Rehabilitation of the Throwing Athlete

Return to Play After Shoulder Arthroscopy in Major League Baseball Pitchers vs Position Players

Background

Recovery from shoulder arthroscopy may vary between professional pitchers and position players in Major League Baseball (MLB). The time that it takes to return to play (RTP) and the level of skills to be regained after surgery are important factors for an athlete to consider when making career decisions.

Purpose

To identify MLB players who had arthroscopic shoulder surgery and observe their rates of RTP to MLB and the minor league, as well as to compare pre- and postinjury performance statistics and career metrics.

Study Design

Descriptive epidemiology study.

Methods

Public records (press releases, http://www.prosportstransactions.com, http://www.baseball-reference.com) were searched and analyzed to determine the number of days from shoulder arthroscopy to RTP and pre- and postinjury statistics for pitchers and position players in the MLB and minor league from 1998 to 2018. To meet inclusion criteria, a player must have undergone shoulder arthroscopy after having played at least 1 game in the MLB and had no identifiable concomitant injuries.

Results

Of 134 players, 89 (66.4%) returned to MLB. Fifty-four of 89 pitchers (60.7%) and 35 of 45 position players (77.8%) returned to MLB (P = .048). Forty-nine of 54 pitchers (90.7%) and 23 of 35 position players (65.7%) who returned to MLB returned to the minor league first. The mean time to RTP was 469.6 days (range, 100-1079 days) for pitchers and 301.6 days (range, 94-1488) for position players (P = .002). The WAR statistic (wins above replacement) for the pitchers decreased significantly (P = .004) after shoulder arthroscopy.

Conclusion

MLB position players returned to play at higher rates and more quickly than did pitchers. The WAR statistic declined in pitchers during the first season of RTP. Players undergoing arthroscopic shoulder surgery should be aware of these possible outcomes in time to RTP and postoperative performance.

The aging athlete

Aging athletes, those 60 years and older, are a growing population of mature, active individuals who value sports and exercise participation throughout their lifespan. Although recommendations for younger and masters athletes have been extrapolated to this population, there remains a paucity of specific guidelines, treatment algorithms, and considerations for aging athletes. The benefits of living an active lifestyle must be weighed against the risks for unique cardiovascular, metabolic, and musculoskeletal injuries requiring diagnostic and therapeutic interventions. In this article, we review the unique cardiovascular and muscular physiology of aging athletes and how it influences the risk of specific medical conditions. We also discuss general prevention and treatment strategies. Finally, we identify areas of future research priorities and emerging treatments.

Differences in Shoulder Internal Rotation Strength Between Baseball Players With Ulnar Collateral Ligament Reconstruction and Healthy Controls

Background:

Studies have indicated decreased shoulder internal rotation (IR) and external rotation (ER) strength in the throwing limb of baseball players after ulnar collateral ligament injury. There is limited evidence on the recovery of shoulder rotation strength after primary ulnar collateral ligament reconstruction (UCLR).

Hypothesis:

At the time of return to throwing, baseball players who underwent UCLR would demonstrate decreased IR and ER shoulder strength in the throwing arm as compared with healthy baseball players.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

Male competitive high school and collegiate baseball athletes participated in this study. Athletes who underwent UCLR were compared with healthy controls who were matched by age, height, weight, and position. Bilateral isometric shoulder ER and IR strength was measured using a handheld dynamometer for all participants at the time of initial evaluation (UCLR group) and throughout the course of a season (healthy group). Independent t tests were run to calculate mean differences in ER and IR shoulder strength between the groups, with significance set at P < .05.

Results:

A total of 86 baseball athletes participated in this study (43 UCLR group, 43 healthy group). At the time of return to throwing (mean ± SD, 194 ± 30 days postoperatively), the 2 groups demonstrated no significant differences in nonthrowing arm ER or IR strength (P = .143 and .994, respectively). No significant difference was found between groups for throwing arm ER strength (P = .921); however, the UCLR group demonstrated significantly less throwing arm IR strength than the healthy group (144.2 ± 27.8 vs 157.6 ± 27.1 N; P = .023).

