Biomechanical assessment of unilateral/bilateral lumbar spondylolysis with and without muscle weakness using finite element analysis

From a biomechanical perspective, this study indicates that unilateral incomplete spondylolysis and unilateral spondylolysis might worsen during different motions. The reduction of muscle strength can cause spondylolysis to spread to adjacent segments and further worsen. A decrease in muscle force led to a decrease in the range of motion in the lumbar spondylolysis defect, but it also led to an increase in the range of motion in the adjacent segments.