Effects of Photobiomodulation on Pain and Return to Play of Injured Athletes: A Systematic Review and Meta-analysis.

ABSTRACT: Morgan, RM, Wheeler, TD, Poolman, MA, Haugen, ENJ, LeMire, SD, and Fitzgerald, JS. Effects of photobiomodulation on pain and return to play of injured athletes: A systematic review and meta-analysis. J Strength Cond Res 38(6): e310-e319, 2024-The aims of this systematic review and meta-analysis were to evaluate the effect of photobiomodulation (PBM) on musculoskeletal pain in injured athletes and to determine if the effects of PBM allowed injured athletes to return to play faster. Electronic databases (MEDLINE Complete, CINAHL, and SPORTDiscus, PubMed, Web of Science, and Embase) were systematically searched (up to and including November 7, 2023) for peer-reviewed randomized controlled trials (RCTs) meeting criteria. Six RCTs, representing 205 competitive and recreational athletes with a mean age of 24 years, were included in the analysis. There were 6 intervention groups using standard physical therapy (n = 1), placebo PBM (n = 4), and aloe gel (n = 1) lasting between 10 minutes and 8 weeks in duration. The level of significance set for the study was p < 0.05. Overall, the use of PBM indicated a positive effect on pain reduction for PBM vs. control groups, standardized mean differences = 1.03, SE = 0.22, 95% confidence intervals = [0.43-1.63], p = 0.0089, but the 2 RCTs found evaluating the effect of PBM on time to return to play after injury in athletes do not support a benefit. Allied healthcare professionals may use PBM to reduce pain, thus allowing an athlete to return to their normal biomechanical movement faster; however, limited evidence suggests that PBM does not reduce time to return to play after an injury.

Diagnosis and management of thoracic outlet syndrome in athletes.

The physical demands of sports can place patients at elevated risk of use-related pathologies, including thoracic outlet syndrome (TOS). Overhead athletes in particular (eg, baseball and football players, swimmers, divers, and weightlifters) often subject their subclavian vessels and brachial plexuses to repetitive trauma, resulting in venous effort thrombosis, arterial occlusions, brachial plexopathy, and more. This patient population is at higher risk for Paget-Schroetter syndrome, or effort thrombosis, although neurogenic TOS (nTOS) is still the predominant form of the disease among all groups. First-rib resection is almost always recommended for vascular TOS in a young, active population, although a surgical benefit for patients with nTOS is less clear. Practitioners specializing in upper extremity disorders should take care to differentiate TOS from other repetitive use-related disorders, including shoulder orthopedic injuries and nerve entrapments at other areas of the neck and arm, as TOS is usually a diagnosis of exclusion. For nTOS, physical therapy is a cornerstone of diagnosis, along with response to injections. Most patients first undergo some period of nonoperative management with intense physical therapy and training before proceeding with rib resection. It is particularly essential for ensuring that athletes can return to their baselines of flexibility, strength, and stamina in the upper extremity. Botulinum toxin and lidocaine injections in the anterior scalene muscle might predict which patients will likely benefit from first-rib resection. Athletes are usually satisfied with their decisions to undergo first-rib resection, although the risk of rare but potentially career- or life-threatening complications, such as brachial plexus injury or subclavian vessel injury, must be considered. Frequently, they are able to return to the same or a higher level of play after full recovery.

Maximal hip muscle strength and rate of torque development 6-30 months after hip arthroscopy for femoroacetabular impingement syndrome: A cross-sectional study.

