Located deep in the front of the hip and connecting the leg, pelvis, and abdomen, the hip flexors— surprise, surprise— flex the hip. But despite being some of the most powerful muscles in our bodies (with a clearly important role), it’s easy to neglect our poor hip flexors— often without even knowing it. It turns out just working at a desk all day (guilty!) can really weaken hip flexors since they tend to shorten up while in a seated position. This tightness disrupts good posture and is a common cause of lower back pain. Weakened hip flexors can also increase the risk of foot, ankle, and knee injuries (especially among runners) Hip muscle weakness and overuse injuries in recreational runners. Niemuth, P.E., Johnson, R.J., Myers, M.J., et al. Rocky Mountain University of Health Professions, Provo, VT. Clinical Journal of Sport Medicine, 2005 Jan; 15 (1): 14-21.. So be sure to get up, stand up every hour or so! And giving the hip flexors some extra attention is not just about injury prevention. Adding power to workouts, working toward greater flexibility, and getting speedier while running is also, as they say, all in the hips The effect of walking speed on muscle function and mechanical energetics. Neptune, R.R., Sasaki, K., and Kautz, S.A. Department of Mechanical Engineering, The University of Texas, Austin, TX. Gait & Posture, 2008 Jul; 28 (1): 135-43..
Following any period of prolonged inactivity, a regimen of low-impact exercises is advised. Speed walking, swimming, or stationary bike riding 30 minutes daily can increase muscle strength and flexibility. Yoga also can help stretch and strengthen muscles and improve posture. Consult a physician for a list of low-impact, age-appropriate exercises that are specifically targeted to strengthening lower back and abdominal muscles. 

Tight hip flexors can also make it harder for your glutes to activate—since they're opposing muscle groups, when one is really tight the other becomes lengthened. When a muscle is more lengthened than it should be, it takes away some of its ability to contract. When your glutes are in this compromised position, it can cause other muscles to do more work than they should, making your workouts less efficient and sometimes, increasing your risk of injury.
Epidural injections of steroid drugs are frequently used to treat sciatica, despite limited evidence for their effectiveness. Moreover, these treatments are based on the assumption that reducing local inflammation in the vertebral column will relieve pain, but an association between structural abnormalities, inflammation, and sciatica symptoms has not been clearly demonstrated. NINDS-funded researchers are using a new imaging technique that can detect inflammation to better understand what causes chronic sciatica pain and to provide evidence to inform treatment selection.
Sciatica is a form of radiculopathy caused by compression of the sciatic nerve, the large nerve that travels through the buttocks and extends down the back of the leg. This compression causes shock-like or burning low back pain combined with pain through the buttocks and down one leg, occasionally reaching the foot. In the most extreme cases, when the nerve is pinched between the disc and the adjacent bone, the symptoms may involve not only pain, but numbness and muscle weakness in the leg because of interrupted nerve signaling. The condition may also be caused by a tumor or cyst that presses on the sciatic nerve or its roots.
In the common presentation of acute low back pain, pain develops after movements that involve lifting, twisting, or forward-bending. The symptoms may start soon after the movements or upon waking up the following morning. The description of the symptoms may range from tenderness at a particular point to diffuse pain. It may or may not worsen with certain movements, such as raising a leg, or positions, such as sitting or standing. Pain radiating down the legs (known as sciatica) may be present. The first experience of acute low back pain is typically between the ages of 20 and 40. This is often a person's first reason to see a medical professional as an adult.[1] Recurrent episodes occur in more than half of people[23] with the repeated episodes being generally more painful than the first.[1]
How to: Lie on your back with your right knee bent and foot flat on the floor (a). Extend your left leg up to the ceiling and wrap a strap around the sole of your left foot (b). While holding both ends with your left hand, extend your right arm directly out to the side in order to anchor yourself (c). Slowly let the left leg fall toward the left while keeping your right side grounded. Hold for six to eight breaths, then repeat on the opposite side.
The lumbar (or lower back) region is made up of five vertebrae (L1–L5), sometimes including the sacrum. In between these vertebrae are fibrocartilaginous discs, which act as cushions, preventing the vertebrae from rubbing together while at the same time protecting the spinal cord. Nerves come from and go to the spinal cord through specific openings between the vertebrae, providing the skin with sensations and messages to muscles. Stability of the spine is provided by the ligaments and muscles of the back and abdomen. Small joints called facet joints limit and direct the motion of the spine.[30]
A recent study from Florida Atlantic University found that doing 45 minutes of chair yoga twice per week reduced pain and improved overall quality of life in older adults with osteoarthritis. Chair yoga is practiced sitting in a chair or standing while holding the chair for support, so it’s a great option for beginners or anyone dealing with an injury or balance problems.
Iliopsoas syndrome, which is also called psoas syndrome or iliopsoas tendonitis, occurs when the iliopsoas muscles are injured. Lower back pain is the most common symptom; however, pain can also occur in the hip, thigh, or leg. The iliopsoas bursa, which is a fluid-filled sac located on the inside of the hip that reduces rubbing and friction, is also likely to become inflamed due to the proximity of the two structures. When this happens, the inflamed bursae will make it difficult to move.
Nucleoplasty, also called plasma disc decompression (PDD), is a type of laser surgery that uses radiofrequency energy to treat people with low back pain associated with mildly herniated discs. Under x-ray guidance, a needle is inserted into the disc. A plasma laser device is then inserted into the needle and the tip is heated to 40-70 degrees Celsius, creating a field that vaporizes the tissue in the disc, reducing its size and relieving pressure on the nerves. Several channels may be made depending on how tissue needs to be removed to decompress the disc and nerve root.
Some of these red flags are much less red than others, especially depending on the circumstances. For instance, “weight loss” is common and often the sign of successful diet! (Well, at least temporarily successful, anyway. 😃) Obviously, if you know of a harmless reason why you have a red flag symptom, it isn’t really a red flag (duh!). But every single actual red flag — in combination with severe low back pain that’s been going on for several weeks — is definitely a good reason to get yourself checked out.