Reducing baseball-related injuries not only makes the game safer but also presents a competitive advantage for teams that identify and implement superior prevention strategies. This article explores effective training methodology and rehabilitation concepts that are potentially capable of reducing one subset of baseball participant injuries; the rotator cuff (RTC) muscle complex. Specific movements are not the emphasis here; exercise strategy is the utility offered to readers.
Concepts of RTC care expressed here are valid both for pitchers and position players but takes on a greater sense of urgency in the former due to their increased likelihood of suffering an upper extremity injury. One study found a 35% increased incidence of upper extremity injuries for pitchers versus position players and pitchers were also on the disabled list 28% more often than non-pitching positions.1 Emphasis here will be on baseball pitchers with the majority of the research cited and recommendations given for training and rehabilitation also applicable to position players.
Thoughtful prescription regarding training volume, intensity and content selection is essential for optimal athlete performance. The time horizon to reach rehabilitation or fitness goals should be optimized by programming these training variables correctly which is especially valuable during time sensitive in-season injury recovery periods. Prior to initiating a shoulder strengthening program it is imperative to evaluate shoulder range of motion and static/dynamic shoulder positioning along with establishing a normalized flexibility balance prior to resistance training if deficient.
Examining Physical Condition
Reduced muscle length, while capable of causing internal impingement, also distorts true strength as a shortened muscle is challenged to deliver comparable performance against a properly lengthened muscle. Flexibility imbalances between shoulder external and internal rotation should be corrected and also expected as acute and chronic adaptive changes among baseball pitchers are known to occur and do contribute to elbow and shoulder complex pathology.2,3 Although extending out of the scope of this article, the process to examine a player's entire physical condition for identification of asymmetries elsewhere at the cervical spine, distal upper extremity, trunk and lower extremities should not be neglected.
Exercise volume and intensity should be low in training the RTC for all baseball players healthy or injured to avoid hypertrophy and fatigue induced deviations in joint position during baseball movements as they can create or worsen injury.4-7 The importance of engaging the athlete in biomechanically correct movements is magnified for those having existing pathology such as impingement as it has been demonstrated that deviations in movement occur with this pathology.8
Repetition totals per set should be high by traditional strength training standards, suggested here is a 15-30 rep range for relative strength/endurance rather than absolute strength/power. Low repetition strength training generally emphasizing either power (1-6 reps) or hypertrophy (7-12 reps) is questionable for muscles that provide joint stabilization exclusively such as the RTC. An inverse relationship between sets and repetitions is thought to exist with our relatively high repetition total necessitating a modest two sets of workload.
Examining Training Volume
Training volume for the deltoids and other power generating muscles could be low but the intensity high during the season while the volume can be increased during the off-season with no ongoing baseball competition. Other muscles besides the RTC with primarily a stabilizer function would include the transverses abdominis, multifidus, posterior tibialis and popliteus. A similar resistance training strategy is proposed for these muscles including the scapular stabilizers worked specifically to minimize impingement risk of the shoulder.
Overhand athletes with internal impingement symptoms have been shown not just to exhibit abnormal humeral positioning but also scapular muscle recruitment patterns requiring at least re-education of these stabilizer muscles for a return to biomechanical efficiency during competition.9 A quick word on the rest periods between sets: avoid hypertrophic protocol rest periods of 60-120 seconds and utilize shorter recovery times thinking about sport specific structure when able.
Eccentric phase training is a recommended area of emphasis for exercise programs especially in the off-season when stress duplication and recovery is not so compromised. The pacing of RTC exercise should generally for all baseball pitchers prioritize the eccentric phase with durations often double the concentric phase for functional carryover.
Training to muscular failure can compromise humeral head positioning acutely which may retard progress if injured or contribute to injuries in previously healthy athletes. While fatigued and recovering from a training session the athlete's ability to control the humeral head position is less efficient, allowing undesired translation. Soft-tissue structures between bony regions can then become impinged or otherwise aggravated during this period with eccentric forces more troublesome as well.
Quantifying intensity is a current void in research, so I propose a simple guideline to training the RTC muscles. Due to their relatively small size each RTC muscle a potent "burn" will result when challenged due to their inherently low oxygen capacity. This occurrence can be used as a landmark for establishing appropriate exercise intensity. The exerciser can be instructed to track repetitions until a burning sensation is realized.
Upon onset of the burn, allow the exerciser to complete up to 50% more of their current rep total before ending the set. For example, if a burn begins at repetition 10 during standing external rotation using a resistance band, five more repetitions would be allowed for a maximum total of fifteen repetitions. Using this methodology will set a repetition cap for a given resistance level and minimize the adverse effects of overtraining on shoulder biomechanics. Repetition ranges will generally be maintained at 15-30 per set as recommended and supported earlier. The methodology just detailed appropriately targets the RTC endurance and stabilization functions while minimizing undesirable hypertrophy effects. These recommendations are applications of published research but are subject to future refinement as our collective working knowledge continues to improve.
Isolation exercises for the rotator cuff and scapular muscles are guided by clinical electromyography (EMG) research providing maximum muscle fiber recruitment in the intended muscle. Also helpful are EMG recordings of unintended muscle activity that could work against a rehabilitation strategy for biomechanics restoration or to delay the exercise's entry until later in the integrated exercise phase of rehabilitation. To illustrate the practical nature of EMG studies consider the subscapularis muscle. When training this muscle it has been recommended to approach it as having two independent muscle units requiring multiple exercises.10 Helpful applications can also be made through research reviews for the rest of the RTC and selected scapular stabilizers that together control upper quarter biomechanics. Low recruitment exercises per EMG studies will inefficiently recruit the intended muscle and may unnecessarily delay an injured player's timetable for return. An uninjured player using poorly designed exercises will have a false sense of security from an injury prevention standpoint and are possibly placing their rotator cuff at greater risk during competitive play due to their exercise program.
