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Currently it is hypothesized that increased body mass index may contribute to overuse injuries. Thus, if hip or shoulder range of motion is affected by body mass index, pitchers may be placing additional stress on joints as they seek to pitch at maximal velocity. The purpose of this study was to examine if range of motion at the hips and shoulders were related to body mass index classification. A sample of 147 female softball pitchers (17.0±4.2 years; 167.6±11.8 cm; 70.6±17.5 kg; body mass index=24.8±4.7 kg/m2) participated. Bilateral hip and shoulder range of motion were assessed. Multivariate analysis of variance results indicated body mass index [Wilks’ Λ=0.742, F=1.722, p=0.014, η2=0.095] significantly affected range of motion of the shoulder and hip. Post hoc results indicated the underweight group had significantly more range of motion than the obese group in hip internal range of motion on both the throwing side (mean difference=12.39, p=0.005) and glove side (mean difference=11.98, p=0.004). Although body composition is not overly emphasized among softball pitchers, the current study reveals excess weight may inhibit proper mechanics. Coaches, athletic trainers, strength and conditioning personnel, and athletes should acknowledge the role that body composition can play in affecting pitch outcomes.

Background: Baseball pitching injuries are increasing at an alarming rate. While weighted ball throwing programs may be effective at increasing pitching velocity, previous research has identified a 24% injury rate and a 3.3° increase in shoulder external rotation (ER) range of motion (ROM) after performing a 6-week program. However, previous research has not investigated, separately, the immediate effects of throwing underloaded and overloaded balls on ROM. The purpose of this study was to examine the acute effects of throwing differently weighted baseballs on shoulder ROM. By analyzing these differences, it may be possible to determine the specific weight range that may lead to the greatest increase in ROM and potential injury risk. Hypothesis: Throwing with weighted balls will result in an increase in shoulder ER ROM. Study Design: Randomized controlled trial. Level of Evidence: Level 2. Methods: A total of 16 male high school baseball pitchers agreed to participate in this study. The participants were (mean ± SD) 17.1 ± 1.0 years of age, 1.81 ± 0.09 m tall, and had a mass of 79.2 ± 11.1 kg. Each participant was tested on 3 different days, 1 week apart, with 3 different conditions in random order: (1) underload throwing, using regulation 5-oz baseballs and 4- and 2-oz balls; (2) overload throwing, using 5-, 6-, and 9-oz balls; and (3) extreme overload throwing, using 5-, 16-, and 32-oz balls. Each testing session began by measuring passive shoulder ROM (external rotation and internal rotation) using standard goniometric measurements. Participants then performed 3 throws with each weighted ball from 3 different positions (kneeling, rocker, and run-and-gun) for a total of 27 throws each test session. ROM measurements were repeated at the end of each test session. The effect of each throwing condition on ROM was compared from pre- to posttraining using a paired t test ( P ≤ 0.05). Results: There was no significant difference in ER after throwing at underloaded weights. The overload condition showed a statistically significant increase of 3.3° in external rotation ( P = 0.05). The extreme overload condition showed a statistically significant increase in ER of 8.4° ( P < 0.001). There were no differences in internal rotation for any group. Conclusion: A significant increase in shoulder ER was observed immediately after throwing overload weighted balls. This effect increased as the weights of the balls increased. Clinical Relevance: Throwing with overload weighted baseballs causes an immediate increase in shoulder ER ROM. It is unknown why these changes occur; however, the results may explain both the increase in velocity and injury rates previously observed from throwing weighted balls. The current study results may be used to develop more scientifically validated weighted ball programs. Heavier balls should be used with caution, and ROM should be monitored during implementation of these programs.

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.

Kevin Wilk, Christopher Arrigo, and Dr. James Andrews deliver the first editorial of the "new" IJSPT. They reflect on the importance of teamwork in successful outcomes in sports medicine.

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 Fastpitch softball is a popular sport for young females. However, data are limited describing youth pitching mechanics. Normative data describing pitching mechanics in the two youngest player pitch leagues are critical to gaining an improved understanding of proper mechanics in an attempt to establish injury prevention programs. Purpose The purpose of this study was to examine pitching mechanics in Little League softball pitchers and examine the relationship of these mechanics and participant anthropometrics to ball velocity. Study Design Cross-sectional. Methods Twenty-three youth softball pitchers (11.4 ± 1.5 years; 154.6 ± 10.5 cm; 51.0 ± 8.0 kg) participated. An electromagnetic tracking system was used to collect kinematic data for three fastball trials for strikes over a regulation distance to a catcher. The pitching motion was divided into three events: top of back swing, stride foot contact, and ball release. Results Youth who were older (r = 0.745, p

Objectives: Rotator cuff tears are rare injuries in adolescents, but can be a cause of significant morbidity if unrecognized. Previous literature on rotator cuff repairs in adolescents is limited to small case series, with little data to guide treatment. The purpose of this study was to investigate the clinical information, demographics, and results of surgical treatment of a consecutive series of adolescent athletes who underwent rotator cuff repair with a minimum 2-year follow-up. We hypothesized that adolescent patients would have excellent functional outcome scores and return to the same level of sports participation after rotator cuff repair, but would have some difficulty returning to the same position in overhead sports. Methods: A retrospective search of the practice’s billing records identified all patients with high-grade (>50%) partial-thickness or rotator cuff tears that underwent rotator cuff repair between 2006 and 2014 with an age of less than 18 years at the time of surgery and a minimum of two years of follow-up. Clinical records were evaluated for demographic information, and telephone follow-up was obtained for return to play, performance, other surgeries and complications, a numeric pain rating scale (0-10) for current shoulder pain, American Shoulder and Elbow Surgeons (ASES) Shoulder Assessment Form, and the Western Ontario Rotator Cuff Index (WORC). Statistical analysis was performed with JMP 10 (SAS Institute, Cary, NC) with p < 0.05 for significance. Descriptive statistics were prepared for all variables, and outcomes were compared according to affected tendon and concomitant procedures using two-sided Fisher’s exact tests and Student’s t-tests. Results: Thirty-two consecutive adolescent athletes (28 boys and 4 girls) with a mean age of 16.1 years (range 13.2-17.9 years, SD=1.3) met inclusion criteria. Twenty-nine patients (91%) had a traumatic event associated with the onset of their shoulder pain, and 27 of these patients (93%) had no symptoms prior to the trauma. The most common tendon affected was the supraspinatus (21 patients, 66%). All seven subscapularis injuries were repaired in open fashion, while all other tears were repaired arthroscopically with either a single-row or double-row configuration depending on tear size and anatomy. Of the 18 partial-thickness tears, eight (44%) were measured intraoperatively to be 50-75% of the footprint, and the remaining ten tears (56%) encompassed greater than 75% of the footprint from medial to lateral. Twenty-seven patients (84%) d the outcome questionnaires at a mean of 6.2 years after surgery (range 2-10 years, SD=2.6 years). The mean ASES score was 93 (range 65-100, SD=9), mean WORC was 89% (range 60%-100%, SD=13%), and mean numeric pain rating was 0.3 (range 0-3, SD=0.8). Table 1 Overall, 25 patients (93%) were able to return to the same level of play or higher. In overhead athletes, 13 patients (93%) were able to return to the same level of play, but 8 patients (57%) were forced to switch positions due to difficulty with throwing. There were no surgical complications, but two patients did undergo a second operation during the study period. Conclusion: Surgical repair of high-grade partial-thickness and rotator cuff tears yielded successful outcomes in adolescents, with excellent functional outcomes at mid-term follow-up. However, overhead athletes may have difficulty playing the same position after surgery due to difficulty throwing. Table 1: Patient outcomes and functional scores obtained from telephone follow-up. Patient Outcomes (n = 27 patients) Time from surgery to follow-up 6.2 years (range 2-10 yrs., SD=2.6 yrs.) Return to sport at same level 25 (93%) Play collegiate athletics 8 (30%) Overhead athletes 14 (52%) Return to play at same level 13 (93%) Forced to switch positions 8 (57%) ASES score mean 93 (range 65-100, SD=9) WORC score mean 89% (range 60%-100%, SD=13%) Numeric Pain Rating Scale (0-10) mean 0.3 (range 0-3, SD=0.8)

