Elbow joint injuries continue to increase in frequency in baseball at all levels. It is the most commonly injured joint in professional baseball and approximately 25% of all Major League Pitchers have had a ulnar collateral ligament (UCL) surgery and approximately 30% of Minor League pitchers. Injuries to the elbow joint are increasing in scholastic and youth baseball players too. Often the differential diagnosis between UCL injuries and flexor/pronator tendinitis is difficult for the clinician. The purpose of this commentary is to describe the clinical thought process used to assist in making an accurate differential diagnosis between a UCL sprain and a flexor-pronator strain. The clinical examination description that follows is not meant to be comprehensive but instead will focus on the elements germane to differentiation between UCL and flexor-pronator issues. # Level of Evidence 5

Background: Injury of the ulnar collateral ligament (UCL) is common in baseball players. Pitchers are most commonly affected and most likely to have surgery for this injury. The gold standard surgical treatment is UCL reconstruction with autograft; yet, UCL repair with collagen-coated suture tape (ie, internal brace) has shown to be equally effective, and both procedures demonstrate high rates of return to sport and similar postoperative elbow function. However, revision UCL reconstructions have less favorable outcomes regardless of technique. Purpose: This pilot case series reports on short-term outcomes of collegiate or professional baseball pitchers whose primary UCL reconstruction failed and who subsequently underwent revision UCL repair with internal brace. Study Design: Case series; Level of evidence, 4. Methods: A retrospective billing query was performed for patients who had undergone revision UCL repair with internal brace. Patients were eligible for inclusion if they were a pitcher at the collegiate or professional level, were at least 1 year postoperative after revision UCL repair with internal brace, and had a history of ipsilateral primary UCL reconstruction. Clinical and surgical data were collected via electronic medical record review. Outcomes data included return to sport as well as elbow-related function from the American Shoulder and Elbow Surgeons elbow form, Kerlan-Jobe Orthopaedic Clinic score, and Andrews-Carson score. Results: A total of 11 pitchers met inclusion criteria (45% professional and 55% collegiate) and had follow-up data collected (mean follow-up time, 2.9 years; range, 1.0-5.0 years). All 11 (100%) were able to return to sport at the preinjury level or higher, and the mean time from surgery to return to competition was 9 months. At follow-up, the mean function score of the American Shoulder and Elbow Surgeons elbow form was 35.8 (out of 36), the mean Kerlan-Jobe Orthopaedic Clinic score was 88.3 (out of 100), and the mean Andrews-Carson score was 95.0 (out of 100). Conclusion: This pilot case series shows promising short-term results of using UCL repair with internal brace for high-level pitchers with recurrent UCL injury after UCL reconstruction. Specifically, we found excellent return-to-sport and patient-reported outcomes. Further study is warranted with larger sample sizes and longer follow-up to evaluate outcomes after revision of UCL surgery with UCL repair utilizing internal bracing.

