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Background: Glenohumeral internal rotation deficit (GIRD) and total arc of motion difference (TAMD) have been associated with elbow injuries in throwing athletes. Hypothesis: Youth pitchers with elbow pain will have greater GIRD and TAMD compared with youth pitchers without elbow pain. Study Design: Cross-sectional study. Level of Evidence: Level 3. Methods: Glenohumeral range of motion of 25 consecutive throwing athletes presenting with elbow pain and that of a matched control group of 18 asymptomatic throwing athletes were compared. Bilateral glenohumeral internal rotation, external rotation, and horizontal adduction at 90° were measured and GIRD and TAMD were then calculated. An analysis of variance was performed to compare range of motion between throwers with and without elbow pain. Results: The average GIRD of the elbow pain group was 32.7° compared with 14.5° in the control group ( P < 0.05). The average TAMD in the elbow pain group was 28.3° compared with 6.7° in the control group ( P < 0.05). GIRD and TAMD were present in 88% (22 of 25) and 96% (24 of 25) of the elbow pain group versus 33.3% (6 of 18) and 55.6% (10 of 18) of the control group, respectively. Conclusion: Compared with asymptomatic youth pitchers, those presenting with elbow pain have a statistically significant GIRD and TAMD. Clinical Relevance: This study suggests that a GIRD and TAMD may predispose youth pitchers to present with symptomatic elbow pain.

Background: A lack of lumbopelvic-hip complex (LPHC) stability is often associated with altered pitching mechanics, thus increasing pain and injury susceptibility. The single-leg squat (SLS) is a simple diagnostic tool used to examine LPHC stability. Purpose: To examine the relationship between trunk compensatory kinematics during the SLS and kinematics at foot contact during the windmill pitch. Study Design: Descriptive laboratory study. Methods: Participants included 55 youth and high school softball pitchers (mean age, 12.6 ± 2.2 years; height, 160.0 ± 11.0 cm; weight, 60.8 ± 15.5 kg). Kinematic data were collected at 100 Hz using an electromagnetic tracking device. Participants were asked to complete an SLS on each leg, then throw 3 fastballs at maximal effort. Values of trunk flexion, trunk lateral flexion, and trunk rotation at peak depth of the SLS were used as the dependent variables in 3 separate backward-elimination regression analyses. Independent variables examined at foot contact of the pitch were as follows: trunk flexion, trunk lateral flexion, trunk rotation, center of mass, stride length, and stride knee valgus. Results: The SLS trunk rotation regression ( F(1,56) = 4.980, P = .030) revealed that trunk flexion predicted SLS trunk rotation (SE = 0.068, t = 2.232, P = .030) and explained approximately 7% of the variance in SLS trunk rotation ( R 2 = 0.083, adjusted R 2 = 0.066). The SLS trunk flexion regression ( F(1,56) = 5.755, P = 0.020) revealed that stride knee valgus significantly predicted SLS trunk flexion (SE = 0.256, t = 2.399, P = .020) and explained approximately 8% of variance in SLS trunk flexion ( R 2 = 0.095, adjusted R 2 = 0.078). Conclusion: Additional trunk rotation and trunk flexion at peak depth of the SLS showed increased knee valgus and trunk flexion at foot contact of the pitch, both of which indicate poor LPHC stability during the softball pitch and may increase the potential for injury. Clinical Relevance: Players and coaches should implement SLS analyses to determine their players’ risk for injury and compensation due to poor core stability.