Conclusion:

The results of this study demonstrate that throwing arm rotator cuff strength may not fully recover before the initiation of a return-to-throwing program after UCLR. These data provide a potential framework for clinicians to assist in the management and exercise prescription of the baseball athlete after UCLR and before medical release and the initiation of a return-to-throwing program.

Neuromuscular shoulder activity during exercises with different combinations of stable and unstable weight mass

BACKGROUND

Recent shoulder injury prevention programs have utilized resistance exercises combined with different forms of instability, with the goal of eliciting functional adaptations and thereby reducing the risk of injury. However, it is still unknown how an unstable weight mass (UWM) affects the muscular activity of the shoulder stabilizers. Aim of the study was to assess neuromuscular activity of dynamic shoulder stabilizers under four conditions of stable and UWM during three shoulder exercises. It was hypothesized that a combined condition of weight with UWM would elicit greater activation due to the increased stabilization demand.

METHODS

Sixteen participants (7 m/9 f) were included in this cross-sectional study and prepared with an EMG-setup for the: Mm. upper/lower trapezius (U.TA/L.TA), lateral deltoid (DE), latissimus dorsi (LD), serratus anterior (SA) and pectoralis major (PE). A maximal voluntary isometric contraction test (MVIC; 5 s.) was performed on an isokinetic dynamometer. Next, internal/external rotation (In/Ex), abduction/adduction (Ab/Ad) and diagonal flexion/extension (F/E) exercises (5 reps.) were performed with four custom-made-pipes representing different exercise conditions. First, the empty-pipe (P; 0.5 kg) and then, randomly ordered, water-filled-pipe (PW; 1 kg), weight-pipe (PG; 4.5 kg) and weight + water-filled-pipe (PWG; 4.5 kg), while EMG was recorded. Raw root-mean-square values (RMS) were normalized to MVIC (%MVIC). Differences between conditions for RMS%MVIC, scapular stabilizer (SR: U.TA/L.TA; U.TA/SA) and contraction (CR: concentric/eccentric) ratios were analyzed (paired t-test; p ≤ 0.05; Bonferroni adjusted α = 0.008).

RESULTS

PWG showed significantly greater muscle activity for all exercises and all muscles except for PE compared to P and PW. Condition PG elicited muscular activity comparable to PWG (p > 0.008) with significantly lower activation of L.TA and SA in the In/Ex rotation. The SR ratio was significantly higher in PWG compared to P and PW. No significant differences were found for the CR ratio in all exercises and for all muscles.

CONCLUSION

Higher weight generated greater muscle activation whereas an UWM raised the neuromuscular activity, increasing the stabilization demands. Especially in the In/Ex rotation, an UWM increased the RMS%MVIC and SR ratio. This might improve training effects in shoulder prevention and rehabilitation programs.

Distance-Based Throwing Programs for Baseball Players From Little League to High School

An estimated 2.4 million children play baseball in 80 countries. The majority of these children have experienced pain with throwing. A key component to a successful rehabilitation after an upper extremity injury for a baseball player is an interval throwing program, which allows a youth athlete to increase the demands of throwing in a progressive and controlled manner. Numerous interval throwing programs are designed for baseball players of high school age and older, but few exist for the baseball player who is skeletally immature. Our interval throwing programs take into consideration various field dimensions, injury types, and position requirements for youth. Our goal is to create a guide for rehabilitation specialists and players to return to throwing as quickly and safely as possible.

The Utilization of Interval Throwing Programs in the Physical Therapy Setting: A Cross-Sectional Survey

