Thrower's Shoulder

Original Editors - Samuel Jacob Melnick

Lead Editors- Severo Saenz, Samuel Jacob Melnick, Ian Wallace, Matthew Seliga

Introduction

Overhead throwing places exceptionally high stresses on the shoulder. The thrower's shoulder must be loose enough to allow excessive external rotation but stable enough to prevent symptomatic humeral head subluxations, requiring a delicate balance between mobility and functional stability. This balance is frequently compromised and believed to lead to various types of injuries to the surrounding tissues.

Epidemiology/Etiology

Throwing injuries in the shoulder often occur in baseball pitchers, they can be seen in athletes partaking in sports that require repetitive overhead motions, examples being volleyball, tennis, and some track and field events. 

Throwing biomechanics help explain why the following injuries occur in defined phases:

• Windup - No injuries are common.
• Cocking - Anterior subluxation, internal impingement, glenoid labrum lesions, subacromial impingement.
• Acceleration - Shoulder instability, labral tears, overuse tendinitis, tendon ruptures.
• Deceleration - Labral tears at the attachment of long head of biceps, subluxation of the long head of biceps by tearing off a transverse ligament, lesions of the rotator cuff.
• Follow Through - Tear of the superior aspect of glenoid labrum at the origin of the biceps tendon, subacromial impingement.

Further Information

The client will present with the classic signs of Internal Impingement of the Shoulder. For up to date information see this page covering all aspects of the condition. Internal Impingement of the Shoulder

Examination

The physical examination of an overhead throwing athlete should involve a thorough upper quarter examination that includes the joints above and below the shoulder. The injuries incurred by these athletes are wide-ranging, requiring an in depth evaluation to tease out the pathology. The basis of the examniation should involve: observation, palpation, range of motion assessment, flexibility testing, manual muscle testing, joint accessory motion, and special tests. Comparisons should be made between the involved and uninvolved shoulders looking for hypertrophy or atrophy of muscles as well total ranges of motion. Due to the tremendous involvement of the shoulder girdle, examinations of the the overhead thrower should  investigate scapulothoracic rhythm as well as the individual motions at the AC, SC, and GH joints. The anterior, inferior, and posterior portions of the joint capsule must be evaluated to determine whether a hyper or hypomobility is present. The following chart gives an itemized examination of the key points of the physical examination.

A lower quarter examination is imperative for these athletes as well. Decreased knee flexion from stride foot contact through the release phase has been correlated with higher pitching velocities, so adequate knee strength and stability should be addressed. Optimal hip alignment has not been established in that it varies depending on what type of pitch is thrown and the type of delivery used by the pitcher. However, the stability, flexibility, strength, and endurance of the hip musculature (including the low back and abdomen) must be assessed for the examination to be adequate and ensure that the thrower is stable from the bottom-up to prevent shoulder or even elbow injuries.

                  Essential UE Examination Points For Overhead Throwing Athletes

File:Abbreviated Shoulder Exam.jpg

Capsular Mobility Assessment 

Subacromial Impingement TIC:

Biceps Load II Test                                                           Shoulder Apprehension Test

(For a Labral Tear involving the Biceps Brachii)                (Anterior Subluxation or dislocation)

Medical Management

While preventative and conservative treatments are the most critical components of rehabilitation for common injuries affecting the throwing athlete, concomitant medical management is indicated for certain conditions. The following medical recommendations should be considered:

NSAID & Corticosteroid Injection: These pharmacotherapies are utilized mainly in the initial periods of shoulder pathology in order to decrease pain and inflammation. The use of NSAIDs is recommended initially in combination with a physical rehabilitation prescription and thermal agents. If the athlete does not respond well to this combination of treatment then an intra-articular corticosteroid injection may be considered alongside continued therapy. Corticosteroids have been shown to be effective for short-term pain reduction for sub-acromial impingement and rotator cuff tendonitis but demonstrate poor long-term pain reduction and continued function. It should be noted that corticosteroid injections have been known to cause adverse events such as transient pain after injection (10.7%) and skin alterations (4.0%) in addition to deleterious connective tissue effects with repeated use. Historically, corticosteroid injections may be selected over NSAID use based upon time of season and demand of the player to perform. Therapeutic consideration of the involved tissues should lead treatment and decisions of return to play as ROM and strength are properly restored.

