The hip flexors are the group of muscles that allow you to lift your knees toward your chest and bend forward from the hips.  What is collectively referred to as the hip flexors is actually a group of muscles that includes the iliopsoas, the thigh muscles (rectus femoris, Sartorius and tensor fasciae latae), and the inner thigh muscles (adductor longus and brevis, pectineus and gracilis).
From a physical therapist’s perspective, these are excellent exercises for lower back pain (LBP) resulting from muscular tightness or stiff joints. However, LBP can also be caused by bulging (or “herniated”) discs, pinched nerves, and the like. If your LBP worsens (or radiates into your leg) upon attempting these or any other low back exercises, you should seek medical attention. Physical therapists are musculoskeletal experts that are able to properly evaluate and treat your back pain symptoms. And, according to a recently passed law in the state of Michigan, a physician referral is no longer necessary to seek treatment from a physical therapist. So, if you are experiencing LBP that is not improving…#getPT!
"Lower back pain is the most common musculoskeletal ailment in the U.S., and can often be mitigated by strengthening the core musculature," Blake Dircksen, D.P.T., C.S.C.S., a physical therapist at Bespoke Treatments New York, tells SELF. "The 'core' is a cylinder of abdominal and back muscles that wraps around the body like a corset," Dircksen explains. (The glutes are also considered a part of the core, since they connect to the pelvis and ultimately the back and abdominal muscles.) As with any muscles, by strengthening them, you will increase the amount of weight your lower back can comfortably move, which means it will be better equipped to handle the same stress from your workouts and everyday life without getting as achey.

A few cancers in their early stages can be hard to tell apart from ordinary back pain — a bone cancer in the vertebrae, for instance — and these create a frustrating diagnostic problem. They are too rare for doctors to inflict cancer testing on every low back pain patient “just in case.” And yet the possibility cannot be dismissed, either! It’s an unsolveable problem.

Degenerative bone and joint conditions: As we age, the water and protein content of the body's cartilage changes. This change results in weaker, thinner, and more fragile cartilage. Because both the discs and the joints that stack the vertebrae (facet joints) are partly composed of cartilage, these areas are subject to wear and tear over time (degenerative changes). Degeneration of the disc is called spondylosis. Spondylosis can be noted on X-rays of the spine as a narrowing of the normal "disc space" between the vertebrae. It is the deterioration of the disc tissue that predisposes the disc to herniation and localized lumbar pain ("lumbago") in older patients. Degenerative arthritis (osteoarthritis) of the facet joints is also a cause of localized lumbar pain that can be detected with plain X-ray testing. These causes of degenerative back pain are usually treated conservatively with intermittent heat, rest, rehabilitative exercises, and medications to relieve pain, muscle spasm, and inflammation.
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.
_{Degenerative bone and joint conditions: As we age, the water and protein content of the body's cartilage changes. This change results in weaker, thinner, and more fragile cartilage. Because both the discs and the joints that stack the vertebrae (facet joints) are partly composed of cartilage, these areas are subject to wear and tear over time (degenerative changes). Degeneration of the disc is called spondylosis. Spondylosis can be noted on X-rays of the spine as a narrowing of the normal "disc space" between the vertebrae. It is the deterioration of the disc tissue that predisposes the disc to herniation and localized lumbar pain ("lumbago") in older patients. Degenerative arthritis (osteoarthritis) of the facet joints is also a cause of localized lumbar pain that can be detected with plain X-ray testing. These causes of degenerative back pain are usually treated conservatively with intermittent heat, rest, rehabilitative exercises, and medications to relieve pain, muscle spasm, and inflammation.}
The more than 20 muscles that make up your hips are responsible for stabilizing your pelvis, moving your legs from side to side, and shortening to draw your knees toward your chest every time you sit down, run, jump or pedal, explains Kelly Moore, a certified yoga instructor and co-founder of Mindfuel Wellness, which brings health and wellness initiatives to companies throughout Chicago.
The medication typically recommended first are NSAIDs (though not aspirin) or skeletal muscle relaxants and these are enough for most people.[13][6] Benefits with NSAIDs; however, is often small.[67] High-quality reviews have found acetaminophen (paracetamol) to be no more effective than placebo at improving pain, quality of life, or function.[68][69] NSAIDs are more effective for acute episodes than acetaminophen; however, they carry a greater risk of side effects including: kidney failure, stomach ulcers and possibly heart problems. Thus, NSAIDs are a second choice to acetaminophen, recommended only when the pain is not handled by the latter. NSAIDs are available in several different classes; there is no evidence to support the use of COX-2 inhibitors over any other class of NSAIDs with respect to benefits.[70][13][71] With respect to safety naproxen may be best.[72] Muscle relaxants may be beneficial.[13]
If you’re worried you’re headed toward a surgeon’s office, there might be hope. According to the Arthritis Foundation, the best way to avoid hip replacement surgery is to get active in an exercise program. In a study, people who participated in an exercise program for 12 weeks were 44 percent less likely to need joint-replacement surgery six years later than those who did not exercise.
The hip flexors play an important role in everyday mobility and exercise. Involved in pulling the knee toward the hip, most movements either directly or indirectly use the hip flexors. That’s why even the slightest injury can cause great discomfort. Learn how you can recover from a hip flexor injury, and what precautions can be taken to avoid them.
^{Vertebroplasty and kyphoplasty are minimally invasive treatments to repair compression fractures of the vertebrae caused by osteoporosis. Vertebroplasty uses three-dimensional imaging to assist in guiding a fine needle through the skin into the vertebral body, the largest part of the vertebrae. A glue-like bone cement is then injected into the vertebral body space, which quickly hardens to stabilize and strengthen the bone and provide pain relief. In kyphoplasty, prior to injecting the bone cement, a special balloon is inserted and gently inflated to restore height to the vertebral structure and reduce spinal deformity.}

