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Ballistic gelatin has gained a status as standard method for terminal ballistic testing and experimenting. Variation considering the recipe and manufacturing of the blocks exists. The golden standard has been a cuboid gelatin block, dimensions varying according to the type and kinetic energy of the ammunition. Powerful ammunition requires larger gelatin blocks, making their handling and manufacturing difficult. This is the case especially with powerful, expanding hunting ammunition that leave most of their kinetic energy within the gelatin block. High speed cameras reveal that blocks tend to expand or swell significantly and even travel upon impact, potentially affecting to some basic values of terminal ballistics such as cavitation and energy transfer. In this study, we wanted to experiment new method to study terminal ballistics of high power, expanding ammunition by using cylinder shaped gelatin blocks. Secondly, we used a plastic tube around the gelatin cylinder to restrict the expansion/swelling. Thirdly we attached our gelatin target to a sturdy platform to restrict the movement of the cylinder and potentially improve the energy transfer of the bullet into the gelatin. To conduct our study we compared our experimental setting with a traditional, cuboid gelatin block. After the test firing the blocks underwent computed tomography scanning with clinical equipment. Three-dimensional reconstructions of gelatin cavitation and bullet fragment deposition were created. Our results clearly demonstrate that the restricted expansion of the block also clearly restricts the cavitation inside the gelatin. We believe that the method can be further developed, and it allows better potential for ballistic testing of heavy ammunition. In addition, it may aid in terminal ballistic reconstruction of forensic cases with gunshot trauma in anatomical structures fully enclosed by connective tissue such as brain and structures of the thorax., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Sex estimation is a necessary part of forensic and osteological analyses of skeletal human remains in the construction of a biological profile. Several skeletal traits are sexually dimorphic and used for skeletal sex estimation. The human mandible and morphological traits therein have been long used for sex estimation, but the validity of using the mandible in this purpose has become a concern. In this study, we examined the potential of artificial intelligence (AI) and especially deep learning (DL) to provide accurate sex estimations from the mandible. We used 193 modern South African mandibles from the Human Osteological Research Collection (HORC) in the Sefako Makgatho Health Sciences university with known sex to conduct our study. All mandibles were photographed from the same angle and the photographs were analyzed with an open-source DL software. The best-performing DL algorithm estimated the sex of males with 100% accuracy and females with 76.9% accuracy. However, further studies with a higher number of specimens could provide more reliable validity for using AI when building the biological profile from skeletal remains., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Three-dimensional (3D) imaging, primarily computed tomography (CT), has proven valuable in the documentation and analysis of gunshot injuries. Explicit visualization of findings may play a pivotal role in judicial settings. This forensic ballistics case study aimed to examine the potential of CT-based 3D reconstruction to digitally visualize gunshot cavities in ballistic gelatine. Three .30 caliber bullets of different types (full metal jacket, soft point, and expanding monolithic) were fired into standardized blocks of 10% ballistic gelatine. The blocks underwent CT scanning with clinical equipment. Gelatine and air were segmented from the CT data using an open-source software. 3D reconstruction views of the segmented gelatine and air components were created. The gunshot cavities were clearly observed in both gelatine and air segmentation. The differences in cavitation between bullet types were evident in both reconstruction approaches, although gelatine segmentation produced higher resolution of small details. The obvious benefit of digital reconstruction was the ability to freely tilt and rotate the 3D images, with the possibility of taking measurements manually or automatically from any plane. Moreover, all the data can be stored for future analysis. This study introduces a preliminary method for digital visualization and documentation of gunshot cavitation in ballistic gelatine, to be fine-tuned and implemented for research purposes and routine practice in forensic institutions., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

A smoothbore musket firing a round ball was the primary weapon of the infantry from the 16th to mid 19th century. Musket ball injuries are thus relatively common when archaeological remains of battlefield victims from that period are studied. Several experimental studies have focused on terminal ballistics of a musket ball. In addition, there is a good supply of historical records directly from the battlefield and military hospitals. Studies and historical records have both concluded that head injuries are among the most lethal types of musket ball damage. In this study we utilized modern day research methods, including Synbone ballistic skull phantoms and computed tomography (CT) imaging, to examine more closely the head injuries and tissue damage caused by a musket ball. We were especially interested to observe how different musket ball velocities and shooting distances would influence bone and soft tissue defects. Our experiments clearly demonstrated that musket ball was a lethal projectile even from a longer distance. Already at low velocities, the musket ball perforated through the skull. Velocity also influenced the appearance of entrance and exit wounds. CT imaging provided us with a three-dimensional view of the wound channel, skull fragments and lead remnants inside the skull phantom. According to our findings, musket ball velocity influenced defect size and cavitation. In addition, velocity influenced the size and distribution of skull fragments and lead remnants in the wound channel. Combining all these aspects could aid us in studies of archaeological musket ball victims. In particular, they could help us to estimate the shooting distance and shed light on the potential course of events in the battlefield., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Computed tomography (CT) may have a crucial role in the forensic documentation and analysis of firearm injuries. The aim of this forensic ballistics case study was to explore whether two types of expanding bullets and a full metal-jacketed bullet could be differentiated by inspecting bullet fragments and fragmentation pattern in CT. Three types of .30 caliber bullets (full metal-jacketed Norma Jaktmatch, expanding full-copper Norma Ecostrike, and expanding soft-point Norma Oryx) were test fired from a distance of 5 m to blocks of 10% ballistic gelatine. CT scans of the blocks were obtained with clinical equipment and metal artifact reduction. Radiopaque fragments were identified and fragmentation parameters were obtained from the scans (total number of fragments, maximum diameter of the largest fragment, distance between entrance and the closest fragment, length of the fragment cloud, and maximum diameters of the fragment cloud). The fragmentation patterns were additionally visualized by means of 3D reconstruction. In CT, the bullet types differed in several fragmentation parameters. While the expanding full-copper bullet Ecostrike left behind only a single fragment near the end of the bullet channel, the soft-point Oryx had hundreds of fragments deposited throughout the channel. For both expanding bullets Ecostrike and Oryx, the fragments were clearly smaller than those left behind by the full metal-jacketed Jaktmatch. This was surprising as the full metal-jacketed bullet was expected to remain intact. The fragment cloud of Jaktmatch had similar mediolateral and superoinferior diameters to that of Oryx; however, fragments were deposited in the second half of the gelatine block, and not throughout the block. This case study provides a basis and potential methodology for further experiments. The findings are expected to benefit forensic practitioners with limited background information on gunshot injury cases, for example, those that involve several potential firearms or atypical gunshot wounds. The findings may prove beneficial for both human and wildlife forensics., (© 2023. The Author(s).)

Purpose: Vertebral dimensions may constitute a potential risk factor for degenerative changes in the spine. Previous studies have found a positive association between vertebral height and both type 2 Modic changes and intervertebral disc height loss. Also, vertebral endplate size has been associated with disc degeneration. However, only a few studies have investigated the association between vertebral dimensions and lumbar disc displacement (LDD). This study aimed to investigate the association between vertebral cross-sectional area (CSA) and LDD among the general middle-aged Finnish population. We hypothesized that larger vertebral CSA is associated with LDD., Materials and Methods: The study was conducted by using data from the Northern Finland Birth Cohort 1966 (NFBC1966). At the age of 46, a subpopulation of NFBC1966 underwent clinical examinations including magnetic resonance imaging (MRI) (n = 1249). MRI scans were used to measure L4 CSA and evaluate the presence of LDD (bulge, protrusion, and extrusion/sequestration) in the adjacent discs. The association between L4 CSA and LDD was analysed using logistic regression, with adjustment for sex, education, body mass index, leisure-time physical activity, smoking, diet, and L4 height., Results: Larger L4 CSA was associated with LDD; an increase of 1 cm 2 in vertebral CSA elevated the odds of LDD relative to no LDD by 10% (adjusted odds ratio 1.10, 95% CI 1.01-1.19). The association was similar among either sex., Conclusions: Larger L4 vertebral CSA was associated with LDD in our study sample. Even though smaller vertebral size exposes our vertebrae to osteoporotic fractures, it simultaneously seems to protect us from LDD., (© 2023. The Author(s).)

