. This might imply dominance of the left hemisphere in processing hearing cues for balance. Frequencies within the speech range (500/1000/2000 Hz) were correlated with balance and mediated the interaction between age and balance. These results should be considered when tailoring hearing and balance rehabilitation programs.

The earliest Pleistocene record of a large-bodied hominin from the Levant supports two out-of-Africa dispersal events.

The paucity of early Pleistocene hominin fossils in Eurasia hinders an in-depth discussion on their paleobiology and paleoecology. Here we report on the earliest large-bodied hominin remains from the Levantine corridor: a juvenile vertebra (UB 10749) from the early Pleistocene site of 'Ubeidiya, Israel, discovered during a reanalysis of the faunal remains. UB 10749 is a complete lower lumbar vertebral body, with morphological characteristics consistent with Homo sp. Our analysis indicates that UB-10749 was a 6- to 12-year-old child at death, displaying delayed ossification pattern compared with modern humans. Its predicted adult size is comparable to other early Pleistocene large-bodied hominins from Africa. Paleobiological differences between UB 10749 and other early Eurasian hominins supports at least two distinct out-of-Africa dispersal events. This observation corresponds with variants of lithic traditions (Oldowan; Acheulian) as well as various ecological niches across early Pleistocene sites in Eurasia.

Geometry of the vertebral bodies and the intervertebral discs in lumbar segments adjacent to spondylolysis and spondylolisthesis: pilot study.

The objective is to evaluate the geometric parameters of vertebral bodies and intervertebral discs in spinal segments adjacent to spondylolysis and spondylolisthesis. This pilot cross-sectional study was an ancillary project to the Framingham Heart Study. The presence of spondylolysis and spondylolisthesis as well as measurements of spinal geometry were identified on CT imaging of 188 individuals. Spinal geometry measurements included lordosis angle, wedging of each lumbar vertebra and intervertebral disc. Last measurements were used to calculate ΣB, the sum of the lumbar L1-L5 body wedge angles; and ΣD, the sum of the lumbar L1-L5 intervertebral disc angles. Using Wilcoxon-Mann-Whitney test we compared the geometric parameters between individuals with no pathology and ones with spondylolysis (with no listhesis) at L5 vertebra, ones with isthmic spondylolisthesis at L5-S1 level, and ones with degenerative spondylolisthesis at L5-S1 level. Spinal geometry in individuals with spondylolysis or listhesis at L5 shows three major patterns: In spondylolysis without listhesis, spinal morphology is similar to that of healthy individuals; In isthmic spondylolisthesis there is high lordosis angle, high L5 vertebral body wedging and very high L4-5 disc wedging; In degenerative spondylolisthesis, spinal morphology shows more lordotic wedging of the L5 vertebral body, and less lordotic wedging of intervertebral discs. In conclusion, there are unique geometrical features of the vertebrae and discs in spondylolysis or listhesis. These findings need to be reproduced in larger scale study.

Morphology and function of the lumbar spine of the Kebara 2 Neandertal.

The morphology of the lumbar spine is crucial for upright posture and bipedal walking in hominids. The excellent preservation of the lumbar spine of Kebara 2 provides us a rare opportunity to observe a complete spine and explore its functionally relevant morphology. The lumbar spine of Kebara 2 is analyzed and compared with the lumbar spines of modern humans and late Pleistocene hominids. Although no size differences between the vertebral bodies and pedicles of Kebara 2 and modern humans are found, significant differences in the size and orientation of the transverse processes (L(1)-L(4)), and the laminae (L(5), S(1)) are demonstrated. The similarity in the size of the vertebral bodies and pedicles of Kebara 2 and modern humans suggests similarity in axial load transmission along the lumbar spine. The laterally projected (L(2)-L(4)) and the cranially oriented (L(1), L(3)) transverse processes of Kebara 2 show an advantage for lateral flexion of the lumbar spine compared with modern humans. The characteristic morphology of the lumbar spine of Kebara 2 might be related to the wide span of its pelvic bones.

Vertebral bodies or discs: which contributes more to human-like lumbar lordosis?

BACKGROUND: The attainment of upright posture, with its requisite lumbar lordosis, was a major turning point in human evolution. Nonhuman primates have small lordosis angles, whereas the human spine exhibits distinct lumbar lordosis (30 degrees -80 degrees ). We assume the lumbar spine of the pronograde ancestors of modern humans was like those of extant nonhuman primates, but which spinal components changed in the transition from small lordosis angles to large ones is not fully understood. QUESTIONS/PURPOSES: We wished to determine the relative contribution of vertebral bodies and intervertebral discs to lordosis angles in extant primates and humans. METHODS: We measured the lordosis, intervertebral disc, and vertebral body angles of 100 modern humans (orthograde primates) and 56 macaques (pronograde primates) on lateral radiographs of the lumbar spine (humans-standing, macaques-side-lying). RESULTS: The humans exhibited larger lordosis angles (51 degrees ) and vertebral body wedging (5 degrees ) than did the macaques (15 degrees and -25 degrees , respectively). The differences in wedging of the intervertebral discs, however, were much less pronounced (46 degrees versus 40 degrees ). CONCLUSIONS: These observations suggest the transition from pronograde to orthograde posture (ie, the lordosis angle) resulted mainly from an increase in vertebral body wedging and only in small part from the increase in wedging of the intervertebral discs.