# Background Interval throwing programs (ITP) are commonly used while returning from injuries in baseball players. Recent advances in the understanding of the biomechanics and workloads of throwing programs have led to the development of ITPs that allow for a precise and gradual increase in workload to the arm. UCL treatment options continue to evolve and now include various procedures using an internal brace and hybrid approach in addition to traditional reconstruction and nonoperative care. Each variation has different timelines for clinicians to follow. # Purpose The purpose of this paper is to describe four ITP variations of various durations that can be used for a variety of non-operative and postoperative injuries in baseball players. While these programs can be used for a variety of shoulder and elbow injuries, the application of these programs for UCL injuries will be explored. # Study Design Cross-sectional descriptive study # Methods Elbow varus torque per throw was estimated from a 2nd order polynomial regression derived from a relationship between throwing distance and elbow varus torque, based on a dataset of 238,611 throws collected from healthy collegiate baseball pitchers. This model was then applied to construct 4 ITPs: 7-month progression for UCL reconstruction (with and without a hybrid internal brace), 5-month progression for a UCL repair with internal brace, and two short-term progressions of 12-weeks and 6-weeks for nonoperative injuries. For each program, individual throws were assigned estimated torque values to calculate cumulative workload (daily, chronic, and acute), and acute-to-chronic workload ratio (ACWR). These values were plotted over time to evaluate workload progression. # Results The 6-week program had a final chronic workload of 7.6 and stayed in the ACWR optimal range (0.7-1.3) the entire time. The 12-week program had a final chronic workload of 7.8 and stayed in the optimal ACWR range 98% of the time. The 5-month program finished with a chronic workload of 10.0 and stayed in the optimal range 95% of the program. The 7-month had a final chronic workload of 10.8, and stayed in the optimal range for 91% of the program. # Conclusion The four variations in ITPs each showed a gradual ramp-up of chronic workload over the duration of the program while maintaining within the recommended range of ACWR. These ITPs may be used to gradually build workload in baseball players returning from injuries. Due to the various lengths, the ITPs may be used as models to apply to a variety of common injuries or surgeries of the throwing shoulder and elbow. # Level of Evidence Level 3

# Background While one-legged and two-legged bodyweight squats on unstable and stable surfaces are commonly used during patellofemoral rehabilitation, patellofemoral loading during these exercises is unknown. Understanding how patellofemoral force and stress magnitudes affects different squat variations will aid clinicians in determining how and when to prescribe and progress these squatting types of exercises in patients with patellofemoral pain. # Hypothesis/Purpose To quantify patellofemoral force and stress between two squat type variations (BOSU squat versus floor squat) and between two leg variations (one-legged squat versus two-legged squat). It was hypothesized that patellofemoral force and stress would be greater in BOSU squat than floor-squat, and greater in one-legged squat than two-legged squat. # Study Design Controlled laboratory biomechanical, repeated-measures, counterbalanced design. # Methods Sixteen healthy participants performed one-legged and two-legged BOSU and floor squats. Kinematic and ground-reaction force data were used to calculate resultant knee force and torque using inverse-dynamics, with electromyographic data employed in a knee muscle model to predict resultant knee force and torque at every 10° between 10°-100° knee-angles during the squat-descent and squat-ascent. Repeated-measures 2-way ANOVA (p < 0.01) was employed for statistical analyses. # Results Collapsed across one-legged and two-legged conditions, patellofemoral joint force and stress were significantly greater during floor squats than BOSU squats at 40°, 50°, and 70° knee-angles during squat descent and 60° and 50° knee-angles during squat ascent. Collapsed across BOSU and floor squats, patellofemoral joint force and stress were significantly greater for one-legged squats than two-legged squats at all knee-angles. Significant interactions between squat types and leg conditions were found at 30°, 40°, 50°, 60°, and 100° knee-angles during squat-descent, and 100°, 90°, 80°, and 70° knee-angles during squat-ascent, with patellofemoral joint force and stress significantly greater in two-legged floor-squat than two-legged BOSU squat, but no significant differences between one-legged floor-squat and one-legged BOSU squat. # Conclusions Squatting progression employing lower to higher patellofemoral loading over time during PFP rehabilitation may be considered: 1) two-legged BOSU squats at lower knee angles (0° - 50°); 2) two-legged floor squats at lower knee angles (0° - 50°); 3) one-legged BOSU and floor squats at lower knee angles (0° - 50°); 4) two-legged BOSU squats at lower and higher knee angles (0° - 100°); 5) two-legged floor squats at lower and higher knee angles (0° - 100°); 6) one-legged BOSU and floor squats at lower and higher knee angles (0° - 100°). # Level of Evidence 2

The overhead throwing athlete possesses distinct physical traits and undergoes adaptive changes due to the repetitive nature of throwing, often resulting in significant injury to the shoulder or elbow joint. An effective rehabilitation program for the throwing athlete is dependent upon an accurate evaluation that identifies the causative factors contributing to the athlete's condition. In this article, we outline the unique physiology of the thrower's shoulder and elbow, the injuries associated with these athletes and a multiphased rehabilitation approach that allows for the restoration of strength, mobility, endurance, and power essential to return to unrestricted overhead sporting activity.