The so-called man-eating wolves of Turku, a pack of three wolves, reportedly killed 22 children in South-Western Finland in 1880-1881. Enormous efforts were carried out to eradicate them. In January 1882 the last remaining wolf was killed. Since then, there has been considerable debate regarding the validity and extent of the man-eating behaviour. This study aims to clarify whether man-eating behaviour can be observed from the remains of these wolves. One of the wolves was mounted in 1882 and is on display at St. Olaf's school in Turku, enabling us to collect hair keratin samples. Additionally, hair keratin was collected from two other suspected man-eaters. We analysed carbon (δ 13 C) and nitrogen (δ 15 N) stable isotope values to study the wolf's diet during the last months of its life. Samples from seven temporally concurrent wolves were used to construct reference values. Our analyses indicated that δ 15 N values of suspected man-eaters were relatively low compared to the reference sample. We could not detect clear trends in isotope ratios associated with potential man-eating behavior. We believe that this lack of distinctive patterns can be explained by the relatively minor role that man-eating played in their overall diet., (© 2024. The Author(s).)

Sex estimation is a key element in the analysis of unknown skeletal remains. The vertebrae display clear sex discrepancy and have proven accurate in conventional morphometric sex estimation. This proof-of-concept study aimed to investigate the possibility to develop a deep learning algorithm for sex estimation even from a single peripheral quantitative computed tomography (pQCT) slice of the fourth lumbar vertebra (L4). The study utilized a total of 117 vertebrae from the Terry Anatomical Collection. There were 58 male and 59 female cadavers, all of the white ethnicity, with the average age at death 49 years and a range of 24 to 77 years. A coronal pQCT scan was taken from the midway of the L4 corpus. Sex estimation was performed in a total of 19 neural network architectures implemented in the AIDeveloper software. Of the explored architectures, a LeNet5-based algorithm reached the highest accuracy of 86.4% in the test set. Sex-specific classification rates were 90.9% among males and 81.8% among females. This preliminary finding advances the field by encouraging and directing future research on artificial intelligence-based methods in sex estimation from individual skeletal traits such as the vertebrae. Combining quickly obtained imaging data with automated deep learning algorithms may establish a valuable pipeline for forensic anthropology and provide aid when combined with traditional methods., (© 2023. The Author(s).)

As modern populations are living longer, age-related health issues have become more common. One growing concern is the age-related bone density loss that increases the individual's risk for fractures, which unfortunately seems to disproportionately afflict women. These fractures are not only detrimental to the individuals' lives but also come with a great economic burden to the societies. Although age-related bone loss is a normal phenomenon, studies on archaeological individuals have demonstrated that the pattern how this occurs has experienced changes due to our changing lifestyles. Hence, to add to our understanding of secular trends in age-related bone loss, we studied age- and sex-related differences in vertebral and femoral bone densities of a recent past population of late 19 th and early 20 th century Americans. We used a sample of 114 individuals (55 males, 59 females) from the Robert J. Terry Anatomical Skeletal Collection. Peripheral quantitative computed tomography (pQCT) was used to scan the dry bones. We took one scan from the 4 th lumbar vertebra and three scans from the femur. The associations between the age, sex and bone density were analyzed. We were able to detect age-related bone loss in both vertebra and femur. It was observed that men tended to lose more bone density on the vertebra, whereas bone loss in women was more pronounced in the femur. We speculate that differences to modern and earlier archaeological populations are related to the major lifestyle differences between the periods.

Although knee measurements yield high classification rates in metric sex estimation, there is a paucity of studies exploring the knee in artificial intelligence-based sexing. This proof-of-concept study aimed to develop deep learning algorithms for sex estimation from radiographs of reconstructed cadaver knee joints belonging to the Terry Anatomical Collection. A total of 199 knee radiographs were obtained from 100 skeletons (46 male and 54 female cadavers; mean age at death 64.2 years, range 50-102 years) whose tibiofemoral joints were reconstructed in standard anatomical position. The AIDeveloper software was used to train, validate, and test neural network architectures in sex estimation based on image classification. Of the explored algorithms, an MhNet-based model reached the highest overall testing accuracy of 90.3%. The model was able to classify all females (100.0%) and most males (78.6%) correctly. These preliminary findings encourage further research on artificial intelligence-based methods in sex estimation from the knee joint. Combining radiographic data with automated and externally validated algorithms may establish valuable tools to be utilized in forensic anthropology., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

The death of King Charles XII of Sweden has remained as a mystery for more than three centuries. Was he assassinated by his own men or killed by the enemy fire? Charles was killed by a projectile perforating his skull from left to right. In this study, we utilized a Synbone ballistic skull phantom and modern radiological imaging to clarify the factors behind the observed head injuries. We examined whether a musket ball fired from the enemy lines would be the most potential projectile. Our experiments with a leaden 19.5 mm musket ball demonstrated that at velocities of 200 to 250 m/s, it could cause similar type of injuries as observed in the remains of Charles . The radiological imaging supported the theory that the projectile was not a leaden but of some harder metal, as we could detect remnants of lead inside the wound channel unlike in Charles' case. In addition, our experiments showed that a 19.5mm musket ball  produces max. 17mm hole into a felt material  . The main evidence supporting 19.5 mm projectile size has been a 19-19.5mm bullet hole in a hat that Charles was wearing during his death. Additional experiments with a 25.4 mm steel ball produced approximately 20 mm hole in the felt. As our musket ball experiments also resulted in considerably smaller cranial injuries than those in Charles' case, we can conclude that the deadly projectile wasn't leaden and was more than 19.5 mm in diameter, potentially an iron cartouche ball that was shot from the enemy lines., (© The Author(s) 2022. Published by Oxford University Press on behalf of the National Academy of Sciences.)

Gestation increases the biomechanical loading of lower extremities. Gestational loading may influence anthropometrics of articular surfaces in similar means as bone diaphyseal properties. This study aimed to investigate whether gravidity (i.e. number of pregnancies) and parity (i.e. number of deliveries) is associated with knee breadth among middle-aged women. The study sample comprised 815 women from the Northern Finland Birth Cohort 1966. The median parity count of our sample was 2 and the median gravidity count 3. At the age of 46, questionnaires were used to enquire gravidity and parity, and posteroanterior knee radiographs were used to obtain two knee breadth parameters (tibial plateau mediolateral breadth (TPML) and femoral condylar mediolateral breadth (FCML)) as representatives of articular size. The associations of gravidity and parity with knee breadth were analyzed using general linear models with adjustments for height, weight, leisure-time physical activity, smoking, and education years. Individuals with osteoarthritic changes were excluded from our sample. The mean TPML in our sample was 70.3 mm and the mean FCML 71.6 mm respectively. In the fully adjusted models, gravidity and parity showed positive associations with knee breadth. Each pregnancy was associated with 0.11-0.14% larger knee breath (p < 0.05), and each delivery accounted for an increase of 0.20% in knee breadth (p < 0.01). Between-group comparisons showed that multiparous women had 0.68-1.01% larger knee breath than nulli- and primiparous women (p < 0.05). Pregnancies and deliveries seem to increase the mediolateral breadth of the knee. This increase is potentially associated with increased biomechanical loadings during gestation., (© 2022. The Author(s).)

Background: Articular surface size is traditionally considered to be a relatively stable trait throughout adulthood. Increased joint size reduces bone and cartilage tissue strains. Although physical activity (PA) has a clear association with diaphyseal morphology, the association between PA and articular surface size is yet to be confirmed. This cross-sectional study aimed to clarify the role of moderate-to-vigorous PA (MVPA) in knee morphology in terms of tibiofemoral joint size., Methods: A sample of 1508 individuals from the population-based Northern Finland Birth Cohort 1966 was used. At the age of 46, wrist-worn accelerometers were used to monitor MVPA (≥3.5 METs) during a period of two weeks, and knee radiographs were used to obtain three knee breadth measurements (femoral biepicondylar breadth, mediolateral breadth of femoral condyles, mediolateral breadth of the tibial plateau). The association between MVPA and knee breadth was analyzed using general linear models with adjustments for body mass index, smoking, education years, and accelerometer weartime., Results: Of the sample, 54.8% were women. Most individuals were non-smokers (54.6%) and had 9-12 years of education (69.6%). Mean body mass index was 26.2 (standard deviation 4.3) kg/m 2 . MVPA was uniformly associated with all three knee breadth measurements among both women and men. For each 60 minutes/day of MVPA, the knee breadth dimensions were 1.8-2.0% (or 1.26-1.42 mm) larger among women (p < 0.001) and 1.4-1.6% (or 1.21-1.28 mm) larger among men (p < 0.001)., Conclusions: Higher MVPA is associated with larger tibiofemoral joint size. Our findings indicate that MVPA could potentially increase knee dimensions through similar biomechanical mechanisms it affects diaphyseal morphology, thus offering a potential target in reducing tissue strains and preventing knee problems. Further studies are needed to confirm and investigate the association between articulation area and musculoskeletal health., (© 2022. The Author(s).)

