Acute Hamstring Injuries Research Articles

Non-surgical management of acute proximal hamstring avulsions can produce clinically acceptable results.

To evaluate the mid-term clinical outcomes for the non-surgical and surgical management of acute proximal hamstring avulsions. Sixty physically active individuals were offered surgical or non-surgical management for their proximal hamstring avulsion injuries. Distal retraction was defined as greater than 2 cm. Primary outcome measures were the Victorian Institute of sport assessment-proximal hamstring tendons (VISA-H) and functional assessment scale for acute hamstring injuries (FASH). Secondary outcome measures included palpable gap (cm), return to sport (RTS) and the ability to perform Nordic hamstring curls. Outcome variables were adjusted in regression models for gender, age, and treatment. Thirty-one patients elected to undertake non-surgical management, and 29 chose surgery with a mean follow-up of 34.8 ± 8.7 and 34.9 ± 7.0 months, respectively. The mean VISA-H for the non-surgical and surgical groups were 87.3 ± 3.4 and 87.9 ± 4.1 (n.s.), respectively. The mean FASH for the non-surgical group was 89.3 ± 2.4 and 88 ± 3.6 for the surgical group (n.s.). This was consistent after adjusting for confounders. The mean gap for the non-surgical group was 4.5 ± 1.09and 4.9 ± 1.19 cm for the surgical group (n.s.). No significant differences were found in the abilities to perform Nordic hamstring curls (n.s.). Both groups achieved comparable RTS rates (n.s.). On average, the non-surgical group achieved RTS at 5.5 ± 1.2 months post-injury, whereas the surgical group was at 5.7 ± 0.7 months (n.s.). Physically active individuals with acute proximal hamstring avulsions and distal retraction of the tendon stump can be managed non-surgically, achieving similar functional levels and RTS compared to patients treated surgically. Level III.

Baseline clinical and MRI risk factors for hamstring reinjury showing the value of performing baseline MRI and delaying return to play: a multicentre, prospective cohort of 330 acute hamstring injuries

ObjectivesStudies identifying clinical and MRI reinjury risk factors are limited by relatively small sample sizes. This study aimed to examine the association between baseline clinical and MRI findings with the...

Laceration of the Distal Biceps Femoris Tendon

BACKGROUND: Rehabilitation strategies addressing impairments caused by hamstring laceration injuries remain insufficiently explored in current literature. CASE PRESENTATION: This case study presents the effective management of a 62-year-old male who experienced pain, weakness, and range-of-motion loss secondary to a distal biceps femoris tendon laceration. Treatment incorporated interventions traditionally utilized for acute athletic hamstring injury. OUTCOME AND FOLLOW-UP: Clinically meaningful improvements were made in active knee extension range of motion, as well as isometric knee flexor and hip extensor strength over 10 weeks. He was able to return to running for aerobic fitness and improved his Lower Extremity Functional Scale score from 13/80, initially, to 76/80 at 12 months. DISCUSSION: This case suggests the use of evidence-based interventions for hamstring strain may be useful for management of partial tendon laceration injuries. JOSPT Cases 2024;4(2):74-78. Epub 2 May 2024. doi:10.2519/josptcases.2024.0003

Prevalence of Hamstring Strain and Association with Fatigue among Domestic Cricketers in Lahore Pakistan

