This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. There are two hypothesis being studied. 1. Women with a history of gynecological surgery (GS) and low back pain (LBP) have lower stiffness of the sacroiliac joint (SIJ) at rest and develop less incremental stiffness of the SIJ with specific muscle contraction maneuvers. and 2. Women with a history of GS and LBP will demonstrate mal-adaptive motor control strategies (MCS) during the active straight leg raise (ASLR) test compared to women with no history of GS and LBP. There are two specific aims to this study: A.1 Understand the effect of GS on the passive and active SIJ stability characteristics using Doppler Imaging of Vibrations (DIV) in older women and correlate to a history of LBP. Determine the stabilizing influence of the MCS and the passive joint structures (i.e., ligaments and joint architecture) as a function of LBP and GS history. A.2 Quantify changes in the MCS in women with LBP and GS history using sonographic and spirometry observations of abdominal muscle contraction, bladder support and respiratory function during a SIJ load transfer maneuver, the ASLR test.