Imaging Concerns: Failure to demonstrate marked progress by 3 months or return to asymptomatic competition by 6 months necessitates imaging if not already obtained. Additionally, if suspicion of a more notable dysfunction or mechanical abnormality presents then clear imaging is warranted.

• In younger throwing athletes, especially pitchers ages 13-16, radiographic images may be useful to rule out a stress fracture to the proximal humeral epiphysis. Termed “Little Leaguer’s” Syndrome, this pathology may present with lateral shoulder pain usually only with hard throwing motions but may progress to include a dull pain at rest.  Adequate rest from sport followed by progressive rotator cuff strengthening and a return-to-throwing program has demonstrated good outcomes for this condition.
• The radiographic evidence of humeral torsion (retrotorsion) in the dominant arm of the throwing athlete is a normal and benign finding regardless of age, gender, or sport. Such presence has actually demonstrated advantageous mechanical efficiency and may account for partial contralateral limb rotational measurement differences.
• Imaging may be useful to detect osseous changes or osteophyte formation, especially in the older throwing athlete due to repetitive trauma. This condition typically responds well to supervised rehabilitation but may require surgical excision if conservative treatment proves ineffective (see Internal Impingement).

Imaging is also used to detect type and severity of other conditions such as SLAP lesions, Rotator Cuff lesions, and Rotator Cuff Tears.

SLAP Lesions: Of the four main categories of SLAP lesions, throwing athletes typically present with a Type II tear which includes a full or partial detachment of the biceps brachii tendon from the superior labral attachment in addition to labrum involvement. This injury results from repeated tensile and torsion forces from external rotation in the late cocking phase as well as the eccentric biceps brachii contraction through deceleration. Type II & IV SLAP tears often do not respond well to physical therapy or corticosteroid injection. Arthroscopic debridement and reattachment via suture is the preferred method of repair with successful outcomes and return to prior-level competition ranging from 70-87% for throwing athletes and greater than 90% success for the general population.  A supervised physical rehabilitation plan is critical for full recovery following surgical SLAP repair.

Rotator Cuff Lesions: Injury to the rotator cuff muscles or the bicipital tendon may be due to primary or secondary impingement of the subacromial structures. Although primary impingement is rare in throwing athletes, both conditions typically respond well to conservative therapy. The most common mechanisms for secondary impingement of rotator cuff muscles is joint instability and laxity, most often involving lack of adequate scapular control. Surgical examination and debridement of the involved tissues for this condition is indicated only after failed attempts at proper conservative therapy as there is not strong evidence to support surgery for this condition.

Rotator Cuff Tears: Full or partial thickness tears of the rotator cuff should attempt no less than two bouts of physical therapy to the complete shoulder complex followed by an interval throwing program.  Corticosteroid injection may then be administered as a viable trial. Current research demonstrates very poor return to play outcomes for throwing athletes who undergo surgical intervention for full rotator cuff tears, especially baseball pitchers. Neither arthroscopic nor mini-open repairs resulted in acceptable outcomes for full-thickness repairs in baseball players with only 15% and 8% of athletes returning to play, respectively.

Acute Traumatic Instability: Although the majority of pathologies related to the dominant shoulder in the throwing athlete are categorized as overuse or damage resultant from repetitive trauma, the occurrence of acute traumatic instability or dislocation most often indicates surgical management. Recurrent dislocation rates have been found as high has 94.5% with young athletes who undergo nonoperative treatment versus 4% with operation.  Arthroscopic surgery using absorbable sutures has not been shown to be of significantly greater benefit than non-absorbable sutures.

Please refer to this Physiopedia link for surgical information on shoulder Internal Impingement.

Physical Therapy Management  

Pitchers have the option of throwing from "The Stretch" or "The Wind-up" positions. It is important for them to be comfortable with both deliveries and for both to be mechanically similar during the follow-through phase.

"The Stretch" vs. "The Wind-up"

Wilk, Meister, and Andrews define 4 phases to the rehab of the throwing athlete: Acute, Intermediate, Advanced Strengthening, and Return-to-Throwing. They also discuss more specific rehab principles for common injuries to overhead throwing athletes. These rehab specifics will be illustrated in the following charts.

File:Shoulder acute phase rehab2.png

 

File:Shoulder intermediate phase rehab.png

 

File:Shoulder advanced strengthening rehab phase.png

File:Shoulder return to throwing phase.png

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Throwers ten exercise programme

The throwers ten exercise programme is a long sanding series of exercises designed to prepare the shoulder for throwing (related videos and PDFs). An extension to the standard thrower's ten exercise programme has been proposed by Wilk et al 2011.