Background: Graft-tunnel mismatch (GTM) is a condition in which the anterior cruciate ligament (ACL) graft is either too long or too short. GTM is particularly problematic when bone–patellar tendon–bone grafts are used because of a potential compromise in fixation of the bone plug on the tibia. Hypothesis: The Blumensaat line (BL), a radiographic landmark representing the roof of the intercondylar fossa, will accurately approximate the native ACL (nACL) length and may aid in the prevention of GTM. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: A total of 130 patients (66 males, 64 females) underwent direct measurement of the nACL during knee arthroscopy. The lengths of the nACL and patellar ligament (PL) were measured intraoperatively, and BL length was measured on lateral knee radiographs. The nACL length was compared with PL and BL lengths to calculate the absolute difference (AD). Mean AD was calculated and used to determine mean percentage difference (MPD). Pearson correlation coefficients (CC) between BL, PL, and nACL length were calculated, along with inter- and intraobserver reliability coefficients for the measurement of BL. Results: For male patients, the mean length of the nACL was 32.5 mm, BL was 30.4 mm, and PL was 49.2 mm. The AD between the BL and nACL was 2.4 ± 1.3 mm, MPD was 2.6% ± 1.9%, and CC was 0.88. The CC between the PL and nACL was 0.08. For female patients, the mean length of the nACL was 30.2 mm, BL was 27.5 mm, and PL was 44.4 mm. The AD between the BL and nACL was 2.7 ± 1.7 mm, MPD was 4.5% ± 2.4%, and CC was 0.93. The CC between the PL and nACL was 0.1. The inter- and intraobserver reliability coefficients for the measurement of BL were 0.86 and 0.83, respectively. Conclusion: A strong correlation was found between BL and nACL with a high inter- and intraobserver reliability. This correlation provides a simple and reliable method to closely approximate nACL length before reconstruction and may aid in the prevention of graft-tunnel mismatch.

Background:There is a paucity of research regarding the relationship between fastpitch softball pitching mechanics and reported pain. Thus, understanding the pitching mechanics of athletes pitching with upper extremity pain and those pain free is paramount.Purpose:To examine lower extremity pitching mechanics, upper extremity kinetics, and upper extremity pain in National Collegiate Athletic Association (NCAA) Division I female softball pitchers.Study Design:Descriptive laboratory study.Methods:A total of 37 NCAA Division I female softball pitchers (mean age, 19.84 ± 1.28 years; mean height, 173.67 ± 7.77 cm; mean weight, 78.98 ± 12.40 kg) from across the United States were recruited to participate. Participants were divided into 2 groups: upper extremity pain (n = 13; mean age, 19.69 ± 1.18 years; mean height, 172.60 ± 11.49 cm; mean weight, 86.75 ± 13.02 kg) and pain free (n = 24; mean age, 19.91 ± 1.35 years; mean height, 174.26 ± 4.96 cm; mean weight, 74.78 ± 9.97 kg). An electromagnetic tracking system was used to obtain kinematic and kinetic data during the riseball softball pitch.Results:At foot contact ( F3,33= 7.01, P = .001), backward elimination regression revealed that stride length, trunk rotation, and center of mass (COM) significantly explained about 33% of variance with softball pitchers experiencing upper extremity pain (adjusted R2= 0.33).Conclusion:At foot contact, the kinematic variables of increased trunk rotation toward the pitching arm side, increased stride length, and a posteriorly shifted COM were associated with upper extremity pain in collegiate softball pitchers. Variables early in the pitching motion that do not set a working and constructive proximal kinetic chain foundation for the rest of the pitch to follow could be associated with breakdowns more distal in the kinetic chain, possibly increasing the susceptibility to upper extremity pain.Clinical Relevance:The identification of pitching mechanics associated with pain allows clinicians to develop exercises to avoid such mechanics. Avoiding mechanics associated with pain may help reduce the prevalence of pain in windmill softball pitchers as well as help coaches incorporate quantitative biomechanics into their instruction.