No Cutting Corners: The Effect of Parental Involvement on Youth Basketball Players in Israel.

This paper explores the nature of parental involvement in youth basketball in Israel with regard to parenting style and in the context of dilemmas and ethical issues. It is well established that parental involvement in their child's sporting activity has vast implications on the child's motivation and enjoyment. With reference to Israeli society, only a few studies have focused on this subject. In order to address this lacuna, we used two questionnaires, given to 173 youth basketball players (child questionnaire) and their parents (parent questionnaire). Key findings illustrate three main themes. First, a higher level of satisfaction and contentment among basketball players whose parents demonstrated greater involvement; second, that parental emotional involvement is the most important variable for young athletes' satisfaction; and finally, differences in gender roles reveal that fathers are more involved with logistics, while mothers are more dominant in emotional involvement. Moreover, the findings demonstrate that parents should mainly place emphasis on emotional involvement. However, we suggest that parents do not bypass logistical care as this may create opportunities for greater emotional support and therefore greater child satisfaction.

Rib cage anatomy in Homo erectus suggests a recent evolutionary origin of modern human body shape.

The tall and narrow body shape of anatomically modern humans (Homo sapiens) evolved via changes in the thorax, pelvis and limbs. It is debated, however, whether these modifications first evolved together in African Homo erectus, or whether H. erectus had a more primitive body shape that was distinct from both the more ape-like Australopithecus species and H. sapiens. Here we present the first quantitative three-dimensional reconstruction of the thorax of the juvenile H. erectus skeleton, KNM-WT 15000, from Nariokotome, Kenya, along with its estimated adult rib cage, for comparison with H. sapiens and the Kebara 2 Neanderthal. Our three-dimensional reconstruction demonstrates a short, mediolaterally wide and anteroposteriorly deep thorax in KNM-WT 15000 that differs considerably from the much shallower thorax of H. sapiens, pointing to a recent evolutionary origin of fully modern human body shape. The large respiratory capacity of KNM-WT 15000 is compatible with the relatively stocky, more primitive, body shape of H. erectus.

Differences in body positional bilateral symmetry between stance and supine positions, and the impact of attention and awareness on postural symmetry.

BACKGROUND AND PURPOSE: Postural asymmetries may cause structural pathological conditions and impaired movement pattern. The influence of body position and awareness towards symmetry has not yet been elucidated. The aim of this study was twofold: First, to compare the body positional bilateral symmetry between standing and supine positions, and second, to examine whether the awareness to symmetry can modify posture perception and body positional bilateral symmetry. METHODS: We analyzed the degree of anterior postural alignment symmetry of 34 healthy subjects by photogrammetric method (three photographs in a standing position and three in a supine position). Each photo captured different state of awareness: Subjective Comfortable Posture (SCP), Subjective Perceived Symmetrical Posture (SPSP), and Guided Posture Protocol (GPP). RESULTS: The standing position increased the symmetrical alignment of the neck (p < 0.013) and the upper limbs (p < 0.011). However, the supine position demonstrated increased symmetrical alignment of the upper trunk (p < 0.019) and the feet (p < 0.002). In the standing position, GPP showed greater symmetry of the neck (p < 0.022), the shoulders (p < 0.014), the thorax midline (p < 0.009), the upper trunk (p < 0.000) and the upper limbs (p < 0.029). No significant changes were observed in the supine position between the three states of awareness. CONCLUSIONS: Study results indicate that the supine position shows greater degree of upper trunk's symmetrical alignment than the standing position. It also indicates that while standing, focusing attention into symmetry improves body positional bilateral symmetry. These results might have clinical implications when working with patients who suffer from asymmetric posture.

Gait, balance, mobility and muscle strength in people with anxiety compared to healthy individuals.