Background: Injury prevalence has been well described among baseball athletes; similarly, a better understanding of injuries in softball athletes is needed. Purpose: To examine shoulder and elbow injury epidemiology among high school softball athletes in the United States. Study Design: Descriptive epidemiological study. Methods: Injury data were obtained from the National High School Sports-Related Injury Surveillance System, which captures data from a large national sample of US high schools. Annually, a random sample of 100 high schools provided a representative sample with respect to the 4 US Census geographic regions and 2 school sizes (cutoff point, 1000 students). Athletic trainers from participating schools reported data for athlete-exposures (AEs; practice or competition) and shoulder and elbow injuries from 2005-2006 through 2016-2017. Results: A total of 239 shoulder injuries and 85 elbow injuries occurred within 2,095,329 AEs. The overall shoulder injury rate was 1.14 per 10,000 AEs, whereas the overall elbow injury rate was 0.41 per 10,000 AEs. Injuries to the shoulder were more likely to occur during competition as compared with practice (rate ratio, 1.28; 95% CI, 0.99-1.65). Half of the shoulder (50.4%) and elbow 48.9% injuries were due to an overuse/chronic mechanism. Of the athletes sustaining an injury, 86.8% with shoulder injuries and 93.0% with elbow injuries returned to play within 21 days. Only 16.7% of shoulder injuries and 17.5% of elbow injuries were sustained by pitchers. Conclusion: Shoulder and elbow injury rates, time to return, and percentage of injuries among pitchers were far lower in high school softball than previously reported values for high school baseball. There were relatively low incidences of shoulder and elbow injuries in high school softball as compared with baseball, with few injuries requiring lengthy time to return to play.

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.

Background: Variable return-to-play (RTP) rates have been reported after surgical repair of superior labral anterior-posterior (SLAP) tears in baseball players. Many studies, however, have not controlled for concomitant shoulder injuries. Purpose/Hypothesis: The purpose of this study was to evaluate rates of RTP and return to previous or higher performance level (RTPP) and long-term outcomes after isolated SLAP tear repair. The hypothesis was that improved outcomes would be identified compared with previous reports. Study Design: Case series; Level of evidence, 4. Methods: The records of 232 players who underwent isolated SLAP tear repair from 2004 to 2014 were reviewed. A total of 98 players who were at least 12 months out from surgery were identified. Through telephone interviews, participants completed the Western Ontario Shoulder Instability Index (WOSI) and Veterans RAND 12-Item Health Survey (VR-12) and answered scripted questions about RTP, RTPP, and current symptoms. Results: Of the 98 players who met the inclusion criteria, 73 (74.5%) participated. The mean age at the time of surgery was 19.8 ± 2.9 years. The mean follow-up time was 86.2 ± 25.1 months overall; it was 84.4 ± 24.4 months for pitchers and 90.3 ± 26.7 months for other position players, (P = .40). There were 10 professional, 36 collegiate, and 27 high school players. Most players perceived successful RTP (83.6%), including 80.0% of pitchers and 91.3% of other position players (P = .23). However, RTPP rates were lower, at 52.3% (n = 26) and 78.3% (n = 18) for pitchers and other position players, respectively (P = .03). Pitchers were younger at the time of surgery (19.3 ± 3.0 vs 20.8 ± 3.0 years, respectively; P = .03) and had greater perceived shoulder and general health impairments compared with other position players (P ≤ .02). Players who perceived successful RTPP had better WOSI of the healthy shoulder and individual physical, sports, lifestyle, and emotion scores compared with players who did not perceive successful RTPP. Conclusion: After the surgical repair of isolated type II or greater SLAP tears, other position players displayed superior RTP (91.3% vs 80.0%, respectively) and RTPP (78.3% vs 52.3%, respectively) rates than pitchers. Long-term follow-up suggests that pitchers may perceive greater long-term impairments than other position players and are less likely to return to their previous or higher performance level.

Background: Softball pitchers have an eminent propensity for injury due to the high repetition and ballistic nature of the pitch. As such, trunk pathomechanics during pitching have been associated with upper extremity pain. The single leg squat (SLS) is a simple diagnostic tool used to examine LPHC and trunk stability. Research shows a lack of LPHC stability is often associated with altered pitching mechanics consequently increasing pain and injury susceptibility. Hypothesis/Purpose: The purpose of this study was to examine the relationship between trunk compensatory kinematics during the SLS and kinematics during foot contact of the windmill pitch. The authors hypothesized there would be a relationship between SLS compensations and pitch kinematics previously associated with injury. In using a simple clinical assessment such as the SLS, athletes, coaches, parents, and clinicians can identify potential risk factors that may predispose the athlete to injurious movement patterns. Methods: Fifty-five youth and high school softball pitchers (12.6±2.2 years, 160.0±11.0 cm, 60.8±15.5 kg) were recruited to participate. Kinematic data were collected at 100Hz using an electromagnetic tracking device. Participants were asked to complete a SLS on their stride leg (contralateral to their throwing arm), 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 three separate backward elimination regression analyses. Independent variables examined at foot contact of the pitch included: 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 trunk flexion significantly predicted SLS trunk rotation (SE = .068, t = 2.232, p = .030) and explained approximately 7% of variance (Adj. R2 = .066). The SLS trunk flexion regression, F(1,56) = 5.755, p = .020, revealed stride knee valgus significantly predicted SLS trunk flexion (SE = .256, t = 2.399, p = .020) and explained approximately 8% of variance (Adj. R2 = .078). Conclusion/Significance: Additional trunk rotation and trunk flexion at peak depth of the SLS indicate increased knee valgus and trunk flexion at foot contact of the pitch, both of which suggest poor LPHC stability, may increase the potential for injury. Athletes, coaches and clinicians should acknowledge the risk of poor LPHC in softball pitching and implement exercises to improve LPHC stability in effort to decrease pitching pathomechanics and associated pain.

