Today’s guest-post is an excellent article from Rob Panariello, a regular guest contributor to my blog. Enjoy!
“Considerations in Elbow Rehabilitation and Athletic Performance Enhancement Training: Glenohumeral Internal Rotation Deficit (G.I.R.D.), It Effects More Than Just the Shoulder”
Robert A. Panariello MS, PT, ATC, CSCS
Professional Orthopedic and Sports Physical Therapy
Professional Athletic Performance Center
New York, New York
Scientific investigations performed over the past few decades have recognized that the overhead throwing motion (i.e. pitching), as well as other high angular velocity overhead activities generates tremendous demands upon the glenohumeral (GH) joint of the shoulder. What should also be taken into consideration are the associated stresses that occur at the elbow joint, and more specifically at the medial aspect of this joint during the performance of these high velocity activities. The act of pitching, and particularly the internal rotation of the shoulder that occurs during the high velocity pitching motion is the fastest human movement recorded with speeds exceeding 7250 degrees per second. It has been well documented that participation in the sport of baseball may result in an upper extremity injury resulting in the consequential loss of significant playing time with the pitcher being the most commonly injured player.
Inquiries of the source(s) of various “overhead” throwing type shoulder injuries have lead to multiple scientific investigations from numerous clinicians and professionals. The findings of many of these professionals have established a discrepancy in the measured shoulder internal rotation (IR) range of motion (ROM) of the dominant (throwing) shoulder when compared to that of the non-dominant (non-throwing) shoulder. This phenomenon has been referred to in the literature as GIRD (Glenohumeral Internal Rotation Deficit) and has been substantiated as one probable cause of various dominant upper extremity pathologies.
The work of my good friend Kevin Wilk and his associates has recognized the “Total Rotational Motion” (TRM) concept of the shoulder. This TRM concept proposes that the passive range of motion (PROM) of the shoulder is measured for both IR and external rotation (ER) at 90 degrees of shoulder abduction (with the scapula stabilized). These two ROM measurements are then added together to determine the shoulder TRM. These measurements are performed for both dominant and non-dominate shoulders and compared for any ROM discrepancies.
In review of Wilk’s research as well as our years of telephone and dinner conversations discussing various topics including the issue of GIRD, Kevin proposes, as substantiated by his research, when comparing the dominant (throwing shoulder) to the non-dominate (non-throwing) shoulder, the IR ROM deficit should not be greater than 15 degrees and the TRM should not exceed more than 5 degrees of the total (IR + ER) shoulder motion. Dominate throwing shoulder IR and/or TRM deficits of greater than 15 degrees or 5 degrees respectively; demonstrate significantly higher shoulder injury rates resulting in a loss of playing time.
The Effect of GIRD upon the Throwing Elbow
Participation in the activity of pitching or other overhead throwing type motions (i.e. javelin, etc.) subjects the elbow joint, much like the GH joint of the shoulder, to tremendous stress forces. Approximately 26% of all injuries to major league baseball pitchers involve the elbow joint. During the overhead pitching motion the elbow extends at speeds greater than 2300 degrees per second, and has both a medial shear force of 300 N and a compressive force of 900N respectively. In addition, a (elbow) valgus stress force of 64 Nm is produced during the acceleration phase of throwing, a force that exceeds the tensile strength of the Ulnar Collateral Ligament (UCL). To “counteract” these high stresses, the elbow joint is reliant on both bony (the ulno-humeral articulation) and soft tissue restraints (UCL) in an effort to preserve appropriate joint stability. The repetitive high valgus stresses that occur during throwing type activities may cause ulnohumeral chrondral and ligamentous overload (UCLO) resulting in such consequences as UCL pathology/insufficiency, osteophytosis, chondral damage (chrondromalacia), disabling elbow pain, and the incapacity to effectively throw at pre-injury performance levels.
It has also been substantiated that during the throwing motion, active shoulder IR establishes a physiologic (varus) counter to the valgus load/torque generated during the late cocking and acceleration phases providing a principal protective influence against valgus loads at the elbow during throwing (pitching) type activities.
The Rehabilitation and Performance Enhancement Training of the UCL Post-operative or Injured Athlete
The rehabilitation of the post-operative or injured UCL of the elbow patient will eventually progress the athlete to the initiation of a staged throwing program during the concluding phases of the elbow rehabilitation process. This throwing program may or may not be supervised by the rehabilitation professional. Often times limitations in health care benefits may influence the athlete to seek other professionals such as their athletic performance training professional and/or pitching coach to guide and/or supervise them through the “throwing program” portion phase of their elbow rehabilitation.
Mike Reinold and his associates have investigated and described that following a pitching performance a pitcher exhibits decreases in dominate shoulder IR of 9.5 degrees as well as decreases in TRM of 10.7 degrees. These documented shoulder IR and TRM variations remain for approximately a 24 hour period of time. The athlete’s throwing efforts during the initiation of a rehabilitation throwing program may not produce the shoulder and elbow joint forces seen during maximal pitching efforts from a mound during game day competition, but perhaps those athletes that initiate and progress with their rehabilitation (repetitive) throwing program would both mimic and reinforce these shoulder IR ROM deficits found upon the conclusion of a pitching performance. Therefore, establishing and/or maintaining acceptable throwing shoulder IR and TRM are paramount in reducing stress not only to the athlete’s shoulder but to the elbow as well.
The Rehabilitation and Strength and Conditioning Professional should be aware and place caution upon those athletes that present with GIRD. GIRD does not only provide increased risk of pathology at the throwing shoulder, but may significantly affect the anatomical structures of the elbow joint as well.
1. Altchek, DA, Attending Orthopedic Surgeon, Co-Chief Sports Medicine and Shoulder Service, Hospital for Special Surgery, New York, NY. Medical Director New York Mets, personal conversation
2. Dines JS, Frank JB, Akerman M, and Yocum LA. Glenohumeral Internal Rotation Deficits in Baseball Players with Ulnar Collateral Ligament Insufficiency. Am J Sports Med. 2009; 37(3): 566-570.
3. McFarland EG, and Wasik M. Epidemiology of Collegiate Baseball Injuries, Clin J Sports Med. 1998; 8(1): 10-13.
4. Osbahr DC, Dines JS, Breazeale NM, Deng X, and Altchek DA. Ulnohumeral Chondral and Ligamentous Overload. Am J sports Med. 2010; 38(12): 2535-2541.
5. Reinold MM, Wilk KE, Macrina LC, Sheheane C, Dun S, Fleisig GS, Crenshaw K, and Andrews JR. Changes in Shoulder and Elbow Passive Range of Motion After Pitching in Professional Baseball Players. Am J Sports Med. 2008; 36(3): 523-527.
6. Wilk KE, Macrina LC, Fleisig GS, Porterfield R, Simpson II CD, Harker P, Paparesta N, and Andrews JR. Correlation of Glenohumeral Internal Rotation Deficit and Total Rotational Motion to Shoulder Injuries in Professional Baseball Pitchers. Am J Sports Med. 2011; 39(2): 329-335.
7. Wilk, KE. Associate Clinical Director, Champion Sports Medicine, Director of Rehabilitative Research ASMI, Birmingham, Alabama personal conversation