It may be mechanical...
Before I start..
I just want to remind you that the information in these posts is not designed to diagnose or treat your symptoms of lower back pain. It is intended purely to help shed some light on what may be causing your discomfort.
As the title says, your symptoms of back pain may be due to a mechanical change/injury.
When we say mechanical, all we mean is... structures that are designed to move. Think along the lines of gears, pulleys, and hinges. This may include a combination of joints, muscles, ligaments, discs, and/or tendons.
When your symptoms are made worse by slouching forwards, we say that your body isn't tolerating the flexed position. This is important information that may point your therapist in the direction of a possible disc bulge type injury. The good news is that the majority of disc bulge patients will recover within 6-8 weeks. However, it's important that you stay active during this time to promote recovery. Additionally, there are a set of exercises, known as "McKenzie exercises", which research has shown to be effective for disc bulge symptom management.
Sometimes your symptoms may be made worse with an extension-style movement, for example bending backward. People with an extension intolerance may also find it hard to lay flat on their bellies. This gives your therapist information about possible fractures in the spine or conditions that may be causing the space where nerves travel through to become narrow, know as spinal stenosis.
Extension with rotation intolerance
This is similar to the previous, however, now we have an added element of rotation too. This usually means that reaching back and down your thigh, like you would if you were scratching your hamstring, would be painful. This may indicate some irritation in one of the joints in the spine, which are called facets. Similarly, this may also be a sign of stenosis.
If your back pain is made worse by activities that cause compression of the spine, such as having a barbell on your back, landing from a jump, or running, this may point to conditions such as osteoarthritis. In which case either age-related or injury-related factors may have led to changes in the structure of the spine bones, which is then producing painful symptoms when compressed.
Furthermore, the muscles in your back may also play a role in the symptoms of back discomfort you are experiencing.
suboptimal postural positions may lead to fatigue in certain muscles, which then becomes an issue over time. This may be due to the way you are sitting, the way you are standing/moving, and/or the way you spend your time at work.
Sometimes muscles may become painful when they need to compensate for other muscles that may be "sleepy". This is commonly seen in people who spend a lot of time sitting for work and have glute muscles that have trouble activating to stabilise the pelvis.... sometimes we refer to this as "glute amnesia"
If your work or a common daily task you perform is repetitive in nature, this too may lead to muscular issues over time. A common example we all use is a supermarket checkout person, who is always scanning and bagging, whilst rotating in the same direction for 9-hours a day.
However, in saying all this...
It's not uncommon for your symptoms to be the result of a combination of multiple factors.
Afterall, the lower back is a complex junction that connects your upper body to your lower body
But rest assured....
When you visit your allied health professional/therapist, these are just some of the things we will be thinking about when you describe what you're feeling.
Then the detective work and puzzle solving starts