Capturing the cervical spine shape: Angular measurements versus geometric morphometric methods.

The cervical spine manifests a wide shape variation. However, the traditional methods to evaluate the cervical spine curve were never tested against its actual shape. The study's main aim was to determine whether the shape classification of the cervical spine, based on traditional angular measurements, coincides with each other and with the shape captured by the 2D landmark-based geometric morphometric method. The study's second aim was to reveal the associations between the cervical spine shape and the demographic parameters, the head's position, and the spine's sagittal balance. CT scans of the cervical spine of 163 individuals were evaluated to achieve these goals. The shape was assessed by measuring the C2-C7 Cobb angle (CA), the C2-C7 posterior tangent angle (PTA), the curvedness of the arch, and by a 2D landmark-based geometric morphometric method. The position of the head and the sagittal balance of the spine were evaluated by measuring the foramen magnum-C2 Cobb angle (FMCA) and the T1 slope angle (T1SA), respectively. Based on the size of the angle measured, each individual was classified into one of the three cervical 'shape groups' (lordotic, straight, and kyphotic). We found that cervical lordosis was the dominant shape regardless of the measuring methods utilized (46.6%-54.6%), followed by straight neck (28.2%-30.1%), and kyphosis (15.3%-25.2%); however, about a third of the 163 individuals were classified into a different shape group using the CA and PTA methods. The cervical spine angle was sex-independent and age-dependent. The T1SA was significantly correlated with CA and PTA (r = 0.640 and r = 0.585, respectively; p < 0.001). In conclusion, the cervical spine shape evaluation is method-dependent and varies with age.

Predictive factors for degenerative lumbar spinal stenosis: a model obtained from a machine learning algorithm technique.

BACKGROUND: Degenerative lumbar spinal stenosis (DLSS) is the most common spine disease in the elderly population. It is usually associated with lumbar spine joints/or ligaments degeneration. Machine learning technique is an exclusive method for handling big data analysis; however, the development of this method for spine pathology is rare. This study aims to detect the essential variables that predict the development of symptomatic DLSS using the random forest of machine learning (ML) algorithms technique. METHODS: A retrospective study with two groups of individuals. The first included 165 with symptomatic DLSS (sex ratio 80 M/85F), and the second included 180 individuals from the general population (sex ratio: 90 M/90F) without lumbar spinal stenosis symptoms. Lumbar spine measurements such as vertebral or spinal canal diameters from L1 to S1 were conducted on computerized tomography (CT) images. Demographic and health data of all the participants (e.g., body mass index and diabetes mellitus) were also recorded. RESULTS: The decision tree model of ML demonstrate that the anteroposterior diameter of the bony canal at L5 (males) and L4 (females) levels have the greatest stimulus for symptomatic DLSS (scores of 1 and 0.938). In addition, combination of these variables with other lumbar spine features is mandatory for developing the DLSS. CONCLUSIONS: Our results indicate that combination of lumbar spine characteristics such as bony canal and vertebral body dimensions rather than the presence of a sole variable is highly associated with symptomatic DLSS onset.

In search of modern humans and the Early Upper Paleolithic at Manot Cave: An overview.

Manot Cave is a unique relict karst cave located in the western Galilee, north-western Israel. The cave was inhabited from the Late Middle Paleolithic through the Early Upper Paleolithic (EUP) periods until its main entrance collapsed, ca. 30 ka. The cave consists of an elongated main hall and two side chambers. The topography of the main hall consists of a steep talus inclining from the original entrance of the cave to the center, a plane area at the lowermost point of the main hall, and a smaller talus inclining from the eastern end of the cave. Nine field seasons (2010-2018) have been conducted so far at the cave. The excavations revealed dense accumulations of EUP deposits near the cave entrance (areas E and I), at the center (area D), at the base of the western talus (area C), and in the plane area (area A). This introductory article describes the cave and its characteristics and provides a background for various contributions in the special issue, devoted to Manot Cave.

Karst terrain in the western upper Galilee, Israel: Speleogenesis, hydrogeology and human preference of Manot Cave.