OBJECTIVES: Reduced sports function is often observed after hip arthroscopy for femoroacetabular impingement syndrome (FAIS). Impaired muscle strength could be reasons for this. We aimed to investigate hip muscle strength after hip arthroscopy for FAIS and its association with sports function and participation. DESIGN: Cross-sectional study. METHODS: We included 45 patients (34 males; mean age: 30.6 ±â€¯5.9 years) after unilateral hip arthroscopy for FAIS (mean follow-up [range]: 19.3 [9.8-28.4] months). Maximal isometric hip muscle strength (Nm/kg) including early- (0-100 ms) and late-phase (0-200 ms) rate of torque development (Nm∗kg-1∗s-1) for adduction, abduction, flexion, and extension was measured with an externally fixated handheld dynamometer and compared between operated and non-operated hip. Associations between muscle strength and self-reported sports function and return to sport were investigated. RESULTS: For maximal hip muscle strength, no between-hip differences were observed for adduction, abduction, flexion, and extension (p ≥ 0.102). For rate of torque development, significantly lower values were observed for the operated hip in flexion at both 0-100 ms (mean difference: 1.58 Nm∗kg-1∗s-1, 95% CI [0.39; 2.77], p = 0.01) and 0-200 ms (mean difference: 0.72 Nm∗kg-1∗s-1, 95% CI [0.09; 1.35], p = 0.027). Higher maximal hip extension strength was significantly associated with greater ability to participate fully in preinjury sport at preinjury level (odds ratio: 17.71 95% CI [1.77; 177.60]). CONCLUSIONS: After hip arthroscopy for FAIS subjects show limited impairments in maximal and explosive hip muscle strength between operated and non-operated hip. Higher muscle strength was positively associated with higher sports function and ability to participate in sport.

Clinical Characteristics and Surgical Outcomes for Collision Athletes with Traumatic Posterior Instability.

BACKGROUND: Diagnosis and treatment of traumatic posterior instability of the shoulder have not been described in detail. The author investigated surgical outcomes for traumatic posterior shoulder joint instability in collision athletes. METHODS: The author surgically treated patients with a diagnosis of traumatic shoulder joint instability and investigated those that had been followed up for >2 years after surgery. RESULTS: Seven shoulders in six collision athletes with a history of traumatic injury were examined. All cases were negative for the general laxity sign and positive for the posterior jerk test; five shoulders showed positive anterior apprehension. Posterior glenoid osseous defects were found in three shoulders, and one shoulder injury involved anterior and posterior osseous lesions. As surgical treatment, one posterior capsulolabral lesion, two posterior osseous lesions, and three combined anterior and posterior capsulolabral lesions were repaired arthroscopically. In a patient with a combined anterior and posterior osseous lesion, the Bristow procedure was perfromed after arthroscopic osseous repair. Patients returned to competition at an average of 6.8 months after surgery. One patient developed anterior subluxation at 7 months, and another exhibited posterior re-dislocation at 8 months after returning to competition. CONCLUSION: Traumatic posterior instability in collision athletes often involves glenoid osseous lesions and is frequently accompanied by anterior apprehension and lesions. Although collision athletes can return to play after arthroscopic repair, such activity is associated with a risk of re-dislocation.

Relationship between upper limb injuries and hip range of motion and strength in high school baseball pitchers.

We aimed to examine the relationship between hip range of motion (ROM) and abduction strength and throwing-related shoulder/elbow injuries in high school baseball pitchers. The study included 135 baseball pitchers. We asked them to fill out a questionnaire at the checkups, that included the dominant arm and the years of baseball experience. To avoid a confirmation bias, the examiners were blinded to the participants' hand dominance. All players underwent physical function measurements, such as height, weight, shoulder and hip strength, and shoulder and hip ROM. Shoulder and elbow injury was defined as shoulder and elbow pain that the patient had been aware of in the past 3 years. The results of injured and non-injured pitchers were compared. Eighty-five pitchers had experienced a shoulder or elbow injury in the past 3 years. The shoulder ROM and strength in the injured and non-injured groups did not differ to a statistically significant extent. The hip external rotation ROM on the dominant side, the hip abduction strength on the non-dominant side, and the hip abduction strength on the dominant side were significantly lower in the injured group than in the non-injured group. The results may contribute to reducing the incidence of these injuries.

