I had a car accident 20 days ago.  There was an injury to the upper arm (tricep right above elbow) due to force.  There was acute swelling and bruising.  The brusising is gone but the pain and mass is still there.  There is also numbness only of the skin, not inside.
Hi, there! It will be useful to make Ultrasonography of Your triceps. As You described, there is no limitation in range of motion. The subcutaneous hematoma (mass) is related to skin numbness and will cure after time. The healing period can take 4-6weksI hope this helps