PitchFX Forensics: Julio Urias and Anterior Shoulder Capsule Tears

The Dodgers Julio Urias is done for the year, and probably most of next season, with a torn Anterior Capsule – a devastating shoulder injury. The anterior capsule is a combination of ligaments which provide stability to the shoulder. Have you ever heard someone state that they had “a frozen shoulder”? Well, frozen shoulders (or, adhesive capsulitis), is impingement of that same capsule, and it results in huge range of motion loss, and incredible discomfort. You can imagine how damage to that structure would be catastrophic to a pitcher.

A review was completed by Dr. Lawrence Gulotta and colleagues (2014) on the surgical procedures used to repair anterior shoulder capsule tears in professional baseball pitchers. They reviewed the cases of 5 professional pitchers who suffered this injury, and found 4 of these pitchers returned to play in an average of 13.3 months (between 8 and 18 months). What is concerning about this research, is the conclusion the authors write about in their abstract; “Anterior capsular tears can occur in older throwing athletes”. The mean age in this review, was 33.5 years, with an age range of 31 to 37 years. Julio Urias is only 20 years old. This type of injury is incredible uncommon in someone of his age.

Examining the list of players who have suffered from this injury, there are a lot of pitchers who were never quite the same again after having this procedure – Johan Santana (2010), Chris Young (2010), Rich Harden (2012), and Dallas Braden (2011). In those cases, the age factor is working hard against these pitchers – they were likely in the portion of their career where they had begun to see a decline in their Stuff. After taking off a year to rehabilitate the shoulder injury, they were one year older, and one year closer to the end of their careers. Urias will be an interesting case for this type of injury – he is so young that he will provide a glimpse as to what is possible in returning to peak form after an Anterior Shoulder Capsule injury.

It’s difficult to identify any primary risk factors that are tied to this type of injury, as it such a rare injury – there are no epidemiological links to contributing factors. In general, pitchers are more susceptible to elbow and shoulder injuries, when they have higher pitching loads per game, and per season (Lyman et al., 2002). Urias has had his workloads carefully monitored, and posted his highest inning total of his career in 2016 – throwing 122 innings across all levels. In all of those games, he never threw more than 100 pitches – hitting the 100 mark once, on June 28th, 2016. These signs all point to a conservative approach for managing Julio’s workload.

Researchers have long identified muscle fatigue as a risk factor for injury. I have attempted to characterize fatigue as a decrease in maximum fastball velocity during a start. I looked at all of Julio Urias’s starts, and something interesting emerged:

Urias has remarkably high stamina during most of his starts in 2016. His final fastball velocity often was higher than his initial fastball velocity. His 2017 season started the same way – but as you can see in that graph, the separation between initial and fastball velocity dropped in his four starts, with a near 2% decrease in his velocity in his final start. This fatigue effect is more than likely a factor of his shoulder injury and impairment, moreso than the cause of the injury. Still, in the 2017 starts – there is a clear difference between his performance compared to the 2016 season.

All the best to Julio – this is a terrible injury for a pitcher to sustain. Hopefully he bounces back stronger than ever, living up to his massive potential.

We hoped you liked reading PitchFX Forensics: Julio Urias and Anterior Shoulder Capsule Tears by Mike Sonne!

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Ergonomist (CCPE) and Injury Prevention researcher. I like science and baseball - the order depends on the day. Twitter: @DrMikeSonne

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Are the starts are supposed to be chronologically ordered left to right in the graph? The April 27, 2017 start label is between the May 9 and May 14 starts

Rollie's Mustache

And the June 2, 2016 start is also inserted between two August 2016 starts for some reason.

Still interesting data though. Despite the Dodgers’ comment about it being a “sudden” injury and not an issue that was ongoing, something about that capsule may have not been right before his final start of the year.

If there’s good news in this it’s that Dr. ElAttrache was more optimistic after actually going in and looking at the shoulder during surgery. Fingers crossed Urias has a long and productive career.