Surgical stabilization of pediatric anterior shoulder instability yields high recurrence rates: a systematic review.

PURPOSE: The purpose of this systematic review was to assess the surgical techniques, indications outcomes and complications for pediatric patients (≤ 19 years old) undergoing shoulder stabilization procedures for anterior shoulder instability. METHODS: The electronic databases MEDLINE, EMBASE, CINAHL, and Web of Science were searched from data inception to March 14, 2019 for articles addressing surgery for pediatric patients with anterior shoulder instability. The Methodological Index for Non-randomized Studies (MINORS) tool was used to assess the quality of included studies. RESULTS: Overall 24 studies, with a total of 688 patients (696 shoulders) and a mean age of 16.6 ± 2.5 years met inclusion criteria. Mean follow-up was 49 ± 26 months. The majority (59%) of studies only offered shoulder stabilization procedures to patients with more than one shoulder dislocation, however, three studies reported operating on pediatric patients after first time dislocations. Of the included patients 525 had arthroscopic Bankart repair (78%), 75 had open Bankart repair (11%), 34 had modified Bristow (5%), and 26 had Latarjet (4%) procedures. The overall complication rate was 26%. Patients undergoing arthroscopic Bankart repair experienced the highest recurrence rate of 24%. There were no significant differences in recurrent instability (n.s.) or loss of external rotation (n.s.) in pediatric patients treated with arthroscopic Bankart repair compared to open Latarjet. Patients had a 95% rate of return to sport at any level (i.e. preinjury level or any level of play) postoperatively (95%). CONCLUSIONS: Pediatric patients are at high risk of recurrent instability after surgical stabilization. The majority of pediatric patients with anterior shoulder instability were treated with arthroscopic Bankart repair. Most studies recommend surgical stabilization only after more than one dislocation. However, given the high rates of recurrence with non-operative management, it may be reasonable to perform surgery at a first-time dislocation, particularly in those with other risk factors for recurrence. With the current evidence and limited sample sizes, it is difficult to directly compare the surgical interventions and their post-operative efficacy (i.e. re-dislocation rates or range of motion). There was an overall high rate of return to sport after surgical stabilization at final follow-up. LEVEL OF EVIDENCE: IV.

Fifth Metatarsal Fractures in Professional Soccer Players: Case Series.

OBJECTIVE: Fifth metatarsal fractures occur mainly in young athletes, with an estimated incidence of 1.8 per 1000 individuals per year. This study aims to evaluate the functional outcome of professional soccer players undergoing surgical treatment of fifth metatarsal base fractures. METHODS: We appraised 34 soccer players operated on from July 2001 to June 2016. All individuals were assessed by the American Orthopedic Foot and Ankle Score (AOFAS) and Visual Analog Scale (VAS) before and after surgery, with a mean 23-month follow-up. The need for grafting, fracture healing, Torg classification, and return to sports were also evaluated. RESULTS: There were 10 attackers, 7 offensive-defensive midfielders, 6 side defenders, 5 central defensive midfielders, 3 defenders, 2 goalkeepers, and 1 defensive midfielder, at an average age of 19 years. Preoperative and postoperative AOFAS averaged 42 and 99 points, respectively, whereas VAS scores were 6 and 0. The longer the time to get operated on, the greater was the need for grafting (P = .011). In our study, all fractures have consolidated. Return to sports occurred, on average, 73 days after surgical treatment, and it was not influenced by the time to get operated on, fracture healing, Torg classification, and grafting. CONCLUSION: Surgical treatment of the fifth metatarsal base fracture in professional soccer players presents good clinical results. Getting back to activities after surgery is not influenced by surgery time, fracture healing, Torg classification, and grafting.Levels of Evidence: Level IV: Therapeutic studies, Case series.

Clinical outcomes of concurrent surgery with weight bearing after modified lasso-loop stitch arthroscopic ankle stabilization.