A karst survey of the western upper Galilee in Israel shows that karst has been a dominant geomorphic factor throughout the Cenozoic. We discuss the geomorphic character of Manot Cave on the background of other karst features of the region, in order to decipher the preferences of the humans who favored this cave over others. Tens of caves distributed over the study area demonstrate that phreatic and hypogene isolated voids and conduit segments are more abundant than vadose shafts, sinking stream caves and spring caves, although all these types are present. Most caves belong to old stages of landform development, prior to Plio-Pleistocene uplift and stream entrenchment. Manot Cave is a relict chamber cave, which corresponds to a plaeo-water table and the erosion plain above it. Subaerial denudation and slope processes have opened the cave to the surface during the mid-late Pleistocene. Manot Cave is compared with other caves in the region, demonstrating its unique character. It may have been selected due to the small entrance facing to the SW, and the large inner chamber which could be used for non-domestic purposes. This suggests a possible role of a unique behavioral and cultural suite of characters which influenced hominin preferences. The cave was used by hominins and animals until being closed again by colluvium and possibly collapse, ∼30 ka. Clastic, chemical, archaeozoological and anthropogenic accumulations reflect the various stages of cave development and gradual sealing of the entrance.

The Marine Isotope Stage 3 landscape around Manot Cave (Israel) and the food habits of anatomically modern humans: New insights from the anthracological record and stable carbon isotope analysis of wild almond (Amygdalus sp.).

The excavation of Manot Cave (Israel) reveals intensive occupation during the Early Upper Paleolithic and provides the first continuous set of anthracological data available for the Ahmarian, Levantine Aurignacian and post-Levantine Aurignacian periods. The paper aims to study the vegetal landscape around Manot Cave in the context of climate changes that characterized the last part of the Marine Isotope Stage 3 (MIS 3) and to address the issue of firewood and food procurement among Paleolithic hunter-gatherers. Charcoal samples recovered from the archaeological layers at Manot Cave shed light on the fuel and food procurement strategies while radiocarbon dating and stable carbon isotope analysis (Δ13C) of selected charcoals provide information about the ancient climate. The results show that five woody taxa were exploited at the site; Amygdalus sp. was the most common species, whereas Quercus ithaburensis, Tamarix sp., Pomoideae indet., and Pistacia atlantica were relatively rare. The representations of the recovered wooden species suggest that an open forest of almonds and oaks existed in the area during MIS 3. Radiocarbon dating of Amygdalus sp. charcoals, coupled with stable carbon isotope analysis (Δ13C) of modern and archaeological Amygdalus sp. clearly indicate variations in rainfall that could have decreased the density of tree cover. These analyses provide high-resolution data on the climate changes affecting the surroundings of Manot Cave between ∼46 and 28 ka cal BP and indicate two drier phases corresponding to the Ahmarian and post-Levantine Aurignacian cultures while a more humid period identified during the Levantine Aurignacian.

The endocast of the late Middle Paleolithic Manot 1 specimen, Western Galilee, Israel.

Studying endocasts has long allowed anthropologists to examine changes in the external topography and the overall size of the brain throughout the evolutionary history of hominins. The nearly complete calvaria of Manot 1 presents an opportunity to gain insights into the external brain morphology, vascular system, and dimensions of the brain of this late Middle Paleolithic hominin. Detailed size and shape analyses of the Manot 1 endocast indicate a modern Homo sapiens anatomy, despite the presence of some primitive features of the calvaria. Traits considered to be derived endocranial features for H. sapiens are present in Manot 1, including an elongated parietal sagittal chord with an elevated superior part of the hemisphere, a widened posterior part of the frontal lobes, a considerable development of the parietal reliefs such as the supramarginal lobules, and a slight posterior projection of the occipital lobes. These findings, together with data presented in previous studies, rule out the possibility of a direct Neanderthal ancestry for the Manot 1 hominin and instead confirm its affiliation with H. sapiens. The Manot 1 calvaria is more similar to that of later Upper Paleolithic H. sapiens than it is to the earlier Levantine populations of Skhul and Qafzeh. The late Middle Paleolithic date of Manot 1 provides an opportunity to analyze the recent developments in human cerebral morphology and organization.

