Blog for Professionals, Healthcare

Treating the competitive volleyball player series, Part 2: Shoulder Impingement Assessment

Congratulations to TEAM USA on their BRONZE medal and TEAM CHINA on their GOLD medal yesterday. Not the outcome that TEAM USA wanted, but it is still a medal and everyone played their hearts out. TEAM CHINA showed that they had the grit to grind it out against a very tough SERBIAN team.

While there can be a plethora of shoulder injury diagnoses in volleyball players, the most common would be overuse of the shoulder leading to impingement (of either form, subacromial or posterior/internal impingement). Front row attackers (hitters) have the highest risk of shoulder injuries due to the high number of repetitions (Top NCAA Division 1 hitters can reach up to 1,600 swings in a season, with an average of 40-50 swings  match*). *This number may not be accurate due to variability in number of sets and points in each set (3 vs. 4 vs. 5 set matches) – it also depends on if the team heavily relies on one athlete for offense or not.

The pathology of subacromial impingement is that the tendon of the supraspinatus muscle is “pinched” under the coracoacromial arch – the supraspinatus muscle passes inferior and anterior to this arch and when the shoulder is flexed in a neutral position, this muscle/tendon is jammed against the inferior portion of the coracoacromial arch. This can also irritate the subacromial bursa, leading to increased pain.

Posterior, or internal, impingement is when the posterior/superior aspect of the labrum is impinged on the underside of the supra and infraspinatus muscles; mostly secondary to laxity in the anterior capsule in overhead athletes.

In most literature, the pathology will focus on the glenohumeral joint and the immediate surrounding/involved structures. However, much of the pathology stems from elsewhere – thoracic spine, cervical spine, costovertebral joints, scapulothoracic “joint” etc… For example, if the client’s thoracic spine is hypomobile or “stuck” in extension, this will induce a relative “anterior tilt” of the scapula (posterior/inferior rotation of the costovertebral joint). If you were to only work on the glenohumeral joint, you’d get no where in your treatment because the CAUSE is NOT the GH joint, but the lack of mobility in the thoracic spine.

costovertebral extensionposture comparison

As you can see from the above image, a flattened T spine (middle image) can also predispose a client to forward head/rounded shoulder posture, thereby increasing the risk of shoulder impingement and muscle imbalances. In this situation, the client’s posture will increase pec minor and major compensation in an overhead athlete due to increased activation while trying to stabilize overhead and during follow through.

Lower traps and serratus anterior may be inhibited or dysfunctional in this posture. Lower trap inhibition reduces overall AROM in flexion – the lower traps are responsible for the final 10-15deg of flexion through inferior stabilization of the scapula, allowing room for GH joint to continue into flexion. If the scapula was not stabilized inferiorly, it would get in the way in the terminal degrees and cause pain and impingement. Lower traps would also act as a counterforce to the pec minor muscle in this situation. Serratus anterior is responsible for upward rotation of the scapula as well as improving congruency between the scapula and the rib cage. If inhibited, can lead to poor congruency and may lead to increased dominance of pec minor/major as well as winging of the scapula.

Another aspect that should be investigated is the SC/AC joint. Often neglected in shoulder rehab, but the SC joint is required to glide inferior and rotate posterior during shoulder elevation. The clavicle is the one bony connection of the scapula to the thorax. If the proximal end of the clavicle does not glide and rotate properly, it will negatively impact the AC joint at the distal end. This, ultimately, leads to poor gliding between the acromion and clavicle – decreasing overall shoulder flexion.

While subacromial impingement is the more talked about form of impingement, Internal/posterior impingement is quite common in the overhead athlete such as baseball pitchers and volleyball players. Any athlete that goes through a similar motion to the “throwing arc” is at risk for developing posterior impingement. This is when there is anterior laxity (or instability) and posterior shoulder pain due to pinching between the underside of the supra/infraspinatus and the posterior capsule/labrum.

Athletes will typically present with Glenohumeral Internal Rotation Deficit (GIRD), where they will have excessive external rotation and lack shoulder internal rotation. This is due to the requirements of their respective sport. In volleyball, if the setter sets the ball to the middle many aspects can go wrong and can lead to the middle hitter compensating to reach for the ball: 1. If the middle hitter’s approach and take off is in front of the hitter, often times the set will be behind the hitter and therefore, in order to hit the ball, they will be reaching way behind them, increasing anterior GH stress. 2. If the setter’s location is off and the set drifts off the net, the hitter will be in the same situation as #1. In both cases, there will be increased anterior capsule stress which can lead to laxity over time. However, only one of these situations is controllable by the hitter (#1).

In many cases, many therapists may give the “Sleeper Stretch”. This is because many believe that the posterior capsule is “tight” and that stretching it will help. In one study conducted by Borsa et al, it was shown that, in fact, the opposite it true – there isn’t “tightness”, but rather laxity in the posterior capsule in many cases. Therefore, the sleeper stretch is not a good idea. It also places the shoulder into further “impingement” if you think about it.

However, deficits in internal rotation can also be traced back to the thoracic spine – if you think about it, you need a bit of CONTRALATERAL thoracic spine rotation to reach up your back (L rotation for R IR up the back). In Treating the Overhead Athlete series, Part 4 I go over sidelying rib cage mobility. This exercise is a good one to give as a home program so that the athlete mobilizes their rib cage and T spine into contralateral rotation.

https://instagram.com/p/BG8nJlunq_O/
The above link is a video of Foluke Akinrawdewo, 2012 Olympic Silver Medalist/2016 Olympic Bronze Medalist/3x First Team All-American during her time at Stanford University. She is a great Middle Blocker and in the above video she is hitting a “slide” where the middle takes off one foot -like a lay up in basketball – behind the setter. It may appear that she is putting her shoulder into further impingement or hurting it.This is a common issue for volleyball hitters. Due to the dynamic nature of the sport and the high number of variables, there is never a black and white answer. As a MIDDLE hitter, Akinrawdewo has to commit to her approach and take off – it is very hard for her to adjust her approach speed and step length once she commits to a play. The setter (Alisha Glass in the above video – 3 time NCAA D1 Champion at Penn State, First Team All American) is taught to put up a hittable ball – in this case against 2 blockers, she cannot/should not put the ball too tight to the net. The ball also can drift off it’s trajectory mid set and the hitter will need to adjust their ARM to hit the ball (cannot adjust their approach very easily from the middle due to the speed of the game).

That was a lot of volleyball jargon. I am in no way criticizing Alisha Glass or Foluke Akinrawdewo – they understand the mechanics of their game as well. This is a snapshot into some of the problems of treating an athlete.  The main point and take away is that when/if you’re treating a volleyball player, DON’T JUMP TO CONCLUSIONS! This is actually very important when treating any athlete. You can try to correct their approach and arm swing, but realize that a lot of it is out of the athlete’s control due to the speed of the game and the number of variables involved. It is out job as sports physical therapists to make sure that out athletes can adapt to any situation during a game.

References:

Escamilla, R. F. et al. Optimal Management of Shoulder Impingement Syndrome. J Sports Med. 2014; 5: 13–24.

Paine, R. et al. The Role of the Scapula. Int J Sports Phys Ther. 2013 Oct; 8(5): 617–629.

Manske, R. C. et al. Shoulder Posterior Internal Impingement in the Overhead Athlete. Int J Sports Phys Ther. 2013 Apr; 8(2): 194–204.

Borsa, P. A. et al. Mobility and Stability Adaptations in the Shoulder of the Overhead Athlete. Sports Medicine. 2008 Jan; 38(1): 17-36

http://iiplab.com/biomechanics-of-the-thorax/

 

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