Women may have acute low back pain from medical conditions affecting the female reproductive system, including endometriosis, ovarian cysts, ovarian cancer, or uterine fibroids.[28] Nearly half of all pregnant women report pain in the lower back or sacral area during pregnancy, due to changes in their posture and center of gravity causing muscle and ligament strain.[29]

Prolonged sitting and activities like running or cycling can lead to tight hip flexor muscles and a variety of skeletal imbalances. Think: if you only cycle for exercise, certain muscles in your legs will get stronger (in a lot of cases you overwork these muscles) yet your core and outer hip muscles might get weaker from lack of engagement. So what? Well, these muscle imbalances often lead to skeletal imbalances and injuries down the line. If you have particularly tight hip flexors, your body will start to create an anterior pull on the pelvis (anterior pelvic tilt). You can identify an anterior pelvic tilt if your belly protrudes slightly in the front while your butt sticks out in the back (what some people refer to as “duck butt”).
Stop focusing on a specific diagnosis. Up to 85% of low back pain can be classified as "non-specific." This means that the origin of your pain cannot be localized to one specific structure or problem. While common diagnostic tests for low back pain can show the bones, discs, and joints with great detail, no test can tell the exact cause of your pain with 100% accuracy.
^{When you tell your doctor your hip hurts, the first thing she should do is confirm that your hip is actually the problem. Women might say they have hip pain, but what they may mean is that they have pain in the side of the upper thigh or upper buttock, or they may be experiencing lower back pain, says Stephanie E. Siegrist, MD, an orthopedic surgeon in Rochester, New York, and a spokeswoman for the American Academy of Orthopaedic Surgeons. Hip pain is often felt in the groin or on the outside of the hip directly over where the hip joint (a ball-and-socket joint) is located.}
_{Spinal manipulation and spinal mobilization are approaches in which professionally licensed specialists (doctors of chiropractic care) use their hands to mobilize, adjust, massage, or stimulate the spine and the surrounding tissues. Manipulation involves a rapid movement over which the individual has no control; mobilization involves slower adjustment movements. The techniques have been shown to provide small to moderate short-term benefits in people with chronic low back pain. Evidence supporting their use for acute or subacute low back pain is generally of low quality. Neither technique is appropriate when a person has an underlying medical cause for the back pain such as osteoporosis, spinal cord compression, or arthritis.}
Moist heat may help relax your muscles. Put moist heat on the sore area for 10 to 15 minutes at a time before you do warm-up and stretching exercises. Moist heat includes heat patches or moist heating pads that you can buy at most drugstores, a wet washcloth or towel that has been heated in a microwave or the dryer, or a hot shower. Don’t use heat if you have swelling.
^{To ease the pain and lower your odds of an injury, don’t try to do too much at once. “Start with just 10 minutes,” says Arina Garg, MD, a rheumatology fellow at The Center for Excellence for Arthritis and Rheumatology at the Louisiana University Health Sciences Center. “Every few days, increase that time by 5 to 10 minutes.” Your goal is to work up to 30 minutes of aerobic exercise, 5 days a week.}
Long periods of inactivity in bed are no longer recommended, as this treatment may actually slow recovery. Spinal manipulation for periods of up to one month has been found to be helpful in some patients who do not have signs of nerve irritation. Future injury is avoided by using back-protection techniques during activities and support devices as needed at home or work.
Keeping your hips mobile is important for overall hip function and athletic performance. Mobility refers to the ability of your joints to move through a pain-free, unrestricted range of motion. For cyclists, hip mobility is critical since pedaling occurs in one plane of motion, and after miles and miles in the saddle, hip tightness and restriction may develop. The following movements will help with hip mobility.

Paget's disease of the bone is a condition of unknown cause in which the bone formation is out of synchrony with normal bone remodeling. This condition results in abnormally weakened bone and deformity and can cause localized bone pain, though it often causes no symptoms. Paget's disease is more common in people over the age of 50. Heredity (genetic background) and certain unusual virus infections have been suggested as causes. Thickening of involved bony areas of the lumbar spine can cause the radiating lower extremity pain of sciatica. 

Sacroiliac joint dysfunction. The sacroiliac joint connects the sacrum at the bottom of the spine to each side of the pelvis. It is a strong, low-motion joint that primarily absorbs shock and tension between the upper body and the lower body. The sacroiliac joint can become painful if it becomes inflamed (sacroiliitis) or if there is too much or too little motion of the joint.

Stand tall with your hips square and bend your right knee, bringing your foot towards your bum. Grab the right foot with your right hand and actively pull the foot closer to your glutes. As you do this, send the right knee down towards the ground and keep both knees together. squeeze your butt to promote a posterior pelvic tilt and hold — then switch sides.