Back pain can cause muscle weakness of this type. Other illnesses and diseases can also cause muscle weakness. Are you having any other symptoms of any kind? Are you in good overall general health?
The answers to these questions may give you an idea what to do next. If you are more tired than usual or having other symptoms like fever, sweats, or nausea, then a visit to the doctor is in order.
If you’ve had chronic back pain you may be losing strength from the pain. Fear of pain can cause changes in the way you move. You may be avoiding movement to avoid pain. This is called fear avoidance and could be leading to weakness.
Are you having any pain, numbness, or tingling down the legs or arms? Has your back pain ever been diagnosed properly? If you’ve answered ‘yes’ to more than one of these questions, see a medical doctor.
If you think it’s more likely that your weakness is linked to inactivity, see a physical therapist or fitness trainer.