Background: Ulnar collateral ligament (UCL) injuries of the elbow are uncommon in the general population but prevalent in the athletic community, particularly among baseball players. Platelet-rich plasma (PRP) injection therapy has become a popular nonoperative adjuvant treatment for such injuries to help reduce recovery time and avoid surgery. Purpose/Hypothesis: To analyze patient outcomes by injury severity and identify injury types that responded most favorably and unfavorably to PRP treatment. It was hypothesized that PRP therapy would prove to be most beneficial in the treatment of lower-grade, partial UCL tears and less effective in the treatment of more severe, complete UCL tears. Study Design: Cohort study; Level of evidence, 3. Methods: A cohort of 50 patients with UCL injuries in their dominant elbow, diagnosed by MRI (magnetic resonance imaging) arthrogram, underwent PRP therapy in conjunction with an established rehabilitation program. UCL injuries were classified by MRI as low-grade partial tear (Type I), high-grade partial tear (Type II), complete tear (Type III), or tear in more than 1 location (Type IV). Results: In total, 24 of 39 (61.5%) Type I and II tears, 3 of 3 (100%) Type III tears, and 1 of 8 (12.5%) patients with Type IV tears responded to UCL PRP injection therapy and were able to return to play without surgery. Ten patients required subsequent UCL PRP injections, of which 3 (30%) were able to return to sport without surgery. Conclusion: PRP treatment for Types I and II UCL tears shows great promise when combined with physical therapy and a rehabilitation program. Type III UCL tears demonstrated a high rate of success, although with low cohort numbers. Type IV UCL tears did not appear to respond well to PRP injection therapy and often required surgical intervention or cessation of sport. Therefore, PRP treatment does not appear to be appropriate for patients with complete Type IV UCL tears but may enhance recovery and improve outcomes in throwing athletes with Types I, II, and III UCL injuries.

Background: Despite evidence that overuse is the most common mechanism of injury, softball pitchers currently have no pitch count regulations. Pain has been associated with certain pitching pathomechanics, and some reports indicate increased pain following a single pitching bout. Hypothesis/Purpose: The purpose of this study was to analyze kinematic variables such as center of mass (COM), trunk, and stride length during the first and last inning of a simulated game in youth softball pitchers. We hypothesized COM to be shifted back toward the drive leg, stride length would be increased, and trunk kinematics would be altered during the last inning of a simulated game as compared to the first inning. Methods: Participants included thirty-two softball pitchers (12.4±1.6yrs., 159.4±8.9cm, 62.0±13.6kg). Participants were deemed injury and surgery free for the past six months and were currently active as a pitcher on their teams’ roster. Kinematic data were collected at 100Hz using an electromagnetic system. After warm-up, participants were instructed to throw random game situations, provided by the investigator, with the catcher located at regulation distance (43ft). Participants were required to produce three outs an inning as per a regulation softball game. Three fastballs from the first and last inning were recorded and used for analysis. Kinematics were analyzed at five different pitch events including: start of pitch, top of pitch, foot contact, ball release, and follow through. Results: A paired samples t-test revealed a statistically significant difference in trunk rotation during the first three pitching events from the first and last inning. Specifically, pitchers exhibited less trunk rotation towards the pitching arm side. A bivariate Pearson’s correlation showed volume of pitches was correlated with stride length (r=.367, p=.039) and COM (r=.364, p=.041) at the start of the pitch, and trunk flexion at top of pitch (r=-.392, p=.026), foot contact (r=-.413, p=.019), and follow-through (r=-.436, p=.013). Conclusion/Significance: Trunk kinematics, stride length, and COM were altered as pitch volume increased. These results provide clinical importance as the trunk pathomechanics seen may be indicative of poor trunk control and fatigue. Although it is out of the realm of this study to state whether the kinematic changes seen are associated with injury, we do know that deficits in the kinetic chain are associated with injury and that trunk pathomechanics are associated with pain in collegiate softball pitchers. Research should continue to investigate the effects of pitch count, pitch mechanics, and injury in youth softball pitchers.

Fastpitch softball is a popular sport for young females. However, data are limited describing youth pitching mechanics. Normative data describing pitching mechanics in the two youngest player pitch leagues are critical to gaining an improved understanding of proper mechanics in an attempt to establish injury prevention programs.The purpose of this study was to examine pitching mechanics in Little League softball pitchers and examine the relationship of these mechanics and participant anthropometrics to ball velocity.Cross-sectional.Twenty-three youth softball pitchers (11.4 ± 1.5 years; 154.6 ± 10.5 cm; 51.0 ± 8.0 kg) participated. An electromagnetic tracking system was used to collect kinematic data for three fastball trials for strikes over a regulation distance to a catcher. The pitching motion was divided into three events: top of back swing, stride foot contact, and ball release.Youth who were older (r = 0.745,The significant relationships found between pitching mechanics and ball velocity only occurred at the trunk, which may highlight the importance of utilizing the trunk to propel the upper extremity in dynamic movements.Diagnosis, Level 4.

Background: While the kinematics of the pitching arm, trunk, and pelvis have been described and studied, glove arm kinematics remain an understudied portion of the pitching motion. Baseball pitchers seek to achieve maximum ball velocity in a fashion that does not place the arm at risk of injury. Purpose: To assess the relationship between glove arm shoulder horizontal abduction and elbow flexion and pitching arm kinematics and kinetics among youth pitchers to determine whether recommendations can be made toward a safer pitching motion. Study Design: Descriptive laboratory study. Methods: Thirty-three right-handed youth male baseball pitchers (mean ± SD: age, 13.6 ± 2.0 years; height, 169.4 ± 14.3 cm; weight, 63.5 ± 13.0 kg; experience, 7.3 ± 3.0 years) threw 3 fastballs to a catcher while kinematic data were collected with an electromagnetic tracking system. The Spearman rank-order test was used to identify relationships between glove arm horizontal abduction and glove arm elbow flexion and various kinematics and kinetics found at maximum shoulder external rotation (MER) and ball release for the fastest fastball delivered by each participant. Results: At MER, there were significant relationships found between a more flexed glove arm elbow and increased pitching arm elbow valgus force (rs[31] = –0.52, P = .002), increased pitching arm shoulder anterior force (rs = –0.39, P = .024), and decreased hip velocity (rs[31] = –0.45, P = .009). Additionally, there were significant relationships between greater glove arm horizontal abduction at MER and increased pitching arm humeral velocity (rs[31] = 0.52, P = .002) and increased trunk rotational velocity (rs[31] = 0.40, P = .022) at MER. Conclusion: A more extended glove arm elbow and more horizontally abducted glove arm shoulder at MER could prove to be more advantageous for performance and possibly be a safer motion for the baseball thrower. Clinical Relevance: The orthopaedic community can dictate safer biomechanics when communicating with pitchers, trainers, and pitching coaches.

