### Introduction

### Methods

### 1. Radiographic evaluation

### 2. Statistical analysis

*T*-test of two independent sample means was used to find significance difference between two independent samples for continuous outcomes. Pearson’s correlation/ Spearman’s rho was used as per the distribution and assumption to determine the correlation between two variables. Fisher exact test or chi-square test was utilized to find the significance of study parameters on a categorical scale between two or more groups. One-way analysis of variance was used to evaluate the significant difference among the SVA types for all radiological parameters. The significance was assessed at the 5% level of significance.

### Results

*p*=0.180, chi-square value=3.943). Twenty-five participants (18 males, seven females) had SVA type 1, 42 participants (31 males, 11 females) had SVA type 2, and 33 participants (20 males, 13 females) had SVA type 3. No significant association was found between gender and the distribution of SVA types in the population (

*p*=0.493, chisquare value=1.646).

*p*=0.027). In addition, post-hoc analysis utilizing Bonferroni correction (with significance at 0.05 level) showed that PT (

*p*=0.037) significantly differed among the various SVA types (Table 3).

*r*=−0.355,

*p*<0.001). In specific, the location of the lumbar apex moved higher as the PI was increased (Table 4). The PI significantly positively correlated with the LLL (

*r*=0.582,

*p*<0.001) and the TLL (

*r*=0.579,

*p*<0.001) but not with the ULL (

*r*=0.196,

*p*=0.05). The PI positively correlated with the PT (

*r*=0.502,

*p*<0.001), SS (

*r*=0.867,

*p*<0.001), and PI–LL (

*r*=0.622,

*p*<0.001).

*r*=0.349,

*p*<0.001) and negatively with the LLL (

*r*=−0.63,

*p*<0.001) but not correlated with the TLL (

*r*=−0.177,

*p*=0.078). As the location of the lumbar apex moved lower, the ULL increased, the LLL decreased, but the TLL showed no significant change. The LLA was strongly correlated with the PI (

*r*=−0.355,

*p*<0.001) and SS (

*r*=−0.386,

*p*<0.001) but not with the PT (

*r*=−0.042,

*p*=0.68) (Table 4).

*r*=0.697,

*p*<0.001) and LLL (

*r*=0.609,

*p*<0.001) were strongly correlated with the TLL. However, the PI– LL was negatively correlated with the ULL (

*r*=−0.395,

*p*<0.001) but not with the LLL (

*r*=0.155,

*p*=0.123). The LLL but not the ULL strongly positively correlated with the PI (LLL:

*r*=0.582,

*p*<0.001; ULL:

*r*=0.196,

*p*=0.05), PT (LLL:

*r*=0.311,

*p*=0.002; ULL: r<0.001,

*p*=0.997), and SS (LLL:

*r*=0.493,

*p*<0.001; ULL:

*r*=0.227,

*p*=0.023) (Table 4).

*r*=0.622,

*p*<0.001), PT (

*r*=0.332,

*p*=0.001), and SS (

*r*=0.528,

*p*<0.001) positively and with the LLA (

*r*=−0.256,

*p*=0.01), ULL (

*r*=−0.395,

*p*<0.001), and TLL (

*r*=−0.204,

*p*=0.041) negatively (Table 4). The LTA had no correlation with any other radiological parameters. However, age was negatively correlated with LTA (

*r*=−0.219,

*p*=0.029).