Although it’s difficult to locate the multifidus, locating and using it are crucial to preserving spine health (saving your back, in other words).
The multifidus is a deep muscle of the back that runs the entire length of the spine. Feeling it contract involves reaching behind the back and feeling the lower back muscles.
Ultimately, since it supports spinal stability, you don’t feel it unless something–such as straining the back while lifting a heavy object–
There is another way to ensure that you’re using it properly, as demonstrated by the video below
The form demonstrated in Ruth Bosarge’s video is (not coincidentally) echoed by other sources and experts on the Web–from physical therapists to weightlifters. (See the examples below.)
Keep this in mind when carrying out daily activities. To maintain proper form when picking up objects is essential to activating the multifidus, and focusing on proper use of the other core muscles are important as well. The proof of the pudding is in the eating. Doing the rest resolves the other.