Background: Emphasis on enhancing baseball pitch velocity has become popular, especially through weighted-ball throwing. However, little is known about the physical effects or safety of these programs. The purpose of this study was to examine the effects of training with weighted baseballs on pitch velocity, passive range of motion (PROM), muscle strength, elbow torque, and injury rates. Hypothesis: A 6-week weighted ball training program would result in a change in pitching biomechanical and physical characteristics. Study Design: Randomized controlled trial. Level of Evidence: Level 1. Methods: During the baseball offseason, 38 healthy baseball pitchers were randomized into a control group and an experimental group. Pitch velocity, shoulder and elbow PROM, shoulder strength, elbow varus torque, and shoulder internal rotation velocity were measured in both groups. The experimental group then performed a 6-week weighted ball throwing program 3 times per week using balls ranging from 2 to 32 ounces while the control group only used a 5-ounce regulation baseball. Both groups performed a strength training program. Measurements were then repeated after the 6-week period. Injuries were tracked over the 6-week training program and the subsequent baseball season. The effect of training with a weighted ball program was assessed using 2-way repeated-measures analysis of variance at an a priori significance level of P < 0.05. Results: Mean age, height, mass, and pretesting throwing velocity were 15.3 ± 1.2 years (range, 13-18 years), 1.73 ± 0.28 m, 68.3 ± 11 kg, and 30.3 ± 0.7 m/s, respectively. Pitch velocity showed a statistically significant increase (3.3%) in the experimental group ( P < 0.001). There was a statistically significant increase of 4.3° of shoulder external rotation in the experimental group. The overall injury rate was 24% in the experimental group. Four participants in the experimental group suffered elbow injuries, 2 during the training program and 2 in the season after training. No pitchers in the control group were injured at any time during the study. Conclusion: Performing a 6-week weighted ball throwing program increased pitch velocity. However, the program resulted in increased shoulder external rotation PROM and increased injury rate. Clinical Relevance: Although weighted-ball training may increase pitch velocity, caution is warranted because of the notable increase in injuries and physical changes observed in this cohort.

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.

Background: Approximately 47 million people in the United States have been diagnosed with arthritis. Autologous platelet-rich plasma (PRP) injections have been documented to alleviate symptoms related to knee osteoarthritis (OA) in randomized controlled trials, systematic reviews, and meta-analyses. Autologous bone marrow aspirate concentrate (BMC) injections have also emerged as a treatment option for knee OA, with a limited clinical evidence base. Purpose: To compare the efficacy of BMC to PRP for the treatment of knee OA regarding pain and function at multiple time points up to 12 months after an injection. We hypothesized that BMC will be more effective in improving outcomes in patients with knee OA. Study Design: Randomized controlled trial; Level of evidence, 2 Methods: A total of 90 participants aged between 18 and 80 years with symptomatic knee OA (Kellgren-Lawrence grades 1-3) were randomized into 2 study groups: PRP and BMC. Both groups completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and subjective International Knee Documentation Committee (IKDC) questionnaires before and 1, 3, 6, 9, and 12 months after a single intra-articular injection of leukocyte-rich PRP or BMC. Results: There were no statistically significant differences in baseline IKDC or WOMAC scores between the 2 groups. All IKDC and WOMAC scores for both the PRP and BMC groups significantly improved from baseline to 1 month after the injection ( P < .001). These improvements were sustained for 12 months after the injection, with no difference between PRP and BMC at any time point. Conclusion: Both PRP and BMC were effective in improving patient-reported outcomes in patients with mild to moderate knee OA for at least 12 months; neither treatment provided a superior clinical benefit. Autologous PRP and BMC showed promising clinical potential as therapeutic agents for the treatment of OA, and while PRP has strong clinical evidence to support its efficacy, BMC has limited support. This study did not prove BMC to be superior to PRP, providing guidance to clinicians treating OA. It is possible that the results were affected by patients knowing that there was no control group. Registration: NCT03289416 ( ClinicalTrials.gov identifier).

BACKGROUND: The number of ulnar collateral ligament (UCL) injuries in adolescent baseball pitchers has risen over the past 2 decades with the incidence of UCL reconstructions also increasing dramatically over that time period. The Joyner-Andrews magnetic resonance imaging (MRI) classification of UCL tears has previously been described to describe the grade and location of tears, which can aid in surgical decision-making. However, the classification of UCL tears in the at-risk adolescent population has yet to fully investigated. Improving our knowledge of these injuries is crucial to help drive targeted evidence-based treatment strategies. The purpose of this study was to examine the grade and location UCL tears using the Joyner-Andrews MRI classification in a large group of adolescent baseball pitchers. METHODS: We reviewed 225 symptomatic adolescent (aged =19 years) male baseball pitchers with UCL injuries treated by the senior author from 2007-2016. All patients had failed conservative treatment prior to evaluation. Pitchers with a prior history of elbow surgery were excluded. Plain radiographs and MRI arthrograms were evaluated for each patient to categorize the UCL injury and associated pathology. The images were reviewed by a sports medicine-trained orthopedic surgeon. UCL tear grade and location were classified using the Joyner-Andrews classification. RESULTS: The mean age at the time of evaluation was 17.2 ± 1.5 years. 56% of the patients were high school athletes. The majority (59.1%) of UCL tears were high-grade partial tears (Type II). Of those 53.4% were on the humeral side (Type II H). The least common tear types were low-grade partial tears (I) and tears in more than one location (Type IV) in 1.3% and 0.9% of patients, respectively. Plain radiographs revealed 31.4% of patients had abnormal findings; calcifications and olecranon osteophytes were present in 10% and 13% of patients, respectively and more commonly occurred in patients with Type II tears. CONCLUSIONS: The results of this study showed that the majority of adolescent baseball pitchers (59%) sustain high-grade partial tears of the UCL. These findings suggest that effective non-reconstruction options such as platelet-rich plasma and UCL repair with internal brace augmentation could be ideal alternatives to UCL reconstruction for these young patients. The high percentage of radiographic abnormalities in these patients highlights the adaptive changes about the elbow in response to the repetitive stresses experienced by the young elbow during throwing.