PURPOSE: To determine the effects of unilateral and bilateral ankle stabilization surgery with or without additional concurrent procedures for other pathologies on return to activity in patients who were allowed unrestricted weight bearing postoperatively. METHODS: Ninety-three athletes underwent 120 ankle stabilization surgeries including 27 that underwent bilateral simultaneous surgery using the all-inside arthroscopy-modified lasso-loop technique and were divided into two groups: arthroscopic ligament repair alone without concurrent procedures (group A) and with simultaneous procedures for other pathologies (group B). Group A was further subdivided into unilateral (group A1) and simultaneous bilateral ankle surgery (group A2), and group B into ankle stabilization surgery with simultaneous procedures not requiring weight bearing postoperatively (Group B1) and with concurrent procedures allowing weight bearing (Group B2). Return to activity postoperatively was assessed by recording the time to walk without any support, jog, and return to full athletic activities. Clinical outcomes were assessed preoperatively and 12 months postoperatively using a subjective clinical score. RESULTS: The average time between surgery and unsupported walk, jog, and return to full athletic activities was 1.6 ± 2.5, 16.9 ± 3.7, and 42.4 ± 19.3 days in group A, 17.2 ± 19.6, 34.5 ± 20.8, and 60.9 ± 22.8 days in group B, 1.7 ± 2.9, 16.1 ± 2.4, and 41.6 ± 18.2 days in group A1, 1.3 ± 0.6, 18.9 ± 5.5, and 44.6 ± 22.5 days in group A2, 25.3 ± 20.2, 43.3 ± 21.1, and 70.7 ± 23.1 days in group B1, and 4.8 ± 11.7, 20.7 ± 11.7, and 45.0 ± 13.7 days in group B2, respectively. These results indicate that the patients in group B2 showed a statistically significant faster time to return to activity than did those restricted from weight bearing. Differences in ankle stabilization alone between patients in groups A1 and A2 as well as groups B2 and A were not statistically significant. Clinical outcomes were similar for patients in groups B2 and A1 versus group A2. CONCLUSION: Time to return to activity and clinical outcomes after ankle stabilization surgery using the modified lasso-loop technique were negatively affected if simultaneous bilateral surgery or simultaneous concurrent procedures were added or if weight bearing was unrestricted. However, a delay in return to athletic activity was observed when ankle stabilization surgery was performed using the modified lasso-loop technique with concurrent procedures that require non-weight bearing postoperatively. LEVEL OF EVIDENCE: Level III.

Autologous osteochondral transplantation for osteochondral lesions of the talus: high rate of return to play in the athletic population.

PURPOSE: (1) To determine the rate of return to play following autologous osteochondral transplantation (AOT) for osteochondral lesions of the talus (OLT) and (2) report subsequent rehabilitation protocols. METHODS: A systematic review of the PubMed, Embase, and The Cochrane Library databases was performed according to the PRISMA guidelines based on specific eligibility criteria. Return to play data was meta-analysed and subsequent rehabilitation protocols were summarised. Level of evidence and quality of evidence (Zaman's criteria) were also evaluated. RESULTS: Nine studies that totalled 205 ankles were included for review. The mean follow-up was 44.4 ± 25.0 (range 16-84) months. The mean OLT size was 135.4 ± 56.4 mm2. The mean time to return to play was 5.8 ± 2.6 months. The mean rate of return to play was 86.3% (range 50-95.2%), with 81.8% of athletes returning to pre-injury status. Based on the fixed-effect model, the rate of return to play was 84.07%. Significant correlation was found between increase age and decrease rate of return to play (R2 = 0.362, p = 0.00056). There was no correlation between OLT sizes and rate of return to play (R2 = 0.140, p = 0.023). The most common time to ankle motion post-surgery was immediately and the most common time to full weight-bearing was 12 weeks. CONCLUSIONS: This systematic review indicated a high rate of return to play following AOT in the athletic population. Size of OLT was not found to be a predictor of return to play, whereas advancing age was a predictor. Rehabilitation protocols were largely inconsistent and were primarily based on individual surgeon protocols. However, the included studies were of low level and quality of evidence. LEVEL OF EVIDENCE: Level IV.