Context: Interval throwing programs (ITPs) have long been used in the physical therapy setting to aid in the safe and efficacious return to sport for an overhead athlete. However, the overall utilization and variation of ITPs are unknown in the physical therapy setting leading to potential inconsistencies in treatment paradigms. Objective: To determine if differences in practice patterns exist among active physical therapists of various experience levels with regard to years of experience and advanced certifications. Design: Cross-sectional survey study. Participants: A total of 133 licensed physical therapists consented to participate in an online-based survey. Experience groups were delineated based on years of practice (0-1, 1-5, 6-15, and 15+) and possession of advanced certification. Main Outcome Measures: For ranking-based data, a generalized linear mixed model was repeated across criteria response with a Bonferroni post hoc adjustment for pairwise comparisons made within and between groups (α < .05). For degree-based questions, chi-square analysis was used to compare response frequencies for options provided within each question. Results: A 76.7% response rate was achieved with 102 out of the 133 consenting individuals completed the survey. Significant differences (P < .05) were found with responses to both ranking-based and degree-based questions. However, across all groups, physical therapists agreed that throwing mechanics and customized ITP implementation were important for a successful return to throwing. Conclusions: There are inherent differences in ITP prescription among physical therapists with dissimilar experience levels. The possession of advanced certifications and years of practice seem to play a role in how interval programs are prescribed to overhead-throwing athletes. This study helps to identify differences in current physical therapy approaches toward the later stages of rehabilitation for throwing athletes. Further research should identify areas of improvement in physical therapist education as well as appropriate ITP prescription parameters to optimize care and treatment for this patient population.

Changes in Throwing Arm Mechanics at Increased Throwing Distances During Structured Long-Toss

BACKGROUND

Elbow injuries among adolescent baseball players have been outpacing those of college and professional players. In attempts to prevent injuries and maximize return-to-play potential following injury, attention has been focused on "return to throw" programs, which include long-toss throws. Because the few studies that were conducted on long-toss throwing focused primarily on college-aged athletes, it is not known what type of load is incurred at the elbow during interval throwing progression among high school baseball players.

PURPOSE

To quantify the change in arm slot, arm speed, shoulder external rotation, and elbow varus torque across increasing throwing distances within a given athlete.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Ninety-five high school baseball players performed a long-toss protocol while wearing an inertial sensor and sleeve. Each participant was tested for 5 throws at distances of 9 m, 18 m, 27 m, 37 m, and 46 m. Linear mixed-effects models and likelihood ratio tests were used to estimate the within-participant relationship between throw distance and arm slot, arm speed, shoulder external rotation, and elbow varus torque.

RESULTS

Arm slot ( P < .01), arm speed ( P < .01), shoulder external rotation ( P < .01), and elbow varus torque ( P < .01) were significantly associated with long-toss throw distance. As the throw distance increased, there was an increase in arm speed and shoulder external rotation and a decrease in arm slot for each distance. However, elbow varus torque increased with each distance up to 37 m and then remained the same at 46 m.

CONCLUSION

The use of longer distances for conditioning and rehabilitation may be beneficial in increasing shoulder range of motion and arm speed; however, precaution needs to be taken, as throwing longer distances are accompanied by an increase in arm rotation, arm speed, and elbow torque, with a decrease in arm slot.

CLINICAL RELEVANCE

Return-to-throw programs have been utilized by sports medicine clinicians and coaches to help guide a player during rehabilitation. These programs involve throwing at increased efforts through increased distances with no immediate feedback on elbow stress. This investigation describes arm biomechanical changes during submaximum interval throwing and demonstrates a tool that can be utilized to measure arm stress in real time for clinicians and athletes progressing through an interval throwing program.

A Novel Method to Determine Optimal Load in Elastic-Based Power Training

Buskard, AN, Oh, J, Eltoukhy, M, Brounstein, SR, and Signorile, JF. A novel method to determine optimal load in elastic-based power training. J Strength Cond Res 32(9): 2401-2408, 2018-The benefits of muscular power on sport performance and older adults' abilities to live independently and resist falls is well documented. Consequently, a substantial volume of research has focused on establishing the optimal loading patterns for improving muscular power using resistance exercise; however, to date, this research has only targeted optimal loading during training with free weights or selectorized exercise machines. Conversely, no approach has been developed to establish optimal loads for elastic modalities, such as tubes and bands, commonly used for sports rehabilitation, injury prevention, and training older adults. Therefore, the purpose of this study was to evaluate a new method for determining the optimal tubes to use in power training performed with elastic resistance. Thirty-eight recreationally active college students (age, 23.7 ± 4.5 years) were recruited to perform 3 single-arm bicep curls at a maximum intended velocity using 6 elastic tubes of varying resistance. Testing was performed in a 3-dimensional (3D) motion analysis laboratory using a specially constructed platform with an integrated strain gauge to which each tube was anchored. Force data from the strain gauge and velocity data from the 3D motion capture system were then used to compute power for each tube. An analysis based on individual's cable arm curl 1-repetition maximum (1RM) was then used to generate general guidelines for the most appropriate tube to use for arm curl power training based on upper arm 1RM. Our results demonstrate the feasibility of using this methodology for other exercises, thereby establishing optimal tube use for power training based on each exercise's 1RM.