Background: Prone, supine, and side position exercises are employed to enhance core stability. Hypothesis: Overall core muscle activity would be greater in prone position exercises compared with supine and side position exercises. Study Design: Controlled laboratory study. Methods: Eighteen men and women between 23 and 45 years of age served as subjects. Surface electrodes were positioned over the upper and lower rectus abdominis, external and internal obliques, rectus femoris, latissimus dorsi, and lumbar paraspinals. Electromyography data were collected during 5 repetitions of 10 exercises, then normalized by maximum voluntary isometric contractions (MVIC). Differences in muscle activity were assessed using 1-way repeated-measures analysis of variance, while t tests with a Bonferroni correction were employed to assess pairwise comparisons. Results: Upper and lower rectus abdominis activity was generally significantly greater in the crunch, bent-knee sit-up, and prone position exercises compared with side position exercises. External oblique activity was significantly greater in the prone on ball with right hip extension, side crunch on ball, and side bridge (plank) on toes compared with the prone and side bridge (plank) on knees, the crunch, or the bent-knee sit-up positions. Internal oblique activity was significantly greater in the prone bridge (plank) on ball and prone on ball with left and right hip extension compared with the side crunch on ball and prone and side bridge (plank) on knees positions. Lumbar paraspinal activity was significantly greater in the 3 side position exercises compared with all remaining exercises. Latissimus dorsi activity was significantly greater in the prone on ball with left and right hip extension and prone bridge (plank) on ball and on toes compared with the crunch, bent-knee sit-up, and prone and side bridge (plank) on knees positions. Rectus femoris activity was significantly greater in the prone on ball with left hip extension, bent-knee sit-up, or prone bridge (plank) on toes compared with the remaining exercises. Conclusion: Prone position exercises are good alternatives to supine position exercises for recruiting core musculature. Side position exercises are better for oblique and lumbar paraspinal recruitment. Clinical Relevance: Because high core muscle activity is associated with high spinal compressive loading, muscle activation patterns should be considered when prescribing trunk exercises to those in which high spinal compressive loading may be deleterious.

In spite of the bodyblade (BB®) being used in clinical settings during shoulder and trunk rehabilitation and training for 24 years, there are only five known scientific papers that have described muscle recruitment patterns using the BB®. Moreover, there are no known studies that have examined muscle activity differences between males and females (who both use the bodyblade in the clinic) or between different BB® devices.The primary purposes of this investigation were to compare glenohumeral and scapular muscle activity between the Bodyblade® Pro (BB®P) and Bodyblade® Classic (BB®C) devices while performing a variety of exercises, as well as to compare muscle activity between males and females. It was hypothesized that glenohumeral and scapular muscle activity would be significantly greater in females compared to males, significantly greater while performing exercises with the BB®P compared to the BB®C, significantly different among various BB® exercises, and greater with two hand use compared to one hand use for the same exercise.Controlled laboratory study using a repeated-measures, counterbalanced design.Twenty young adults, 10 males and 10 females, performed seven BB® exercises using the BB®C and BB®P, which are: 1) BB®1 - one hand, up and down motion, arm at side; 2) BB®2 - one hand, front to back motion, shoulder flexed 90 °; 3) BB®3 - one hand, up and down motion, shoulder abducted 90 °; 4) BB®4 - one hand, side to side motion, shoulder and elbow flexed 45 °; 5) BB®5 - two hands, side to side motion, shoulders and elbows flexed 45 °; 6) BB®6 - two hands, up and down motion, shoulders flexed 90 °; and 7) BB®7 - two hands, front to back motion, shoulders flexed 90 °. EMG data were collected from anterior and posterior deltoids, sternal pectoralis major, latissimus dorsi, infraspinatus, upper and lower trapezius, and serratus anterior during 10 sec of continuous motion for each exercise, and then normalized using maximum voluntary isometric contractions (MVIC). A two-factor repeated measures Analysis of Variance (p 0.05) was employed to assess differences in EMG activity between BB® devices (BB®C and BB®P) and genders.As hypothesized, for numerous exercises and muscles glenohumeral and scapular EMG activity was significantly greater in females compared to males and was significantly greater in the BB®P compared to BB®C. There were generally no significant interactions between BB® devices and gender. Overall glenohumeral and scapular muscle activity was significantly greater in BB®3 and BB®6 compared to the remaining exercises, but generally not significantly different between using one hand and using two hands.It may be appropriate to employ BB® exercises during shoulder rehabilitation earlier for males compared to females and earlier for the BB®C compared to the BB®P given less overall muscle activation in males and BB®C compared to in females and BB®P. There was generally no difference in muscle activity between performing the BB® with one-hand or two-hands. Differences in muscle activity between exercises generally was the similar regardless if the BB®C or the BB®P was employed.Level 2.

The activities required during overhead sports, particularly during baseball pitching, produce large forces at the elbow joint. Injuries to the elbow joint frequently occur in the overhead athlete because of the large amount of forces observed during the act of throwing, playing tennis, or playing golf. Injuries may result because of repetitive overuse, leading to tissue failure. Rehabilitation following injury or surgery to the throwing elbow is vital to fully restore normal function and return the athlete to competition as quickly and safely as possible. Rehabilitation of the elbow, whether following injury or postsurgical, must follow a progressive and sequential order, building on the previous phase, to ensure that healing tissues are not compromised. Emphasis is placed on restoring full motion, muscular strength, and neuromuscular control while gradually applying loads to healing tissue. In addition, when one is creating a rehabilitation plan for athletes, it is imperative to treat the entire upper extremity, core, and legs to create and dissipate the forces generated at each joint.

Context: The ulnar collateral ligament of the elbow (UCL) is frequently injured in throwing athletes, most commonly baseball pitchers. The ligament is reconstructed through bone tunnels using palmaris longus or gracilis autograft. Results: This study highlights the following technique for UCL reconstruction in over 2000 athletes. 2 Conclusion: When conservative management fails, ligament reconstruction can allow the athlete to return to their sport. 1

Synopsis There is a growing body of evidence documenting loads applied to the anterior cruciate ligament (ACL) for weight-bearing and non—weight-bearing exercises. ACL loading has been quantified by inverse dynamics techniques that measure anterior shear force at the tibiofemoral joint (net force primarily restrained by the ACL), ACL strain (defined as change in ACL length with respect to original length and expressed as a percentage) measured directly in vivo, and ACL tensile force estimated through mathematical modeling and computer optimization techniques. A review of the biomechanical literature indicates the following: ACL loading is generally greater with non—weight-bearing compared to weight-bearing exercises; with both types of exercises, the ACL is loaded to a greater extent between 10° to 50° of knee flexion (generally peaking between 10° and 30°) compared to 50° to 100° of knee flexion; and loads on the ACL change according to exercise technique (such as trunk position). Squatting with excessiv...

