Below are the main rubriks (i.e strongest indications or symptoms) of Natrum Phosphoricum in traditional homeopathic usage, not approved by the FDA.
Arm (l.) feels gone, tired.
Arms weak, must let them drop.
Heaviness of r. arm.
Contraction of extensors in back of arm, often, when writing.
Rheumatic pain in r. shoulder; feels nervous.
Shooting pains from neck over r. shoulder.
Deep-seated pain in r. wrist going into palm.
Drawing cramping; paralytic aching (during menses) in r. wrist.
Numbness in r. hand and arm.
Crampy pain in l. hand, esp. index finger.
Numbness in r. fingers, occasional darting, agg. ring fingers.
Severe shooting pains in l. middle and index fingers.
Sudden giving way of legs while walking, as though they would be paralysed.
Sharp, shooting front of l. thigh.
Knees feel as if tendons shortened; (also at menses).
Stitching in l. knee.
When walking calves feel pulled tight, as if needles piercing calf.
Pain in ball of foot; in (r.) big toe.
Much itching at ankle-joints; even eczematous eruption.≡ more ...