There are many different things that a hard boil type knot with no core on the lower part of the back could be. It could be infection.
sure
calves core biceps and lower back
is it white
The superman exercise is good for strengthening your lower back. Just like crunches for example strengthens your core. Having a strong lower back is beneficial for heavy compound exercises like squads and aids in a stronger all round core so do them with your core exercises.
Lower mantle heats up, rises out to the crust/upper layers of earth, cools down, then circulates back to the core, heats back up, rises, etc. (circulates like ocean currents)
how are the lower mantle and the inner core diffrent
how are the lower mantle and the inner core diffrent
how are the lower mantle and the inner core diffrent
No. The top hose goes to the engine. The bottom hose feeds from the engine to the heater core back to the radiator.
I'm not aware of any pain that can be done to the back specifically unless you have poor form which puts strain on your lower back muscles. Ideally you're supposed to be working your core. If you feel pain in your lower back then you should stop.
The lower mantle is about 7,200 degrees F, while the inner core is about 10,000 degrees F. The inner core is the innermost layer and the lower mantle is the 5th innermost layer.
Poor core strength, meaning you're using your lower back muscles when you shouldn't be. Don't do so many at once.