Climatic and environmental conditions in the Western Galilee, during Late Middle and Upper Paleolithic periods, based on speleothems from Manot Cave, Israel.

Early Ahmarian, Levantine Aurignacian and Post-Levantine Aurignacian archeological assemblages show that the karstic Manot Cave, located 5 km east of the Mediterranean coast in the Western Galilee region of Israel, was intensively occupied during the Early Upper Paleolithic. The coexistence of these rich archaeological layers with speleothems in Manot Cave provides a window of opportunity for determining the relationships between climatic conditions and the nature of human activity and mobility patterns in the Western Galilee region during the Early Upper Paleolithic period. This study, based on four stalagmites that grew almost continuously from ∼75 to 26.5 ka, covers most of the last glacial, and overlaps with the human occupation of the cave. The speleothems oxygen (δ18O) and carbon (δ13C) isotopic records indicate that climate and environmental conditions fluctuated during the last glacial, some of which correspond with Dansgaard-Oeschger (D-O) cycles 12, 10, 7 and Heinrich (H) events VI and V. Consistent with independent evidence from botanic and faunal remains, these climatic shifts brought about significant environmental changes in the region, ranging from dominant thick Mediterranean forest to more open landscape. A good correlation with less negative δ13C values is most pronounced during the Early Ahmarian time period, but there was also a change to less negative δ13C values during the Levantine Aurignacian and Post-Levantine Aurignacian industries in the Levant. These positive δ13C shifts suggest that environmental transformation towards a more open grassy landscape dominated by C4 vegetation might have played an important role in the development of these cultural entities (mainly the Early Ahmarian) in Manot Cave region.

Preliminary observations on the Levantine Aurignacian sequence of Manot Cave: Cultural affiliations and regional perspectives.

A well-preserved sequence of Early Upper Paleolithic (EUP) occupations has been revealed in the past decade in Manot Cave, the studies of which shed light on the cultural dynamics and subsistence patterns and paleoenvironment. Most intriguing is the series of overlying Levantine Aurignacian occupation layers, exposed near the entrance to the cave. Area E is considered the inner part of the main activity area in Manot Cave. Remains of intact combustion features, as well as numerous flint artifacts and faunal remains, were found, indicating a high level of preservation. Within a 2.5 m sequence, nine distinct occupation layers were defined. The presence of characteristic flint and osseous industries alongside a rich mollusk assemblage led to the initial association of the sequence as a whole to the Levantine Aurignacian. However, as research advanced and variability in the material culture became apparent, it became clear that a division of the sequence into two phases, early and late, is required. A preliminary study of the assemblage variability implies distinct changes in human behavior between the two phases. Most prominently, these are indicated by a change in bladelet production method and morphology alongside an increase in the significance of the bladelet component within the flint assemblage, the disappearance of composite osseous industries, and a steep decrease in mollusk shell representation in the late occupation phase. Radiocarbon dating indicates a short time span between the two phases. The earlier phase defined as, Levantine Aurignacian, was ascribed an age range of 38-34 ka cal BP with a more constrained age range of 37-35 ka cal BP suggested based on Bayesian models. In the late phase, which is temporarily referred to as "post-Levantine Aurignacian," an age range of 36-33 ka cal BP is suggested.

Personal ornaments from Hayonim and Manot caves (Israel) hint at symbolic ties between the Levantine and the European Aurignacian.