Background: Hamstring strains are a common injury among athletes, particularly affecting those involved in sports requiring high-speed running and abrupt movements, such as cricket. The association between these injuries and factors like fatigue has been of particular interest within the sports medicine community, aiming to enhance injury prevention and management strategies. Objective: This study aimed to investigate the prevalence of hamstring strains and their association with fatigue among domestic cricketers in Lahore, Pakistan, providing insights into effective strategies for injury prevention and management in this athletic population. Methods: A cross-sectional study was conducted from December 2022 to May 2023 among 82 domestic cricketers in Lahore, using non-probability convenient sampling. Participants underwent assessments including the Functional Assessment Scale for Acute Hamstring Injuries (FASH) and the Fatigue Assessment Scale (FAS), alongside demographic and physical fitness data collection. Data were analyzed using IBM SPSS Statistics Version 25, with the chi-square test applied to evaluate the association between hamstring strain and fatigue. Results: The average age of participants was 26.68±1.395 years, with the majority (81.7%) having a normal BMI. About 28.0% of the athletes reported hamstring strains, with varying degrees of pain from mild to severe. The chi-square test indicated a significant association between hamstring strains and fatigue (p<0.001), highlighting fatigue as a key factor in the occurrence of hamstring injuries among cricketers. Conclusion: The study underscores the significant prevalence of hamstring strains among domestic cricketers in Lahore and their association with fatigue. These findings emphasize the necessity for targeted interventions focusing on fatigue management to mitigate the risk of such injuries, thereby enhancing athlete health and performance sustainability.

Accelerated IVIM-corrected DTI in acute hamstring injury: towards a clinically feasible acquisition time

BackgroundIntravoxel incoherent motion (IVIM)-corrected diffusion tensor imaging (DTI) potentially enhances return-to-play (RTP) prediction after hamstring injuries. However, the long scan times hamper clinical implementation. We assessed accelerated IVIM-corrected DTI approaches in acute hamstring injuries and explore the sensitivity of the perfusion fraction (f) to acute muscle damage.MethodsAthletes with acute hamstring injury received DTI scans of both thighs < 7 days after injury and at RTP. For a subset, DTI scans were repeated with multiband (MB) acceleration. Data from standard and MB-accelerated scans were fitted with standard and accelerated IVIM-corrected DTI approach using high b-values only. Segmentations of the injury and contralateral healthy muscles were contoured. The fitting methods as well as the standard and MB-accelerated scan were compared using linear regression analysis. For sensitivity to injury, Δ(injured minus healthy) DTI parameters between the methods and the differences between injured and healthy muscles were compared (Wilcoxon signed-rank test).ResultsThe baseline dataset consisted of 109 athletes (16 with MB acceleration); 64 of them received an RTP scan (8 with MB acceleration). Linear regression of the standard and high-b DTI fitting showed excellent agreement. With both fitting methods, standard and MB-accelerated scans were comparable. Δ(injured minus healthy) was similar between standard and accelerated methods. For all methods, all IVIM-DTI parameters except f were significantly different between injured and healthy muscles.ConclusionsHigh-b DTI fitting with MB acceleration reduced the scan time from 11:08 to 3:40 min:s while maintaining sensitivity to hamstring injuries; f was not different between healthy and injured muscles.Relevance statementThe accelerated IVIM-corrected DTI protocol, using fewer b-values and MB acceleration, reduced the scan time to under 4 min without affecting the sensitivity of the quantitative outcome parameters to hamstring injuries. This allows for routine clinical monitoring of hamstring injuries, which could directly benefit injury treatment and monitoring.Key points• Combining high-b DTI-fitting and multiband-acceleration dramatically reduced by two thirds the scan time.• The accelerated IVIM-corrected DTI approaches maintained the sensitivity to hamstring injuries.• The IVIM-derived perfusion fraction was not sensitive to hamstring injuries.Graphical

Comparison of post isometric relaxation and post facilitation stretching techniques on hamstring muscle flexibility in collegiate athletes: A randomized clinical trial

