Return to play following muscle injuries in professional footballers

Acute and Chronic Effects of Static Stretching on Intramuscular Hamstring Stiffness

Passive hamstring stiffness varies proximo-distally, resulting in inhomogeneous tissue strain during stretching that may affect localized adaptations and risk of muscle injuries. The purpose of the present study was to determine the acute and chronic effects of static stretching (SS) on intramuscular hamstring stiffness. Thirty healthy active participants had acute changes in passive biceps femoris (BF), semimembranosus (SM), and semitendinosus (ST) stiffness measured at 25% (proximal), 50% (middle), and 75% (distal) muscle length, using shear-wave elastography, immediately after SS. Participants then completed 4 weeks of either a SS intervention (n = 15) or no intervention (CON, n = 15) with stiffness measured before and after the interventions. The acute and chronic effects of SS were compared between anatomical regions and between regions on the basis of their relative stiffness pre-intervention. Acutely, SS decreased stiffness throughout the BF and SM (p ≤ 0.05) but not the ST (p = 0.326). However, a regional effect of stretching was observed for SM and ST with greater reduction in stiffness occurring in stiffer muscular regions (p = 0.001-0.013). Chronically, SS increased BF and ST (p < 0.05), but not SM (p = 0.422) stiffness compared with CON, but no regional effect of stretching was observed in any muscle (p = 0.361-0.833). SS resulted in contrasting acute and chronic effects, acutely decreasing stiffness in stiffer regions while chronically increasing stiffness. These results indicate that the acute effects of SS vary along the muscle's length on the basis of the relative stiffness of the muscle and that acute changes in stiffness from SS are unrelated to chronic adaptations.

MRI radiomics for hamstring strain injury identification and return to sport classification: a pilot study

OBJECTIVE

To determine if MRI-based radiomics from hamstring muscles are related to injury and if the features could be used to perform a time to return to sport (RTS) classification. We hypothesize that radiomics from hamstring muscles, especially T2-weighted and diffusion tensor imaging-based features, are related to injury and can be used for RTS classification.

SUBJECTS AND METHODS

MRI data from 32 athletes at the University of Wisconsin-Madison that sustained a hamstring strain injury were collected. Diffusion tensor imaging and T1- and T2-weighted images were processed, and diffusion maps were calculated. Radiomics features were extracted from the four hamstring muscles in each limb and for each MRI modality, individually. Feature selection was performed and multiple support vector classifiers were cross-validated to differentiate between involved and uninvolved limbs and perform binary (≤ or > 25 days) and multiclass (< 14 vs. 14-42 vs. > 42 days) classification of RTS.

RESULT

The combination of radiomics features from all diffusion tensor imaging and T2-weighted images provided the most accurate differentiation between involved and uninvolved limbs (AUC ≈ 0.84 ± 0.16). For the binary RTS classification, the combination of all extracted radiomics offered the most accurate classification (AUC ≈ 0.95 ± 0.15). While for the multiclass RTS classification, the combination of features from all the diffusion tensor imaging maps provided the most accurate classification (weighted one vs. rest AUC ≈ 0.81 ± 0.16).

CONCLUSION

This pilot study demonstrated that radiomics features from hamstring muscles are related to injury and have the potential to predict RTS.

Surgical treatment of distal hamstring tendon injuries yield a higher return-to-sports rate: A systematic review

PURPOSE

The purpose of this study is to compare the patient-reported outcomes and return to sports of the conservative and surgical treatment of distal hamstring tendon injuries.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, two reviewers searched PubMed, Scopus and Virtual Health Library databases in January 2023. Clinical studies evaluating conservative or surgical management outcomes of distal hamstring tendon injuries were considered eligible for this systematic review if predefined criteria were fulfilled: (1) published in English or Spanish; (2) evaluated any of the following: patient-reported outcomes, return-to-sports rate (RTS-R) or return-to-sports time (RTS-T). Data were presented in tables using absolute values from individual studies and derived pooled percentages.

RESULTS

Eighteen studies were included for 67 patients and 68 distal hamstring tendon injuries. Initially, 39 patients (58.2%) underwent surgical treatment, whereas 28 (41.8%) were treated conservatively. Among conservative treatment patients, 15 failed and had to be operated on (53.6%), all with distal semitendinosus tendon injuries. Anchor fixation was the technique of choice in 20 lesions (36.4%), tenodesis in 16 (29.1%), tenectomy in 14 (25.5%) and sutures were preferred in five (9%). Thirteen out of 28 patients (46.4%) undergoing initial conservative treatment returned to sports at a mean of 3.6 months (range 1 week to 12 months), in contrast to surgical treatment, in which 36 out of 39 patients (92.3%) returned at a mean of 4.2 months (range 6 weeks to 12 months). Additionally, 14 of 15 patients (93.3%) converted to surgical treatment after failed conservative treatment returned to sports at a mean of 7.6 months after injury.