BACKGROUND: Anxiety disorders are the most common mental disorders. Changes in psychomotor behavior can be observed in gross motor skills, with gait disturbances thought to reflect defective brain functions in psychiatric conditions. While balance deficits are well documented in anxiety, only little is known about gait characteristics of people with anxiety. OBJECTIVE: This study wishes to examine the existence of differences in gait, balance, mobility and muscle strength between people with anxiety and healthy individuals, and to investigate the relationship between level of anxiety and motor characteristics. METHODS: An observational study was conducted in a psychiatric out-patient unit at a large Israeli general hospital. The sample consisted of 93 participants, ages 18-65: 48 of them (27 female, 21 male) categorized as having anxiety, and 45 (25 female, 20 male) without anxiety. Participants were divided into two groups of various ages and both genders, and completed two questionnaires and four physical tests: objective anxiety assessment (Hamilton Anxiety Rating Scale); spatiotemporal gait parameters (10-meter walking test); balance function (Unipedal Stance Test); muscle strength evaluation, and mobility (Time Up and Go Test). No attempt was made to correlate between the anxiety and control groups based on age and/or gender. RESULTS: Participants with anxiety (both genders) were characterized by slower walking speed, shorter step length, and fewer steps per minute (p < 0.001), as well as balance deficiency and mobility dysfunction (p < 0.001), compared to the control group. Muscle strength in women with anxiety was found to be significantly lower than in healthy women. CONCLUSIONS: To the best of our knowledge, this study is the first of its kind to examine spatiotemporal gait components in patients with anxiety. Based on the findings, there is room to consider implementing gait analysis into the physical examination of patients with anxiety, as well as muscle strength, balance, and mobility function. Correct assessment and proper treatment of these aspects might contribute to the well-being of patients with anxiety.

Development of Pelvic Incidence and Lumbar Lordosis in Children and Adolescents.

Pelvic incidence (PI) is a measure of the sagittal orientation of the sacrum relative to the acetabula and is not dependent on posture. In asymptomatic adults, PI correlates with lumbar lordosis. Lumbar lordosis is shown to increase with age following the onset of unassisted bipedal locomotion in children, but to what extent PI changes in relation to lumbar lordosis during skeletal maturation is unclear. The purpose of this study is to understand how PI, lumbar lordosis, and age are related in children and adolescents. PI, supine lumbar lordosis (SLL), and individual wedging angles of the lumbar vertebral bodies were measured on mid-sagittal reformatted images from 144 abdominal computed tomographic scans of individuals aged 2-20 years old, divided into three separate age categories representing pre-growth spurt (ages 2-9), growth spurt (10-15), and post-growth spurt (16-20). Our results showed that, while SLL significantly increased with age during development, PI did not. Despite the fact that PI hardly changed with age, the difference between PI and SLL decreased nonlinearly with age. SLL did not correlate with PI in the youngest age category, but positively correlated with PI in the middle and oldest age categories. The relationship between lumbar lordosis and PI, which is correlated in adults, was significant in our older age categories and not in our youngest age category. Our results indicate that PI in children and adolescents may have some predictive value for adult lumbar lordosis. Anat Rec, 302:2132-2139, 2019. © 2019 American Association for Anatomy.

Persistent Neanderthal occupation of the open-air site of 'Ein Qashish, Israel.

Over the last two decades, much of the recent efforts dedicated to the Levantine Middle Paleolithic has concentrated on the role of open-air sites in the settlement system in the region. Here focus on the site of 'Ein Qashish as a cases study. Located in present-day northern Israel, the area of this site is estimated to have been >1300 m2, of which ca. 670 were excavated. The site is located at the confluence of the Qishon stream with a small tributary running off the eastern flanks of the Mt. Carmel. At the area of this confluence, water channels and alluvial deposits created a dynamic depositional environment. Four Archaeological Units were identified in a 4.5-m thick stratigraphic sequence were dated by Optically Stimulated Luminescence (OSL) to between-71 and 54 ka, and probably shorter time span-~70-~60 ka. Here we present the diverse material culture remains from the site (lithics, including refitted sequences; modified limestone pieces; molluscs; faunal remains) against their changing paleogeographic backdrop. Skeletal evidence suggests that these remains were associated with Neanderthals. The large-scale repeated accumulation of late Middle Paleolithic remains in the same place on the landscape provides a unique opportunity to address questions of occupation duration and intensity in open-air sites. We find that each occupation was of ephemeral nature, yet presents a range of activities, suggesting that the locale has been used as a generalized residential site rather than specialized task-specific ones. This role of 'Ein Qashish did not change through time, suggesting that during the late Middle Paleolithic settlement system in this part of the southern Levant were stable.

3D virtual reconstruction of the Kebara 2 Neandertal thorax.

The size and shape of the Neandertal thorax has been debated since the first discovery of Neandertal ribs more than 150 years ago, with workers proposing different interpretations ranging from a Neandertal thoracic morphology that is indistinguishable from modern humans, to one that was significantly different from them. Here, we provide a virtual 3D reconstruction of the thorax of the adult male Kebara 2 Neandertal. Our analyses reveal that the Kebara 2 thorax is significantly different but not larger from that of modern humans, wider in its lower segment, which parallels his wide bi-iliac breadth, and with a more invaginated vertebral column. Kinematic analyses show that rib cages that are wider in their lower segment produce greater overall size increments (respiratory capacity) during inspiration. We hypothesize that Neandertals may have had a subtle, but somewhat different breathing mechanism compared to modern humans.