Situated at the crossroads of Africa and Eurasia, the Levant is a crucial region for understanding the origins and spread of Upper Paleolithic (UP) traditions associated with the spread of modern humans. Of the two local Early Upper Paleolithic technocomplexes, the Ahmarian and the Levantine Aurignacian, the latter appears to be unique in the endemic UP sequence, exhibiting greater similarity to the West European 'classic' Aurignacian than to the local preceding and proceeding UP entities. Previous publications have mostly focused on the similarities between the two lithic industries and less on studies conducted on Levantine Aurignacian bone tools and ornaments. Here, we present an archaeozoological, technological and use-wear study of ornaments on animal teeth from the Levantine Aurignacian layers at Manot and Hayonim caves (the Galilee, Israel). The selection of taxa, the choice of teeth, the mode of modification, and the use-wear analysis exhibit clear similarities with the European Aurignacian. This, with the technology of the osseous raw material exploitation, the presence of antler simple-base points, and some lithic typotechnological features, suggest a link between the symbolic spheres of the Levantine and the European Aurignacian cultural entities. Such similarity also supports some contribution of European Aurignacians groups to the local cultural entities, intermingling with the local material culture features.

Levantine cranium from Manot Cave (Israel) foreshadows the first European modern humans.

A key event in human evolution is the expansion of modern humans of African origin across Eurasia between 60 and 40 thousand years (kyr) before present (bp), replacing all other forms of hominins. Owing to the scarcity of human fossils from this period, these ancestors of all present-day non-African modern populations remain largely enigmatic. Here we describe a partial calvaria, recently discovered at Manot Cave (Western Galilee, Israel) and dated to 54.7 ± 5.5 kyr bp (arithmetic mean ± 2 standard deviations) by uranium-thorium dating, that sheds light on this crucial event. The overall shape and discrete morphological features of the Manot 1 calvaria demonstrate that this partial skull is unequivocally modern. It is similar in shape to recent African skulls as well as to European skulls from the Upper Palaeolithic period, but different from most other early anatomically modern humans in the Levant. This suggests that the Manot people could be closely related to the first modern humans who later successfully colonized Europe. Thus, the anatomical features used to support the 'assimilation model' in Europe might not have been inherited from European Neanderthals, but rather from earlier Levantine populations. Moreover, at present, Manot 1 is the only modern human specimen to provide evidence that during the Middle to Upper Palaeolithic interface, both modern humans and Neanderthals contemporaneously inhabited the southern Levant, close in time to the likely interbreeding event with Neanderthals.

Are chin and symphysis morphology facial type-dependent? A computed tomography-based study.

INTRODUCTION: The chin is a major determinant of the facial profile; hence, it plays a major role in orthodontics and orthognathic surgery. It is thus essential to follow and better understand its expression in different facial types. The major objectives of the current study were to characterize morphometrically the chin and symphysis and reveal their association with different facial types. METHODS: Computed tomography scans of the head and neck of 311 adults (163 males, 148 females; age range, 18-95 years) were classified into 3 facial types: short, average, and long. Height, width, projection, inclination, thickness, and area were measured on the chin and symphysis. RESULTS: The majority of the population (70%) manifested an average facial type; the other 30% were almost equally distributed between short and long facial types. The long facial type was more common among females and the short facial type among males. Chin projection, area, and size were significantly greater in short-faced patients. Chin width in males was similar for all facial types, whereas, in females, chin width was the widest in the short facial type and the narrowest in the long facial type. Symphysis height was significantly greater in long-faced patients in both sexes. The mandibular incisors' inclination relative to the mandibular plane was not significantly associated with the chin or symphysis morphology. CONCLUSIONS: Chin and symphysis morphology is facial type-dependent. Orthodontists and maxillofacial surgeons should be aware of the complex relationship between facial types and chin/symphysis size and shape when planning treatment.

The torg ratio of C3-C7 in African Americans and European Americans: A skeletal study.

The ratio between the sagittal diameter of the spinal canal and the sagittal diameter of the vertebral body, known as the "Torg ratio", is often used to test for spinal canal narrowing. Here, we investigate this ratio in a large population, consisting of two ethnicities, both sexes and three age groups. Measurements were taken on the dry cervical verterbrae (C3-C7) of 277 individuals using a digital apparatus allowing for the recording of 3D coordinates of a set of landmarks on the vertebral body. Vertebral body and vertebral foramen lengths were compared across the different subgroups. Vertebral body and vertebral foramen lengths differ significantly between males and females and between African Americans and European Americans. With age, the vertebral body length increases while the foramen length does not undergo significant changes. These anatomical differences are reflected in differences in the Torg ratio calculated for the different subgroups. In conclusion, our findings suggest that a hard cutoff on the Torg ratio used to define a pathological narrowing of the cervical spine should be adapted to the population the patients come from. Clin. Anat. 32: 84-89, 2019. © 2018 Wiley Periodicals, Inc.