CONCLUSION

Initial surgical treatment of distal hamstring tendon injuries yields a high RTS-R (92.3%) at a mean of 4.2 months. Furthermore, 15 out of 28 patients (53.6%) initially treated conservatively had to be operated on, delaying the RTS-T (mean 7.6 months after injury) without affecting their RTS-R.

LEVEL OF EVIDENCE

IV.

Magnetic resonance imaging predicts the days lost from training and competition: evaluation of 56 indirect muscle injuries in professional football players

BACKGROUND

Lower limb muscle injuries have a strong impact in training and official competitions stoppage for professional football players. This study aimed to explore the relationship between oedema-like changes found on magnetic resonance imaging (MRI) in acute indirect thigh injuries muscles and the time required for the athlete to return to individual training - "return to training" (RTT) and for full availability for official competitions - "return to play" (RTP).

METHODS

Professional football players from 2017/2018 to 2021/2022 seasons top league team with clinical and ultrasound (US) diagnosis of acute hamstrings or quadriceps muscle injury, confirmed on 48/72h subsequent MRI, were included. MRI images were retrospectively re-evaluated. MRI parameters evaluated were cross-sectional area (CSA), cranio-caudal extension (CCE), distance to nearest insertion (DI) and volume (V). Univariate and multivariate analysis was performed to find factors related to RTT, RTP, and episodes of reinjuries.

RESULTS

Thirty-four first traumatic muscle injuries met the inclusion criteria. The mean time to RTT and RTP was 22 (4-49) and 25 (4-55) days, respectively. CCE and V resulted as independent predictive MRI variables for the time to RTT (P=0.012) and RTP (P=0.02), respectively. Thresholds of CCE≥11.31 cm and V ≥19.5cc can predict a time to RTT≥22 days (Odds Ratio [OR] 9.5) and RTP≥25 days (OR 4.583), respectively.

CONCLUSIONS

The decision on the time required for RTP is based on clinic and imaging evaluation; CCE and V of the MRI oedema-like changes help to define the prognosis of the injury.

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

PURPOSE

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.

METHODS

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 4 weeks. Outcomes included Tegner scores, return to sport, Lower Extremity Functional Score (LEFS), current hamstring symptoms and complications including re-injury.

RESULTS

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 33.7 months (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 3.1 months (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.

CONCLUSIONS

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.

LEVEL OF EVIDENCE

IV.

Association Between Magnetic Resonance Imaging Findings and Time to Return to Sport After Muscle Injuries in High-Level Youth Athletes

OBJECTIVE

To describe the relationship between magnetic resonance imaging (MRI) findings and time to return to sport (RTS) from muscle injuries in youth athletes.

DESIGN

Prospective collection of injury surveillance data over 6 seasons (2014-2015 to 2019-2020) and reanalysis of MRIs by a radiologist blinded to RTS time after the data collection period.

SETTING

National sports academy and sports medicine hospital.

PARTICIPANTS

Male youth (11-19 years) athletes participating in the football (soccer) or athletics (track and field) programs with a muscle injury.

INDEPENDENT VARIABLES

Magnetic resonance imaging findings (eg, grade and location) in time-loss muscle injuries.

MAIN OUTCOME VARIABLES

Injury incidence, distributions, and RTS time.

RESULTS

In total, 353 time-loss muscle injuries were recorded for 1089 athlete-seasons, of which 85 satisfied our inclusion criteria (MRI within 14 days). Return to sport time was significantly longer for reinjuries compared with index injuries. Associations between MRI findings and RTS time were specific to the muscle group, with significant differences in RTS time observed between categories of structure, location, and grade. The largest number of injuries was to the hamstrings (n = 46), where injuries involving the tendon were more severe than those involving the myotendinous junction and muscle, proximal injuries were more severe than mid-portion and distal, and longer RTS time was observed for higher injury grade ( P < 0.05).

CONCLUSIONS

Muscle injuries in youth are diverse and cannot be treated as a single injury type. Specific injury durations can be expected depending on injury characteristics such as reinjury, location, structure, and grade.

[Groin pain in sports games: a systematic review]

BACKGROUND

In sports games, epidemiological data show that groin pain is relatively common and can lead to repeated loss of time. Consequently, it is essential to be aware of the evidence-based prevention strategies. The aim of this systematic review was to examine risk factors and prevention strategies for groin pain and to rank them based on their evidence in sports games.

METHODS

The review was conducted according to the PRISMA guidelines, using a PICO-scheme in the PubMed, Web of Science and SPOLIT databases. We included all available intervention and observational studies on the influence of risk factors and prevention strategies on groin pain in sports games. The methodological quality and level of evidence was assessed using the PEDro-Scale and OCEBM model, respectively. Finally, the quantity, quality and level of evidence was used to rank each risk factor for its grade.