Synopsis Rehabilitation following anterior cruciate ligament surgery continues to change, with the current emphasis being on immediate weight bearing and range of motion, and progressive muscular strengthening, proprioception, dynamic stability, and neuromuscular control drills. The rehabilitation program should be based on scientific and clinical research and focus on specific drills and exercises designed to return the patient to the desired functional goals. The goal is to return the patient's knee to homeostasis and the patient to his or her sport or activity as safely as possible. Unique rehabilitation techniques and special considerations for the female athlete will also be discussed. The purpose of this article is to provide the reader with a thorough scientific basis for anterior cruciate ligament rehabilitation based on graft selection, patient population, and concomitant injuries. J Orthop Sports Phys Ther 2012;42(3):153–171. doi:10.2519/jospt.2012.3741

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

Case report.Joint stiffness, also called arthrofibrosis, remains the primary complication following any reconstructive knee surgery. Acute anterior cruciate ligament surgery, performed with concomitant multiple ligamentous repair and/or reconstruction, further increases the likelihood of developing impaired knee motion following surgery. The purpose of this case report is to present a criteria-based approach to the postoperative management of a multiligament knee injury.A 25-year-old male professional football player sustained a contact injury to his right knee while making a tackle during a regular season game in 2007. He underwent an acute anterior cruciate ligament reconstruction, with concomitant posterolateral corner repair, biceps femoris/iliotibial band repair, lateral collateral ligament repair, and a medial meniscocapsular junction repair. He completed 17 weeks of a multiphased rehabilitation program that emphasized immediate range of motion, low-load long-duration stretching, therapeutic exercise, neuromuscular reeducation/perturbation training, plyometrics, and sport-specific functional drills. Electrical neurostimulation was implemented during the early stages of rehabilitation to control postoperative pain and to promote a steady progression of therapeutic exercise activity.The patient was cleared to begin sport-specific activity 7 months after major multistructure reconstructive knee surgery. He began the 2008 season on the physically-unable-to-perform list, but was activated midseason and played in every game thereafter. During the 2009 and 2010 seasons, he played all regular season games and all playoff games as a starter, and continues to start as a defensive cornerback in the National Football League.This case report highlights the clinical decision-making process and management involved in an acute multiple ligamentous knee injury/reconstruction.Therapy, level 4.

Purpose: The purpose of this study was to compare cruciate ligament forces between the forward lunge with a short step (forward lunge short) and the forward lunge with a long step (forward lunge long). Methods: Eighteen subjects used their 12-repetition maximum weight while performing the forward lunge short and long with and without a stride. EMG, force, and kinematic variables were input into a biomechanical model using optimization, and cruciate ligament forces were calculated as a function of knee angle. A two-factor repeated-measure ANOVA was used with a Bonferroni adjustment (P < 0.0025) to assess differences in cruciate forces between lunging techniques. Results: Mean posterior cruciate ligament (PCL) forces (69-765 N range) were significantly greater (P < 0.001) in the forward lunge long compared with the forward lunge short between 0[degrees] and 80[degrees] knee flexion angles. Mean PCL forces (86-691 N range) were significantly greater (P < 0.001) without a stride compared with those with a stride between 0[degrees] and 20[degrees] knee flexion angles. Mean anterior cruciate ligament (ACL) forces were generated (0-50 N range between 0[degrees] and 10[degrees] knee flexion angles) only in the forward lunge short with stride. Conclusions: All lunge variations appear appropriate and safe during ACL rehabilitation because of minimal ACL loading. ACL loading occurred only in the forward lunge short with stride. Clinicians should be cautious in prescribing forward lunge exercises during early phases of PCL rehabilitation, especially at higher knee flexion angles and during the forward lunge long, which generated the highest PCL forces. Understanding how varying lunging techniques affect cruciate ligament loading may help clinicians prescribe lunging exercises in a safe manner during ACL and PCL rehabilitation.

Controlled laboratory study using a repeated-measures, counterbalanced design.To test the ability of 8 Swiss ball exercises (roll-out, pike, knee-up, skier, hip extension right, hip extension left, decline push-up, and sitting march right) and 2 traditional abdominal exercises (crunch and bent-knee sit-up) on activating core (lumbopelvic hip complex) musculature.Numerous Swiss ball abdominal exercises are employed for core muscle strengthening during training and rehabilitation, but there are minimal data to substantiate the ability of these exercises to recruit core muscles. It is also unknown how core muscle recruitment in many of these Swiss ball exercises compares to core muscle recruitment in traditional abdominal exercises such as the crunch and bent-knee sit-up.A convenience sample of 18 subjects performed 5 repetitions for each exercise. Electromyographic (EMG) data were recorded on the right side for upper and lower rectus abdominis, external and internal oblique, latissimus dorsi, lumbar paraspinals, and rectus femoris, and then normalized using maximum voluntary isometric contractions (MVICs).EMG signals during the roll-out and pike exercises for the upper rectus abdominis (63% and 46% MVIC, respectively), lower rectus abdominis (53% and 55% MVIC, respectively), external oblique (46% and 84% MVIC, respectively), and internal oblique (46% and 56% MVIC, respectively) were significantly greater compared to most other exercises, where EMG signals ranged between 7% to 53% MVIC for the upper rectus abdominis, 7% to 44% MVIC for the lower rectus abdominis, 14% to 73% MVIC for the external oblique, and 16% to 47% MVIC for the internal oblique. The lowest EMG signals were consistently found in the sitting march right exercise. Latissimus dorsi EMG signals were greatest in the pike, knee-up, skier, hip extension right and left, and decline push-up (17%-25% MVIC), and least with the sitting march right, crunch, and bent-knee sit-up exercises (7%-8% MVIC). Rectus femoris EMG signal was greatest with the hip extension left exercise (35% MVIC), and least with the crunch, roll-out, hip extension right, and decline push-up exercises (6%-10% MVIC). Lumbar paraspinal EMG signal was relative low (less than 10% MVIC) for all exercises.The roll-out and pike were the most effective exercises in activating upper and lower rectus abdominis, external and internal obliques, and latissimus dorsi muscles, while minimizing lumbar paraspinals and rectus femoris activity. J Orthop Sports Phys Ther 2010;40(5):265-276, Epub 22 April 2010. doi:10.2519/jospt.2010.3073.

