1 Most episodes of acute lower back pain are caused by muscle strain, such as from lifting a heavy object, a sudden movement or a fall. 2  The low back pain can be very severe and last for several hours, several days or even a few weeks.
3. Characteristics of the Normal ECG. It is important to remember that there is a wide range of normal variability in the 12 lead ECG. The following normal ECG characteristics, therefore, are not absolute. It takes considerable ECG reading experience to discover all the normal variants.
Compared to a normal 12-lead ECG system which uses 10 wires (four on the legs and arms and six on the chest), the two or three electrodes used with these handheld units are much simpler and not a hassle. The cables and adhesive snap electrodes were used in all of the recordings done for this article.