Chronic risk factors of posterior circulation ischemic strokes remain unknown. There is, however, evidence that anatomical variations within the vertebrobasilar system could potentially lead to the development of posterior circulation strokes. We investigated the association of forward head posturing (FHP), a chronic anatomic change seen in patients with cervicalgia, with posterior circulation strokes. In this case control study, we identified adult patients diagnosed with cervicalgia and ischemic posterior circulation infarcts from 2007 to 2023. Patients were paired to cervicalgia controls without posterior circulation stroke and matched for known risk factors. Patients' C0-C2 angle, C2-C7 angle, and sagittal vertical axis (SVA) shift were measured as metrics for FHP severity on lateral cervical spine x-rays. Paired T-tests were applied to compare patient stroke risk factors and FHP between groups. 206 patients (103 cases and 103 controls) were included with an average age of 64.4 years with 51.5% female. There were no statistically significant differences between the patients' risk factors for stroke, including hypertension, hyperlipidemia, diabetes, smoking, hypercoagulable state, and atrial fibrillation. There were statistically significant differences in C0-C2 angle (30.7 degrees vs 23.2 degrees, P-value=0.002) and SVA shift (35.4 mm vs 25.3 mm, P-value<0.001). This case control matched pair study found that within adults with cervicalgia, posterior circulation ischemic stroke was associated with more severe FHP as noted in C0-C2 angle and SVA shift measurements. This study further speculates that this association may be because of chronic changes in circulation flow dynamics within the vertebrobasilar system with the postural change.