Background: The number of adolescent anterior cruciate ligament (ACL) injuries is rising with increased participation in higher level athletics at earlier ages. With an increasing number of primary ACL reconstructions (ACLRs) comes a rise in the incidence of revision ACLRs. Purpose: To evaluate the clinical results of revision ACLR across a group of high-level adolescent athletes with at least 2-year follow-up. Study Design: Case series; Level of evidence, 4. Methods: A retrospective review of 21 adolescent athletes (age range, 10-19 years) who underwent revision ACLR with at least 2-year follow-up was conducted. Patient-reported outcome measures (PROMs) included the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Lysholm knee scoring scale, Tegner activity level scale, and modified Cincinnati Knee Rating System. Return to sport (RTS) and overall patient satisfaction were also assessed. Results: The mean age at the time of surgery was 16.5 years (range, 14-19 years), and the mean follow-up was 46.4 months (range, 24-97 months); 42.9% of patients were female, and 52.4% of patients participated in collision sports. The mean time to failure after primary ACLR was 13.1 ± 8.0 months, and the most common mechanism of failure was noncontact in at least 66.7% of cases. The revision graft type included bone–patellar tendon–bone (BPTB) in 71.4% of cases; 26.7% of BPTB grafts were from the contralateral extremity. Concomitant procedures were performed for intra-articular lesions in 71.4% of patients. The mean patient satisfaction rate was 95.3%. There were 3 cases of a graft reinjury at a mean of 25 months postoperatively. The mean PROM scores were as follows: IKDC, 87.5 ± 12.7; Tegner, 7.2 ± 2.0; Lysholm, 93.7 ± 9.8; and Cincinnati, 93.4 ± 10.0. Of those attempting to RTS, 68.4% of patients successfully returned at the same level of competition. Patients with a lateral compartment chondral injury were less likely to RTS ( P < .05). Independent variables shown to have no significant relationship to PROMs or RTS included age, follow-up, sport classification, associated meniscal tears, revision graft size/type, and concomitant procedures. Conclusion: Revision ACLR can be an effective surgical option in adolescents participating in collision and contact sports, with good to excellent subjective outcome scores. At a minimum 2-year follow-up, a graft rupture after revision ACLR occurred in 14% of cases. Of the athletes attempting to RTS, 68.4% returned to their preinjury level of competition.

There is concern among sports medicine practitioners that the number of youth baseball pitchers with elbow injuries appears to be increasing. Research points to overuse as the principle risk factor. The risk of elbow pain in youth pitchers is correlated with the number of pitches thrown in a game and in a season. Adolescents who competitively pitch more than 85 pitches per game, more than 8 months out of a year, or with arm fatigue are several times more likely to require elbow surgery. Poor pitching mechanics also appear to contribute to injury risk. Existing research does not show a significant correlation between curveballs and injury. Adults should help youth pitchers avoid fatigue, overuse, and improper mechanics. If elbow pain develops, the youth pitcher should be evaluated by a sports medicine physician.

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.

BackgroundMuscle weakness, particularly of shoulder external rotation, is common after rotator cuff repair surgery. Neuromuscular electrical stimulation has been shown to be an effective adjunct in the enhancement of muscle recruitment.HypothesisShoulder external rotation peak force can be enhanced by neuromuscular electrical stimulation after rotator cuff repair surgery.Study DesignControlled laboratory study.MethodsThirty-nine patients (20 men, 19 women) who had undergone rotator cuff repair surgery were tested a mean of 10.5 days after surgery. Testing consisted of placing patients supine with the shoulder in 45° of abduction, neutral rotation, and 15° of horizontal adduction. Neuromuscular electrical stimulation was applied to the infraspinatus muscle belly and inferior to the spine of the scapula. Placement was confirmed by palpating the muscle during a resisted isometric contraction of the external rotators. Patients performed 3 isometric shoulder external rotation contractions with and without neuromuscular electrical stimulation, each with a 5-second hold against a handheld dynamometer. Neuromuscular electrical stimulation was applied at maximal intensity within comfort at 50 pulses per second, symmetrical waveform, and a 1-second ramp time. The 3 trials under each condition were recorded, and an average was taken. The order of testing was randomized for each patient tested. A paired samples t test was used to determine significant differences between conditions ( P < .05). Each group was also divided based on age, rotator cuff tear size, number of days postoperative, and neuromuscular electrical stimulation intensity. Analysis of variance Models were used to determine the influence of these variables on external rotation force production ( P < .05).ResultsPeak force production was significantly greater ( P < .001) when tested with neuromuscular electrical stimulation (3.75 kg) as opposed to without neuromuscular electrical stimulation (3.08 kg) for all groups tested. There was no significant difference based on the size of the tear, age of the patient, number of days after surgery, or level of neuromuscular electrical stimulation intensity.ConclusionPeak shoulder external rotation force was significantly increased by 22% when tested with neuromuscular electrical stimulation after rotator cuff repair surgery. Neuromuscular electrical stimulation significantly increased force production regardless of the age of the patient, size of the tear, intensity of the current, or the number of days postoperative.Clinical RelevanceNeuromuscular electrical stimulation may be used concomitantly with exercises to enhance the amount of force production and potentially minimize the inhibition of the rotator cuff after repair surgery.

Background It has long been thought by many baseball coaches and players that throwing the fastball from the stretch is more stressful to the shoulder and elbow than throwing the fastball from the wind-up. However, no research has compared the biomechanics of these 2 pitch variations. Hypothesis There are differences in shoulder and elbow kinetics, kinematic position at front-foot contact, timing, and ball velocity between the 2 pitching variations. Study Design Controlled laboratory study. Methods Twenty-eight professional baseball pitchers (aged 22.1 ± 2.8 years) pitched fastballs from both the wind-up and stretch positions in an indoor laboratory setting. Three-dimensional motion-analysis systems were employed to capture the pitching motion. Kinetic variables, kinematic variables at lead-foot contact, and temporal variables of the 2 pitching variations were compared. Results There was no significant difference between the 2 pitch variations for the kinetic, kinematic, or temporal variables. The difference between the ball velocities was statistically significant, but the mean difference was only 0.2 m/s. Conclusions The pitching biomechanics between the wind-up and stretch fastball showed no statistical differences in joint kinetics, kinematics, or timing, and clinically insignificant differences in ball velocity. Clinical Relevance The current results suggest that pitching the fastball from the stretch is not necessarily more stressful to the shoulder and elbow.

