Shoulder Injuries in Throwing – Chris Hook (Physiotherapist)

 

Strength

As previously mentioned the rotator cuff plays a vital role in the stability of the shoulder. These muscles play an important role in the deceleration phase of the throwing mechanics. Without good strength in our external rotator cuff musculature the shoulder isn’t able to decelerate adequately which puts a greater force through the shoulder and makes the shoulder susceptible to injury. Research has shown that strengthening the muscles that help slow down the arm will allow the body to generate greater forces in speeding the arm up and create greater torque. Strengthening exercises need to be performed for both the musculature around the scapula and the shoulder. These muscles need to have good ratios between the opposite muscles to help facilitate good range of motion, maximise performance and reduce injury risk. Like any other body part these small stabilising muscles need to have a focused strengthening phase performed for them. Strengthening can be performed with either resistance band, dumbbells or cable; Dumbbells and cables are the preferred method as they allow for a progressive approach and an equal resistance throughout range of motion.

Overhead athletes particularly throwers are faced with a predicament; the throwers shoulder must have enough laxity to allow excessive external rotation, but stable enough to prevent symptomatic humeral head subluxation, creating an intriguing balancing process for mobility and functional stability. It is when this balance is not maintained that a variety of injuries to the surrounding tissues can occur3.

High rotational forces experienced by the shoulder during the acceleration and deceleration phases of the movements place the soft tissue structures at rick of microtrauma and an ensuing injury. The shoulder rotates at up to 7000 ͦ/sec through the late cocking phase as it accelerates to the follow though4

 

Overload

Like any activity a period of building up is required to reduce the risk of overload and overuse injuries.  In adolescence it was shown that there is a 4 times increase in shoulder injuries in throwing athletes whom threw over 80 pitches in the one game and 5 times increase for those which pitched  for 8 months or more per year.5 Management of throwing loads can be achieved in a number of ways in many sports which do not affect the overall playing participation and performance these include; cricket – restricting fielding positions during games and the number of throws during fielding practice, baseball – most young leagues have restrictions on pitch limits and then positions which they can play following pitching, these can also be managed at training again by limiting the throws made during fielding practice. These simple strategies allow for monitoring of the throwing volume and intensity throughout the week which can be useful. The body needs time to recover and adapt to the load placed on it while throwing to avoid repetitive and overload cycle which can result in injury.

Total body strength and kinetic chain

Many injury that happen at the shoulder may actually come from a weakness or poor biomechanics further down the kinetic chain which places a greater load or stress on the shoulder of the throwing athlete.

Key area which overhead athletes need to work on to help limit shoulder injuries include but not limited to the following 7

• Lumbar and thoracic spine mobility

• Hip and pelvic mobility

• Pelvic and truck stability

• Trunk strength for energy transfer

• Lower limb strength

Without these key kinetic chain areas both performance can be decreased and the associated injury risk is significantly increased in the shoulder. Thus providing a stable base for the arm motion and providing a rotational momentum for force generation to occur. If this cant not be achieved the arm is then forced further behind the body which puts it in a position of greater vulnerability for the structures of the shoulder.4 There have been a number of studies which have shown over 50% of throwing velocity is generated in the lower half of the body.

Throwing mechanics

Correct throwing mechanics play a vital role in the prevention of injuries in the overhead athlete, without correct mechanics increased forces are placed on the shoulder;

Some key factors to look at with throwing include; keeping your hand on top of the ball, delaying truck and pelvic rotation and keeping shoulder and landing leg closer and pointed at the target.

If you would like to have your throwing mechanics assessed you should talk to your physio or a high level throwing coach to have them look at your throwing technique.

Exercises

There are a number of exercises which can be performed to help with preventing throwing injuries. If these are incorporated into your training, then over time they can help reduce your risk of injury. The best person to assess and prescribe these is  Physiotherapist with a special interest in throwing.

References

1. Orthoinfo.org. (n.d.). Shoulder Injuries in the Throwing Athlete - OrthoInfo - AAOS. [online] Available at: https://www.orthoinfo.org/en/diseases--conditions/shoulder-injuries-in-the-throwing-athlete/ [Accessed 29 Jun. 2018]

2. Loudner, K. and Sipes, R. (2009). the incidence of shoulder injury among collegiate overhead athletes. [ebook] journal of intercollegiate sport, pp.260-268. Available at: http://www.humankinetics.com/acucustom/sitename/Documents/DocumentItem/17656.pd [Accessed 28 Jun. 2018].

3. Wilk et al. Shoulder Injuries in the Overhead Athlete. J Orthop Sports Phys Ther. 2009;39(2):38-54. Article

4. Burkhart, S., Morgan, C. and Ben Kibler, W. (2003). The disabled throwing shoulder: spectrum of pathology part III: the SICK scapula, scapular dyskinesis, the kinetic chain and rehbilitation. Arthroscopy: The Journal of Arthroscopic & Related Surgery, 19(6), pp.641-661.

5. Olsen S, Fleisig G, Dun S, Loftice J, Andrews J. Risk Factors For Elbow and Shoulder Injuries In Adolescent Baseball Pitchers. The American Journal of Sports Medicine. 2006; 34(6): 905-912

6. Reinold, M. (2013). What You Need to Know About GIRD; What It Is and What it Isn’t. [online] Mike Reinold. Available at: https://mikereinold.com/gird-glenohumeral-internal-rotation-deficit/[Accessed 29 Jun. 2018].

7. Seroyer, S., Nho, S., Bach, B., Bush-Joseph, C., Nicholson, G. and Romeo, A. (2010). The Kinetic Chain in Overhand Pitching: It’s potential Role for Performance Enhancement and Injury Prevention. Sports Health: A Multidisciplinary Approach, 2(2), pp.135-146.

About the Author.

Chris Hook is a Physiotherapist who is also a baseball catcher. He has played baseball under a college scholarship in the USA and still an active player in the Newcastle competition.