Two separate things here. The dull ache at the injection site is ordinary post-injection myositis - Neurobin is thick and irritant; with no swelling, redness or heat there is no abscess, and it settles over 1-2 weeks with warm compresses and gentle movement. The bigger issue is the pain running from the buttock down the back of the thigh, calf and foot, and the same in the arm from the armpit down - that is nerve root pain, not injection related, and both limbs plus an arm points to a cervical/lumbar spine or a
B12/peripheral neuropathy problem that needs examination.
Next Steps
Warm compress on the thigh twice a day and keep walking. For the radiating pain get a physician/neuro examination with CBC,
HbA1c,
vitamin B12,
vitamin D,
TSH and
calcium; spine imaging only if the examination suggests it. Get seen urgently if you develop weakness, numbness in the saddle area or urinary difficulty. Consult me on Practo or at Synergy Multispeciality Hospital, Miraj for a proper nerve examination.