Level of Evidence 5. Clinical Relevance Emerging evidence in support of SI joint fusion indicates that clinicians should examine the SI joint and include SI joint pain in their differential diagnosis for low back pain patients. ©International Society for the Advancement of Spine Surgery 2020.Background Anatomic variation in the relationship between the lumbar spine and sacrum was first described in the literature nearly a century ago and continues to play an important role in spine deformity, low back pain (LBP), and pelvic trauma. This review will focus on the clinical and surgical implications of abnormal lumbosacral anatomy in the context of sacroiliac joint (SIJ) disease, spine deformity, and pelvic trauma. Methods A PubMed search using the keywords "lumbosacral transitional vertebrae," "LSTV," "transitional lumbosacral vertebrae," "TLSV," and "sacral dysmorphism" was performed. The articles presented here were evaluated by the authors. Clinical Significance The prevalence of LSTV varies widely in the literature from 3.9-% to 35.6% in the spine literature, and sacral dysmorphism is described in upwards of 50% of the population in the trauma literature. The relationship between LSTV and LBP is well established. While there is no agreed-on etiology, the source of pain is multifactorial and may be related to abnormal biomechanics and alignment, disc degeneration, and arthritic changes. Surgical Implications Understanding abnormal lumbosacral anatomy is crucial for preoperative planning of SIJ fusion, spine deformity, and pelvic trauma surgery. LSTV can alter spinopelvic parameters crucial in planning spine deformity correction. Traditional safe zones for sacroiliac screw placement do not apply in the first sacral segment in sacral dysmorphism and risk iatrogenic nerve injury. Conclusions LSTV and sacral dysmorphism are common anatomic variants found in the general population. Abnormal lumbosacral anatomy plays a significant role in clinical evaluation of LBP and surgical planning in SIJ fusion, spine deformity, and pelvic trauma. Further studies evaluating the influence of abnormal lumbosacral anatomy on LBP and surgical technique would help guide treatment for these patients. ©International Society for the Advancement of Spine Surgery 2020.Background The sacroiliac joints (SIJs), the largest axial joints in the body, sit in between the sacrum and pelvic bones on either side. They connect the spine to the pelvis and thus facilitate load transfer from the lumbar spine to the lower extremities. The majority of low back pain (LBP) is perceived to originate from the lumbar spine; however, another likely source of LBP that is mostly overlooked is the SIJ. This study (Parts I and II) aims to evaluate the clinical and biomechanical literature to understand the anatomy, biomechanics, sexual dimorphism, and causes and mechanics of pain of the SIJ leading to conservative and surgical treatment options using instrumentation. Part II concludes with the mechanics of the devices used in minimal surgical procedures for the SIJ. Methods A thorough review of the literature was performed to analyze studies related to normal SIJ mechanics, as well as the effects of sex and pain on SIJ mechanics. Results A total of 65 studies were selected related to anatomy, biome/loads, and pelvis ligament strains compared to male SIJs. Sacroiliac pain can be due to, but not limited to, hypo- or hypermobility, extraneous compression or shearing forces, micro- or macro-fractures, soft tissue injury, inflammation, pregnancy, adjacent segment disease, leg length discrepancy, and prior lumbar fusion. These effects are well discussed in this review. This review leads to Part II, in which the literature on mechanics of the treatment options is reviewed and synthesized. ©International Society for the Advancement of Spine Surgery 2020.Sports group participation may have greater effects on health outcomes than exercising alone. Unhealthy lifestyles were reported to be specifically associated with lower socioeconomic positions (SEPs), and child poverty and the bipolarization of sports participation are currently major policy concerns in children. However, it remains unclear whether childhood SEP has any long-latency effect on sports group participation among older Japanese. Data were obtained from the Japan Gerontological Evaluation Study 2010 project, which used self-report questionnaires to survey individuals aged ≥65 years without disability from 27 municipalities (n = 23,320). According to their answers, respondents were assigned to one of three SEP groups high, middle, or low. Poisson regression with robust variance and multiple imputations was used to examine the association between childhood SEP and sports group participation. After adjusting for health-related factors, low childhood SEP was negatively associated with sports group participation in men (prevalence ratio [PR] = 0.82, 95% confidence interval [CI] = 0.74-0.91) and women (PR = 0.88, 95% CI = 0.80-0.97). The PR was greatly attenuated after adjusting for educational attainment in both men (PR = 0.92, 95% CI = 0.83-1.02) and women (PR = 0.98, 95% CI = 0.89-1.08), and the significant association disappeared. Low childhood SEP is thus associated with lower sports group participation among older Japanese, though this may be attenuated by education. These findings suggest that it may be necessary to consider childhood SEP and the importance of education to increase sports group participation at an older age.  https://www.selleckchem.com/products/resatorvid.html  © 2020 The Authors.Most empirical economic research is conducted with the goal of providing scientific evidence that will be informative in assessing causal relationships of interest based on relevant counterfactuals. The implementation of regression methods in this context is ubiquitous. With this as motivation, we detail a comprehensive regression-based potential outcomes framework for causal modeling, estimation and inference. This framework facilitates rigorous specification of the effect parameter of interest and makes clear the sense in which it is causally interpretable, when appropriately defined in a potential outcomes setting. It also serves to crystallize the conditions under which the effect parameter and the underlying regression parameters are identified. The consistent sample analog estimator of the effect parameter is discussed. Juxtaposing this framework with a stylized version of a commonly implemented and routinely applied modeling and estimation protocol reveals how the latter is deficient in recognizing, and fully accounting for, conditions required for identification of the relevant effect parameter and the causal interpretability of estimation results.