RESULTS

Moderate evidence was found for four risk factors that significantly influence the risk of groin pain: male sex, previous groin pain, hip adductor strength and not participating in the FIFA 11+ Kids. Moreover, moderate evidence was found for the following non-significant risk factors: older age, body height and weight, higher BMI, body fat percentage, playing position, leg dominance, training exposure, reduced hip abduction, adduction, extension, flexion, and internal rotation-ROM, hip flexor strength, hip abductor, adductor, flexor and core strengthening with balance exercises, clinical hip mobility tests and physical capacities.

CONCLUSION

The identified risk factors can be considered when developing prevention strategies to reduce the risk of groin pain in sports games. Thereby, not only the significant, but also the non-significant risk factors should be considered for prioritisation.

Isolated Adductor Magnus Injuries in Athletes: A Case Series

Background

Little is known about injuries to the adductor magnus (AM) muscle and how to manage them.

Purpose

To describe the injury mechanisms of the AM and its histoarchitecture, clinical characteristics, and imaging features in elite athletes.

Study Design

Case series; Level of evidence, 4.

Methods

A total of 11 competitive athletes with an AM injury were included in the study. Each case was clinically assessed, and the diagnosis and classification were made by magnetic resonance imaging (MRI) according to the British Athletics Muscle Injury Classification (BAMIC) and mechanism, location, grade, and reinjury (MLG-R) classification. A 1-year follow-up was performed, and return-to-play (RTP) time was recorded.

Results

Different mechanisms of injury were found; most of the athletes (10/11) had flexion and internal rotation of the hip with extension or slight flexion of the knee. Symptoms consisted of pain in the posteromedial (7/11) or medial (4/11) thigh during adduction and flexion of the knee. Clinically, there was a suspicion of an injury to the AM in only 3 athletes. According to MRI, 5 lesions were located in the ischiocondylar portion (3 in the proximal and 2 in the distal myoconnective junction) and 6 in the pubofemoral portion (4 in the distal and 2 in the proximal myoconnective junction). Most of the ischiocondylar lesions were myotendinous (3/5), and most of the pubofemoral lesions were myofascial (5/6). The BAMIC and MLG-R classification coincided in distinguishing injuries of moderate and mild severity. The management was nonoperative in all cases. The mean RTP time was 14 days (range, 0-35 days) and was longer in the ischiocondylar cases than in the pubofemoral cases (21 vs 8 days, respectively). Only 1 recurrence, at <10 months, was recorded.

Conclusion

Posteromedial thigh pain after an eccentric contraction during forced adduction of the thigh from hip internal rotation should raise a suspicion of AM lesions. The identification of the affected portion was possible on MRI. An injury in the ischiocondylar portion entailed a longer RTP time than an injury in the pubofemoral portion.

Comparison of eccentric hamstring strength and asymmetry at return-to-sport after hamstring strain injury among those who did and did not re-injure

OBJECTIVES

The primary aim of this study was to describe eccentric hamstring strength magnitude and asymmetry at the time of return-to-sport (RTS) after an index hamstring strain injury (HSI) and determine if there were differences in strength asymmetry at RTS between those who did and did not go on to re-injure within 1-month and within 3-months of RTS.

DESIGN

Cross-sectional study.

SETTING

Laboratory-based.

PARTICIPANTS

Sixty National Collegiate Athletic Association Division I athletes with index HSI.

MAIN OUTCOME MEASURES

Maximum hamstring eccentric strength for each limb, total maximum strength summed across limbs, and between-limb asymmetry at the time of RTS following the index HSI, assessed using the NordBord Hamstring Testing System.

RESULTS

Of the 60 index HSIs, 8 (13%), and 11 (18%) re-injuries occurred within 1 and 3-months of RTS, respectively. There were no differences between those who did and did not re-injure in maximum eccentric force of either limb (p-values≥0.52), total force from both limbs (p-values≥0.47), and between limb force asymmetry (p-values≥0.91), regardless if re-injury occurred within 1 or 3-months after RTS.

CONCLUSIONS

Eccentric hamstring strength and asymmetry measured at the time of RTS did not differ between those who did and did not re-injure within 3-months of RTS.

Associations of time to return to performance following acute posterior thigh injuries with running biomechanics, hamstring function, and structure in collegiate sprinters: A prospective cohort design

BACKGROUND

The time to return to sport from acute hamstring strain injuries is associated with several functional and structural impairments. However, not all previous studies assessed the preinjury level before acute hamstring strain injuries directly. The purpose of this study was to examine the associations of the time to return to performance following acute hamstring strain injuries with deficits in running biomechanics, hamstring function and structure in collegiate sprinters by a prospective study.