Objectives: Gunshot wounds are frequently studied using computed tomography (CT) to examine tissue damage. In this study, we aimed to test the potential of post-mortem CT (PMCT) in shooting distance estimation at distances 0-100 cm. We hypothesized that in addition to the wound channel, we could also potentially detect tissue damage caused by muzzle pressure on PMCT., Results: A total of 59 gunshot wounds (23 contact shots, 21 close-range shots, 15 distant shots) were inflicted on eight piglet carcasses with a .22 Long Rifle handgun. PMCT scans were obtained using clinical equipment, and they were evaluated for wound characteristics by visual inspection and numeric measurements. In our data, contact shots could be clearly distinguished from close-range and distant shots by a hyperdense ring-shaped area surrounding the outermost part of the wound channel. Close-range and distant shot wounds did not have this feature and were difficult to distinguish from each other. The mean wound channel diameter ranged from 3.4 to 5.4 mm, being smallest in contact shots and largest in distant shots. These preliminary findings suggest that PMCT may aid the estimation of shooting distance. As this study only addressed low velocity gunshot wounds in carcasses, further studies are warranted., (© 2022. The Author(s).)

Objectives: Limb length and trunk proportions are determined in a large, taxonomically and environmentally diverse sample of gorillas and related to variation in locomotion, climate, altitude, and diet., Materials and Methods: The sample includes 299 gorilla skeletons, 115 of which are infants and juveniles, distributed between western lowland (G. gorilla gorilla), low and high elevation grauer (G. beringei graueri), and Virunga mountain gorillas (G. b. beringei). Limb bone and vertebral column lengths scaled to body mass are compared between subgroups by age group., Results: All G. beringei have relatively short 3rd metapodials and manual proximal phalanges compared to G. gorilla, and this difference is apparent in infancy. All G. beringei also have shortened total limb lengths relative to either body mass or vertebral column length, although patterns of variation in individual skeletal elements are more complex, and infants do not display the same patterns as adults. Mountain gorillas have relatively long clavicles, present in infancy, and a relatively long thoracic (but not lumbosacral) vertebral column., Discussion: A variety of environmental factors likely contributed to observed patterns of morphological variation among extant gorillas. We interpret the short hand and foot bones of all G. beringei as genetic adaptations to greater terrestriality in the last common ancestor of G. beringei; variation in other limb lengths to climatic adaptation, both genetic and developmental; and the larger thorax of G. b. beringei to adaptation to reduced oxygen pressure at high altitudes, again as a product of both genetic differences and environmental influences during development., (© 2021 Wiley Periodicals LLC.)

Family's socioeconomic profile collected prenatally is known to predict offspring mortality during early life, but it remains unclear whether it has the potential to predict offspring mortality until later life. In this study, 12,063 individuals belonging to the Northern Finland Birth Cohort 1966 were followed up from mid-pregnancy for 52 years (570,000 person years). Five distinct socioeconomic profiles were identified by latent class analysis based on mother's marital status, education, and occupation; father's occupation; number of family members; location of residence, room count, and utilities; and family's wealth. The classes were highest status families (15.4% of the population), small families (22.1%), larger families (15.4%), average wealth families (23.4%), and rural families (23.3%). Their associations to offspring mortality, via linkage to national offspring death records, were analysed by Cox regression, stratified by sex and age groups (0-19, 20-38 and 40-52 years). In total, mortality was 9.2% among male and 5.0% among female offspring. Risk for midlife mortality was higher among male offspring from larger families (hazard ratio 2.19, 95% confidence interval 1.32-3.63), average wealth families (1.66, 1.02-2.73) and rural families (1.63, 1.00-2.68), relative to offspring from highest status families. It seems that family's socioeconomic profile constructed prenatally has predictive value for midlife mortality among male offspring. Premature mortality of men and women seem to be two distinct phenomena with differing underlying factors as socioeconomic profile was not associated with mortality among female offspring., (Copyright © 2021. Published by Elsevier Inc.)

Little is known about the potential of artificial intelligence in forensic shotgun pattern interpretation. As shooting distance is among the main factors behind shotgun patterning, this proof-of-concept study aimed to explore the potential of neural net architectures to correctly classify shotgun pattern images in terms of shooting distance. The study material comprised a total of 106 shotgun pattern images from two discrete shooting distances (n = 54 images from 10 m and n = 52 images from 17.5 m) recorded on blank white paper. The dataset was used to train, validate and test deep learning algorithms to correctly classify images in terms of shooting distance. The open source AIDeveloper software was used for the deep learning procedure. In this dataset, a TinyResNet-based algorithm reached the highest testing accuracy of 94%. Of the testing set, the algorithm classified all 10 m patterns correctly, and misclassified one 17.5 m pattern. On the basis of these preliminary data, it seems achievable to develop algorithms that would serve as a beneficial tool for forensic investigators when estimating shooting distances from shotgun patterns. In the future, studies with larger and more complex datasets are needed to develop robust and applicable algorithms for forensic shotgun pattern interpretation., (Copyright © 2021 Elsevier B.V. All rights reserved.)

While the applications of deep learning are considered revolutionary within several medical specialties, forensic applications have been scarce despite the visual nature of the field. For example, a forensic pathologist may benefit from deep learning-based tools in gunshot wound interpretation. This proof-of-concept study aimed to test the hypothesis that trained neural network architectures have potential to predict shooting distance class on the basis of a simple photograph of the gunshot wound. A dataset of 204 gunshot wound images (60 negative controls, 50 contact shots, 49 close-range shots, and 45 distant shots) was constructed on the basis of nineteen piglet carcasses fired with a .22 Long Rifle pistol. The dataset was used to train, validate, and test the ability of neural net architectures to correctly classify images on the basis of shooting distance. Deep learning was performed using the AIDeveloper open-source software. Of the explored neural network architectures, a trained multilayer perceptron based model (MLP&#95;24&#95;16&#95;24) reached the highest testing accuracy of 98%. Of the testing set, the trained model was able to correctly classify all negative controls, contact shots, and close-range shots, whereas one distant shot was misclassified. Our study clearly demonstrated that in the future, forensic pathologists may benefit from deep learning-based tools in gunshot wound interpretation. With these data, we seek to provide an initial impetus for larger-scale research on deep learning approaches in forensic wound interpretation., (© 2021. The Author(s).)

Sex estimation is an important part of osteological analysis of skeletons and forensic identification process. Traditionally cranial and pelvic traits are utilized for accurate sex estimation. However, post-cranial measurements have also been proven to accurately estimate sex especially from robust bones such as the femur. In this study, we investigated the potential of knee breadth dimensions in sex estimation in a Finnish population. To conduct this study we utilized a study sample (n = 1654) belonging to the Northern Finland Birth Cohort 1966. All individuals were 46 years of age at the time of the examination. Three knee breadth dimensions were measured from subjects' knee posteroanterior radiographs: femoral biepicondylar breadth (FBEB), mediolateral breadth of the femoral condyles (FCML), and mediolateral breadth of the tibial plateau (TPML). Sex estimation was performed using logistic regression. The study clearly demonstrated that all three measurements were different between males and females. Sectioning points for individual knee breadth measurements were 82.9 mm for FBEB, 76.6 mm for FCML and 75.4 mm for TPML. The classification rates ranged from 90.9% to 93.6%. The less commonly used measurements of FCML and TPML showed higher accuracy than FBEB in sex estimation. Our study confirmed that knee breadths can be successfully utilized to improve sex estimation in cases where the skeleton is only partially preserved and other major components of sex estimation are absent. We can also provide new standards for sex estimation from the knee joint in a Finnish population., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Small vertebral size is a well-known risk factor for vertebral fractures. To help understanding the factors behind vertebral size, we aimed to investigate whether physical activity and participation in high-impact exercise are associated with the growth rate of the vertebral cross-sectional area (CSA) among young adults. To conduct our study, we utilized the Northern Finland Birth Cohort 1986 as our study population ( n  = 375). Questionnaire data about physical activity was obtained at 16, 18 and 19 years of age and lumbar magnetic resonance imaging scans at two timepoints, 20 and 30 years of age. We used generalized estimating equation (GEE) models to conduct the analyses. We did not find any statistically significant associations between vertebral CSA, physical activity, and high-impact exercise in our study sample. We conclude that neither physical activity nor high-impact sports seem to influence the change in vertebral CSA among young adults., Competing Interests: The authors have no conflict of interest., (© 2021 The Authors. Published by Elsevier Inc.)