Background: The multi-jointed nature of the hamstring muscles causes them to shorten which impacts the biomechanics of the pelvis and lumber region. Hamstring tightness is more common in women than in males. Objective: To compare the effect of post-isometric relaxation and post-facilitation stretching in improving hamstring muscle flexibility among collegiate athlete's athlete. Methods: Study was a randomized clinical trial. Patients following the inclusion criteria from Pakistan Sports Board, Lahore were categorized in two groups; group A and group B. Male patients aged from 18 to 35 years, with a history of hamstring muscle tightness (bilateral) or acute hamstring injuries were included. Group A was treated with post isometric relaxation and conventional treatment while group B received post facilitation stretching and conventional treatment; for 4 weeks and with 3 sessions per week. The baselines data was taken for range of motion, sit and reach test, active knee extension test, and straight leg raise and lower extremity functional scale. Results: There were a total of 17 male volunteers in each group. Group A's mean age was 28.58±3.9, years whereas group B's mean age was 29.25±4.4 The groups' respective Lower Limb Functional Scores (LEFS) were 58.41±4.84 in group A and 40.52±2.85 in group B, with a p-value of less than 0.05. Lower limb functional score (LEFS) within the groups with p &lt;0.05 was 22.17±8.63 and 40.52±2.85. Conclusion: The current investigation found that post-isometric relaxing and stretching both improve hamstring flexibility. Clinical Trial Number: NCT05727501

Video Analysis of Acute Hamstring Injury Mechanisms During Deadlifts

Video Analysis of Acute Hamstring Injury Mechanisms During Deadlifts

Bilateral Corticomotor Reorganization and Symptom Development in Response to Acute Unilateral Hamstring Pain: A Randomized, Controlled Study

Accumulating evidence demonstrates that pain induces adaptations in the corticomotor representations of affected muscles. However, previous work has primarily investigated the upper limb, with few studies examining corticomotor reorganization in response to lower limb pain. This is important to consider, given the significant functional, anatomical, and neurophysiological differences between upper and lower limb musculature. Previous work has also focused on unilateral corticomotor changes in response to muscle pain, despite an abundance of literature demonstrating that unilateral pain conditions are commonly associated with bilateral motor dysfunction. For the first time, this study investigated the effect of unilateral acute hamstring pain on bilateral corticomotor organization using transcranial magnetic stimulation (TMS) mapping. Corticomotor outcomes (TMS maps), pain, mechanical sensitivity (pressure pain thresholds), and function (maximal voluntary contractions) were recorded from 28 healthy participants at baseline. An injection of pain-inducing hypertonic (n = 14) or pain-free isotonic (n = 14) saline was then administered to the right hamstring muscle, and pain ratings were collected every 30 seconds until pain resolution. Follow-up measures were taken immediately following pain resolution and at 25, 50, and 75 minutes post-pain resolution. Unilateral acute hamstring pain induced bilateral symptom development and changes in corticomotor reorganization. Two patterns of reorganization were observed—corticomotor facilitation and corticomotor depression. Corticomotor facilitation was associated with increased mechanical sensitivity and decreased function bilaterally (all P < .05). These effects persisted for at least 75 minutes after pain resolution. PerspectiveThese findings suggest that individual patterns of corticomotor reorganization may contribute to ongoing functional deficits of either limb following acute unilateral lower limb pain. Further research is required to assess these adaptations and the possible long-term implications for rehabilitation and reinjury risk in cohorts with acute hamstring injury.

Surgical treatment of high-grade acute intramuscular hamstring tendon injuries in athletes leads to predictable return to sports and no re-injuries.

The purpose of this study was to assess the post-operative return to sport and re-injury rates following surgical repair of acute, first-time, high-grade intramuscular hamstring tendon injuries in high level athletes. Patients were identified using the databases of two sports surgeons. Once patients were identified their clinical notes and imaging were reviewed to confirm that all patients had injuries to the intramuscular portion of the distal aspect of the proximal biceps femoris tendon. All imaging was reviewed by an experienced musculoskeletal radiologist to confirm diagnosis. Surgery for such injuries was indicated in high-level athletes presenting with acute hamstring injuries. All patients were operated on within 4weeks. Outcomes included Tegner scores, return to sport, Lower Extremity Functional Score (LEFS), current hamstring symptoms and complications including re-injury. Eleven injuries (10 patients) were included in the study. All patients were male and Australian Rules Football players. Six patients were professional athletes and 4 semi-professional athletes. Median age was 24.5 (range 21-29) and median follow-up period was 33.7months (range; 16-65). 91% were British Athletic Muscle Injury Classification (BAMIC) 3c and 9% were BAMIC 4c. 91% were classed as MR2 and 9% as MR3 on the simplified four-grade injury classification. Athletes achieved return to play (RTP) at an average of 3.1months (SD 1.0) post repair. All but one patient achieved a Tegner score equal to pre-injury levels. Maximum LEFS was achieved by all patients. Minor pain scores (all with VAS < 1/10) on sciatic and functional stretch were recorded in 36% and 27% of patients respectively, with subtle neural symptoms (9%) and subjective tightness (36%) also noted. There were no surgical complications in our patient cohort. No patients had a re-injury or re-operation. Surgical repair of high-grade intramuscular tendon injuries of the biceps femoris hamstring muscle in athletes resulted in high levels of return to pre-injury sporting levels and no re-injuries. The intra-muscular tendon should be scrutinized when assessing hamstring injuries in elite sport and offer surgery in high-grade cases. IV.