METHODS

Using a prospective cohort design, 72 participants were recruited from a collegiate track and field team. At the preinjury assessment, a 60-m running-specific test, passive straight leg raise test and isometric knee flexion strength test were assessed at the beginning of the competitive season for three consecutive years (2017-2019). Afterwards, postinjury examinations were performed only in sprinters with acute hamstring strain injuries.

FINDINGS

Twelve sprinters strained their hamstring muscle (incidence rate of hamstring strain injuries: 16.7%); the majority (n = 10) were classified as grades 0-2. The running speed deficit of the running-specific test was associated with the time to return to performance as well as the passive straight leg raise test deficit. In the running-specific test, lower-limb kinetic deficits were more strongly associated with the time to return to performance compared to lower-limb kinematic deficits.

INTERPRETATION

A running-specific test may be considered one of the most convenient and valid tests for assessing rehabilitation progress after acute hamstring strain injuries.

Effects of Fatigue Induced by Repeated Sprints on Sprint Biomechanics in Football Players: Should We Look at the Group or the Individual?

The aim of this study was to analyse the influence of fatigue on sprint biomechanics. Fifty-one football players performed twelve maximal 30 m sprints with 20 s recovery between each sprint. Sprint kinetics were computed from running speed data and a high-frequency camera (240 Hz) was used to study kinematic data. A cluster analysis (K-mean clustering) was conducted to classify individual kinematic adaptations. A large decrease in maximal power output and less efficiency in horizontally orienting the ground reaction force were observed in fatigued participants. In addition, individual changes in kinematic components were observed, and, according to the cluster analysis, five clusters were identified. Changes in trunk, knee, and hip angles led to an overall theoretical increase in hamstring strain for some players (Cluster 5, 20/51) but to an overall decrease for some others (Cluster 1, 11/51). This study showed that the repeated sprint ability (RSA) protocol had an impact on both kinetics and kinematics. Moreover, fatigue affected the kinematics in a different way for each player, and these individual changes were associated with either higher or lower hamstring length and thus strain.

Sport-Specific Rehabilitation, but Not PRP Injections, Might Reduce the Re-Injury Rate of Muscle Injuries in Professional Soccer Players: A Retrospective Cohort Study

Platelet-rich plasma (PRP) injections are extremely popular in the management of sports injuries in elite athletes. However, data on the use of various administration protocols of PRP are contradictory. The efficacy of platelet-rich plasma in the treatment of muscle injuries in professional soccer players has to be contextualized within the sport-specific rehabilitation program. Despite the questionable role of PRP, a well-structured rehabilitation program is still regarded as the gold standard. We examined the efficacy of various PRP protocols in the management of muscle injuries in professional soccer players in respect to treatment duration and injury recurrence. A retrospective cohort study. Muscle injuries in professional soccer players (n = 79, height 182.1 ± 5.9 cm, weight 76.8 ± 5.8 kg, BMI 23.1 ± 1.4 kg/m2) from three elite soccer clubs from the Russian Premier League were recorded during the 2018−2019 season. The injuries were graded based on MRI, using the British Athletic Muscle Injury Classification. Treatment protocols included the POLICE regimen, short courses of NSAID administration, and the specific rehabilitation program. The sample group of players were administered PRP injections. The average treatment duration with PRP injection was significantly longer than conventional treatment without PRP, 21.5 ± 15.7 days and 15.3 ± 11.1 days, respectively (p = 0.003). Soccer-specific rehabilitation and obtaining MRI/US before the treatment was associated with significantly reduced injury recurrence rate (p < 0.001). There was no significant difference between the PRP injection protocol applied to any muscle and the treatment duration in respect of grade 2A−2B muscle injuries. The total duration of treatment of type 2A−2B injuries was 15 days among all players. In the group receiving local injections of PRP, the total duration of treatment was 18 days; in the group without PRP injections, the treatment duration was 14 days. In our study, PRP treatment was associated with longer treatment duration, regardless of which muscle was injured. This may reflect the tendency to use PRP in higher-degree injuries. Soccer-specific rehabilitation significantly reduced the injury recurrence rate when compared to the administration of PRP injections. MRI/US imaging before returning to play was also associated with a lower injury recurrence rate. There was no significant difference between the PRP injection protocol applied to any muscle and the treatment duration in treatment of type 2A−2B muscle injuries.

The British Athletics Muscle Injury Classification grading system as a predictor of return to play following hamstrings injury in professional football players

OBJECTIVES

Investigate the British Athletics Muscle Injury Classification (BAMIC) grading system as a predictor of return to play (RTP) following primary hamstring strain injury (HSI) and its agreement with the Peetron's classification system in professional footballers.