Study Design: Population-based birth cohort study., Objective: The aim of this study was to evaluate the relationship between vertebral dimensions and lumbar MC., Summary of Background Data: Low back pain (LBP) has become the leading cause of disability worldwide. Modic changes (MC) of the lumbar spine are one potential LBP-associated etiological factor. Mechanical stress is considered to play a key role in the development of MC through damage to endplates. There is speculation that vertebral dimensions play a role in some degenerative changes in the spine. Previous studies have also shown a positive association between moderate-to-vigorous physical activity (MVPA) and both vertebral dimensions and MC. In this study, we aimed to evaluate the relationship between vertebral dimensions and MC., Methods: The study population consisted of 1221 participants from the Northern Finland Birth Cohort 1966 who underwent lumbar magnetic resonance imaging (MRI) and physical activity measurements at the age of 46-48. The presence of Type 1 (MC1) and Type 2 (MC2) MC and the height, axial cross-sectional area (CSA), and volume of the L4 vertebra were determined from MRI scans. MVPA (≥3.5 metabolic equivalents) was measured by a wrist-worn accelerometer. We analyzed the association between lumbar MC and vertebral height, CSA, and volume using logistic regression models before and after adjustment for sex, height, weight, smoking, education level, and MVPA., Results: Vertebral height was positively associated with the presence of MC2 (odds ratio [OR] 3.51; 95% confidence interval [CI] 1.43-8.65), whereas vertebral CSA was not associated with the presence of lumbar MC. Vertebral volume was positively associated with the presence of any MC (OR 1.04; 95% CI 1.00-1.07), but the association did not persist when analyzing MC1 and MC2 separately., Conclusion: Vertebral height was associated with the presence of MC2. Further studies are needed to clarify the role of vertebral dimensions as independent risk factors for MC.Level of Evidence: 3., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

The Finnish population has a long life expectancy but ranks high in unnatural deaths on the European scale. Mortality has historical regional discrepancy in Finland, as Northern Finns are overrepresented in both natural and unnatural deaths. This study aimed to characterize the age- and sex-related trends in unnatural mortality among Northern Finns. Altogether 12 143 individuals, constituting >95% of births in Northern Finland in 1966, were followed up for a median of 52 years. The mortality patterns of this population were studied using death record data. Crude annual mortality rates were calculated and graphed for 10-year age strata (all-cause, natural-cause, and unnatural-cause mortality, as well as accident, suicide, and homicide mortality). Cox regression was used to analyze the sex discrepancy in mortality. A total of 874 deaths (7.2%) occurred during the follow-up period. Women had 47% and 73% lower risks of any death and unnatural death than men, respectively. From the second decade of life onwards, the unnatural mortality of men was 3-5 times that of women. Accident and suicide mortality rates of men were 2-13 and 2-3 times those of women, respectively. Homicides were rare among either sex. We conclude that Northern Finnish women have a substantially lower risk of all-cause mortality and unnatural mortality than men. To aid the development of preventive strategies, future studies should aim to identify the underlying factors behind unnatural mortality. Primarily, emphasis should be placed on the increased mortality of men from the second decade of life onwards., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Author(s).)

Bone loss and heightened fracture risk are common conditions associated with ageing in modern human populations and have been attributed to both hormonal and other metabolic and behavioural changes. To what extent these age-related trends are specific to modern humans or generally characteristic of natural populations of other taxa is not clear. In this study, we use computed tomography to examine age changes in long bone and vertebral structural properties of 34 wild-adult Virunga mountain gorillas ( Gorilla beringei beringei ) whose skeletons were recovered from natural accumulations. Chronological ages were known or estimated from sample-specific dental wear formulae and ranged between 11 and 43 years. Gorillas show some of the same characteristics of skeletal ageing as modern humans, including endosteal and some periosteal expansion. However, unlike in humans, there is no decline in cortical or trabecular bone density, or in combined geometric-density measures of strength, nor do females show accelerated bone loss later in life. We attribute these differences to the lack of an extended post-reproductive period in gorillas, which provides protection against bone resorption. Increases in age-related fractures (osteoporosis) in modern humans may be a combined effect of an extended lifespan and lower activity levels earlier in life. This article is part of the theme issue 'Evolution of the primate ageing process'.

Objectives: While many attempts have been made to estimate body mass in hominins from lower limb bone dimensions, the upper limb has received far less attention in this regard. Here we develop new body mass estimation equations based on humeral articular breadths in a large modern human sample and apply them to 95 Plio-Pleistocene specimens., Materials and Methods: Humeral head superoinferior and total distal articular mediolateral breadths were measured in a morphologically diverse sample of 611 modern human skeletons whose body masses were estimated from bi-iliac breadth and reconstructed stature. Reduced major axis regressions were used to compute body mass estimation equations. Consistency of the resulting estimates with those derived previously using lower limb bone equations was assessed in matched Plio-Pleistocene individuals or samples., Results: In the modern reference sample, the new humeral body mass estimation equations exhibit only slightly lower precision compared to the previously derived lower limb bone equations. They give generally similar estimates for Pleistocene Homo, after accounting for the different shape of the humeral head articular surface in archaic Middle and Late Pleistocene Homo, except for distal humeral estimates for Late Pleistocene specimens, which average somewhat below lower limb estimates. Humeral equations give body mass estimates for australopiths that appear much too high, except for Australopithecus sediba. A chimpanzee-based distal humeral articular formula appears to work well for larger australopith specimens., Discussion: The new formulae provide a more secure foundation for estimating hominin body mass from humeri than previously available equations., (© 2020 Wiley Periodicals, Inc.)

Smoking remains among the leading causes of mortality worldwide. Obtaining a comprehensive understanding of a population's smoking behaviour is essential for tobacco control. Here, we aim to characterize lifelong smoking patterns and explore underlying sociodemographic and lifestyle factors in a population-based birth cohort population followed up for 46 years. Our analysis is based on 5797 individuals from the Northern Finland Birth Cohort 1966 who self-reported their tobacco smoking behaviour at the ages of 14, 31 and 46. Data on sex, education, employment, body mass index, physical activity, alcohol consumption, and substance addiction were also collected at the follow-ups. We profile each individual's annual smoking history from the age of 5 to 47, and conduct a latent class trajectory analysis on the data. We then characterize the identified smoking trajectory classes in terms of the background variables, and compare the heaviest smokers with other classes in order to reveal specific predictors of non-smoking and discontinued smoking. Six smoking trajectories are identified in our sample: never-smokers (class size 41.0%), youth smokers (12.6%), young adult quitters (10.8%), late adult quitters (10.5%), late starters (4.3%), and lifetime smokers (20.7%). Smoking is generally associated with male sex, lower socioeconomic status and unhealthier lifestyle. Multivariable between-class comparisons identify unemployment (odds ratio [OR] 1.28-1.45) and physical inactivity (OR 1.20-1.52) as significant predictors of lifetime smoking relative to any other class. Female sex increases the odds of never-smoking and youth smoking (OR 1.29-1.33), and male sex increases the odds of adult quitting (OR 1.30-1.41), relative to lifetime smoking. We expect future initiatives to benefit from our data by exploiting the identified predictors as direct targets of intervention, or as a means of identifying individuals who may benefit from such interventions.