Backheel Pass During Forward Running as a Mechanism of Severe Acute Hamstring Injury in Football: A Case Report.

Proximal hamstring tendon avulsions represent the most severe hamstring injury in sports and are typically sustained during stretch-related movements in closed kinetic chain: forced hip hyperflexion combined with knee extension. Here, we present the case study of the right-foot dominant professional football player with a severe proximal hamstring tendon avulsion injury and concomitant lower-grade injuries of hamstring muscle-tendon complex caused by a potentially new football-specific injury mechanism: right-foot backheel pass during forward running (ie, a kick directly backward). This mechanism involves a specific stretch-shortening cycle action of hamstring muscles in open-kinetic chain movement that has not yet been described in the scientific literature. Although further studies related to this football-specific hamstring injury mechanism are needed, clinicians and coaches working in football should be aware of it and potentially introduce additional injury mechanism-specific exercises and strategies for prevention of severe hamstring injuries which often require surgical intervention.

The Inclusion of a Complementary Running Progression Program in the Rehabilitation of Acute Hamstring Injuries: A Critically Appraised Topic

Introduction/Clinical Scenario: As many hamstring injuries occur when the hamstrings are in a lengthened state during the deceleration phase of running when the muscle is eccentrically contracting to slow the body down this functional aspect needs to be addressed. Thus, a rehabilitation program with a focus on progressive targeted eccentric hamstring exercises by gradually placing and exposing the muscle to eccentric force in a lengthened state supplemented with progressive running drills should be evaluated. Focused Clinical Question: Does the inclusion of a complementary running progression program for the rehabilitation of an acute hamstring injury reduce the time to safe return to sport with less hamstring reinjury occurrence for an athletic population? Summary of Key Findings: Three studies assessed the inclusion of a progressive running program with several types of running progression parameters addressed. Progressive running drills will load the hamstring in a functional manner, with a gradual increase in velocity of movement and lengthening of the muscle. Clinical Bottom Line: It appears that a complementary progressive running program within an acute hamstring rehabilitation program should be included as it caused no further harm and does not tend to increase hamstring reinjury occurrence. Strength of Recommendation: There is grade B evidence to include a complementary running progression program within an acute hamstring rehabilitation program.

Diffusion tensor imaging and quantitative T2 mapping to monitor muscle recovery following hamstring injury.

