This study examined the use of the hip walking (HW) distance test as a physical performance parameter, and investigated the association between HW distance and strength, balance, and gait speed in the elderly. The study involved 106 community-dwelling elderly individuals (mean age 75.4 years). Participants performed the following physical performance tests: the HW distance test, the functional reach test (FRT), and tests for knee extensor strength, trunk extensor, and flexor strength, and 5 m maximum gait speed. For the HW distance test, participants were asked to move forward as fast as possible from the starting position with legs stretched out forwards and arms folded across the chest. Trunk rotation with lifting of the ischium was permitted during HW. The distances between right lateral malleoli was measured for HW distances of 10 seconds. To assess the test–retest reliability of HW, intra-class correlation coefficients (ICCs) were calculated from two trials. Pearson’s correlation analysis and linear regression analysis were used to examine the association between HW and physical performance using adjusted variables such as age, sex, and body mass index. ICC (1.1) for the test–retest reliability of HW was 0.95. HW was significantly associated with all physical performance tests according to Pearson’s correlation analysis (trunk flexor strength, r = 0.31; trunk extensor strength, r = 0.31; knee extensor strength, r = 0.29; FRT, r = 0.29; gait speed, r = 0.45). In linear regression analyses, HW distance scores were found to be significant determinants of each physical performance parameter. HW influenced physical performance by affecting muscle strength, balance, and gait ability. HW can be easily and safely performed on a floor or platform without the risk of falling. These results indicate that HW is a safe, simple, and reliable method for the assessment of physical performance in the elderly.
This study examines the changes with age of 15 musculoskeletal stress markers (MSMs) in the upper and lower limb bones of modern Japanese with documented ages-at-death, on the basis of original scoring criteria corresponding to each advanced stage. The procedure investigated significant differences of mean scores among five age classes at intervals of 10 years from 20 to 69 years for each MSM, and also calculated Pearson’s correlation coefficients between MSM scores and age-at-death. These examinations found that most MSMs had significant correlations with aging in both sexes. MSM data of the people from the Yoshigo shell-mound in the Jomon period (Yoshigo Jomon, c. 3000–2300 BP), the Doigahama site in the Yayoi period (Doigahama Yayoi, c. 2100–1800 BP), and modern Japanese were then compared between the 20–39 and 40–59 age categories (younger adult and older adult groups, respectively) for both sexes. Kruskal–Wallis tests found that many MSMs showed significant differences between periods in each age category. Mann–Whitney tests revealed that many MSMs of the prehistoric Yoshigo Jomon and Doigahama Yayoi showed few significant differences, whereas those of many modern Japanese differed significantly. Principal component analysis indicated that the results of a scatter diagram in the younger adult group were considerably different from those of the older adult group. These findings suggest that MSMs are age structured within human populations, but that differences also arise in association with intensity of activity.
Pulp volume decreases throughout life owing to secondary dentin deposition. Here, we present a Bayesian approach for human age estimation on the basis of the pulp volume ratio from lower-canine teeth. We measured the pulp and tooth volumes of 363 subjects (209 males, 154 females) of known age based on three-dimensional imageries from microcomputed tomography scans. Pulp volume ratio was defined as pulp/tooth volume within the root portion (PVRrt) and its reduction with age was modeled by simple statistical assumptions to produce a likelihood function of PVRrt by fitting the model to the observed data. Following Bayes’ theorem, we obtained the probability density function (PDF) of estimated age for a given PVRrt, for males, females, and gender unknowns; we used the modern Japanese population as of 2012 as prior age distribution. The PDF of estimated age provided the mean and 50%, 70%, and 90% prediction intervals, based on which we compared the present age- estimation method with that of Brooks and Suchey (Human Evolution, 5: 227–238), which is based on pubic symphysis metamorphosis. We could not find any advantages of the PVRrt method compared to the Suchey–Brooks method for the case of males or gender unknowns as far as the prediction intervals were concerned. However, for females, the PVRrt method offered comparable precision to the Suchey–Brooks method. Taking into account other advantages such as sustainability of the material and continuous property of the age-indicator value, we conclude that the PVRrt method is useful in forensic cases, especially those involving female victims.
Patterns of genetic variation among geographically and ethnically diverse African populations have been under-represented in human genetics studies despite their importance for describing the evolutionary history of modern human populations. We conducted a study on 133 individuals, belonging to four northern Ivorian ethnic groups, based on the allele distribution of 11 Alu insertion loci, and compared the results with other African populations. All loci proved to be polymorphic in all ethnic groups, with the exception of HS2.43 and HS3.23, which were fixed for the absence and for the presence, respectively, of the Alu element. No significant departure from Hardy–Weinberg equilibrium was found among polymorphic loci, except for TPA25 loci in the Baoulé and Bété groups. Average heterozygosity (0.193 ± 0.042) was lower than that observed for the same loci in other African populations and the FST value among ethnic groups for all loci was also notably low (0.0456). Multidimensional scaling analysis clearly separated Ivorians from other African samples, while in the neighbor-joining tree this population represented a basal branch of the tree, close to the hypothetical ancestral lineage. The picture emerging from our analyses reveals a conspicuous genetic homogeneity among Dioulà, Sénoufos, Boulè, and Bètè despite their sociocultural subdivision. Moreover, this northern Ivory Coast population, as a whole, turns out to be relatively isolated from the other African populations, possibly as a consequence of local patterns of population history, limited migration rates, and random genetic drift.
The basilar part of the occipital bone is occasionally partially divided by lateral notches, termed transverse basilar clefts (TBCs). In the present paper, we describe the condition of the TBC in six skulls from prehistoric Jomon sites in the Japanese archipelago and then compare TBC frequencies between the Jomon and recent Japanese cranial series. The frequencies of TBCs in Jomon skulls from the southern Hokkaido and Tohoku districts are higher than in recent Japanese specimens from the Tohoku district. Since the TBC is considered a variation that appears at an early developmental stage in the human cranium, it is worthwhile investigating this trait as one of the nonmetric cranial variants in various human population groups, including immature individuals.