Injuries to the ulnar collateral ligament (UCL), have become increasingly prevalent among overhead-throwing athletes, especially baseball pitchers. From 2011 to 2023, UCL injuries were the most common injury in Major League Baseball (MLB). Contributing factors include high pitching velocity, fatigue, overuse, and year-round pitching. Research indicates that 25% of MLB pitchers and 14% of Minor League pitchers have undergone UCL surgery, with these numbers steadily rising. After traditional UCL reconstruction, 83% of athletes return to the same or higher levels of play. While the success rate for UCL surgery is high, revision surgeries are becoming more frequent, with mixed outcomes. This underscores the need for improved surgical techniques and rehabilitation strategies. The hybrid UCL reconstruction technique presents a reliable and effective solution for treating UCL injuries, combining the benefits of autogenous grafting with internal brace augmentation. Current research, however, lacks focus on the surgical technique and rehabilitation following UCL hybrid surgery. Achieving successful outcomes with this procedure relies on a collaborative approach, from surgery to rehabilitation with adherence to the rehabilitation protocol and throwing program. Full recovery typically requires 12-14 months, depending on the athlete's level of play. With over 400 successful surgeries to date, this technique has proven to enhance stability and facilitate recovery, particularly in elite-level throwing athletes. The purpose of this paper is to describe this new surgical technique and its associated rehabilitation programs, emphasizing the importance of rehabilitation under the guidance of a rehabilitation professional experienced with overhead athletes. Level of Evidence: 5

Background: The forward lunge is a closed-chain weight-bearing multi-joint exercise simulating the activities of daily living, such as walking or stair climbing, which mainly activates hip, knee, and ankle musculature and is also used by athletes and other individuals to train lower-extremity musculature. Objectives: The purpose of this study is to compare lower-extremity muscle recruitment patterns between stride and step length variations in forward lunges. Methods: Twenty participants had a mean (±SD) age, mass, and height of 26 ± 6 y, 79 ± 8 kg, and 176 ± 7 cm, respectively, for males, and 27 ± 4 y, 62 ± 6 kg, and 161 ± 7 cm, respectively, for females. All participants used their 12-repetition maximum weight while performing a short step and long step forward lunge with a stride (striding forward and pushing back to the starting position) and without a stride (lunging up and down with feet stationary). During each lunge variation, surface electromyography (EMG) data were collected from the quadriceps, hamstrings, gastrocnemius, hip adductors, gluteus maximus, and gluteus medius muscles, and then normalized as a percent of each muscle’s maximum voluntary isometric contraction. A repeated measures two-way analysis of variance was employed (p < 0.01), with step length and stride comprising the two factors. Results: The following had no significant interactions: (1) quadriceps, hamstrings, gastrocnemius, hip adductor, and gluteus maximus EMG activities were significantly greater in lunges with a long step compared to lunges with a short step; and (2) gluteus maximus and gluteus medius EMG activities were significantly greater in lunges with a stride compared to lunges without a stride. The following had significant interactions: (1) gluteus medius EMG activities were significantly greater in lunges with a long step with and without a stride compared to lunges with a short step with and without a stride; (2) quadriceps EMG activities were generally significantly greater in lunges with long and short steps with a stride compared to lunges with long and short steps without a stride, in lunges with a long step with a stride compared to lunges with a short step with a stride, and in lunges with a short step without a stride compared to lunges with a long step without a stride; (3) hamstring and hip adductor EMG activities were significantly greater in lunges with a long step with a stride compared to lunges with a long step without a stride, and in lunges with a long step with and without a stride compared to lunges with a short step with and without a stride; and (4) gastrocnemius EMG activities were significantly greater in lunges with a long step with and without a stride compared to lunges with a short step with and without a stride. Conclusions: Lower-extremity muscle activity is generally greater in forward lunges with a long step compared to a short step, and greater in lunges with a stride compared to without a stride. During the externally loaded forward lunge, high to very high muscle activity occurs in the quadriceps, gluteus maximus, and gluteus medius, thus enhancing muscle hypertrophy and strength in these muscles, while moderate muscle activity occurs in the hamstrings, gastrocnemius, and adductor longus.