MRI examinations are accurate for diagnosing sports-related acute hamstring injuries. However, sensitive imaging methods for assessing recovery of these injuries are lacking. Diffusion tensor imaging (DTI) and quantitative T2 (qT2) mapping have both shown promise for assessing recovery of muscle micro trauma and exercise effects. The purpose of this study was to explore the potential of DTI and qT2 mapping for monitoring the muscle recovery processes after acute hamstring injury. In this prospective study, athletes with an acute hamstring injury underwent a 3-T MRI examination of the injured and contralateral hamstrings including DTI and qT2 measurements at three time points: (1) within 1 week after sustaining the injury, (2) 2 weeks after time point 1, and (3) return to play (RTP). A linear mixed model was used for time-effect analysis and paired t-tests for the detection of differences between injured and uninjured muscles. Forty-one athletes (age 27.8 ± 7 years; two females and 39 males) were included. Mean RTP time was 50 (range 12-169) days. A significant time effect was found for mean diffusivity, radial diffusivity, and the second and third eigenvalues (p ≤ 0.001) in the injured muscles. Fractional anisotropy (p = 0.40), first eigenvalue (p = 0.02), and qT2 (p = 0.61) showed no significant time effect. All DTI indices, except for fractional anisotropy, were significantly elevated compared with control muscles right after the injury (p < 0.001). Values normalized during the recovery period, with no significant differences between control and injured muscles at RTP (p values ranged from 0.08 to 0.51). Mean qT2 relaxation times in injured muscles were not significantly elevated compared with control muscles at any time point (p > 0.04). In conclusion, DTI can be used to monitor recovery after an acute hamstring injury. Future work should explore the potential of DTI indices to predict RTP and recovery times in athletes after an acute strain injury.

Mechanisms of Hamstring Injury in Professional Soccer Players: Video Analysis and Magnetic Resonance Imaging Findings.

To describe the injury mechanisms and magnetic resonance imaging (MRI) findings in acute hamstring injuries of male soccer players using a systematic video analysis. Descriptive case series study of consecutive acute hamstring injuries from September 2017 to January 2022. Two specialized sports medicine hospitals. Professional male soccer players aged between 18 and 40 years, referred for injury assessment within 7 days after an acute hamstring injury, with an available video footage of the injury and positive finding on MRI. Hamstring injury mechanisms (specific scoring based on standardized models) in relation to hamstring muscle injury MRI findings. Hamstring injury mechanism (playing situation, player/opponent behavior, movement, and biomechanical body positions) and MRI injury location. Fourteen videos of acute hamstring injuries in 13 professional male soccer players were analyzed. Three different injury mechanisms were seen: mixed-type (both sprint-related and stretch-related, 43%), stretch-type (36%), and sprint-type (21%). Most common actions during injury moments were change of direction (29%), kicking (29%), and running (21%). Most injuries occurred at high or very high horizontal speed (71%) and affected isolated proximal biceps femoris (BF) (36%). Most frequent body positions at defined injury moments were neutral trunk (43%), hip flexion 45-90 degrees (57%), and knee flexion <45 degrees (93%). Magnetic resonance imaging findings showed that 79% were isolated single-tendon injuries. According to a video analysis, most hamstring injuries in soccer occur during high-speed movements. Physicians should suspect proximal and isolated single-tendon-most often BF-hamstring injury, if represented injury mechanisms are seen during game play. In addition to sprinting and stretching, also mixed-type injury mechanisms occur.

Therapeutic Exercises and Modalities in Athletes With Acute Hamstring Injuries: A Systematic Review and Meta-Analysis.

Hamstring strain is a common injury to the lower limbs. Early intervention in the acute phase aids with restoring hamstring function and prevents secondary related injury. To systematically review and summarize the effectiveness of exercise-based interventions combined with physical modalities currently used in athletes with acute hamstring injuries. Five databases (EMBASE, Medline, Cochrane Library, SPORTDiscus, and Web of Science) were searched from inception to July 2021. A total of 4569 studies were screened. Nine randomized controlled trials (RCTs) on the effect of therapeutic exercise programs with and without physical agents in athletes with acute hamstring injuries were identified for meta-analysis. Systematic review and meta-analysis. Level 1. The studies were screened, and the evidence was rated using the PEDro scale. Nine RCTs with PEDro scores ranging between 3 and 9 were included and extracted pain intensity, time to return to play (TTRTP), and reinjury rate in the study. Loading exercises during extensive lengthening were shown to facilitate TTRTP at P < 0.0001 but did not prevent recurrence (P = 0.17), whereas strengthening with trunk stabilization and agility exercise did not reduce the duration of injury recurrence (P = 0.16), but significantly reduced the reinjury rate (P < 0.007) at a 12-month follow-up. The results of the stretching programs and solely physical modalities could not be pooled in the statistical analysis. The meta-analysis indicated that a loading program helps athletes to return to sports on a timely basis. Although strengthening with trunk stabilization and agility exercise cannot significantly reduce recovery time, the program can prevent reinjury. The clinical effects of stretching programs and pure physical modality interventions could not be concluded in this study due to limited evidence. CRD42020183035.