Background: Modic changes (MC) in the lumbar spine are considered one potential etiological factor behind low back pain (LBP). Multiple risk factors for MC have been suggested, including male gender, smoking and factors affecting hyperloading and mechanical stress such as high body mass index (BMI), strenuous physical work and high occupational and leisure-time physical activity (PA). So far, the effect of PA on the occurrence of MC has remained under debate due to contradictory findings. The purpose of this study was to investigate the possible association between device-measured moderate-to-vigorous PA (MVPA) (≥ 3.5 METs) and lumbar MC., Methods: The study had 1374 participants from the Northern Finland Birth Cohort 1966. At the age of 46-48, PA was measured by a wrist-worn accelerometer, and lumbar magnetic resonance imaging (MRI) was carried out to determine MC. We analyzed the association between Type 1 (MC1) and Type 2 (MC2) MC and daily amount of MVPA (min/day) using sex-stratified logistic regression models before and after adjustment for BMI, socioeconomic status, smoking, and accelerometer wear time., Results: Among men, increased amount of MVPA was positively associated with any MC (adjusted OR corresponding to every 60 min/day of MVPA 1.41; 95% confidence interval (CI) 1.01 to 1.95) and MC2 (OR 1.54; 95% CI 1.14 to 2.08), but not with MC1 (OR 1.06; 95% CI 0.80 to 1.39). Among women, we only found a positive association between MVPA and MC1 before adjustments (unadjusted OR 1.42; 95% CI 1.06 to 1.92)., Conclusion: Among men, increased amount of MVPA was associated with increased odds of any MC and particularly MC2. Among women, MVPA was not independently associated with MC.

The vertebral cross-sectional area (CSA) has an independent effect on vertebral strength. Recent evidence has shown that vertebral dimensions significantly increase in the third decade of life, and that lifestyle factors such as body size and composition are clearly associated with vertebral CSA. This study aimed to test the hypothesis that general anthropometric traits (stature, total body mass, lean body mass, fat mass, body mass index, waist circumference), each objectively measured at baseline, predict the change in vertebral CSA over the subsequent decade. A representative sample of young Northern Finnish adults was used (n = 371) with repeated magnetic resonance imaging (MRI) scans from ~20 and ~30 years (baseline and follow-up, respectively). Vertebral CSA was measured from the MRI scans with high reliability and low measurement error. The statistical analysis was performed using linear regression models adjusted for sex and exact length of MRI interval. According to the regression models, in descending order of effect size, lean body mass (standardized beta coefficient 0.243 [95% confidence interval 0.065-0.420]), total body mass (0.158 [0.043-0.273]), body mass index (0.125 [0.026-0.224]), waist circumference (0.119 [0.010-0.228]), and fat mass (0.104 [0.004-0.205]) were positively and significantly associated with CSA gain over the follow-up, whereas stature (0.079 [-0.066-0.224]) was not associated with CSA change. The results of this study suggest that anthropometric indices may be used for estimating subsequent change in vertebral size. In particular, greater lean body mass seems to be beneficial for vertebral size and thus potentially also for vertebral strength. Future studies should aim to replicate these associations in a dataset with longitudinal anthropometric trajectories and identify the potential common factors that influence both anthropometric traits and vertebral CSA gain., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Anatomical stature estimation methods reconstruct stature for skeletal specimens by adding up the heights of skeletal elements contributing to stature. In addition, these estimations factor in a certain amount of soft tissue known as "soft tissue correction". Our study focuses on the relationship between living stature and one of the major soft tissue contributors to stature: the intervertebral disc thickness/height. The purpose of this study was to clarify whether intervertebral disc thickness is greater in tall individuals and whether there is a linear correlation between stature and intervertebral disc height. To conduct this study, we utilized a subsample of the Northern Finland Birth Cohort of 1966 (n = 12,058) with known stature. We measured vertebral heights and intervertebral disc heights from low back MRI examination performed at the age of 46 years (n = 200). All subjects were considered healthy with no spinal injuries or pathologies. Our results clearly indicate that stature and intervertebral disc height have positive, statistically significant association. According to our results it is advisable to take into account the individual's skeletal height when soft tissue corrections for anatomical stature estimations are performed. Further studies utilizing full body MRI are needed to produce more accurate soft tissue corrections.

Vertebral fractures and other back problems represent a major, increasing worldwide health problem. This has increased the need to better understand the reasons behind this phenomenon. In addition to a reduction in bone mineral density and overall size of the vertebral body, research has indicated a possible association between the shape of the endplate and spinal disorders. As one previous study has shown changes in vertebral body dimensions between contemporary people and their medieval counterparts, we wanted to examine the potential temporal trends in vertebral size and dimensions in Finnish samples of archaeological and contemporary individuals. To conduct this study, we utilized three archaeological populations from the 16 th -19 th century and clinical materials from two population-based Finnish birth cohorts. As the average height of people has increased greatly since the first time period, we also height-adjusted the dimensions to provide a clearer picture of the dimensional changes that have occurred in the later temporal group. Our results were in agreement with those of the earlier study. The archaeological samples had a larger vertebral size than the contemporary population when height was adjusted for. Vertebral mediolateral width in particular had decreased, and the shape of the vertebral body had changed.

Only a few previous studies have investigated paraspinal musculature (i.e., multifidus (MF), psoas major (PSM), erector spinae (ES)) in longitudinal, population-based settings. This study aimed to evaluate changes in the cross-sectional area (CSA) of the paraspinal muscles between the ages of 20 and 30 years. The study population consisted of a sub-cohort from the Northern Finland Birth Cohort 1986 (n = 298; 156 men, 142 women). Baseline magnetic resonance imaging was performed at a mean age of 21.3 years and follow-up imaging at 30.6 years. The CSA measurements were performed by tracing the paraspinal muscle outlines individually (MF, ES, PM) and all combined (total muscle area (TMA)) at the L4 cranial endplate level. The longitudinal data analysis was performed using generalized estimating equations modelling. The CSA of MF and ES increased during the follow-up among both sexes (men: MF + 5.7%, p < 0.001; ES + 2.7%, p = 0.001; and women: MF + 10.5%, p < 0.001; ES 9.2%, p = 0.001). The CSA of PM decreased among men (PM -4.0%, p < 0.001) but not among women (PM + 0.5%, p = 0.553). TMA increased significantly only among women (men: +0.5%, p = 0.425; women: +6.5%, p < 0.001). The increases in ES and TMA were more distinct among women than men (p < 0.001). Our study demonstrated clear age- and sex-related changes in paraspinal muscle size in early adulthood.

Objectives: Body mass estimation from skeletal dimensions is a useful tool when studying archeological human samples. Bony articular surface dimensions of the lower limb have frequently been utilized to estimate body size. In the present study, we investigated the association between knee breadth and body mass in a Northern European population. Our study aimed to confirm both methodology and results presented in earlier studies., Materials and Methods: The study sample consists of 1,290 subjects belonging to the Northern Finland Birth Cohort 1966. Three knee breadth dimensions-femoral biepicondylar breadth, mediolateral breadth of femoral condyles, and mediolateral breadth of the tibial plateau-were measured from subjects' knee PA-radiographs. Measurements and their association with body weight at 31 years were utilized for creating body mass estimation equations using linear regression and reduced major axis regression. Correlations between knee measurements and body weight at three different ages (18, 31, and 46) were also analyzed., Results: Positive associations were detected between each knee breadth variable and weight in the total sample and both genders separately. Body mass estimation equations were created for the total sample, for males and for females. R values of the models ranged from 0.38 to 0.74. Median absolute percent prediction errors ranged from 6.89 to 9.72%. The highest correlations were obtained between knee breadth and body weight in early adulthood., Discussion: Our large sample confirmed that equations derived from knee breadth dimensions are accurate when estimating body mass of modern humans. Knee breadth measurements clearly have a positive association with body weight in early maturity., (© 2019 Wiley Periodicals, Inc.)