Improved recovery from skeletal muscle damage is largely unexplained by myofibrillar protein synthesis or inflammatory and regenerative gene expression pathways.

The contribution of myofibrillar protein synthesis (MyoPS) to recovery from skeletal muscle damage in humans is unknown. Recreationally active men and women consumed a daily protein-polyphenol beverage targeted at increasing amino acid availability and reducing inflammation (PPB; n = 9), both known to affect MyoPS, or an isocaloric placebo (PLA; n = 9) during 168 h of recovery from 300 maximal unilateral eccentric contractions (EE). Muscle function was assessed daily. Muscle biopsies were collected for 24, 27, 36, 72, and 168 h for MyoPS measurements using 2H2O and expression of 224 genes using RT-qPCR and pathway analysis. PPB improved recovery of muscle function, which was impaired for 5 days after EE in PLA (interaction P < 0.05). Acute postprandial MyoPS rates were unaffected by nutritional intervention (24-27 h). EE increased overnight (27-36 h) MyoPS versus the control leg (PLA: 33 ± 19%; PPB: 79 ± 25%; leg P < 0.01), and PPB tended to increase this further (interaction P = 0.06). Daily MyoPS rates were greater with PPB between 72 and 168 h after EE, albeit after function had recovered. Inflammatory and regenerative signaling pathways were dramatically upregulated and clustered after EE but were unaffected by nutritional intervention. These results suggest that accelerated recovery from EE is not explained by elevated MyoPS or suppression of inflammation.NEW & NOTEWORTHY The present study investigated the contribution of myofibrillar protein synthesis (MyoPS) and associated gene signaling to recovery from 300 muscle-damaging, eccentric contractions. Measured with 2H2O, MyoPS rates were elevated during recovery and observed alongside expression of inflammatory and regenerative signaling pathways. A nutritional intervention accelerated recovery; however, MyoPS and gene signaling were unchanged compared with placebo. These data indicate that MyoPS and associated signaling do not explain accelerated recovery from muscle damage.

Use of double leg injury screening to assess single leg biomechanical risk variables.

OBJECTIVES: The purpose of this article was to determine if differences in kinematic and kinetic variables observed in a double-leg screen carried over to a single-leg task. DESIGN: We used a case-control design with grouping based on performance during a double-leg jump landing. SETTING: All participants were selected from a large university setting and testing was performed in a biomechanics laboratory. PARTICIPANTS: Participants were females between 18 and 25 years of age with at least high school varsity experience in one or more of the following sports: soccer, lacrosse, field hockey, rugby, basketball, or team handball. MAIN OUTCOME MEASURES: Primary outcome measures were knee angles in the frontal and sagittal planes as well as vertical ground reaction force (vGRF). RESULTS: There were significant between group differences in peak knee flexion and knee flexion displacement during both the double and single-leg tasks, however between group differences for peak knee valgus and knee valgus displacement noted in the double-leg task were not observed in the single-leg task. vGRF was significantly different in the single-leg task but not the double-leg task. CONCLUSION: A double leg screening may not provide complete identification of risk of injury during sports requiring single leg tasks.

Rehabilitation After Shoulder Instability Surgery: Keys for Optimizing Recovery.

The specific approach to rehabilitation after surgical management of the unstable shoulder is dependent on the severity and chronicity of the instability. Establishing dynamic stability throughout the athlete's functional range of movement is critical to a successful outcome. The pace progression is guided by surgical (technique, injury pattern, and strength of repair) and patient factors (healing potential, prior health status, and psychosocial factors). The primary goal of treatment is to restore function and return the athlete to sport. The process should be guided by surpassing functional criteria for progression and tissue healing time.

