I can't figure out what is causing my tennis elbow. I have it on both sides (in both elbows). I understand this problem doesn't just affect people who play tennis (I don't play), but I don't get why I have it in both arms.
True tennis elbow occurs when repetitive motion of the forearm and elbow causes microtrauma of the extensor carpi radialis brevis tendon where the tendon attaches to the elbow. It might seem funny but tennis elbow (also known as lateral epicondylitis) could be caused by a problem in the neck. In other words, it may not be coming directly from the elbow.
That same spot along the outside of the elbow that is linked with tennis elbow is where pain can also be referred when pressure is placed on the C67 nerve root. This condition is referred to as cervical radiculopathy. The C67 nerve root leaves the spinal cord in the lower cervical spine and travels from the neck down the arm. When this nerve gets pinched or compressed, neck and arm pain can develop with pain traveling down to the elbow and below.
With cervical radiculopathy at the C67 level, elbow pain can occur as a result of muscle weakness because the C67 spinal nerve is compromised. The elbow pain and dysfunction aren't caused by local microtrauma of the tendon at all but from altered muscle function as a result of the cervical radiculopathy. When nerve innervation of the muscles is interrupted, then weakness can make even everyday activities seem like overuse resulting in what looks like traditional tennis elbow.
Making the differential diagnosis is important because the treatment differs from trauma-induced (overuse) tennis elbow and cervical radiculopathy. Instead of just treating painful elbow symptoms locally (at the elbow), efforts are directed toward the neck as well. Unnecessary surgery can even be avoided.
The fact that you are having symptoms in both elbows is a tip off to look for a problem in the neck. Further testing may be necessary such as MRI, EMG, and nerve conduction tests. This will help rule out local nerve entrapment at the elbow and confirm the presence of a possible nerve compression in the cervical spine area.