As has been highlighted by research presented at the national meeting of the American College of Rheumatology, a very important aspect of the individual evaluation is the patient's own understanding and perception of their particular situation. British researchers found that those who believed that their symptoms had serious consequences on their lives and that they had, or treatments had, little control over their symptoms were more likely to have a poor outcome. This research points out to physicians the importance of addressing the concerns and perceptions that patients have about their condition during the initial evaluations.
Premkumar et al present evidence that the traditional “red flags” for ominous causes of back pain can be quite misleading. The correlation between red flags and ominous diagnoses is poor, and prone to producing false negatives: that is, no red flags even when there is something more serious than unexplained pain going on. In a survey of almost 10,000 patients “the absence of red flag responses did not meaningfully decrease the likelihood of a red flag diagnosis.“ This is not even remotely a surprise to anyone who paid attention in back pain school, but it’s good to have some harder data on it.

The hip is a common site of osteoarthritis. To help protect the hip joint from "wear and tear," it is important to strengthen the muscles that support it. Your hip also controls the position of your knee, and strengthening your hips may be one component of your rehab program for knee pain. Your physical therapist may also prescribe hip exercises after total hip replacement if you have a hip labrum tear or as part of your hip exercise program for hip pain.
The hip rotators not only rotate the thigh on the pelvis but more functionally rotate the pelvis on the weight bearing fixed thigh. Activities such as swing a golf club, and even just walking require some rotation of the pelvis on the weight bearing leg.  While we don't need that much range of motion to walk, activities such as running, dancing, tennis, and many other sports can require more hip rotation.

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.
It is unclear if among those with non-chronic back pain alternative treatments are useful.[84] For chiropractic care or spinal manipulation therapy (SMT) it is unclear if it improves outcomes more or less than other treatments.[18] Some reviews find that SMT results in equal or better improvements in pain and function when compared with other commonly used interventions for short, intermediate, and long-term follow-up;[19][20][85] other reviews find it to be no more effective in reducing pain than either inert interventions, sham manipulation, or other treatments, and conclude that adding SMT to other treatments does improve outcomes.[17][21] National guidelines reach different conclusions, with some not recommending spinal manipulation, some describing manipulation as optional, and others recommending a short course for those who do not improve with other treatments.[3] A 2017 review recommended spinal manipulation based on low quality evidence.[6] Manipulation under anaesthesia, or medically assisted manipulation, has not enough evidence to make any confident recommendation.[86]

^ Enke, Oliver; New, Heather A.; New, Charles H.; Mathieson, Stephanie; McLachlan, Andrew J.; Latimer, Jane; Maher, Christopher G.; Lin, C.-W. Christine (2 July 2018). "Anticonvulsants in the treatment of low back pain and lumbar radicular pain: a systematic review and meta-analysis". Canadian Medical Association Journal. 190 (26): E786–E793. doi:10.1503/cmaj.171333. PMC 6028270. PMID 29970367.

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.