A Review of Workload-Monitoring Considerations for Baseball Pitchers.

Because of the unique demands of a pitch, baseball players have the greatest percentage of injuries resulting in surgery among high school athletes, with a majority of these injuries affecting the shoulder and elbow due to overuse from throwing. These injuries are believed to occur because of repeated microtrauma to soft tissues caused by the repetitive mechanical strain of throwing. Researchers and practitioners have suggested that baseball pitchers' workloads are a significant risk factor for injury in adolescent players, resulting in lost time and slowing of performance development. The purpose of our review was to investigate the current research relative to monitoring workload in baseball throwers and discuss techniques for managing and regulating cumulative stress on the arm, with a focus on preventing injury and optimizing performance in adolescent baseball pitchers.

Management of Anterior Shoulder Instability for the In-Season Athlete.

Management of in-season anterior instability poses a unique challenge to providers as they are faced with the conundrum of helping an athlete return to play as quickly as possible, while minimizing the risk of recurrent instability and progressive damage to the glenohumeral joint. The decision for early return to play versus in-season surgery ultimately is a collective decision-making process between the athlete, provider and training staff. However, it is the physician's obligation to properly counsel the athlete on the risks of early return to play following conservative management. Apart from athletes who are in the last season of their career or have other extenuating circumstances, requiring return to play (RTP) in the same season (i.e. upcoming championship or combine), given the high risk of recurrence in athletes managed conservatively, physicians should strongly encourage early surgical stabilization. Surgical management of instability most commonly includes arthroscopic Bankart repair and capsulorrhaphy, however open Bankart repair should be considered in high-risk athletes (i.e. contact athletes, recurrent instability, sub-critical glenoid bone loss). In athletes with critical glenoid bone loss an osseous augmentation procedure should be performed, such as the Latarjet procedure.

Acute and Chronic Syndesmotic Instability: Role of Surgical Stabilization.

Acute and chronic syndesmotic injuries significantly impact athletic function and activities of daily living. Patient history, examination, and judicious use of imaging modalities aid diagnosis. Surgical management should be used when frank diastasis, instability, and/or chronic pain and disability ensue. Screw and suture-button fixation remain the mainstay of treatment of acute injuries, but novel syndesmotic reconstruction techniques hold promise for treatment of acute and chronic injuries, especially for athletes. This article focuses on anatomy, mechanisms of injury, diagnosis, and surgical reduction and stabilization of acute and chronic syndesmotic instability. Fixation methods with a focus on considerations for athletes are discussed.

Peroneal Tendinosis and Subluxation.

Peroneal tendinosis and subluxation are lifestyle-limiting conditions that can worsen if not properly diagnosed and treated. Adequate knowledge of ankle anatomy and detailed history and comprehensive physical examination is essential for diagnosis. Peroneal tendinopathy is likely to result from overuse, whereas subluxation often precipitates from forceful contraction of peroneals during sudden dorsiflexion while landing or abruptly stopping. In athletes, conservative measures remain first-line treatment of tendinopathy, but surgery is often immediately indicated in cases of recurrent symptomatic subluxation or dislocation. Surgical technique varies on the type, mechanism, and severity of injury, but most procedures have a high success rate.

Painful Accessory Navicular and Spring Ligament Injuries in Athletes.

Painful accessory navicular and spring ligament injuries in athletes are different entities from more common posterior tibialis tendon problems seen in older individuals. These injuries typically affect running and jumping athletes, causing medial arch pain and in severe cases a pes planus deformity. Diagnosis requires a detailed physical examination, standing radiographs, and MRI. Initial treatment focuses on rest, immobilization, and restriction from sports. Orthotic insoles may alleviate minor pain, but many patients need surgery to expedite recovery and return to sports. The authors review their approach to these injuries and provide surgical tips along with expected rehabilitation to provide optimal outcomes.