Paper 16: Effectiveness of hematoma aspiration and platelet-rich plasma muscle injections for the treatment of hamstring strains in athletes

Objectives:The effect of platelet-rich plasma (PRP) treatment on recovery in acute hamstring injuries is controversial. Previous study results are inconsistent, and a standardized therapeutic approach has not been established yet. The objective of the study was to assess the treatment effect using a combination of hematoma aspiration and muscle strain PRP injection in partial hamstring muscle tears (grade 2 strains) in athletes.Methods:MRIs of athletes with grade 2 hamstring strains were reviewed from 2013 to 2018. From 2013 to 2015 athletes were treated conservatively and from 2016 to 2018 with a combination of ultrasound-guided hematoma aspiration and PRP muscle strain injection. The outcome, including return-to-play (in days) and recurrence rate, was compared retrospectively between both groups (conservative vs. aspiration/PRP) using ANOVA and Fisher’s Exact test. There was no significant difference in age, type of sport, and muscle involvement (including injury grade/location, hamstring muscle type, and length/cross-sectional area of the strain).Results:Fifty-five athletes (28 treated conservatively, 27 with hematoma aspiration/PRP injection) were included. Average return-to-play time (mean) was 32.4 days in the conservative group and 23.5 days in the aspiration/PRP group (p<0.001). Recurrence rate of the hamstring strain was 28.6% (8/28) in the conservative treatment group and less than 4% (1/27) in the aspiration/PRP group (p=0.025).Conclusions:Athletes with grade 2 hamstring strains treated with a combination of hematoma aspiration and PRP injection had a significantly shorter return-to-play and a lower recurrence rate compared to athletes receiving conservative treatment.Axial T2-weighted fat saturated image in a 24-year-old athlete shows a grade 2 strain of the biceps femoris muscle with hemorrhage/hematoma (dashed arrow) surrounding the sciatic nerve (solid arrow).Corona STIR image of the thighs in a 27-year-old athlete with a grade 2 strain of the right biceps femoris muscle shows muscle edema and fluid (solid arrow). A feathery pattern of edema is also present (dashed arrow).Axial/cross-sectional ultrasound image of the right hamstring muscle in a 25-year-old athlete shows a grade 2 strain of the semitendinosus muscle (dashed arrow) and the adjacent normal portion of the muscle (solid arrow).Long axis ultrasound image in the same patient shows hemorrhage/hematoma (solid arrow) surrounding the sciatic nerve (asterisk).

Early versus delayed lengthening exercises for acute hamstring injury in male athletes: a randomised controlled clinical trial

BackgroundTo evaluate the efficacy of early versus delayed introduction of lengthening (ie, eccentric strengthening) exercises in addition to an established rehabilitation programme on return to sport duration for acute hamstring...

Location of Hamstring Injuries Based on Magnetic Resonance Imaging: A Systematic Review.