Objectives: Muscle activation patterns and the kinetics of overhead throwing have been well described in the baseball athlete but not in the football athlete. Injury patterns vary between these two populations. The purpose of this controlled laboratory study was to describe the muscle activation patterns of the elbow and forearm during the overhead football throw. A better understanding of muscle activation patterns and kinetics will help clinicians understand the difference in injury between these two populations, with an objective of preventing injury in both groups. The hypothesis was that the unique grip and obligatory pronation upon ball release will cause the elbow and forearm muscles to have a unique activation pattern during the overhead football throw. Methods: IRB approval was obtained. Electromyographic (EMG) and motion capture data was collected on eight male quarterbacks. An EMG direct transmission system measuring at 1200 Hz with 9 surface electrodes was used to collect EMG data, with signals normalized to maximal voluntary contraction values for each subject. EMG sensors were placed on the biceps, triceps, brachialis, brachioradialis, anconeus, extensor digitorum communis, flexor digitorum superficialis, pronator teres, and pronator quadratus. A 13 camera motion capture system measuring at 240 Hz with a full body marker set of 39 retro-reflective 9mm markers was used to capture motion data. The throwing motion was divided into four event segments: early cocking, late cocking, acceleration, and follow through. Results: All athletes had NCAA experience and were aged 18-30 years old. The anconeus (26.9%, 36.3%, 57.6%, and 105.8% MVCs), extensor digitorum communis (22.7%, 28.0%, 31.0%, and 42.8% MVCs), and flexor digitorum superficialis (19.4%, 39.3%, 22.3%, and 104.7% MVCs) had high levels of activity throughout all phases of the football throw. The brachioradialis (56.8%MVC) and anconeus (57.6%MVC) were the most active muscles during the acceleration phase. The pronator teres (78.4%MVC), pronator quadratus (90.9%MVC), and flexor digitorum superficialis (104.7% MVCs) have very high levels of activation during the follow through phase. Conclusion: High levels of activity of the anconeus suggest that it functions as a dynamic stabilizer during all phases of the throwing motion. High levels of activity of the extensor digitorum communis and flexor digitorum superficialis suggest that they are important for grip. The pronator teres and pronator quadratus are important at ball release to produce a spiral motion of the football. High activity of the medial sided musculature may impart dynamic stability to the elbow. These findings may explain why quarterbacks have a lower rate of UCL injury and a higher return to play without surgery.

Context: Although baseball is a relatively safe sport, numerous reports suggest a rapid rise in elbow injury rate among youth baseball pitchers. Evidence Acquisition: PubMed was searched for epidemiologic, biomechanical, and clinical studies of elbow injuries in baseball (keywords: “youth OR adolescent” AND baseball AND pitching AND “ulnar collateral ligament OR elbow”; published January 2000 – April 2012). Studies with relevance to youth baseball pitchers were reviewed. Relevant references from these articles were also retrieved and reviewed. Original data, insight, and recommendations were added. Results: The majority of baseball elbow injuries are noncontact injuries to the dominant arm resulting from repetitive pitching. Five percent of youth pitchers suffer a serious elbow or shoulder injury (requiring surgery or retirement from baseball) within 10 years. The risk factor with the strongest correlation to injury is amount of pitching. Specifically, increased pitches per game, innings pitched per season, and months pitched per year are all associated with increased risk of elbow injury. Pitching while fatigued and pitching for concurrent teams are also associated with increased risk. Pitchers who also play catcher have an increased injury risk, perhaps due to the quantity of throws playing catcher adds to the athlete’s arm. Another risk factor is poor pitching biomechanics. Improper biomechanics may increase the torque and force produced about the elbow during each pitch. Although throwing breaking pitches at a young age has been suggested as a risk factor, existing clinical, epidemiologic, and biomechanical data do not support this claim. Conclusions: Some elbow injuries to youth baseball pitchers can be prevented with safety rules, recommendations, education, and common sense. Scientific and medical organizations have published safety rules and recommendations, with emphasis on prevention of overuse and pitching while fatigued. Strength-of-Recommendation Taxonomy (SORT): A

Injuries to the ulnar collateral ligament (UCL) in throwing athletes frequently occurs from the repetitive valgus loading of the elbow during the throwing motion, which often results in surgical reconstruction of the UCL requiring a structured postoperative rehabilitation program. Several methods are currently used and recommended for UCL reconstruction using autogenous grafts in an attempt to reproduce the stabilizing function of the native UCL. Rehabilitation following surgical reconstruction of the UCL begins with range of motion and initial protection of the surgical reconstruction, along with resistive exercise for the entire upper extremity kinetic chain. Progressions for resistive exercise are followed that attempt to fully restore strength and local muscular endurance in the rotator cuff and scapular stabilizers, in addition to the distal upper extremity musculature, to allow for a return to throwing and overhead functional activities. Rehabilitation following UCL reconstruction has produced favorable outcomes, allowing for a return to throwing in competitive environments.

