Could Stiffness In Muscles And Joints Be Due To Low Thyroid Levels?

Hashimotos patient ft3: 323, ft4: 1.1 tsh: 0.02 on 180 mg armour per day...experiencing muscle & joint stiffness, soreness and weakness...i have read my T3 could still be low, but my dr will not increase dosage, even though a few years back when i experienced this, the dose was increased and symptoms completely went away. There is still room to increase this dose and be within range, correct?