Achilles Tendinosis Injuries-Tendinosis to Rupture (Getting the Athlete Back to Play).

Recreational athletes are susceptible to experiencing pain in the Achilles tendon, affecting their ability to complete daily activities. Achilles tendinosis is a degenerative process of the tendon without histologic or clinical signs of intratendinous inflammation, which can be categorized by location into insertional and noninsertional tendinosis. This condition is one that can be treated conservatively with great success or surgically for refractory cases. Currently, there is a lack of consensus regarding the best treatment options. This review aims to explore both conservative and operative treatment options for Achilles tendinopathy and Achilles tendon rupture.

Rehabilitation Nutrition for Injury Recovery of Athletes: The Role of Macronutrient Intake.

An adequate and balanced diet is of utmost importance in recovery and rehabilitation. "Rehabilitation nutrition" for injury recovery of athletes is similar to sports nutrition, except for the differences that concern the prevention of the risk or presence of sarcopenia, malnutrition, or dysphagia. Rehabilitation nutrition also aims, combined with training, to an adequate long-term nutritional status of the athlete and also in physical condition improvement, in terms of endurance and resistance. The aim of this paper is to define the proper nutrition for athletes in order to hasten their return to the sports after surgery or injury. Energy intake should be higher than the energy target in order to fight sarcopenia-that is 25-30 kcal/kg of body weight. Macro- and micro-nutrients play an important role in metabolism, energy production, hemoglobin synthesis, lean mass and bone mass maintenance, immunity, health, and protection against oxidative damage. Nutritional strategies, such as supplementation of suboptimal protein intake with leucine are feasible and effective in offsetting anabolic resistance. Thus, maintaining muscle mass, without gaining fat, becomes challenging for the injured athlete. A dietary strategy should be tailored to the athlete's needs, considering amounts, frequency, type and, most of all, protein quality. During rehabilitation, simultaneous carbohydrates and protein intake can inhibit muscle breakdown and muscle atrophy. The long-term intake of omega-3 fatty acids enhances anabolic sensitivity to amino acids; thus, it may be beneficial to the injured athlete. Adequate intakes of macronutrients can play a major role supporting athletes' anabolism.

Examination of Corticospinal and Spinal Reflexive Excitability During the Course of Postoperative Rehabilitation After Anterior Cruciate Ligament Reconstruction.

OBJECTIVE: To investigate corticospinal and spinal reflexive excitability and quadriceps strength in healthy athletes and athletes after anterior cruciate ligament reconstruction (ACLR) over the course of rehabilitation. DESIGN: Prospective cohort study. METHODS: Eighteen athletes with ACLR and 18 healthy athletes, matched by sex, age, and activity, were tested at (1) 2 weeks after surgery, (2) the "quiet knee" time point, defined as full range of motion and minimal effusion, and (3) return to running, defined as achieving a quadriceps index of 80% or greater. We measured (1) corticospinal excitability, using resting motor threshold (RMT) and motor-evoked potential amplitude at a stimulator intensity of 120% of RMT (MEP120) to the vastus medialis, (2) spinal reflexive excitability, calculating the ratio of the maximal Hoffmann reflex to the maximal M-wave to the vastus medialis, and (3) isometric quadriceps strength. RESULTS: The ACLR group had higher RMTs in the nonsurgical limb and higher MEP120 in the surgical limb at all time points. The healthy-athlete group did not have interlimb differences. The RMT was positively associated with quadriceps strength 2 weeks after surgery; MEP120 was associated with quadriceps strength at all time points. CONCLUSION: Compared to healthy athletes, athletes after ACLR had altered corticospinal excitability that did not change from 2 weeks after surgery to the time of return to running. J Orthop Sports Phys Ther 2020;50(9):516-522. Epub 1 Aug 2020. doi:10.2519/jospt.2020.9329.