Interaction of Applied Forces Joints in Women with Non-Specific Low Back Pain

Low back pain is one of the most common musculoskeletal problems. Although abnormal muscle function is known as one of the possible causes of low back pain, no research was found concerning the forces applied on the lumbosacral joint in patients with low back pain. Thus, the aim of this study was an investigation of the interaction of forces applied on lumbosacral and lower limb joints in patients with chronic low back pain compared to healthy subjects while walking. The present study consisted nine female with nonspecific low back pain (NLBP) with mean height and weight of 158.81±5.56cm and 61.68±8.88 kg, respectively and 8 height and weight matched healthy females. Medio-lateral, vertical, braking and propulsive joint contact forces of lumbosacral and lower limbs joints are the variables of this study. Qualysis motion capture system and a Kistler force plate were used to record spatiotemporal and kinetic (joint contact forces) data. Qualysis and Open-SIM software were used to extract the data. All data were analyzed by utilizing the SPSS 22 software at α=0.05. Joint contact forces applied on ankle joint (P=0.04), knee (P<0.01) and lumbosacral (P<0.01) joint were different between two groups. There also was an interaction between joint forces and groups in this regards. Although total forces applied on ankle and knee in both groups were the same, however, the forces acting on the hip and lumbosacral joints in NLBP was more than that of healthy group. The patterns of forces applied on these joints were different between groups. Different pattern of forces applied on the joints NLBP is associated with different muscle activity; therefore, it is recommended that rehabilitation program should be focus on these joints and surrounding muscles in order to help NLBP patients and reduces pain.