Gluteal shape is influenced by several factors such as gender, age, weight, and lifestyle. Another factor, puberty, is the milestone in the development of the gluteal region. With puberty, physiologic psychological, and morphologic changes take place in the body. These changes shape the buttocks in different ways according to the gender of the subject. The development of pubic hair, testicles, and breasts under the effect of growth and puberty have been documented in detail [2], but because of its apparently less significant physiologic role, the morphology of the gluteal region was neglected for a long time. Another important step in a woman’s life is menopause, during which the hormonal milieu changes. During this period, possible changes in the gluteal region have not yet been studied intensively.

In a previous study [1], the author demonstrated the changes in the gluteal region under the influence of age and weight gain in young and middle-aged women from the perspective of aesthetic surgery. The current study aimed to document the changes taking place in gluteal region through four major periods: the prepubertal, pubertal, postpubertal, and menopausal–postmenopausal periods.

Materials and Methods

All measurements were performed by the same investigator (B.B.) on 132 randomly selected females 5 to 83 years of age in a comfortable, well-lighted room. The subjects younger than 7 years of age were from the pediatric clinic of the hospital.

The measurements were performed in primary schools for the group 7 to 14 years of age, and in high schools of Zonguldak region for the group 15 to 17 years of age.

The subjects 18 to 24 years old were among the nursing staff and female patients who presented to the outpatient department reporting problems such as a nevus or scar. The subjects older than 24 years were selected randomly from female patients with a problem not affecting gluteal region morphology.

The subjects were asked to wear an examination dress and to stand barefoot in an anatomic position while measurements were taken. The body mass index (BMI) was calculated as the current weight (kg)/height (m2). The criteria for exclusion of subjects from the study specified morbid obesity, emaciation, a history of congenital hip dislocation, major trauma or surgery to the gluteal region, and pregnancy.

In this study, the anatomic reference points and measurements described previously [1] were used with some modifications (Fig. 1). Briefly, the reference points were the anterosuperior iliac spine (point A), the most prominent part of the major trochanter (point B), the cephalic point of the intergluteal sulcus (point D), the divergence point of the two infragluteal sulci caudal to the intergluteal sulcus (point E), and the lateral (point F) and most inferior (point C) points of the infragluteal sulcus.

Figure 1
figure 1

The measurements and the anatomic used as reference points (A) anterosuperior iliac spine (ASIS), (B) most prominent point of the greater trochanter, (C) most caudal point of the gluteal sulcus, (D) cephalic point of the intergluteal sulcus, (E) caudal point of the intergluteal sulcus, (F) lateral end point of the gluteal sulcus.

Full size image

Using these points, 11 measurements were performed (Table 1). The age, height, and weight of the subject were recorded as well.

Table 1 Descriptions of lines and circumferences
Full size table

In the current study, the circumference of the gluteal region was measured at the three different levels passing through points AA, BB, and CC. To calculate the lateral extension of the infragluteal sulcus, the distance from the lateral point of the gluteal sulcus (point F) to the midaxillary line (FML), ipsilateral trochanter (point B), and cephalic part of the intergluteal sulcus (point D) was recorded. Downsloping of the gluteal sulcus was estimated by recording the distance from point A to ipsilateral point F and point C (Table 2, Fig. 1). The leg circumference (LC) measurement was performed at the widest region of the proximal limb.

Table 2 Average measurements age, height, weight, BMI, and gluteal region
Full size table

The subjects were divide into four groups on the basis of physiologic milestones as follows: Group 1 (n = 10): Prepubertal group (ages, 5–8 years)

  • Group 2 (n = 38): Pubertal group (ages, 9–14 years)

  • Group 3 (n = 34): Postpubertal group (ages, 15–41 years)

  • Group 4 (n = 29): Menopausal–postmenopausal group (ages, >42 years).

Statistical Analyses

The correlation between the measurement was evaluated with Spearmen correlation analyses for group 1 and with Pearson correlation analyses according to the group size for groups 2, 3, and 4. For statistical significance, an alpha level of 0.05 was determined.

Results

The data obtained from the groups are presented in Table 2. The statistically significant results from the comparisons for each group are given in Tables 3 to 6.

Table 3 Statistical results for group 1a
Full size table

Group 1

Neither BMI nor intergluteal sulcus (DE) length showed any significant correlation with other parameters. Age was not strongly related to gluteal region dimensions. Weight was found to affect the width of the gluteal region rather than the height of this region because it was associated with AA (r = 0.672; p = 0.033), BB (r = 0.675; p = 0.032), CC (r = 0.691; p = 0.027), FLM (r = 0.685; p = 0.029), and LC (r = 0.743; p = 0.014). The other measurement, which was in close correlation with the width of the gluteal region, was BB. It was strongly correlated with AA (r= 0.719; p = 0.019), CC (r = 0.703; p = 0.023), LC (r = 704; p = 0.023), and FLM (r = 0.659; p = 0.038). The height of the subject was found to be in close relation with both vertical and horizontal dimensions such as AA (r = 0.818; p = 0.004), BB (r = 0.719; p = 0.019), AC (r = 0.749; p = 0.013), AF (r = 0.663; p = 0.037), FLM (r = 0.704; p = 0.023), and BF (r = 0.706; p = 0.023). The group 1 results are presented in Table 3.

Group 2

All dimensions were significantly in close association with each other. That is, any change in one dimension or measurement directly was reflected in the other parameters. The group 2 results are presented in Table 4.