BACKGROUND:The increasing prevalence of ulnar collateral ligament (UCL) injuries, particularly in young athletes, necessitates optimization of treatment options. The introduction of UCL repair with internal bracing offers an exciting alternative to traditional UCL reconstruction. PURPOSE:To compare midterm outcomes between UCL repair with internal bracing and UCL reconstruction in competitive athletes. STUDY DESIGN:Cohort study; Level of evidence, 3. METHODS:The authors identified competitive athletes who underwent primary UCL repair with internal bracing or UCL reconstruction between 2013 and 2021 and were at least 2 years postsurgery. To have qualified for repair, patients must have shown complete or partial UCL avulsion from the sublime tubercle or medial epicondyle. Relevant patient, injury, operative, and revision surgery data were collected via chart review. Preoperative American Shoulder and Elbow Surgeons Elbow assessment form (ASES-E), Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow (KJOC), and Andrews-Carson scores were obtained from an ongoing data repository. ASES-E, KJOC, and Andrews-Carson scores, and return-to-sport (RTS) data were collected at follow-up. Linear regression modeling controlling for relevant covariates was utilized to compare patient-reported outcome (PRO) scores between groups. Proportions of athletes who successfully returned to sport and proportions of subsequent revision procedures between groups were compared using chi-square tests. Lastly, for those with baseline questionnaire data, the authors compared magnitude of change between preoperative and postoperative scores between groups using linear regression modeling with baseline scores and follow-up time as the covariates, and follow-up scores as the dependent variable. RESULTS:A total of 461 athletes were eligible for inclusion with complete clinical and outcome data available (mean age at surgery, 19.1 years; 92% male). The UCL repair group had a significantly shorter follow-up time than the UCL reconstruction group (4.4 vs 6.3 years; P < .01). When controlling for follow-up time, the groups did not differ in ASES-E, KJOC, or Andrews-Carson scores at follow-up. There was no significant difference in proportion of revisions between UCL repair (9%) and UCL reconstruction (8%) (P = .77). Of the 268 athletes with complete follow-up in the repair group, 247 attempted to return to their preinjury sport, and 241 (98%) were able to RTS. Six athletes reported that they were unable to RTS due to limitations from their surgery. Of the 155 athletes with follow-up in the reconstruction group, 147 attempted to return to their preinjury sport; 145 (99%) were able to successfully RTS, and 2 were unable to return due to limitations from their surgery. The 2 groups, repair with internal brace versus reconstruction, did not statistically differ in the proportions that returned to preinjury sport (P = .20) but did differ regarding time in months to return to practice (6.7 ± 3.5 vs 10.2 ± 11.7) (P < .01) and time in months to return to competition (9.2 ± 4.6 vs 13.4 ± 13.3) (P < .01). CONCLUSION:Athletes who underwent UCL repair with internal brace reported excellent midterm PROs statistically similar to those after UCL reconstruction, including proportion successfully returning to preinjury sport. There was no significant difference in revision rates between procedures. However, athletes who underwent UCL repair had a statistically significantly shorter time to RTS.

