Objective To analyze the biomechanical distribution of the adult lumbar spine in the elbow-knee support position by integrating musculoskeletal modeling and lumbar finite element analysis.Methods A comprehensive three-dimensional finite element model of the human lumbar spine was developed using Computed Tomography(CT) images combined with image processing and finite element analysis software. Musculoskeletal modeling was employed to analyze muscle contraction forces during the elbow-knee support position, while stress distribution across lumbar vertebrae, intervertebral discs, and ligaments was evaluated using the finite element model.Results In the elbow-knee support position, the lumbar(L3–L5) vertebrae sustained the highest stress (1.2881–4.6092 MPa), with stress concentration observed at the facet joints and posterior vertebral margins via cloud maps. The stress in the central vertebral region ranged between 0.001 and 0.5 MPa. Stress on the nucleus pulposus of intervertebral discs measured 0.00192–0.01 MPa, with central nucleus pulposus stress below 0.004 MPa.Conclusion Finite element analysis revealed lower stress on the anterior column of the lumbar spine and higher stress on the middle and posterior columns during the elbow-knee support position. The intervertebral disc stress remained below 0.004 MPa, indicating relatively low compressive stress on the lumbar discs during rehabilitation using this posture.