METHODS

A retrospective cohort study of 39 hamstrings strains in a professional English football club were identified. Two musculoskeletal radiologists reviewed historical MRI's and classified them against the BAMIC and Peetron's grading system. Classification, oedema length and cross-sectional area were compared against RTP.

RESULTS

Pearson's correlation coefficient demonstrated a weak but statistically significant correlation between BAMIC and RTP (r = 0.32; 95%CI 0.01 to 0.58; p = 0.05). Maximum length of intramuscular oedema demonstrated weak correlations with RTP (r = 0.3; 95%CI -0.02 to 0.56; p = 0.06). Percentage cross sectional demonstrated a weak correlation with RTP (r = 0.02; 95%CI -0.3 to 0.33; p = 0.91). Multiple regression demonstrated that 16% of the variance in RTP was explained by the model. Kappa for the agreement between BAMIC and Peetron's was 0.21 (95%CI 0 to 0.42).

CONCLUSIONS

A significant association between the grade of HSI on the BAMIC system and RTP was found. Findings suggest BAMIC could provide valuable prognostic information on the RTP.

Preseason Eccentric Strength Is Not Associated with Hamstring Strain Injury: A Prospective Study in Collegiate Athletes

INTRODUCTION

Established risk factors for hamstring strain injuries (HSI) include older age and prior HSI. However, these are nonmodifiable and have a limited role in injury prevention. Eccentric hamstring strength is a common component of HSI prevention programs, but its association with injury is less clear.

PURPOSE

This study aimed to determine if eccentric hamstring strength was prospectively associated with HSI among collegiate athletes, while controlling for sex, age, and prior HSI. We hypothesized that athletes with lower eccentric hamstring strength or greater between-limb strength asymmetry at preseason would have an increased risk of HSI.

METHODS

Hamstring eccentric strength measures, maximum total force ( FTotal ) and between-limb asymmetry in maximum force ( FAsym ), were measured at preseason on male and female athletes. HSIs were tracked over the subsequent 12 months. Generalized estimating equations were used to identify univariable and multivariable associations between athlete demographics, eccentric hamstring strength, and HSI risk.

RESULTS

Data for 326 athletes (85 female; 30 track, 43 basketball, 160 American football, 93 soccer) were included, and 64 HSIs were observed. Univariable associations between eccentric hamstring strength and subsequent HSI were nonsignificant ( FTotal : odds ratio [OR], 0.99 (95% confidence interval (CI), 0.93-1.05); P = 0.74; FAsym : OR, 1.35 (95% CI, 0.87-2.09); P = 0.23). No relationship between eccentric hamstring strength and HSI ( FAsym : OR, 1.32 (95% CI, 0.84-2.08); P = 0.23) was identified after adjusting for confounders including sex, age, and prior HSI.

CONCLUSIONS

No association between preseason eccentric hamstring strength and risk of subsequent HSI was identified after controlling for known risk factors and sex among collegiate athletes. Eccentric hamstring strengthening may continue to serve as a preventative approach to HSI, but it does not provide additional insight into HSI risk beyond factors such as age and prior HSI.

The development of a HAMstring InjuRy (HAMIR) index to mitigate injury risk through innovative imaging, biomechanics, and data analytics: protocol for an observational cohort study

Background

The etiology of hamstring strain injury (HSI) in American football is multi-factorial and understanding these risk factors is paramount to developing predictive models and guiding prevention and rehabilitation strategies. Many player-games are lost due to the lack of a clear understanding of risk factors and the absence of effective methods to minimize re-injury. This paper describes the protocol that will be followed to develop the HAMstring InjuRy (HAMIR) index risk prediction models for HSI and re-injury based on morphological, architectural, biomechanical and clinical factors in National Collegiate Athletic Association Division I collegiate football players.

Methods

A 3-year, prospective study will be conducted involving collegiate football student-athletes at four institutions. Enrolled participants will complete preseason assessments of eccentric hamstring strength, on-field sprinting biomechanics and muscle–tendon volumes using magnetic-resonance imaging (MRI). Athletic trainers will monitor injuries and exposure for the duration of the study. Participants who sustain an HSI will undergo a clinical assessment at the time of injury along with MRI examinations. Following completion of structured rehabilitation and return to unrestricted sport participation, clinical assessments, MRI examinations and sprinting biomechanics will be repeated. Injury recurrence will be monitored through a 6-month follow-up period. HAMIR index prediction models for index HSI injury and re-injury will be constructed.

Discussion

The most appropriate strategies for reducing risk of HSI are likely multi-factorial and depend on risk factors unique to each athlete. This study will be the largest-of-its-kind (1200 player-years) to gather detailed information on index and recurrent HSI, and will be the first study to simultaneously investigate the effect of morphological, biomechanical and clinical variables on risk of HSI in collegiate football athletes. The quantitative HAMIR index will be formulated to identify an athlete’s propensity for HSI, and more importantly, identify targets for injury mitigation, thereby reducing the global burden of HSI in high-level American football players.

