The left image above is one of the tests used for the diagnosis of TFCC. Push/bend your hand towards your little finger to compress the TFCC between the forearm bone (ulna, right image) and the triquetrum that makes up the hand to see if it causes pain.

This means that the closer these two bones get to each other, the more likely the TFCC is to get compressed in between. Very rarely, some people are born with the longer ulna, but in most cases, the two bones will come close due to poor posture or tightness of surrounding muscles.

Firstly, if the structural alignment is poor due to poor posture, such as rounded shoulders, the arms will roll inwards. Then, the bones that make up the forearm also become twisted as the whole arm rotates. In addition, the arm line (See the images below) from the back of the shoulder to the pinky also gets twisted and lengthened in the rounded shoulder posture, which means the muscles in the line can weaken over time.

Weak muscles cannot provide stability to the outside of the wrist where the TFCC is located. Instead, they are more likely to become tight due to overload and strongly pull the ulna and triquetrum closer to each other during daily activities.

Secondly, the tendons that pass near the wrist can become painful and misunderstood as pain caused by TFCC injuries. For example, when the Extensor Carpi Ulnaris muscle (ECU, see the images below) gets tight, it will pull its tendon away from the attachment, which can cause friction between the tendon itself and the protruding bone on the outside of the wrist. This sometimes makes a clicking sound, and If continued, the tendon eventually becomes inflamed.

In particular, if there is pain even though no TFCC damage was found in imaging tests such as an MRI, it is likely to be a problem with the tendon constantly being rubbed/irritated.

In fact, studies on various musculoskeletal conditions such as lumbar disc injuries and hip labral tear have shown that structural damages on MRI are not directly related to pain. Although they are not about TFCC, it is likely that TFCC damage on an MRI is not associated with pain too. The more important thing here is to continue to manage what you can actually do to help with the condition rather than simply linking it to pain unconditionally and giving up.