My arm is sore and feels like it is locked at the elbow ?

How long?: If you did a lot of recent activity with the arm, the soreness may be muscular and should improve in 3-4 days. If your elbow actually locks in place where you can not bend or straighten it that's different. If it locks that is usually a sign of a piece of loose or damaged cartilage in the elbow and should be evaluated by your primary care doctor or an orthopedist.

Loose body.: If your elbow motion is compromised, you may have a loose body floating in the joint, or, it may be contractures of soft tissue. Nonetheless, you should see an orthopedic elbow specialist for accurate diagnosis and treatment.