In addition to the training already discussed, throwing programs are an effective means to prevent injury and improve performance. Please note that throwing is not done on a mound, does not incorporate the various grips needed to throw a variety of pitches, and otherwise does not hold the characteristics of pitching. A throwing program is an indispensible off-season tool for healthy and effective in-season performance. Stan Conte, then athletic trainer for the San Francisco Giants expressed this well in his presentation for the American Sports Medicine Institute's 23rd Annual Injuries in Baseball event: "The best strengthening program for the pitcher may be throwing the baseball."
One caveat to this is to be conservative in progressing the distance and intensity of the program to avoid undesirable kinematic changes.11 Throwing too far or hard will cause the thrower to deviate from their natural throwing motion and will alter the stresses on soft tissue. Several consistent components should without fail be present in a throwing program: warm-up period, distance and rest period parameters and a progressive nature. Off-season is the ideal time for a program although in-season injuries warrant their use for rehabilitation purposes.
Any discussion of the rotator cuff in the context of baseball would be incomplete without a discussion of using pitch counts during competition. "The biggest problem I see in baseball are overuse related injuries" says Mike Guerrero, ATC at Garner Magnet High School in Garner, NC, "pitch counts are critically important in the younger developing athletes on middle and high school teams." Recognizing the workload capacity and recovery abilities of each pitcher is advisable rather than over generalizing based on age, month of the season, or other pitch count range identifiers. An overworked pitcher will not necessarily become symptomatic while on the mound but his pitching biomechanics will be altered due to fatigue and in time injury is inevitable.
The Pitch-Count Factor
A final game management consideration is the ideal warm up and recovery period content. EMG analysis should again be relied upon to select low-intensity content for pre-throwing warm up periods while an active recovery along with ice use is also recommended versus using ice alone. Low volume and low intensity would again be used in the performance of these warm up or recovery period routines with some possible tweaks in design for individual sports psychology issues.
The leading professional baseball organization, Major League Baseball (MLB), has enhanced its global presence with more foreign countries represented on team rosters since the early 1990s. As more youth take up the game globally establishing effective prevention and treatment strategies are an essential task for the sports medicine community. Using Forbes, Inc. team valuation estimates, the 30 MLB teams have a collective intrinsic financial value of over $17 trillion as of March 2012 which is over 6x higher than the 10 highest valued publically held companies worldwide.12 As the game expands with interest growing globally the financial resources are there for MLB to drive research in injury prevention and treatment now such as the NFL has begun doing for concussion related injuries.
1. Posner M, Cameron KL, Wolf JM, Belmont PJ Jr, Owens BD. Epidemiology of Baseball Injuries. Am J Sports Med. 39:1676-1680. 2011.
2. Hurd WJ, Morrey BF, Kaufman KR. Relationship between Measurements of Shoulder Motion and Strength and Baseball Pitching Biomechanics. Conference Proceedings of the Annual Meeting of the American Society of Biomechanics. pp. 899-901. 2010.
3. Crockett HC, Groiss LB, et al. Osseous Adaptation and Range of Motion at the Glenohumeral Joint in Professional Baseball Pitchers. Am J Sports Med. 30:20-26. 2002.
4. Tripp BL, Boswell L, Gansneder BM, Shultz SJ. Functional Fatigue Decreases 3-Dimensional Multijoint Position Reproduction Acuity in the Overhead-Throwing Athlete. J of Athl Training. 39:316-320. 2004.
5. Chopp JN, Dickerson CR. Resolving the contributions of fatigue-induced migration and scapular reorientation on the subacromial space: An orthopaedic geometric simulation analysis. Hum Mov Sci. 31:448-460. 2012.
6. Teyhen DS, Miller JM, Middaq TR, Kane EJ. Rotator cuff fatigue and glenohumeral kinematics in participants without shoulder dysfunction. J of Athl Training. 43:352-358.
7. Chopp JN, O'Neil JM, Hurley K, Dickerson CR. Superior head migration occurs after a protocol designed to fatigue the rotator cuff: a radiographic analysis. J Shoulder Elbow Surg. 19:1137-1144. 2010.
8. Royer PJ, Kane EJ, Parks KE, Morrow JC, Moravec RR, Christie DS, Teyhen DS. Fluoroscopic assessment of rotator cuff fatigue on glenohumeral arthrokinematics in shoulder impingement syndrome. J Shoulder Elbow Surg. 18:968-975. 2009.
9. Cools AM, Witvrouw EE, et al. Scapular Muscle Recruitment Patterns: Trapezius Muscle Latency with and without Impingement Symptoms. Am J of Sports Med. 31:542-549. 2003.
10. Decker, MJ,Tokish JM, Ellis, HB, Torry MR, and Hawkins RJ. Subscapularis Muscle Activity during Selected Rehabilitation Exercises. Am J of Sports Medicine., 31:126-134. 2003. 4
11.Fleisig G, Bolt B, Fortenbaugh D, Wilk KE, Andrews JR. Biomechanical Comparison of baseball pitching and long-toss: implications for training and rehabilitation. J Orthop Sports Phys Ther. 41: 293-303. 2011.
12. Forbes.com Web. Retrieved July 18,2012. http://www.forbes.com/mlb-valuations/list/
Ken Stack earned his physical therapy degree from D'Youville College in 2003. He has attained certification as a Strength and Conditioning Specialist and has been a Certified Level 1 USA Track and Field Coach since 2007. He holds a permanent position on the Shrine Bowl of the Carolinas medical team benefiting Shriner's hospitals.