Trial Registration The trial is prospectively registered on ClinicalTrials.gov (NCT05343052; April 22, 2022).

Association Between Injury Mechanisms and Magnetic Resonance Imaging Findings in Rectus Femoris Injuries in 105 Professional Football Players

OBJECTIVE

To describe the injury mechanism and its association with magnetic resonance imaging (MRI) injury findings in acute rectus femoris injuries.

DESIGN

Combined retrospective and prospective descriptive injury study. Retrospective cohort from January 2010 to October 2013 and prospective cohort from October 2013 to January 2019.

SETTING

Specialized sports medicine hospital.

PARTICIPANTS

Male professional football players older than 18 years playing in a national football league, referred for injury assessment within 7 days after an acute rectus femoris injury, with a positive finding on MRI.

INDEPENDENT VARIABLES

Rectus femoris muscle injury MRI findings in relation to injury mechanism in male football players.

MAIN OUTCOME MEASURES

Rectus femoris injury mechanism (kicking, sprinting, and others), MRI injury location, and grade.

RESULTS

There were 105 injuries in total, with 60 (57.1%) and 45 (42.8%) injuries from the retrospective and prospective cohorts, respectively. Kicking was the injury mechanism in 57 (54.3%) of all acute rectus femoris injuries, sprinting represented 32 (30.4%), and 16 (15.2%) were classified as others. There were 20 (19.05%) free tendon, 67 (63.8%) myotendinous junction and/or intramuscular tendon, and 18 (17.1%) peripheral myofascial located injuries. All free tendon injuries were related to kicking and graded as a complete tear of at least one of the tendons in 15/20 (75.0%) cases.

CONCLUSIONS

Kicking seems to be an important mechanism related to complete ruptures and injuries occurring at the proximal free tendon. Sprinting was the other most common mechanism but was never associated with injury to the proximal free tendon.

Risk Factors for Quadriceps Muscle Strain Injuries in Sport: A Systematic Review

OBJECTIVE

To identify risk factors for quadriceps muscle strain injury in sport.

DESIGN

Risk factor systematic review.

LITERATURE SEARCH

A systematic search was conducted in the MEDLINECINAHL, Embase, AMED, AUSPORT, SPORTDiscus, PEDro, and Cochrane Library databases (from inception to September 2021).

STUDY SELECTION CRITERIA

Studies reporting prospective data to evaluate risk factors related to index and/or recurrent quadriceps muscle strain injury.

DATA SYNTHESIS

A risk-of-bias assessment (using a modified Quality in Prognosis Studies tool) was performed, and we used best-evidence synthesis to qualitatively synthesize the data to quantify relationships between risk factors and quadriceps muscle injury.

RESULTS

Sixteen studies were included, capturing 2408 quadriceps injuries in 11 719 athletes. Meta-analyses were not performed due to clinical heterogeneity. The dominant kicking leg (over 3154 individuals, 1055 injuries), a previous history of quadriceps muscle injury (6208 individuals, 975 injuries), and a recent history of hamstring strain (4087 individuals, 581 injuries) were intrinsic factors associated with quadriceps injury. Extrinsic factors relating to the preseason period and competitive match play increased quadriceps injury risk; participating at higher levels of competition decreased quadriceps injury risk. Age, weight, and flexibility (intrinsic factors) had no association with quadriceps injury.

CONCLUSION

Previous quadriceps injury, recent hamstring injury, the dominant kicking leg, and competitive match play were the strongest risk factors for future quadriceps muscle injury in sport. J Orthop Sports Phys Ther 2022;52(6):389-400. doi:10.2519/jospt.2022.10870.

Tensiomyography Allows to Discriminate between Injured and Non-Injured Biceps Femoris Muscle

The hamstring muscle group is the most frequently injured muscle group in non-contact muscle injuries in sports involving high-speed running. A total of 84% of hamstring injuries affect the biceps femoris (BF) muscle. Clinical assessments and magnetic resonance imaging (MRI) are routinely used for diagnosis and plan management. MRI-negative scans for clinically diagnosed hamstring injuries range from 14% to 45%. We tested the hypothesis that the functional differences between injured and non-injured BF assessed by tensiomyography can be used for diagnostic and classification purposes. We compared an injured group of 53 international-level soccer players and sprinters with 53 non-injured international-level soccer players and sprinters of both sexes. Comparing the injured vs. non-injured athletes and the left vs. right side in all of the athletes, we used the percentage of absolute differences in the BF contraction time (Tc) to classify non-injured and injured BF muscles. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) and the precision−recall curve (PRC) were used to measure the classification accuracy and to identify cut-off limits using the Tc differences. There was a very high ROC AUC value of 0.981 (SE = 0.009, p < 0.000), with 98.11% of the injured muscles being correctly classified (cut-off point 12.50% on Tc differences), and an AUPRC value of 0.981, with association classification criteria at >9.87. Tensiomyography has a high predictive ability to discriminate between injured and non-injured BF non-invasively and functionally.

