If you get frequent lower back pain that is not an underlying disease, the issue is likely due to a weak Gluteus Medius Muscle.
The Gluteus Medius is one of the three gluteus (butt) muscles that play a role in stabilizing the hips. The other two areas being the Gluteus Maximus and the Gluteus Minimus. The Medius muscle begins on the outer surface of the Illium, the hip bone, and attaches to the greater trochanter of the femur (a bony landmark at the top/outer side of the thigh bone). Its fibers run in a superior/inferior direction anchoring the pelvis to the femur.
This matters the most when we remember that the spine rests upon the sacrum, a portion of the pelvis, specifically at the L5-S1 junction. Providing a foundation for the vertebral column can help in reducing back pain that is felt from prolonged standing and/or walking. Instability of the vertebrae can result in disproportionate compression of an intervertebral disc, causing nerve irritation prevalent in low back pain.
More often than not, a patient will walk through our doors with reports of low back pain, and after some investigative work, we’ll learn that their job requires daily long hours of sitting. Jeong et. al1 demonstrate that the Gluteus Medius provides that stability to the pelvis when our body needs it. However, after sitting in a chair for many hours every day, these muscles will atrophy and no longer perform their designated job for months. This can result in vertebral instability, as mentioned above or worse, to leave a person susceptible to graver spinal cord injury when dealing with bigger movements such as deadlifting or squatting.
How to Strengthen the Gluteus Medius Muscle
This article aims not to scare you from performing these movements; it is more the opposite. One of our strongest recommendations to those experiencing low back pain is to purchase a standing desk, which now creates a need yet again for those Gluteus muscles to stabilize the hip. We also frequently recommend performing exercises that target the Gluteus Medius, such as clamshells, bridges, sidestepping, side planks, as safe movements that re-introduce the patient to healthy activity while developing the musculature around the hip.
To conclude, when treating low back pain, often a Physical Therapist elects to focus on establishing “core” strength by concentrating on the Transverse Abdominis and Abdominal Oblique muscles. Choosing to develop the Gluteus Medius is an alternative approach that many patients have experienced more relief than core work. If you’re someone who has no pain but is apprehensive about lifting, or if you are currently experiencing low back pain, the Gluteus Medius is a solid place to start. 
 Jeong UC, Sim JH, Kim CY, Hwang-Bo G, Nam CW. The effects of gluteus muscle strengthening exercise and lumbar stabilization exercise on lumbar muscle strength and balance in chronic low back pain patients. J Phys Ther Sci. 2015;27(12):3813-3816. doi:10.1589/jpts.27.3813