hi In the absence of any history of wear & tear or injury, constant calf muscle pain can be due to: 1. Deficiency of certain nutrients like Iron, Vitamin B 12, Vitamin D, Calcium, etc. which interferes with blood formation & nerve conduction. 2. Decrease in blood sugar levels (Hypoglycemia) 3. Any fluctuation in blood pressure levels such as Hypotension. 4. Hormonal imbalance like Hypothyroidism. 5. Lack of adequate hydration, proper nutrition & good sleep. 6. Even emotional factors like stress/tension can lead to such symptoms. Feeling of low levels of energy & chronic back pain can also be attributed to fatigue & above mentioned factors. Investigations like complete blood count, estimation of blood pressure and blood sugar levels will be helpful in clinching the diagnosis. So, it will be better to consult her General Physician & get a proper physical examination done to find out the exact cause.