Purpose: To evaluate the effect of tourniquet use during ACL reconstruction on quadriceps strength, intraoperative and postoperative blood loss, operative time, thigh girth or calf girth, and postoperative pain. Methods: A systematic review using PubMed, EMBASE, and Cochrane Database of Systematic Reviews was conducted following the PRISMA guidelines. Randomized controlled trials and nonrandomized studies that evaluated intraoperative and postoperative effects of tourniquet usage during arthroscopic ACL reconstruction published between November 1996 and January 2023 were included. Outcomes evaluated included intraoperative visualization, pain, quadricep strength thigh or calf girth, blood loss, and operative time. Results: Eight studies with 502 total patients were included in this review. There were 253 total patients in the tourniquet (T) group and 249 in the non-tourniquet (NT) group. Postoperative blood loss was higher in the T group (P < .05). Two studies reported significantly increased postoperative analgesic usage within the T group (P < .05), while 2 studies listed no significant differences between groups. Postoperative pain was not significantly increased in either group 2 days postoperation; however, 2 studies reported an increase in pain in the T group within the 10-hour, postoperative window (P <.05). Although 3 studies indicated an initial decrease in quadriceps strength within the T group following surgery (P < .05), overall findings consistently demonstrated a recovery of quadriceps strength within a few weeks. Similarly, there were no long-term significant differences in thigh or calf girth reported. Decreased operative time was reported with tourniquet use across included studies with 1 study demonstrating a significant difference (P < .05). Conclusions: Tourniquet use during ACL reconstruction does not have negative long-term effects on quadriceps strength. Although tourniquet use was associated with increased quadriceps atrophy and pain in the immediate postoperative period, these effects did not persist. Level of Evidence: Level II, systematic review of Level I and II studies.

Isokinetics is a proven method to train and objectively assess the capability of muscle groups, particularly at the knee. The current re-injury rates and less than optimal return to sport percentages seen following anterior cruciate ligament surgery highlights the need for greater focus on what tests and methods are used to make these critical decisions. Isokinetics remains the best single method to objectively determine dynamic muscle strength, power, rate of force development and endurance. These factors make it well-suited to play a crucial role in influencing the appropriate patient progression through a rehabilitation program and assisting in determining return to play readiness following injury or surgery. In this article we will discuss why we believe isokinetics is a useful and necessary testing method, and elucidate testing parameters and goals used during knee extension/flexion assessment.

The distal tibiofibular joint is described as a syndesmosis. The syndesmosis is important to the structural integrity of the ankle joint by maintaining the proximity of the tibia, fibula, and talus. Syndesmotic or high ankle sprains, involving the syndesmotic ligaments, pose a significant rehabilitative challenge due to their intricate anatomy, prolonged recovery periods following injury, and high susceptibility to persistent disability. Traditional management strategies have often been conservative, marked by lengthy periods of immobilization and a gradual return to activity. Severe syndesmotic injuries with diastasis have been treated surgically with screw fixation which may require a second intervention to remove the hardware and carries an inherent risk of breaking the screw during rehabilitation. Another fixation technique, the Tightrope™, has gained popularity in treating ankle syndesmosis injuries. The TightRope™ involves inserting Fiberwire® through the tibia and fibula, which allows for stabilization of the ankle mortise and normal range of motion. The accelerated rehabilitation protocol promotes early weight-bearing and has been shown to expedite the return to sport. This emerging strategy has shown promise in reducing recovery time as it is now possible to return to sport in less than 2 months after a tightrope repair and accelerated rehabilitation, compared with 3–6 months post screw fixation. This clinical commentary delves into this novel approach, highlighting the procedure, rehabilitation protocols, and the implications for physical therapy practice. Level of Evidence V

Shoulder instability is a common pathology seen in athletes and in active individuals. The glenohumeral joint is the most commonly dislocated major joint in the human body. This is probably due to the inherent laxity and tremendous range of motion (ROM) exhibited by individuals along with the large amounts of stress applied to the shoulder joint. Thus, the glenohumeral joint is inherently unstable in many individuals. Mannava et al1 reported 15% of all players reporting to the National Football League Combine exhibited labral tears. Brophy et al2,3 stated it was the fourth most common procedure seen at the Combine. Furthermore, it is the fourth most common procedure performed in college football players.4

