My father is suffering from severe back pain. Can it be treated with manual adjustment of the spine?
However, there are many metabolic disorders, genetic disorders, etc... example would be GAD1 enzyme antibodies causes, ( https://en.m.wikipedia.org/wiki/Stiff_person_syndrome) or AS (Ankylosing spondylitis).
So, make an appointment with someone that is referred to by a trusted source such as another doctor or a few friends. Read reviews and plan on giving health history along with any blood work to help aid in the diagnosis. Imaging is always helpful
Muscle pain or Nociception, can be shortly inhibited by activation C-fibers for a short time will inhibit the type 4 nociceptors. so will a tens unit.
Cupping, cross tissue massage, Graston Technique, Active release technique, etc are designed to help repair muscle tissue faster after injury. Manipulation to keep joints mobile and joint fluids hydrated due to lack of blood vessel all improve time of healing.
In short, a Chiropractor is taught how to improve the quality of muscle tissue and healing. This should improve the pain both directly and indirectly.