Muscle Imbalance and Risk of Fatigue Fractures: When performing an arabesque, if you focus on forcibly contracting only the erector spinae muscles to bend your lower back, the balance between the muscles in the front and back of the torso is disrupted. If this incorrect movement is repeated, it can cause severe pain in the lumbar region and, in severe cases, lead to **spondylolysis**, a type of fatigue fracture caused by the repeated bending of the bones.