Although body mass is not a stable trait over the lifespan, information regarding body size assists the forensic identification of unknown individuals. In this study, we aimed to study the potential of using the fourth lumbar vertebra (L4) for body mass estimation among contemporary Finns. Our sample comprised 1158 individuals from the Northern Finland Birth Cohort 1966 who had undergone measurements of body mass at age 31 and 46 and lumbar magnetic resonance imaging (MRI) at age 46. MRI scans were used to measure the maximum and minimum widths, depths, and heights of the L4 body. Their means and sum were calculated together with vertebral cross-sectional area (CSA) and volume. Ordinary least squares (OLS) and reduced major axis (RMA) regression was used to produce equations for body mass among the full sample (n = 1158) and among normal-weight individuals (n = 420). In our data, body mass was associated with all the L4 size parameters (R = 0.093-0.582, p ≤ 0.019 among the full sample; R = 0.243-0.696, p ≤ 0.002 among the normal-weight sample). RMA regression models seemed to fit the data better than OLS, with vertebral CSA having the highest predictive value in body mass estimation. In the full sample, the lowest standard errors were 6.1% (95% prediction interval ±9.6 kg) and 7.1% (±9.1 kg) among men and women, respectively. In the normal-weight sample, the lowest errors were 4.9% (±6.9 kg) and 4.7% (±5.7 kg) among men and women, respectively. Our results indicate that L4 dimensions are potentially useful in body mass estimation, especially in cases with only the axial skeleton available., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Vertebral fractures reduce the quality of life and are a major burden to the health care sector. Small vertebral size is associated with increased vertebral fracture risk. Previous studies have investigated the relationship between physical activity (PA) and vertebral size, but their results seem somewhat contradictory. In this population-based birth cohort study, we aimed to evaluate the relationship between objectively measured PA and vertebral size., Methods: The study population consisted of 1202 cohort participants who underwent PA and vertebral size measurements at the age of 46 to 48 yr. Moderate-to-vigorous PA (MVPA, ≥3.5 METs) was measured by a wrist-worn accelerometer (Polar Active; Polar Electro, Finland) for 14 d. The vertebral axial cross-sectional area (CSA) of the L4 vertebra was measured and calculated from lumbar magnetic resonance imaging scans at 46 to 48 yr. We analyzed the association between the daily amount of MVPA (min·d) and vertebral CSA using multivariable linear regression analysis., Results: The daily amount of MVPA was significantly and positively associated with CSA in both sexes. For every minute per day of MVPA, men had 0.71 mm (95% confidence interval, 0.36-1.06) and women 0.90 mm (95% confidence interval, 0.58-1.21) larger CSA., Conclusions: Physical activity of at least moderate intensity is positively associated with vertebral size and may thus prevent future vertebral fractures.

Among a representative sample of 1064 Northern Finns, we studied the association of dairy- and supplement-based calcium intake in adulthood with vertebral size in midlife. Inadequate calcium intake (< 800 mg/day) from age 31 to 46 predicted small vertebral size and thus decreased spinal resilience among women but not men., Introduction: Small vertebral size predisposes individuals to fractures, which are common among aging populations. Although previous studies have associated calcium (Ca) intake with enhanced bone geometry in the appendicular skeleton, few reports have addressed the axial skeleton or the vertebrae in particular. We aimed to investigate the association of dairy- and supplement-based Ca intake in adulthood with vertebral cross-sectional area (CSA) in midlife., Methods: A sample of 1064 individuals from the Northern Finland Birth Cohort 1966 had undergone lumbar magnetic resonance imaging at the age of 46, and provided self-reported data on diet and Ca intake (dairy consumption and use of Ca supplements) at the ages of 31 and 46. We assessed the association between Ca intake (both continuous and categorized according to local recommended daily intake) and vertebral CSA, using generalized estimating equation and linear regression models with adjustments for body mass index, diet, vitamin D intake, education, leisure-time physical activity, and smoking., Results: Women with inadequate Ca intake (< 800 mg/day) over the follow-up had 3.8% smaller midlife vertebral CSA than women with adequate Ca intake (p = 0.009). Ca intake among men showed no association with vertebral CSA., Conclusions: Inadequate Ca intake (< 800 mg/day) from the age of 31 to 46 predicts small vertebral size and thus decreased spinal resilience among middle-aged women. Future studies should confirm these findings and investigate the factors underlying the association of low Ca intake in women but not in men with smaller vertebral size.

Previous studies have shown that vertebral height increases until the early twenties, but very few studies have been conducted on other vertebral dimensions. Growth in vertebral size is believed to take place in elderly age but not in early adulthood. In this study, we wanted to clarify the potential changes in the dimensions of the lumbar vertebrae during early adulthood. We used the Northern Finland Birth Cohort 1986 as our study material, with a final sample size of 375 individuals. We performed lumbar magnetic resonance imaging (MRI) when the participants were 20 and 30 years of age (baseline and follow-up, respectively). We recorded the width, depth, height, and cross-sectional area (CSA) of the fourth lumbar vertebra (L4) using the MRI scans. We used generalized estimating equation (GEE) models to analyse the data. Men had 7.6%-26.5% larger vertebral dimensions than women at both baseline and follow-up. The GEE models demonstrated that all the studied dimensions increased during the follow-up period among both sexes (p < 0.001). Men had a higher growth rate in vertebral depth and CSA than women (p < 0.001). Among women, small vertebral width (p = 0.001), depth (p = 0.05) and height (p = 0.02) at baseline were associated with a higher vertebral growth rate during the follow-up than among those with large dimensions at baseline. Among men, small baseline width was associated with higher vertebral growth rate (p = 0.001). Our results clearly indicate that vertebral dimensions increase after 20 years of age among both sexes., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Small vertebral size increases the risk of osteoporotic vertebral fractures. Obese individuals have larger vertebral size and potentially lower fracture risk than lean individuals, but scarce data exist on the association between vertebral size and anthropometric measures beyond height, weight, and body mass index (BMI). Here, we evaluated several anthropometric measures (height, weight, BMI, waist circumference, hip circumference, waist-to-hip ratio [WHR], waist-to-height ratio [WHtR], fat mass [FM], lean body mass [LBM], percentage FM [%FM], percentage LBM [%LBM]) as predictors of vertebral cross-sectional area (CSA). We used a representative sample from the Northern Finland Birth Cohort 1966 (n = 1087), with anthropometric measurements from the ages of 31 and 46, bioimpedance analysis from the age of 46, and lumbar magnetic resonance imaging from the age of 46 years. In our data, height and LBM correlated most strongly with vertebral CSA among both sexes (0.469 ≤ r ≤ 0.514), while WHR, WHtR, %FM, and %LBM had the weakest correlations with vertebral CSA (|r| ≤ 0.114). We conclude that height and LBM have the highest, yet only moderate correlations with vertebral size. High absolute LBM, rather than FM or abdominal mass accumulation, correlates with large vertebral size and thus potentially also with lower osteoporotic vertebral fracture risk.

Background: Accurate stature estimation plays an essential role in the identification of unknown deceased individuals. For cases in which conventional methods of stature estimation are not applicable, we studied the stature estimation potential of the fourth lumbar vertebra (L4) among a large living sample of representative contemporary Finns. We also generated stature estimation equations for the middle-aged Finnish population., Material and Methods: Our study population comprised the Northern Finland Birth Cohort 1966 for which lumbar magnetic resonance imaging (MRI) scans and objective measurements of stature were available from midlife (n=1358). After screening the MRI scans for vertebral pathologies, we measured the maximum and minimum widths, depths and heights of the L4 body with high precision and reliability. We then calculated their sums and means together with approximations of vertebral cross-sectional area and volume. By constructing simple and multiple linear regression models around the L4 parameters, we generated equations for stature prediction, and investigated their accuracy on the basis of the adjusted R squared (R 2 ) and standard error of the estimate (SEE) values of the models., Results: The multiple linear regression models of the mean width, depth and height of L4 yielded the highest prediction accuracies with the lowest prediction errors (for the entire sample, R 2 =0.621 and SEE=5.635cm; for men, R 2 =0.306 and SEE=5.125cm; for women, R 2 =0.367 and SEE=4.640cm)., Conclusion: When conventional methods for estimating stature are not applicable, the lumbar vertebrae may be utilized for this purpose. Relatively accurate stature estimates can be given on the basis of only L4 dimensions., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objectives: A number of studies have demonstrated the ontogenetic plasticity of long bone diaphyseal structure in response to mechanical loading. Captivity should affect mechanical loading of the limbs, but whether captive apes grow differently than wild apes has been debated. Here, we compare captive and wild juvenile and adult Gorilla to ascertain whether growth trajectories in cross-sectional diaphyseal shape are similar in the two environments., Materials and Methods: A sample of young juvenile (n = 4) and adult (n = 10) captive Gorilla gorilla gorilla specimens, with known life histories, were compared with age-matched wild G.g. gorilla (n = 62) and G. beringei beringei (n = 75) in relative anteroposterior to mediolateral bending strength of the femur, tibia, and humerus. Cross sections were obtained using peripheral quantitative CT., Results: Captive and wild adult G.g. gorilla differed in bending strength ratios for all three bones, but these differences were not present in young juvenile G.g. gorilla. In comparisons across taxa, captive juvenile G.g. gorilla were more similar to wild G.g. gorilla than to G.b. beringei, while captive adult G.g. gorilla were more similar in shape to G.b. beringei in the hind limb., Discussion: Captive and wild G. gorilla follow different ontogenetic trajectories in long bone diaphyseal shape, corresponding to environmental differences and subsequent modified locomotor behaviors. Differences related to phylogeny are most evident early in development., (© 2018 Wiley Periodicals, Inc.)