BackgroundThere is little evidence supporting current safety recommendations for adolescent pitchers.HypothesisPitching practices of adolescent pitchers without history of arm injury will be significantly different from those of adolescent pitchers who required shoulder or elbow surgery.Study DesignCase control study; Level of evidence, 3.MethodsNinety-five adolescent pitchers who had shoulder or elbow surgery and 45 adolescent pitchers who never had a significant pitching-related injury completed a survey. Responses were compared between the 2 groups using t tests and analyses. Multivariable logistic regression models were developed to identify the risk factors.ResultsThe injured group pitched significantly more months per year, games per year, innings per game, pitches per game, pitches per year, and warm-up pitches before a game. These pitchers were more frequently starting pitchers, pitched in more showcases, pitched with higher velocity, and pitched more often with arm pain and fatigue. They also used anti-inflammatory drugs and ice more frequently to prevent an injury. Although the groups were age matched, the injured group was taller and heavier. There were no significant differences regarding private pitching instruction, coach's chief concern, pitcher's self-rating, exercise programs, stretching practices, relieving frequency, pitch type frequency, or age at which pitch types were first thrown.ConclusionPitching practices were significantly different between the groups. The factors with the strongest associations with injury were overuse and fatigue. High pitch velocity and participation in showcases were also associated with increased risk for injury.Clinical RelevanceNew recommendations were made based on these results. Adherence to the recommendations may reduce the incidence of significant injury to adolescent pitchers.

Descriptive postoperative follow-up research.The purpose of this investigation was to describe the return-to-competition rate and functional outcome of overhead athletes following arthroscopic thermal-assisted capsular shrinkage (TACS).Traditional open procedures to correct instability in overhead athletes, such as capsulolabral repairs and capsular shifts, have produced less-than-favorable results, which have led to the development of TACS. Currently there are no long-term follow-up studies documenting the efficacy of this procedure in groups greater than 31 subjects or for a time period greater than 27 months.Two hundred thirty-one consecutive overhead athletes who due to symptoms of hyperlaxity had previously undergone a TACS procedure from 1997 to 1999 were selected for inclusion in the study. During a 1-month period, 130 of these athletes (mean age +/- SD, 24 +/- 6 years; 113 male, 17 female) were contacted by phone for follow-up at a mean of 29.3 months postoperatively (range, 15.4-46.6 months). Of the 130, 105 participated in baseball (80 pitchers), 14 in softball, 4 in football (quarterbacks), 4 in tennis, and 3 in swimming. Fifty-four (42%) subjects were professional, 49 (38%) collegiate, 16 (12%) high school, and 11 (8%) recreational athletes. One hundred twenty-three of the 130 (95%) underwent 1 or more concomitant procedure(s) at the time of TACS. Most commonly performed were labral debridements (69%), rotator cuff debridements (65%), and superior labral repairs (35%). Subjects who returned to competition were retrospectively evaluated using a modified Athletic Shoulder Outcome Rating Scale to subjectively assess pain, strength and endurance, stability, intensity, and performance. Overall results were based on a 90-point scale with scores of 80 to 90 representing excellent, 60 to 79 good, 40 to 59 fair, and less than 40 poor results.One hundred thirteen out of 130 subjects (87%) returned to competition. Mean (+/-SD) time from surgery to return to competition was 8.4 +/- 4.6 months. Mean outcome score for all subjects was 79/90; 75 (66%) subjects had excellent, 24 (21%) good, 11 (10%) fair, and 3 (3%) poor result. The mean outcome score for males was 80/90 and for females was 70/90.The majority of overhead athletes (87%) successfully returned to competition following a TACS procedure with good-to-excellent long-term outcomes (88%). Based on the results of this study, TACS of the glenohumeral joint is a viable option for overhead athletes with pathological instability.

Background: Literature on arthroscopic stabilization in adolescent patients participating in collision and contact sports is limited, as most studies include adolescents within a larger sample group comprised primarily of adults. Purpose: To review the outcomes of arthroscopic Bankart repair for anterior shoulder instability in an adolescent population participating in collision and contact sports. Study Design: Case series; Level of evidence, 4. Methods: This retrospective review included 39 shoulders in 37 adolescent (≤19 years) athletes who underwent primary arthroscopic Bankart repair using suture anchors with at least 2-year follow-up. All patients had a history of trauma to their shoulder resulting in an anterior dislocation. Outcome measures included patient satisfaction, the visual analog scale (VAS) for pain, American Shoulder and Elbow Surgeons (ASES) score, and Rowe score. Recurrence of dislocation and return to sporting activity were also assessed. Results: The mean age at the time of surgery was 16.9 years (range, 15-19 years), and the mean follow-up was 6.3 years (range, 4.3-10.0 years); 58.6% of patients participated in collision sports. Time to surgery after the initial dislocation episode was 9.2 months (range, 0.5-36.2 months). Four shoulders (10.3%) had dislocation events postoperatively. The majority (78.1%) of patients returned to sports at the same level of competition. Mean VAS was 0.49 ± 1.0, and the mean ASES and Rowe scores were 92.8 ± 12.6 and 85.0 ± 24.2, respectively. Univariate analyses demonstrated that subjective functional outcomes were negatively correlated with recurrence (ASES, P = .005; Rowe, P = .001) and failure to return to sport (ASES, P = .016; Rowe, P = .004). Independent variables shown to have no significant relationship to functional outcomes included age, follow-up, number of preoperative dislocations, time to surgery, sport classification, competition level, tear extent, number of anchors, concurrent Hill-Sachs lesion, and repair of a superior labral anterior-posterior (SLAP) lesion. Conclusion: Arthroscopic Bankart repair is an effective surgical option for traumatic shoulder instability in adolescents participating in collision and contact sports. At a minimum 4-year follow-up, arthroscopic Bankart repair effectively restored stability in 90% of cases; 80% returned to their preinjury level of sport.

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.

Previous studies among young pitchers have focused on the frequency and description of elbow injuries. The purpose of this study was to evaluate the frequency of elbow and shoulder complaints in young pitchers and to identify the associations between pitch types, pitch volume, and other risk factors for these conditions.A prospective cohort study of 298 youth pitchers was conducted over two seasons. Each participant was contacted via telephone after each game pitched to identify arm complaints. Generalized estimating equations were used to assess associations between arm complaints and independent variables.The frequency of elbow pain was 26%; that of shoulder pain, 32%. Risk factors for elbow pain were increased age, increased weight, decreased height, lifting weights during the season, playing baseball outside the league, decreased self-satisfaction, arm fatigue during the game pitched, and throwing fewer than 300 or more than 600 pitches during the season. Risk factors for shoulder pain included decreased satisfaction, arm fatigue during the game pitched, throwing more than 75 pitches in a game, and throwing fewer than 300 pitches during the season.Arm complaints are common, with nearly half of the subjects reporting pain. The factors associated with elbow and shoulder pain were different, suggesting differing etiologies. Developmental factors may be important in both. To lower the risk of pain at both locations, young pitchers probably should not throw more than 75 pitches in a game. Other recommendations are to remove pitchers from a game if they demonstrate arm fatigue and limit pitching in nonleague games.