Anterior cruciate ligament (ACL) injury rates are on the rise, despite improved surgical techniques and prevention programs. While traditional rehabilitation emphasizes the restoration of motion, strength, and physical performance, emerging research highlights the importance of addressing neurocognitive deficits that can persist after injury. These deficits, including altered proprioception, impaired motor control and muscle recruitment, as well as heightened reliance on visual feedback, can significantly increase the risk of re-injury and impede return to sport. The purpose of this clinical commentary is to outline a proposed comprehensive approach to rehabilitation that challenges the neurocognitive system to optimize rehabilitation outcomes and reduce reinjury risk. Thus, this clinical commentary discusses the rationale for integrating neurocognitive training into all phases of ACLR rehabilitation, from initial injury to eight weeks post-surgery. It details the neurophysiological changes caused by ACL injury and presents evidence supporting the use of exercises that challenge visual attention, decision-making, and motor planning. A comprehensive rehabilitation framework incorporating both physical and neurocognitive components is proposed, aiming to improve long-term outcomes and reduce re-injury risk. Level of Evidence: 5

# Background Anterior cruciate ligament (ACL) injury and reinjury rates are on the rise, despite improved surgical techniques and prevention programs. ACL injuries also lead to a variety of neuroplastic and neuromuscular alterations. Emerging research highlights the importance of addressing neurocognitive deficits that can persist after injury including altered proprioception, impaired motor control, muscle recruitment and heightened reliance on visual feedback. This suggests a shift from subconscious movement, to movements that require increased volitional control, which may contribute to increased risk of re-injury and thus impede return to sport. # Clinical Question Given the neurophysiological changes associated with anterior cruciate ligament (ACL) injury that persistent into the late stages of rehabilitation, does the integration of neurocognitive training into mid to late stage rehabilitation protocols improve functional outcomes and reduce the risk of re-injury following ACL reconstruction (ACLR) in athletes? # Purpose The purpose of Part 2 of this clinical commentary is to offer strategies to implement neurocognitive training elements into the traditional ACLR rehabilitation (in weeks 9+) and review updated testing metrics that may better discern an athletes readiness to return to competition. A comprehensive rehabilitation framework incorporating both physical and neurocognitive components is proposed, aiming to improve both long-term outcomes and return to sport testing, as well as diminishing re-injury risk. # Conclusion Updates to the traditional rehabilitation approach post ACLR, that include increased emphasis on neuroplastic, cognitive, and visual-motor capabilities exist. These help prepare athletes for the unpredictable and chaotic nature of the sporting environment and may facilitate a more effective return to sport for athletes, potentially mitigating the risk of re-injury. # Level of Evidence 5

Background Interval throwing programs (ITP) have been used for decades to enable baseball pitchers to return to competition after injury or surgery by gradually applying load to the throwing arm. Past programs have been based on personal experience; however, advances in our understanding of the biomechanics and workloads of throwing allow for a more modern data -based program to be developed. Hypothesis/Purpose To 1) develop a updated ITP for rehabilitation of modern baseball pitchers based upon biomechanical and throwing workload data, and 2) compare the updated program with a past program to determine differences in chronic workload and acute:chronic workload ratios (ACWR). Study Design Cross-sectional study Methods Workloads (i.e. daily, acute, chronic, and ACWR) for the original ITP were built from the prescribed throwing schedule. Elbow varus torque per throw was calculated based upon a relationship between elbow varus torque and throwing distance. Throw counts, daily/ chronic/acute workloads, and ACWR were calculated and plotted over time. A new ITP was built to model current pitcher's throwing schedules and gradually increased ACWR over time. Results The original ITP had a throwing schedule of 136 days, final chronic workload 15.0, and the ACWR above or below the "safe" range (i.e. 0.7 - 1.3) for 18% of the program with a peak of 1.61. The updated ITP was built to consist of a 217 -day schedule, final chronic workload of 10.8, and deviated from the safe range for 9% of the program, with a peak of 1.33. Conclusion The newly created ITP is more familiar to modern baseball pitchers while exhibiting a more gradual buildup of chronic workload than traditional ITP programs. This ITP may be used to return baseball pitchers back to competition as safely and efficiently as possible, and potentially with less risk of setbacks or reinjury. The ITP may be used following common injuries or surgeries to the throwing shoulder and elbow, such as Tommy John surgery, while also serving as a basis for future development of shorter duration ITPs. Level of Evidence 2c