Study Design: A population-based birth cohort study., Objective: To investigate the association between gravidity, parity, and vertebral geometry among middle-aged women., Summary of Background Data: Vertebral size is a recognized determinant of vertebral fracture risk. Yet, only a few lifestyle factors that influence vertebral size are known. Pregnancy is a labile period that may affect the maternal vertebral size or shape. The lumbar lordosis angle is permanently deepened by pregnancy, but it remains unclear whether vertebral shape or size contribute to this deepened angle., Methods: We aimed to investigate whether gravidity and parity were associated with vertebral cross-sectional area (CSA) and height ratio (anterior height to posterior height) among 705 middle-aged women from the Northern Finland Birth Cohort 1966. We measured the corpus of their fourth lumbar vertebra using magnetic resonance imaging of the lumbar spine at the age of 46. Gravidity and parity were elicited using a questionnaire also at the age of 46. Linear regression analysis was used with adjustments for body mass index, vertebral CSA (height ratio models), and vertebral height (CSA models). We also ran a subgroup analysis that did not include nulliparous women, and we compared nulliparous women with grand multiparous women., Results: The models found no statistically significant associations between the predictors and outcomes. Crude and adjusted results were highly similar, and the subgroup analyses provided analogous results., Conclusion: Pregnancy, or even multiple pregnancies, do not seem to have long-term effects on vertebral geometry. In order to enhance the prevention of vertebral fractures, future studies should aim to reveal more lifestyle determinants of vertebral size., Level of Evidence: 3.

Background: Accurate sex estimation (sexing) is crucial for successful forensic identification. For the cases in which only a part of the skeleton or individual skeletal elements are available, we investigated the sex estimation potential of the fourth lumbar vertebra (L4) among 20-, 30-, and 46-year-old Northern Finns., Material and Methods: Magnetic resonance imaging scanned living subsamples of the Northern Finland Birth Cohort 1966 (scan at 46years, n=1363) and the Northern Finland Birth Cohort 1986 (repeated scans at 20 and 30years, n=375) provided the material for the study. After screening the scans for vertebral pathologies, we measured the maximum and minimum widths, depths, and heights of the L4 body. The mean vertebral width, depth and height were calculated together with vertebral cross-sectional area and volume. Sex estimations were performed using univariate and multivariate logistic regression analysis., Results: We detected marked sex discrepancy in all the studied parameters of L4 (p<0.001). In the groups aged 20, 30, and 46years, the regression models reached correct sex estimation rates of 86.4%, 87.7%, and 82.8%, respectively. At each time point, multivariate models proved more accurate than univariate models. Men showed consistently lower correct sex estimation rates than women., Conclusion: Among 20-, 30-, and 46year-old Finns, combining the measurements of width, depth, and height of the L4 body can be used to estimate sex with an accuracy of >80%. Vertebral width, depth, and height seem to yield as accurate sex estimates as more complicated vertebral parameters., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Vertebral fracture risk is higher among individuals with small vertebral dimensions. Obesity is a global health problem and may also contribute to bone size and fracture risk. In this work we report the association between life course body mass index (BMI) and vertebral cross-sectional area (CSA) in midlife. The Northern Finland Birth Cohort 1966 study with its 46-year follow-up provided the material for this study. A subsample of 780 individuals had attended lumbar magnetic resonance imaging (MRI) at the age of 46 years, and had records of objectively measured BMI from the ages of 0, 7, 15, 31, and 46 years. Of these, MRI-derived data on vertebral size was available for 682 individuals. We identified latent lifelong BMI trajectories by performing latent class growth modeling (LCGM) on the BMI data, and then used sex-stratified linear regression models to compare the identified trajectory groups in terms of midlife vertebral CSA. Gestational age, education years, adult height, lifelong physical activity, lifelong smoking history, and adulthood diet were assessed as potential confounders. Three distinct trajectory groups ("stable slim," "stable average," and "early onset overweight") were identified among both sexes. Comparisons to the stable slim trajectory revealed that vertebral CSA was significantly ( p  < 0.001) larger among the stable average and early onset overweight trajectories (69.8 and 118.6 mm 2 larger among men, 57.7 and 106.1 mm 2 larger among women, respectively). We conclude that lifelong BMI has a positive association with midlife vertebral size among both sexes. Future studies should characterize the mediating factors of this association., (© 2018 American Society for Bone and Mineral Research.)

We report possibly the oldest evidence of gynecomastia in mummified human remains. Computed tomography was performed on the mummified remains of an early 17th century Northern Finnish vicar. The examination of the scans revealed large bilateral subareolar irregular masses resembling female mammary glands. The nearly septuagenarian vicar appears to have had gynecomastia, as it is a common condition in elderly men, and is sometimes associated with obesity. Gynecomastia is the most likely explanation for these findings. Clin. Anat. 31:641-644, 2018. © 2018 Wiley Periodicals, Inc., (© 2018 Wiley Periodicals, Inc.)

Objectives: The effects of phylogeny and locomotor behavior on long bone structural proportions are assessed through comparisons between adult and ontogenetic samples of extant gorillas., Materials and Methods: A total of 281 wild-collected individuals were included in the study, divided into four groups that vary taxonomically and ecologically: western lowland gorillas (G. g. gorilla), lowland and highland grauer gorillas (G. b. graueri), and Virunga mountain gorillas (G. b. beringei). Lengths and articular breadths of the major long bones (except the fibula) were measured, and diaphyseal cross-sectional geometric properties determined using computed tomography. Ages of immature specimens (n = 145) were known or estimated from dental development. Differences between groups in hind limb to forelimb proportions were assessed in both adults and during development., Results: Diaphyseal strength proportions among adults vary in parallel with behavioral/ecological differences, and not phylogeny. The more arboreal western lowland and lowland grauer gorillas have relatively stronger forelimbs than the more terrestrial Virunga mountain gorillas, while the behaviorally intermediate highland grauer gorillas have intermediate proportions. Diaphyseal strength proportions are similar in young infants but diverge after 2 years of age in western lowland and mountain gorillas, at the same time that changes in locomotor behavior occur. There are no differences between groups in length or articular proportions among either adults or immature individuals., Conclusion: Long bone diaphyseal strength proportions in gorillas are developmentally plastic, reflecting behavior, while length and articular proportions are much more genetically canalized. These findings have implications for interpreting morphological variation among fossil taxa., (© 2018 Wiley Periodicals, Inc.)