Hamstring muscle injury location using magnetic resonance imaging (MRI) is not so well described in the literature. To describe the location of hamstring injuries using MRI. PubMed, Web of Science, Scopus, SPORTDiscus, Cochrane Library. The full text of studies, in English, had to be available. Case reports and reviews were excluded. Included studies must report the location of hamstring injuries using MRI within 8 days of the acute injury. Systematic review. Level 4. A first screening was conducted based on title and abstract of the articles. In the second screening, the full text of the remaining articles was evaluated for the fulfillment of the inclusion criteria. From the 2788 references initially found in 5 databases, we included 34 studies, reporting a total of 2761 acute hamstring injuries. The most frequent muscle head involved was the long head of the biceps femoris (BFLH) (70%), followed by the semitendinosus (ST) (15%), generally associated with BFLH. The most frequent tissue affected was the myotendinous junction (MTJ) accounting for half the cases (52%). Among all lesions, the distribution between proximal, central, and distal lesions looked homogenous, with 34.0%, 33.4% and 32.6%, respectively. The stretching mechanism, while only reported in 2 articles, represented 3% of all reported mechanisms, appears responsible for a specific lesion involving the proximal tendon of the semimembranosus (SM), and leading to a longer time out from sport. BFLH was the most often affected hamstring injuries and MTJ was the most affected tissue. In addition, the distal, central, and proximal locations were homogeneously distributed. We also noted that MRI descriptions of hamstring injuries are often poor and did not take full advantage of the MRI strengths. Before study initiation, the study was registered in the PROSPERO International prospective register of systematic reviews (registration number CRD42018107580).

Return to match running performance after a hamstring injury in elite football: a single-centre retrospective cohort study

ObjectivesTo determine the number of matches to return to pre-injury match running performance after sustaining an acute hamstring injury.MethodsIn this retrospective cohort study, the injuries of the players of the...

Hamstring injury patterns in professional male football (soccer): a systematic video analysis of 52 cases

ObjectiveTo closely describe the injury inciting events of acute hamstring injuries in professional male football (soccer) using systematic video analysis.MethodsVideo footage from four seasons (2014–2019) of the two highest divisions...

Evidence-Based Management and Factors Associated With Return to Play After Acute Hamstring Injury in Athletes: A Systematic Review.

Background:Considering the lengthy recovery and high recurrence risk after a hamstring injury, effective rehabilitation and accurate prognosis are fundamental to timely and safe return to play (RTP) for athletes.Purpose:To analyze methods of rehabilitation for acute proximal and muscular hamstring injuries and summarize prognostic factors associated with RTP.Study Design:Systematic review; Level of evidence, 4.Methods:In August 2020, MEDLINE, CINAHL, Cochrane Central Register of Controlled Trials, and SPORTDiscus were queried for studies examining management and factors affecting RTP after acute hamstring injury. Included were randomized controlled trials, cohort studies, case-control studies, and case series appraising treatment effects on RTP, reinjury rate, strength, flexibility, hamstrings-to-quadriceps ratio, or functional assessment, as well as studies associating clinical and magnetic resonance imaging factors with RTP. Risk of bias was assessed using the Cochrane Risk-of-Bias Tool for Randomized Trials or the Methodological Index for Non-Randomized Studies (MINORS).Results:Of 1289 identified articles, 75 were included. The comparative and noncomparative studies earned MINORS scores of 18.8 ± 1.3 and 11.4 ± 3.4, respectively, and 12 of the 17 randomized controlled trials exhibited low risk of bias. Collectively, studies of muscular injury included younger patients and a greater proportion of male athletes compared with studies of proximal injury. Surgery for proximal hamstring ruptures achieved superior outcomes to nonoperative treatment, whereas physiotherapy incorporating eccentric training, progressive agility, and trunk stabilization restored function and hastened RTP after muscular injuries. Platelet-rich plasma injection for muscular injury yielded inconsistent results. The following initial clinical findings were associated with delayed RTP: greater passive knee extension of the uninjured leg, greater knee extension peak torque angle, biceps femoris injury, greater pain at injury and initial examination, “popping” sound, bruising, and pain on resisted knee flexion. Imaging factors associated with delayed RTP included magnetic resonance imaging-positive injury, longer lesion relative to patient height, greater muscle/tendon involvement, complete central tendon or myotendinous junction rupture, and greater number of muscles injured.Conclusion:Surgery enabled earlier RTP and improved strength and flexibility for proximal hamstring injuries, while muscular injuries were effectively managed nonoperatively. Rehabilitation and athlete expectations may be managed by considering several suitable prognostic factors derived from initial clinical and imaging examination.