Table 4 Statistical results for group 2a
Full size table

Group 3

The height of the subject did not have any correlation with the other measurements. Age was significantly correlated with AA (r = 0.001; p = 567), DE (r = 0.001; p = 509), AC (r = 0.445; p = 0.008). Weight and BMI were found to be strongly related to AA (r = 0.778; p = 0.001), BB (r = 0.814; p = 0.001), CC (r = 0.642; p = 0.001), DE (r = 0.395; p = 0.021), AC (r = 0.547; p = 0.001), AF (r = 0.626; p = 0,001), AD (r = 0.772; p =0.001), FLM (r = 0.413; p = 0.015), and LC (r = 0.670; p = 0.001). The circumference taken at the level of AA was strongly correlated with BB (r = 0.843; p = 0.001), CC (r = 0.562; p = 0.001), LC (r = 0.539; p = 0.001), DE (r = 0.515; p = 0.002), AD (r = 0.670; p = 0.001), AC (r = 0.608; p = 0.001), AF (r = 0.467; p = 0.005), and FLM (r = 0.432; p = 0.015) measurements. Limb circumference was another parameter that significantly affected gluteal region morphology as a whole. The group 3 results are presented in Table 5.

Table 5 Statistical results for group 3a
Full size table

Group 4

Age had no statistically significant effect on gluteal region dimensions. The height of the subject was correlated with circumferential measurements, namely, AA (r = 0.441; p = 0.017), BB (r = 0.421; p = 0.023), CC (r= 0.507; p = 0.005), LC (r = 0.434; p = 0.019), and DE (r = 0.402; p = 0.031). No significant correlation was found between the height of the subject and gluteal sulcus–related measurements (i.e. AC, AF, DF, BF, and FLM). Weight and BMI were strongly correlated with AA, BB, CC, LC, DE, AC, DF, BF, and LC (Table 6). The four circumferential measurements (AA, BB, CC, and LC) were closely correlated with each other. Limb circumference, as in the groups 2 and 3, was significantly correlated with almost all the parameters of the gluteal region. The group 3 results are presented in Table 6.

Table 6 Statistical results for group 4a
Full size table

Discussion

The approach to gluteal region morphology varies from studying the effect of the fat accumulation on health [3] to investigating human mate selection [4]. In this study, the changes in gluteal morphology between the ages of 5 and 83 years in female population were assessed for four age groups: prepubertal, pubertal, postpubertal, and menopausal–postmenopausal.

The gluteal region is a very dynamic part of the body. The effect of the age, weight, height, and BMI on the gluteal region dimensions is not the same throughout life. Between the ages of 5 and 8 years, the age does not seem to influence the gluteal region morphology directly. During the same period, weight gain relates to increased circumference of the gluteal region, but the vertical dimensions remain unaffected. Interestingly, in this study, the infra- and intergluteal sulci were not affected by weight gain and age. Rather, the height of the subject was closely related to the downsloping of the infragluteal sulci. The four circumferential diameters of the gluteal region (AA, BB, CC, and LC), act in a harmony. This is the reason why BMI has no correlation with any parameters, whereas the height and weight of the subject constitute a dilemma.

Another finding that needs clarification is the absence of correlation between the intergluteal suleus (DE) length and other measurements of this region. The reason may be that this groove is highly dependent on the pelvic development, which is not characteristic of this age group.

When group 2, composed of the subjects supposedly at puberty (age, 9–14 years), is evaluated, dramatic expansions of all the pararmeters are seen. As can easily be seen in Table 4, very strong correlation exists between all the parameters. Age, height, weight, and BMI of the subjects unexceptionally affect all the parameters. The gluteal region develops in all directions at puberty. The intergluteal sulcus (DE) also takes part in this dynamic period. Its length increases as the gluteal region grows. In this age group, the gluteal region can be regarded as a closed system because any change in any dimension significantly affects all the other measurements.

After puberty and until the menopause (age, 15–41 years), age is related with only AA and DE, whereas the height of the subject has no effect on gluteal shape. This is not surprising because the growth of the body is ceased. Weight and BMI are the major factors influencing gluteal region dimensions. While infragluteal sulci move downward and laterally, increase in the FLM distance indicates local fat accumulation in this region, which is one of the major problems with female buttocks. Changes in the gluteal region are directly related to limb circumference. This means that if the gluteal region is to be shaped, the proximal part of the limbs also should be addressed.

In the last group, consisting of females older than 41 years, age has no effect on the gluteal region morphology. In contrast to the previous group, the height of the patient is closely related to intergluteal sulcus length and circumference of the gluteal region. In this age group, weight and BMI are major determinants of the gluteal shape. As in group 3, with weight gain, the intergluteal sulcus DE lengthens, and the infragluteal sulci move downward and laterally, but these changes are not related to FLM distance. This may be attributable to possible atrophy of the subcutaneous fat tissue seen in the elderly, which should be taken into consideration when liposuction is used for a woman in this age group. Limb circumference also is related to gluteal region morphology, as in the group 3. The increase in intergluteal sulcus (DE) length probably is attributable to sagging of the buttocks because this increment is closely related to the increase in DC, AC, and BF length. This type of relation is not seen in the groups 1 and 3.

In summary, in group 1, the intergluteal sulcus and infragluteal sulci do not actively change. Weight gain is the major factor influencing the shape of the gluteal region. As the surge of the hormones during puberty takes place (group 2), the gluteal region expands in all directions. During this period, it is difficult to discuss any specific relation between dimensions because of the significant correlation among all the parameters.

In the current study, age significantly affected the shape of the gluteal region only in group 2. In the other three groups, weight seemed to be major determinant. In both groups 3 and 4, the buttocks sagged with weight gain. This caused the infragluteal sulci (DE) to move in downward and lateral directions and a lengthening of the intergluteal sulcus.

It should be remembered that gluteal shape is open to the effects the demographic factors such as ethnicity, feeding habits, and lifestyle. Finally, in assessments of the gluteal region morphology, it would be better to consider its dynamic nature. Reshaping one part is devastating unless the whole gluteal region and upper limb are addressed.