Hello, * Most possible reason is seeming sprain or strain which has gone unnoticed during the gym work out. * My guidelines at present - heating pad application 3 times a day 5 minutes each - local application of analgesic spray or ointment consisting of diclofenac, menthol or camphor - tablet ibuprofen or diclofenac for 2-3 days after meals 3 times a day depending upon the pain score out of 10 (provided no history of drug sensitivity to the same molecules). * X-ray may be a requirement of future if there is no significant recovery from the above measure, which would be a very unlikely possibility. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr Bhagyesh V. Patel, General Surgeon