Abstract: A method and equipment for the detection of mechanical injuries in the lumbar spine of a patient and the identification of these injuries, using a mathematical model applicable to the five lumbar vertebrae of a human being, and to to their disks. According to this method, the electromyographis (EMG) activities of the erectores and abdominals of the patient are measured in the bilateral and symmetrical manner with respect to the spine of the patient while the same is flexing forward in the mediane plane and pulling up a small load. The angle of flexion of the patient is measured during this flexion and is supplied as variable input to the mathematical model. A computer is used to run the model with its variable input in order to calculate the EMG activites of the erectores and abdominals that would normally be used by a healthy person to produce the same task.