The effect of impact tool geometry and soft material covering on long bone fracture patterns in children.

INTRODUCTION: The effect of impact tool geometry and soft material covering on bone fracture patterns plays a major role in fracture patterns. However, the literature is nearly void of such studies and only general correlations between the fracture pattern and the mechanism underlying the insult were reported. PURPOSE: The aim of this study is to reveal the association between the geometry of the impact tool and the presence of soft material covering on bone fracture patterns. The Dynatup Model POE 2000 (Instron Co.) low energy pendulum impact machine was utilized to apply impact loading on fresh pig femoral bones (n = 50). The bone clamp shaft was adjusted to position the bone for three-point bending with additional bone compression simulating a situation occurring in pedestrian road traffic accidents. Five different tests using varying impact tool sizes with and without soft interface covering were carried out. RESULTS: A significant positive correlation was found between the fracture features and the impact tool's geometry. Only bones that were damaged by a rounded impact body result in a "false" butterfly fragment; in all other cases where the impact body is flat and wide, double trapezoid fragments are observed in the area of impact. The impacted aspect is the most affected. All fracture line features were significantly greater in bones subjected to an impact by tools without soft covering. With an impact with soft covering, the impacted aspect exhibits numerous unique fracture lines and a fragmented pattern. Our study clearly shows that impact tool geometry and soft material covering markedly affect the fracture pattern.

In the quest for degenerative lumbar spinal stenosis etiology: the Schmorl's nodes model.

BACKGROUND: Degenerative lumbar spinal stenosis (DLSS) is a common health problem in the elderly and usually associated with three-joint complex degeneration. Schmorl's nodes (SNs) are described as vertical herniation of the disc into the vertebral body through a weakened part of the end plate that can lead to disc degeneration. Since SNs can harm the spine unit stability, the association between DLSS and SNs is expected. The aim of this study is to shed light on the relationship between degenerative lumbar spinal stenosis and SNs. METHODS: Two groups of individuals were studied: the first included 165 individuals with DLSS (age range: 40-88, sex ratio: 80 M/85 F) and the second 180 individuals without spinal stenosis related symptoms (age range: 40-99, sex ratio: 90 M/90 F). The presence or absence of SNs on the cranial and caudal end plate surfaces at the lumbosacral region (from L1 to S1 vertebra) was recorded, using CT images (Brilliance 64 Philips Medical System, Cleveland Ohio, thickness of the sections was 1-3 mm and MAS, 80-250). Chi-Square test was taken to compare the prevalence of SNs between the study groups (control and stenosis) by lumbar disc level, for each gender separately. Multivariable logistic regression analysis was also used to determine the association between DLSS and SNs. RESULTS: The prevalence rate of SNs was significantly greater in the stenosis males (L1-2 to L5-S1) and females (L4-5 and L4-S1) compared to their counterparts in the control (P < 0.001). In addition, the presence of SNs in both males and females was found to increase the likelihood for DLSS. CONCLUSIONS: Our results indicate that SNs prevalence is significantly greater in the DLSS group compared to the control. Furthermore, SNs are strongly associated with DLSS.

Lower extremity and spine characteristics in young dancers with and without patellofemoral pain.

