Most of the instances of lower back pain are a result of strain and over exertion which puts lots of tension on the muscles causing micro tears in the soft tissues around the lower lumbar region. These tears can stop or restrict blood circulation which leads to the pain receptors sending signals to the brain.
Lower back muscle spasms range from really awful pain to stiffness. However heat therapy has the ability to provide relief lower back pain as a result of reducing muscle spasms, stiffness and tightness.
When heat, such as with a microwavable wheat bag, is applied to the affected area it increases blood supply which causes your blood vessels to open up. The pinkness visible is actually the blood vessels expanding when heated.
When it comes to the spine the blood vessels around the spine are dilated when constant heat is applied. This increases the flow of fresh blood which brings oxygen and nutrients along hence decreasing healing times.
The increased flow of blood also helps in reducing muscle spasms as well as trigger points. This works because the pain can often be due to reduced blood supply so increased supply can do the opposite.
The increased blood circulation helps to relieve pain and its pain production centres which result from inflammation.
When a heat pack is applied to the area it works by activating the pain gate which is stimulated by the sensory receptors buried under your skin, it also helps to reduce the overall volume of your pain which the brain has to deal with. This is the same mechanism which is at play when you instinctively begin to rub an area on your body which has been accidentally banged. The heat you generate with rubbing helps to eliminate the transmission of pain. This is exactly how instances of awful pain are overtaken by the new sensation which takes up the bandwidth used to send pain signals to the brain. Your brain later just focuses on the heat as opposed to the pain which is considered a ‘counter irritant' according to modern medicine.
When a heated wheat bag is applied it also triggers your body's own pain killers called endorphins which help to ease the pain.
The heat also helps by stretching your spine's soft tissue which also includes your muscles, connective tissue and its adhesions. This reduces overall stiffness and injury with a higher instance of flexibility and the feeling of relief, since flexibility is imperative to a healthy back.
People suffering from back pain have reported that heat therapy works best when it is combined with other modes of treatment including physical therapy and exercise. However when compared to other treatments heat therapy is considered best since it is non-invasive and will not require drugs. You can simply use a microwavable wheat bag or heat pack which moulds itself to the contours of your back and helps relieve almost all instances of back pain.