The incidence of upper extremity (UE) injuries in sport, particularly with the shoulder and elbow in baseball/softball players, appears to be increasing yearly, especially in younger age athletes. Improving the objective criteria and testing methods used to determine return to play (RTP) readiness following non-operative or post-operative management of UE injuries is one aspect of the rehabilitation process that may significantly help in reducing reinjury rates. Currently, the majority of clinicians are still using post operative time frame and/or strength/range of motion as their main criteria for clearance to RTP following UE injury. This demonstrates an inadequate reflection of the actual unpredictable, dynamic environment athletes are returning to participate in. In our clinical experiences, objective testing to allow for clearance to sport participation should incorporate neurocognitive and reactive testing to promote improvements in the athlete's ability to dual task and focus/concentrate on the multi-dimensional tasks at hand. We know that neuroplastic changes occur following UE injury resulting in decreased proprioception and increased motor activation with simple UE tasks. Currently the research on UE return to play testing is limited. The purpose of this clinical commentary was to describe the utilization and provide reference values for a series of reactive neurocognitive UE tests, to assist with RTP, in high school and collegiate overhead athletes (baseball and softball) utilizing the Blaze Pod light system. The use of a more dynamic reactive testing battery may decrease the reinjury rates when an athlete is cleared for participation by measuring readiness in chaotic circumstances that are more reflective of the sporting environment the athlete is working to return to resulting in a greater sense of confidence, performance and prevention of reinjuries.

CONTEXT:Improper baseball pitching biomechanics are associated with increased stresses on the throwing elbow and shoulder as well as an increased risk of injury. EVIDENCE ACQUISITION:Previous studies quantifying pitching kinematics and kinetics were reviewed. STUDY DESIGN:Clinical review. LEVEL OF EVIDENCE:Level 5. RESULTS:At the instant of lead foot contact, the elbow should be flexed approximately 90° with the shoulder at about 90° abduction, 20° horizontal abduction, and 45° external rotation. The stride length should be about 85% of the pitcher's height with the lead foot in a slightly closed position. The pelvis should be rotated slightly open toward home plate with the upper torso in line with the pitching direction. Improper shoulder external rotation at foot contact is associated with increased elbow and shoulder torques and forces and may be corrected by changing the stride length and/or arm path. From foot contact to maximum shoulder external rotation to ball release, the pitcher should demonstrate a kinematic chain of lead knee extension, pelvis rotation, upper trunk rotation, elbow extension, and shoulder internal rotation. The lead knee should be flexed about 45° at foot contact and 30° at ball release. Corrective strategies for insufficient knee extension may involve technical issues (stride length, lead foot position, lead foot orientation) and/or strength and conditioning of the lower body. Improper pelvis and upper trunk rotation often indicate the need for core strength and flexibility. Maximum shoulder external rotation should be about 170°. Insufficient external rotation leads to low shoulder internal rotation velocity and low ball velocity. Deviation from 90° abduction decreases the ability to achieve maximum external rotation, increases elbow torque, and decreases the dynamic stability in the glenohumeral joint. CONCLUSION:Improved pitching biomechanics can increase performance and reduce risk of injury. SORT:Level C.

