News broke yesterday that Iman Shumpert will miss 12-14 weeks after undergoing surgery to repair a ruptured tendon in his wrist. The tendon was the extensor carpi ulnaris, which naturally made things confusing:

HOW THE HELL DID HE SPRAIN AN ENTIRE FRATERNITY HOUSE IN HIS WRIST — FearTheSword (@FearTheSword) September 29, 2015

As always, there are questions to be answered, both about what the injury is and how it affects Shumpert. Let's try to answer both.

Extensor Carpi What Now?

The extensor carpi ulnaris is one of the three muscles in the wrist primarily responsible for extending the wrist (Push against a wall, and this is the direction your wrist moves). The extensor carpi ulnaris runs from the elbow along the ulna to the pinky side of the wrist, where it attaches to the metacarpal bone of the fifth digit. It has two siblings on the thumb side that run along the radius, called the extensor carpi radialis longus and brevis. Observe:

(Image from realbodyworks.com)

These muscles contract together to extend the wrist, but the extensor carpi ulnaris can contract by itself to move the wrist and hand towards the pinky, or ulnar, side.

How can this tendon rupture?

Per the British Journal of Sports Medicine, this is a very rare injury in sports. Most commonly it's seen in tennis or golf, where the tendon can be stressed through repetitive flexion and extension of the wrist. It's also seen in rugby, where carrying the ball is done in a position of wrist flexion, supination (palm facing up), and radial deviation of the wrist, which puts the tendon in a vulnerable position during contact. Much like a patellar tendon rupture or Achilles rupture, there is more often than not a history of tendon inflammation or subluxation (the tendon moving abnormally within of its connective tissue sheath) that leads up to tendon sheath rupture.

While this is extremely rare in basketball, it can occur because of the combination of shooting causing repetitive stress, and potential for traumatic injury. I do not have #Sources, so this is purely speculation, but my guess in Shumpert's case is that he has had wrist issues that were ongoing, and catching his hand on the rim in practice caused the tendon sheath to rupture.

How is it fixed?

Surgically there are a few options, but per Radsource, the most common repair is to take a piece of connective tissue from the wrist and re-tether the tendon down the tendon with a new sheath. After the tendon repair, the wrist is casted in an extended position for four weeks to allow the tendon to heal, and then rehab can begin. Rehab will focus on first returning wrist flexion and finger range of motion, and return grip strength, which is commonly lost during periods of immobilization. After that, forearm and hand strength can be regained, and at that point Shumpert will likely return to basketball activities.

What are the long-term basketball effects?

This could be a big problem for Shump, given that it's his shooting hand. A wrist extensor injury could definitely change his shooting stroke, and he's going to have to work very hard to try to regain his form, and potentially change his form slightly so that it doesn't over-stress the newly repaired tendon. The long-term effects on his shooting are difficult to predict, just because wrists are incredibly fickle and the extent of the injury can't truly be gauged until surgery is performed. Also, this is just an injury we don't commonly see. Fractured or sprained wrists are somewhat common in the NBA, but a ruptured wrist extensor tendon is a weird occurrence in basketball. This just doesn't happen often, so it's hard to draw predictions based on prior cases like we can with something like an ankle sprain or an ACL tear.

However, based on the anatomy, there are some things we can assume might be issues. Because of the strain placed on the tendon by extending the wrist, I'd expect Shump to struggle shooting the ball initially, as he regains wrist strength and attempts to correct his form. Dribbling might be affected as well, though that's not something Shumpert has ever been particularly good at, so I don't know how much of a dent this puts on things. I also wouldn't be surprised to see him be a little bit tentative to be physical defensively right off the bat. A lot of the things you have to do defensively to make plays - deflecting passes, blocking shots, pushing guys off spots - require either an extended wrist or a force to be placed on the wrist that the ECU tendon will have to absorb. I wouldn't be surprised to see that Shumpert is a little timid in defensive playmaking for the first couple of weeks after he returns as he regains confidence in the joint.

However, I also don't see this being a long-term problem for Shumpert, either. His shot will likely take the longest to recover, but this could be something that ultimately ends up improving his shooting, as he will likely work on improving his release during his rehab, and this could result in a more consistent shot. It remains to be seen exactly how this will affect Shumpert though, as it's a very interesting case. I will be eager to follow Shump closely after he returns in January, and see just how it affects him as he returns to play. I don't expect it to be a huge issue, but we just don't have a great idea at this point.