Previous attempts to estimate body mass in pre-Holocene hominins have relied on prediction equations derived from relatively limited extant samples. Here we derive new equations to predict body mass from femoral head breadth and proximal tibial plateau breadth based on a large and diverse sample of modern humans (avoiding the problems associated with using diaphyseal dimensions and/or cadaveric reference samples). In addition, an adjustment for the relatively small femoral heads of non-Homo taxa is developed based on observed differences in hip to knee joint scaling. Body mass is then estimated for 214 terminal Miocene through Pleistocene hominin specimens. Mean body masses for non-Homo taxa range between 39 and 49 kg (39-45 kg if sex-specific means are averaged), with no consistent temporal trend (6-1.85 Ma). Mean body mass increases in early Homo (2.04-1.77 Ma) to 55-59 kg, and then again dramatically in Homo erectus and later archaic middle Pleistocene Homo, to about 70 kg. The same average body mass is maintained in late Pleistocene archaic Homo and early anatomically modern humans through the early/middle Upper Paleolithic (0.024 Ma), only declining in the late Upper Paleolithic, with regional variation. Sexual dimorphism in body mass is greatest in Australopithecus afarensis (log[male/female] = 1.54), declines in Australopithecus africanus and Paranthropus robustus (log ratio 1.36), and then again in early Homo and middle and late Pleistocene archaic Homo (log ratio 1.20-1.27), although it remains somewhat elevated above that of living and middle/late Pleistocene anatomically modern humans (log ratio about 1.15)., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Femoral head breadth is widely used in body mass estimation in biological anthropology. Earlier research has demonstrated that reduced major axis (RMA) equations perform better than least squares (LS) equations. Although a simple RMA equation to estimate body size from femoral head breadth is sufficient in most cases, our experiments with male skeletons from European data (including late Pleistocene and Holocene skeletal samples) and the Forensic Anthropology Data Bank data (including the W. M. Bass Donated Skeletal Collection sample) show that including femoral length or anatomically estimated stature in an equation with femoral head breadth improves body mass estimation precision. More specifically, although directional bias related to body mass is not reduced within specific samples, the total estimation error range, directional bias related to stature, and temporal fluctuation in estimation error are markedly reduced. The overall body mass estimation precision of individuals representing different temporal periods and ancestry groups (e.g., African and European ancestry) is thus improved., (Copyright © 2017. Published by Elsevier Ltd.)

The stature/bi-iliac breadth method provides reasonably precise, skeletal frame size (SFS) based body mass (BM) estimations across adults as a whole. In this study, we examine the potential effects of age changes in anthropometric dimensions on the estimation accuracy of SFS-based body mass estimation. We use anthropometric data from the literature and our own skeletal data from two osteological collections to study effects of age on stature, bi-iliac breadth, body mass, and body composition, as they are major components behind body size and body size estimations. We focus on males, as relevant longitudinal data are based on male study samples. As a general rule, lean body mass (LBM) increases through adolescence and early adulthood until people are aged in their 30s or 40s, and starts to decline in the late 40s or early 50s. Fat mass (FM) tends to increase until the mid-50s and declines thereafter, but in more mobile traditional societies it may decline throughout adult life. Because BM is the sum of LBM and FM, it exhibits a curvilinear age-related pattern in all societies. Skeletal frame size is based on stature and bi-iliac breadth, and both of those dimensions are affected by age. Skeletal frame size based body mass estimation tends to increase throughout adult life in both skeletal and anthropometric samples because an age-related increase in bi-iliac breadth more than compensates for an age-related stature decline commencing in the 30s or 40s. Combined with the above-mentioned curvilinear BM change, this results in curvilinear estimation bias. However, for simulations involving low to moderate percent body fat, the stature/bi-iliac method works well in predicting body mass in younger and middle-aged adults. Such conditions are likely to have applied to most human paleontological and archaeological samples., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: Vertebral size and especially cross-sectional area (CSA) are independently associated with vertebral fracture risk. Previous studies have suggested that physical activity and especially high-impact exercise may affect vertebral strength. We aimed to investigate the association between high-impact exercise at 31 and 46 years of age and vertebral dimensions in midlife., Methods: We used a subsample of 1023 individuals from the Northern Finland Birth Cohort 1966 study with records of self-reported sports participation from 31 and 46 years and MRI-derived data on vertebral dimensions from 46 years. Based on the sports participation data, we constructed three impact categories (high, mixed, low) that represented longitudinal high-impact exercise activity in adulthood. We used linear regression and generalized estimating equation (GEE) models to analyse the association between high-impact exercise and vertebral CSA, with adjustments for vertebral height and body mass index., Results: Participation in high-impact sports was associated with large vertebral CSA among women but not men. The women in the 'mixed' group had 36.8 (95% confidence interval 11.2-62.5) mm 2 larger CSA and the women in the 'high' group 43.2 (15.2-71.1) mm 2 larger CSA than the 'low' group., Conclusions: We suggest that participation (≥ 1/week) in one or more high-impact sports in adulthood is associated with larger vertebral size, and thus increased vertebral strength, among middle-aged women.

Small vertebral size is an independent risk factor for osteoporotic vertebral fractures. Physical growth in early life is related to bone health in later life, but the relationship of early growth versus vertebral size has been inconclusively studied. Utilizing the Northern Finland Birth Cohort 1966 with a 47-year follow-up, we investigated how physical growth in early life is associated with midlife vertebral dimensions. We obtained several physical growth parameters of 1) birth (gestational age, length, weight, BMI), 2) infancy and childhood (peak height velocity (PHV), peak weight velocity (PWV), adiposity peak (AP), adiposity rebound (AR)), and 3) puberty (BMI at growth spurt take-off (TO), PHV, height change). We also studied 4) the ages at which AP, AR, pubertal TO and pubertal PHV occurred. The outcome variable, vertebral cross-sectional area (CSA), was obtained from magnetic resonance imaging scans at the mean age of 46.7years (n=517). Sex-stratified linear regression analyses were used with adjustments for gestational age, smoking, and education. Birth length/weight/BMI, and adult height/weight/BMI were also used as covariates, depending on the model. According to our results, birth weight (p≤0.006) and infant PWV (p≤0.001) were positively associated with midlife vertebral CSA among both sexes. Length/height variables were associated with vertebral size only before including adult height in the models, and became non-significant thereafter. Among women, BMIs at birth, AP, AR, and pubertal TO were positively associated with midlife vertebral CSA (p<0.05), whereas among men, only high BMI at AR was associated with large vertebral size (p=0.028). Gestational age and timing of growth were not associated with future vertebral CSA. We conclude that early life weight gain is positively associated with midlife vertebral CSA, and suggest that adult height may mediate the effect of height gain on vertebral size., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: The vertebral cross-sectional area (CSA) is a major determinant of vertebral strength. Since leisure-time physical activity (LTPA) is known to affect vertebral CSA, we hypothesised that engagement in physical activity at work might have similar effects on vertebral size. We aimed to examine the association between various adulthood occupational physical activities (OPA) and vertebral CSA, and to evaluate the association between OPA intensity and vertebral CSA., Methods: We used the prospective population-based Northern Finland Birth Cohort 1966. Our sample consisted of 712 participants with a mean age of 46.8 years. We assessed their engagement in various individual physical work activities at the ages of 31 and 46, and created overall OPA categories (high, moderate and low intensity), which we used in the analyses to study their association with vertebral CSA in middle age. Linear regression was used as the statistical method with adjustments for LTPA, vertebral height, body mass index and smoking., Results: A statistically significant association was found between occupational sitting and smaller vertebral CSA in men, but only at the age of 31 (49.2 mm 2 smaller among those who sit often vs rarely (95% CI -96.0 to -2.4)). No significant differences were detected between OPA categories and vertebral CSA (p>0.05). Thus, we found no consistent association between OPA and vertebral size among either sex., Conclusions: OPA seems to have very little effect on vertebral size. Our results suggest that the effect of LTPA on vertebral size is different to that of OPA., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Objectives: Research on a limited number of samples suggests that trabecular bone density (i.e., bone volume fraction, BVF) within specific articulations is lower among more sedentary Holocene agricultural populations compared with Holocene foragers, implying that activity levels have a significant effect on trabecular BVF. However, it is unclear to what extent BVF differs among groups with varying activity levels and how general this phenomenon is across multiple limb articulations. Here, we test two hypotheses that: (i) sedentary populations have lower BVF compared with active populations across limb articulations; and (ii) these declines are more uniform in the lower limb (because of its more direct relationship to mobility), and more variable in the upper limb., Materials and Methods: We estimated BVF in seven lower and upper limb articulations of five Holocene population samples with subsistence strategies spanning from foraging through horticultural to industrial using pQCT (peripheral Quantitative Computed Tomography)., Results: Both hypotheses are largely supported. First, the most active groups have significantly greater BVF in most limb elements compared with more sedentary groups. Second, all sedentary groups have relatively similar (and lower) BVF in the lower limb but show more variation in upper limb articulations., Conclusions: These results suggest that a decline in activity levels associated with the adoption of agriculture and industrialization significantly contributed to the reduction in BVF in recent modern humans, but specific behavioral changes, particularly in the upper limb, also affected these patterns., (© 2017 Wiley Periodicals, Inc.)