Youtube video demonstrating the Throwers Ten exercise programme.

Return To Throwing Interval Program - Developed by: Raymond "Smokey" Kubacak, PT

10 Guidelines to Follow:

1. Perform a proper full body warm-up
2. Use proper stretching techniques
3. Throw with proper mechanics
4. Throws must be made on a line (minimize arch in the trajectory of the ball)
5. Throwing needs to be pain-free before progressing to the next level
6. Take a day off between steps to ensure adequate tissue recovery
7. Use legs and trunk during throwing
8. "Crow Hop" at distances of 60 feet or greater Crow Hop Video
9. General soreness is expected - sharp pain and swelling is abnormal - contact appropriate medical professional before continuing with protocol
10. You may take a more conservative approach depending on how you feel

                                        31 day Program:

Lyman et al established the following recommendations for adolescent pitchers:

File:Pitching recommendations.png

Injury Prevention and Strengthening

Pre-game tubing warmup for pitchers:

• Perform with tubing on fixed object (pole or fence)@ level of finger tips of fully flexed arm (shoulder flex)

      o Shoulder Extension

      o Throwing Acceleration

• Perform with tubing @ height from the ground equal to the athlete’s fingertips in anatomical position

      o Shoulder Flexion

      o Throwing Deceleration

      o External Rotation at 90^o of Abduction

      o Scapular Punch

      o Low Scapular Rows

• Recommended dosage of the warm-up is 1 set of 30 repetitions per exercise

• These 7 exercises were chosen based on the EMG results from a group of 12 showing a greater than 20% maximal voluntary isometric contraction of at least 11 of the 13 tested shoulder muscles.

Ballistic Six Exercise Program

6 Exercises:

1) Elastic External Rotation

2) Elastic 90^o/90^o External Rotation

3) Overhead Soccer Throw

4) 90/90 External Rotation Side Throw

5) Deceleration Baseball Throw

6) Baseball Throw 

                                     Ballistic Six Exercise Progression

The ballistic six exercises were developed to reproduce the conditions under which the shoulder girdle musculature must act to control the head of the humerus on the glenoid during the overhead throwing motion. The sets, reps, and progression of the ballistic six training regimen was developed to follow the SAID principle of progressive resistance exercise and also to tax the anaerobic and aerobic systems of the pitcher in a similar pattern to that of a baseball game. Exercises 1,2,4,5,6 are performed unilaterally while exercise 3 is to be performed with both hands.

Key Research

Whiteley's review entitled: "Baseball throwing mechanics as they relate to pathology and performance - A review," does an exceptional job relating the biomechanics of throwing to physical therapy based on the research of over 100 articles. Physical therapists can use this information to educate the athlete and their coaches to better protect and/or rehabilitate throwing athletes.

In the article: “Risk Factors For Elbow And Shoulder Injuries In Adolescent Baseball Pitchers,” Olsen et al focused on the little clinical evidence surrounding current safety recommendations for little league pitchers. By doing a retrospective survey they were able to identify four significant risk factors surrounding adolescent pitchers who required elbow or shoulder surgery versus those who didn’t. Identification of these factors can help little league coaches and associations determine rules and regulations to further protect adolescent pitchers.

The purpose of the article: “Shoulder Injuries in the Overhead Athlete,” is to discuss the physical characteristics of the overhead athlete, common pathologies, and the non-operative, surgical, and postoperative treatment. It was found that the thrower’s shoulder must be lax enough to allow excessive external rotation but stable enough to prevent symptomatic humeral head subluxations, thus requiring a delicate balance between mobility and functional stability. They determined frequently, injuries can be successfully treated with a well-structured and carefully implemented non-operative rehabilitation program.

Resources

ChrisOleary.com Review of Pitching Mechanics. This site has nice images and media related to faulty pitching mechanics.

Clinical Bottom Line

Throwers generate massive amounts of force through highly skillful and intricate movements of the shoulder.  Despite the meticulous research into the biomechanics of throwers and the forces exerted on surrounding tissues, a lack of high level evidence into therapeutic interventions exists. Current evidence necessitates performing a comprehensive examination to differentially diagnose the multiple deficiencies that may result from the substantial repetitive forces on the shoulder complex of a thrower.