Background There is lack of consensus on which tests, particularly upper extremity functional performance tests (FPT) that should be used for clinical decision making to progress a patient through a rehabilitation program or criteria for return to sport (RTS). Consequently, there is a need for tests with good psychometric properties that can be administered with minimal equipment and time. Purpose (1) To establish the intersession reliability of several open kinetic chain FPT in healthy young adults with a history of overhead sport participation. (2) To examine the intersession reliability of the limb symmetry indices (LSI) from each test. Study Design Test-retest reliability, single cohort study. Methods Forty adults (20 males, 20 females) completed four upper extremity FPT during two data collection sessions three to seven days apart: 1) prone medicine ball drop test 90°shoulder abduction (PMBDT 90°), 2) prone medicine ball drop test 90°shoulder abduction/90° elbow flexion (PMBDT 90°-90°), 3) half-kneeling medicine ball rebound test (HKMBRT), 4) seated single arm shot put test (SSASPT). Measures of systematic bias, absolute reliability and relative reliability were computed between the sessions for both the original test scores and LSI. Results Except for the SSASPT, all tests demonstrated significant (p ≤ 0.030) improvements in performance during the second session. Generally, for the medicine ball drop/rebound tests, the absolute reliability was the highest (less random error) for the HKMBRT, next the PMBDT 90°followed by PMBDT 90°-90°. Excellent relative reliability existed for the PMBDT 90°, HKMBRT, and SSASPT, whereas fair to excellent relative reliability for the PMBDT 90°-90°. The SSASPT LSI revealed the highest relative and absolute reliability. Conclusion Two tests, HKMBRT and SSASPT demonstrated sufficient reliability; therefore, the authors’ recommend those tests can be used for serial assessments to advance a patient through a rehabilitation program as well as criteria for progression to RTS. Level of Evidence 3

Background:Interval throwing programs are used in rehabilitation of throwing injuries, especially ulnar collateral ligament injuries. Athletes who are rehabilitating begin by throwing on flat ground progressing through increasing distances, number of throws, and intensity of throwing. If the athlete is a baseball pitcher, the flat-ground throwing phase is followed by pitching on a mound at progressively increased effort. The goal is to build back arm strength and capacity with an emphasis on proper mechanics.Purpose:To determine whether interval throwing progressively builds joint kinetics (specifically, elbow varus torque) to the level required during full-effort baseball pitching. A secondary purpose was to examine the kinematics produced during interval throwing compared to those seen during baseball pitching.Study Design:Systematic Review.Methods:Following PRISMA guidelines, PubMed, Embase, Web of Science, SPORTDiscus, and Google Scholar were systematically searched for biomechanical studies of flat-ground throwing and partial-effort pitching in baseball between 1987 and 2023. Studies that reported the biomechanics of either flat-ground throwing, or partial-effort pitching were included in this review. The AXIS tool was used to assess study quality.Results:Thirteen articles met the inclusion criteria. Ten studies were determined to be of moderate quality, while three studies were deemed high quality. Elbow varus torque during partial-effort pitching was less than during full-effort pitching. Elbow varus torque for most flat-ground throws did not exceed full-effort pitching torque. While most studies showed increased elbow varus torque with increased flat-ground throwing distance, the distance at which elbow varus torque matched or exceeded full-effort pitching elbow varus torque was not consistent.As flat-ground throwing distance increased, shoulder external rotation angle and shoulder internal rotation velocity increased. Arm slot (forearm angle above horizontal) decreased as flat-ground throwing distance increased. For varied effort pitching, shoulder external rotation angle, shoulder internal rotation velocity, elbow extension velocity, and ball velocity increased as effort increased. While the front knee extended slightly from foot contact to ball release in full-effort pitching, the front knee flexed slightly during partial-effort pitching.Conclusions:An interval throwing program progressively builds elbow varus torque up to levels produced in full-effort baseball pitching. While differences exist between interval throwing kinematics and pitching kinematics, the patterns are similar in general.Level of Evidence:2.