Context: Baseball pitching kinematics, kinetics, ball velocity, and injuries at the shoulder and elbow are related. Evidence Acquisition: PubMed and Sport Discus were searched for original studies published between 1994 and 2008. Relevant references in these studies were retrieved. Inferential studies that tested relationships between kinematics and kinetics were included, as were studies that tested relationships between kinematics and ball velocity. Descriptive studies that simply quantified kinematics and/or kinetics were excluded. Results: Several kinematic parameters at the instant of foot contact were associated with increased upper extremity kinetics: front foot position, front foot orientation, shoulder abduction, and shoulder horizontal adduction. The timing of shoulder external rotation, pelvis rotation, and upper trunk rotation was associated with increased kinetics and decreased ball velocity. Low braking force of the lead leg and a short stride were associated with decreased ball velocity. Decreased maximum shoulder external rotation, shoulder abduction, knee extension, and trunk tilt were also associated with decreased ball velocity. As pitchers develop, kinematic values remain similar, their variability reduces, and kinetic values gradually increase. Slight kinematic variations were seen among pitch types, although the kinetics of fastballs and curveballs were relatively the same; changeup kinetics were the lowest. As pitchers fatigued, kinetic values remained constant, but increases in arm pain were reported. Conclusions: Several kinematic parameters were related to joint kinetics and ball velocity. To enhance performance and reduce injury risk, pitchers need to learn proper fastball mechanics at an early age. A changeup is recommended as a safe secondary pitch to complement the fastball; the curveball can be added after fastball and changeup mechanics are mastered. Avoiding overuse and pitching while fatigued is necessary to minimize the risk of arm injury.

Objectives: Shoulder instability is a common and limiting injury to football players. The return to play (RTP) percentage and factors affecting RTP after shoulder stabilization in National Football League (NFL) players are not defined. The purpose of this study was to determine the rate of return to professional football play in the NFL after shoulder stabilization and to determine what factors may affect RTP in these athletes. Methods: Sixty NFL players who had undergone shoulder stabilization at our institution were followed to determine the rate of RTP and factors predicting RTP. Chart review was performed to glean perioperative data and follow-up was performed by accessing the statistics database maintained by the NFL. Successful RTP was defined as return to play in at least one regular season NFL game following surgery. Chi square and Student’s t-tests were performed to examine differences between perioperative and athletic history variables and a player’s ability to RTP. Results: Ninety percent (54 of 60) of NFL players were able to return to game play following shoulder stabilization. The average time to RTP was 8.6 months. Age, number of games before surgery, and career length were not statistically different between those that returned and those that did not. Eleven of the sixty patients underwent open stabilization. Ninety-two percent (45/49) of the arthroscopically treated and eighty-two percent (9/11) of the openly treated athletes were able to RTP; these rates were not found to be significantly different. Playing history and demographics were similar between the open and arthroscopic groups. Players selected before the fourth round of the NFL draft were 7.6 times more likely to RTP. Circumferential labral tears were found in seven athletes, all of whom were able to RTP following surgery. Conclusion: The RTP rates for NFL players following shoulder stabilization are quite high (90%). There is no difference in RTP rates between open and arthroscopic repairs. Being selected in the first four rounds of the NFL draft is highly predictive of a player’s ability to RTP.

Objectives: The purpose of this study was to determine whether GIRD and/or bilateral difference in total rotational motion (TRM) of the glenohumeral joint (external rotation + internal rotation) correlated with elbow injuries in professional baseball pitchers. Methods: This study was conducted over eight competitive seasons (2005-2012). Each year during spring training, the same examiners assessed passive range of motion (PROM) of both the dominant and non-dominant shoulders of professional pitchers using a bubble goniometer. In total, 505 examinations were conducted on 296 pitchers. Glenohumeral joint motion was assessed in supine with the arm at 90 degrees of abduction and in the plane of the scapula for ER and IR. During ER and IR ROM assessment, the scapula was stabilized per methods previously established. Elbow injuries and days missed due to injury were assessed and recorded by the medical staff of the team. Results: Significant differences were noted during side-to-side comparisons (pConclusion: Based on these results, pitchers with bilateral differences in total rotational motion had a significant impact on the risk of elbow injuries. This information can help guide the clinician during the evaluation and progression of the professional baseball pitcher.