Hamstrings injuries in football

Background

Hamstrings injuries are a major concern in football (soccer), affecting both recreational players and professional athletes. Although being a recognized issue within the football community, its incidence has been increasing over the last years and still poses a challenge to all practitioners involved.

Study objectives and rationale

The goal of this narrative review is to outline hamstrings injuries epidemiology and mechanisms of injury, identify and discuss its risk factors, provide an approach to a proper early diagnosis, evaluate the efficacy of current treatment options and return to sports, and present the best strategies for hamstrings injury prevention. These guidelines will help the sports medicine staff team on how to better manage their players with or at risk of hamstrings injuries.

Conclusion

Despite several breakthroughs in research of hamstrings injuries, there is still heterogeneity across studies and lack of consensus in regards to classification, diagnosis, treatment and prevention. Hamstrings injuries compromise the athlete's performance with time loss due to injury, shortens their highest-level career longevity with higher risk of reinjury rates, and is a defying problem for clubs to balance financial losses due to having their players off the pitch. Further research is warranted to keep moving forward with evidence on treating and preventing hamstrings injuries to mitigate its high incidence and keep the players safe.

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

CONTEXT

Hamstring muscle injury location using magnetic resonance imaging (MRI) is not so well described in the literature.

OBJECTIVE

To describe the location of hamstring injuries using MRI.

DATA SOURCES

PubMed, Web of Science, Scopus, SPORTDiscus, Cochrane Library.

STUDY SELECTION

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.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

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.

RESULTS

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.

CONCLUSION

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.

SYSTEMATIC REVIEW REGISTRATION

Before study initiation, the study was registered in the PROSPERO International prospective register of systematic reviews (registration number CRD42018107580).

Knee Flexor Eccentric Strength, Hamstring Muscle Volume and Sprinting in Elite Professional Soccer Players with a Prior Strained Hamstring

Simple Summary

Given the link between a prior hamstring injury and the increased risk of suffering a subsequent injury in professional soccer, an understanding of the features displayed by previously injured players is important. The aim of the present study was to investigate if players with a history of hamstring injury exhibit bilateral deficits in knee flexor eccentric strength, hamstring muscle volume, and sprinting performance. The eccentric knee flexor strength was greater in the previously injured limbs compared to both the contralateral uninjured limbs in the previously injured group and the uninjured limbs in the previously uninjured players. Previously injured limbs showed possibly larger short heads of the biceps femoris and likely semitendinosus muscle volumes. Sprinting performances in the 5-m were possibly worse in players with a history of hamstring muscle strain injury compared to the previously uninjured players.

Abstract

The aim was to determine if players with a prior hamstring strain injury (HSI) exhibit bilateral deficits in knee flexor eccentric strength and hamstring muscle volume and differences in sprinting performance compared with players without a history of HSIs. Forty-six male professional soccer players participated in this study. Eccentric knee flexor strength, hamstring muscle volume (MRI), and a 20-m running sprint test (5- and 10-m split time) were assessed at the start of the preseason. Eccentric knee strength of the previously injured limbs of injured players was greater (ES: 1.18–1.36) than the uninjured limbs in uninjured players. Previously injured limbs showed possibly larger biceps femoris short heads (BFSh) and likely semitendinosus (ST) muscle volumes than the contralateral uninjured limbs among the injured players (ES: 0.36) and the limbs of the uninjured players (ES: 0.56), respectively. Players who had experienced a previous HSI were possibly slower in the 5-m (small ES: 0.46), while unclear differences were found in both the 10-m and 20-m times. Players with a prior HSI displayed greater eccentric knee flexor strength, possibly relatively hypertrophied ST and BFSh muscles, and possibly reduced 5-m sprinting performances than previously uninjured players. This can have implication for the design of secondary hamstring muscle injury prevention strategies.

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.

Indirect Structural Muscle Injuries of Lower Limb: Rehabilitation and Therapeutic Exercise

Muscle injuries are the most common trauma in team and individual sports. The muscles most frequently affected are those of the lower limb, and in particular hamstrings, adductors, rectus femoris and calf muscles. Although several scientific studies have tried to propose different rehabilitation protocols, still too often the real rehabilitation process is not based on scientific knowledge, especially in non-elite athletes. Moreover, the growing use of physical and instrumental therapies has made it increasingly difficult to understand what can be truly effective. Therefore, the aim of the present paper is to review proposed therapeutic algorithms for muscle injuries, proposing a concise and practical summary. Following a three-phase rehabilitation protocol, this review aims to describe the conservative treatment of indirect structural muscle injuries, which are the more routinely found and more challenging type. For each phase, until return to training and return to sport are completed, the functional goal, the most appropriate practitioner, and the best possible treatment according to current evidence are expressed. Finally, the last section is focused on the specific exercise rehabilitation for the four main muscle groups with a structured explanatory timetable.