Exercise prescription for overhead athletes with shoulder pathology: a systematic review with best evidence synthesis

OBJECTIVE

To produce a best evidence synthesis of exercise prescription used when treating shoulder pathology in the overhead athlete.

DESIGN

A systematic review of exercises used in overhead athletes including case studies and clinical commentaries.

DATA SOURCES

MEDLINE, PubMed, SPORTDiscus and CINAHL from database inception through July 8, 2016.

METHODS

We examined data from randomised controlled trials and prospective cohort (level I-IV evidence) studies that addressed exercise intervention in the rehabilitation of the overhead athlete with shoulder pathology. Case studies and clinical commentaries (level V evidence) were examined to account for expert opinion-based research. Data were combined using best evidence synthesis and graded (A-F) recommendations (Centre for Evidence-Based Medicine).

RESULTS

There were 33 unique exercises in six level I-IV studies that met our inclusion criteria. Most exercises were single-plane, upper extremity exercises performed below 90^o of elevation. There were 102 unique exercises in 33 level V studies that met our inclusion criteria. These exercises emphasised plyometrics, kinetic chain and sport-specific training.

CONCLUSIONS AND RELEVANCE

Overall, evidence for exercise interventions in overhead athletes with shoulder pathology is dominated by expert opinion (grade D). There is great variability between exercise approaches suggested by experts and those investigated in research studies and the overall level of evidence is low. The strongest available evidence (level B) supports the use of single-plane, open chain upper extremity exercises performed below 90° of elevation and closed chain upper extremity exercises. Clinical expert pieces support a more advanced, global treatment approach consistent with the complex, multidimensional nature of sport.

GIRD, TRROM, and humeral torsion-based classification of shoulder risk in throwing athletes are not in agreement and should not be used interchangeably

OBJECTIVES

Clinicians commonly interpret the findings of shoulder rotational ranges of motion using various approaches: an apparent reduction in dominant arm internal rotation ("GIRD"), a difference in total rotational range of motion-i.e. differences in the sum of internal and external rotational range (TRROM), and a combination of rotational ROM and torsional difference ("GIRD-torsion"). We have noticed that these approaches are being considered to provide equivalent estimates of shoulder rotational range. This investigation sought to document the extent of agreement of these three different approaches when classifying athletes' "at-risk" status.

DESIGN

Observational cohort study.

METHODS

162 professional male athletes participating in overhead sports (baseball, handball, and volleyball) had their GIRD, TRROM, and GIRD-torsion calculated, and classified as "at risk" using standard cut-points of 20°, 5°, and 10°, respectively.

RESULTS

25 (15.4%) athletes were classified as "at-risk" using GIRD, 55 (34%) with TRROM, and 30 (18.5%) using GIRD-torsion. Only 3/162 (1.9%) athletes were classified as "at-risk" by all 3 approaches, 4 athletes were concurrently classified as "at-risk" by GIRD and TRROM (Kappa=-0.142, poor agreement), 11 by GIRD and GIRD-torsion (Kappa=0.279, fair agreement), and 11 by TRROM and GIRD-torsion (Kappa=0.025, slight agreement).

RESULTS

25 (15.4%) athletes were classified as at risk using GIRD, 55 (34%) with TRROM, and 30 (18.5%) using GIRD-torsion. Only 3/162 (1.9%) athletes were classified as at risk by all 3 approaches, 4 athletes were concurrently classified as at risk by GIRD and TRROM (Kappa=-0.142, poor agreement), 11 by GIRD and GIRD-torsion (Kappa=0.279, fair agreement), and 11 by TRROM and GIRD-torsion (Kappa=0.025, slight agreement).

CONCLUSIONS

The three described approaches yield demonstrably different findings, and these approaches cannot be used interchangeably. Examples of clinical reasoning are provided to assist with the interpretation of these different measures.