Very little is known about patellofemoral pain syndrome (PPFS) among young dancers. Understanding the mechanism of the injury and implementing a preventative programme are important in order to minimize the risk of PFPS. The aim of the current study is to determine the extent to which factors such as lower extremity and back characteristics are common among dancers with PFPS. The study population included 271 dancers with PFPS and 271 non-injured dancers, aged 10-16 years. All dancers were screened for morphometric profile, dance discipline (h/week), anatomical anomalies (present/absent of scoliosis, genu valgus/varum, etc.), and joint range of motion (measured by goniometer at the hip, knee, ankle, foot, and spinal joints). The predicting factors for PFPS among young dancers (10-11 years old) were: hyper hip abduction (OR = 0.906) and lower back and hamstring flexibility (OR = 3.542); for adolescent dancers (12-14 years old): hyper ankle dorsiflexion (OR = 0.888), hind foot-varum (OR = 0.260), and mobility of patella (OR = 2.666); and, for pre-mature dancers (15-16 years old): scoliosis (OR = 5.209), limited ankle plantar-flexion (OR = 1.060), and limited hip internal rotation (OR = 1.063). In conclusion, extrinsic and intrinsic parameters predisposing the dancers to knee injuries should be identified by screening in early stages of dance classes.

Trabecular architecture in the thumb of Pan and Homo: implications for investigating hand use, loading, and hand preference in the fossil record.

OBJECTIVES: Humans display an 85-95% cross-cultural right-hand bias in skilled tasks, which is considered a derived behavior because such a high frequency is not reported in wild non-human primates. Handedness is generally considered to be an evolutionary byproduct of selection for manual dexterity and augmented visuo-cognitive capabilities within the context of complex stone tool manufacture/use. Testing this hypothesis requires an understanding of when appreciable levels of right dominant behavior entered the fossil record. Because bone remodels in vivo, skeletal asymmetries are thought to reflect greater mechanical loading on the dominant side, but incomplete preservation of external morphology and ambiguities about past loading environments complicate interpretations. We test if internal trabecular bone is capable of providing additional information by analyzing the thumb of Homo sapiens and Pan. MATERIALS AND METHODS: We assess trabecular structure at the distal head and proximal base of paired (left/right) first metacarpals using micro-CT scans of Homo sapiens (n = 14) and Pan (n = 9). Throughout each epiphysis we quantify average and local bone volume fraction (BV/TV), degree of anisotropy (DA), and elastic modulus (E) to address bone volume patterning and directional asymmetry. RESULTS: We find a right directional asymmetry in H. sapiens consistent with population-level handedness, but also report a left directional asymmetry in Pan that may be the result of postural and/or locomotor loading. CONCLUSION: We conclude that trabecular bone is capable of detecting right/left directional asymmetry, but suggest coupling studies of internal structure with analyses of other skeletal elements and cortical bone prior to applications in the fossil record.

Paraspinal muscles density: a marker for degenerative lumbar spinal stenosis?

BACKGROUND: The condition of paraspinal muscles is known to be associated with some variables such as age, gender, and low back pain. It is generally agreed that these muscles play an important role in the stability and functional movements of the lumbar vertebral column. Although spinal instability has been shown to play an essential role in degenerative lumbar spinal stenosis (DLSS), the role of paraspinal muscles remains elusive. The main purpose of this study was to shed light on the relationship between the condition of paraspinal muscles and symptomatic DLSS. METHODS: Two sample populations were studied. The first included 165 individuals with DLSS (age range: 40-88, sex ratio: 80 M/85 F) and the second 180 individuals without spinal stenosis related symptoms and low back pain (age range: 40-99, sex ratio: 90 M/90 F). Measurements were taken at the middle part of L3 vertebral body, using CT axial images (Philips Brilliance 64). Muscles density was measured in Hounsfield units (HU) using a 50 mm2 circle of the muscle mass at three different locations and the mean density was then calculated. The cross-sectional area (CSA) was also measured using the quantitative CT angiography method. Analysis of Covariance (adjusted for body mass index and age) was performed in order to determine the relationship between the condition of paraspinal muscles and symptomatic DLSS. RESULTS: Individuals in the stenosis group had higher muscle density as compared to the control group. The CSA values for the erector spinae (both sexes) and psoas (males) muscles were significantly greater in the stenosis group as compared to their counterparts in the control group. Additionally, density of multifidus (both sexes) and erector spinae (males) muscles was significantly associated with symptomatic DLSS. CONCLUSIONS: Our results show that individuals with symptomatic DLSS manifest greater paraspinal muscles density and CSA (erector spinae), compared to the control group. Density of multifidus increases the likelihood of symptomatic DLSS.