Rehabilitation of a patient with bilateral rectus abdominis full thickness tear sustained in recreational strength training: a case report

STUDY DESIGN

Case Report.

BACKGROUND

Abdominal wall muscle injuries have been reported in handball, tennis, and baseball; however, a bilateral full-thickness tear of the rectus abdominis muscle and its rehabilitation have not previously been described. This report aims to describe a case of an acute bilateral full-thickness rectus abdominis tear simulating an acute abdomen that presented to an emergency department.

CASE DESCRIPTION

A 25-year-old male (169 cm, 84 kg) was transferred to the emergency room due to severe lancinating (Numerical Pain Rating 10/10) abdominal pain that occurred during weight training at a gym. An orthopedic surgeon, an internist, and a general surgeon assessed him for internal and surgical emergencies. The magnetic resonance imaging of his abdomen revealed a bilateral full-thickness tear of the rectus abdominis muscle. The patient was given an option of surgical repair of the RA, but he refused. Six weeks later, he attended our sports medicine department. A criteria-based rehabilitation program was planned, with weekly follow-ups.

OUTCOMES

The patient could walk pain-free at 4^th week and jog at 10^th week of rehabilitation. Significant improvements in the range of movement of the trunk, pain levels and functional capacity were noted at discharge and 6 and 12-month follow-ups.

DISCUSSION

Clinical management of this patient is described in detail, with emphasis on diagnostic ultrasonography. The structured rehabilitation program used for this patient resulted in a return to pre-injury level function.

Role of ultrasound and magnetic resonance imaging in the prognosis and classification of muscle injuries in professional football players: correlation between imaging and return to sport time

Purpose

To study distractive muscle injuries applying US and MRI specific classifications and to find if any correlation exists between the results and the return to sport (RTS) time. The second purpose is to evaluate which classification has the best prognostic value and if the lesions extension correlates with the RTS time.

Methods

A total of 26 male, professional soccer players (age 21.3 ± 5.6), diagnosed with traumatic muscle injury of the lower limbs, received ultrasound and MRI evaluation within 2 days from the trauma. Concordance between US and MRI findings was investigated. The relationships between MRI and US based injury grading scales and RTS time were evaluated. Correlation between injuries’ longitudinal extension and RTS time was also investigated.

Results

The correlation between US and MRI measurements returned a Spearman value of r_s = 0.61 (p = .001). Peetrons and Mueller-Wohlfahrt grading scales correlations with RTS time were r = 0.43 (p = .02) and r = 0.83 (p =  < .001). The lesion’s extension correlation with RTS time was r = 0.63 (p < .001). The correlation between the site of the lesion and its location with the RTS time were r_s = 0.2 and r_s = 0.25.

Conclusions

Both US and MRI can be used as prognostic indicators along with the Peetrons (US) and the Mueller-Wohlfahrt (MRI) classifications. MRI is more precise and generates more reproducible results. The lesion craniocaudal extension must be considered as a prognostic indicator, while the injury location inside the muscle or along its major axis has doubtful significance.

Hip and Groin Pain in Soccer Players

Purpose  The aim of this article is to illustrate the recent framework necessary to standardize studies on groin pain and review the existing literature on groin pain in football. Methods  The common pathological processes underlying groin pain such as muscle, tendon or ligament strain, bone injury or fracture, sport hernia, bursitis, osteitis pubis, and hip-related diseases have been reviewed and current management options have been considered. Results  Groin pain is considered a pain in pubic or lower abdominal or adductors region which can be monolateral or bilateral. It is common in high-intensity team sports and can negatively affect an athlete's professional carrier, causing serious disruption in the performance. Despite a high prevalence of groin pain in athletes, diagnosis and management of the underlying pathological processes remain a challenge for surgeons, radiologists, and physiotherapists alike. Conclusion  A multidisciplinary approach is essential for patients with groin pain allowing prompt diagnosis and initiation of treatment thus facilitating more rapid return to play and preventing potential long-term sequelae of chronic groin pathology.

Return to Play After a Hamstring Strain Injury: It is Time to Consider Natural Healing

Return to play (RTP) criteria after hamstring strain injuries (HSIs) help clinicians in deciding whether an athlete is ready to safely resume previous sport activities. Today, functional and sport-specific training tests are the gold standard in the decision-making process. These criteria lead to an average RTP time between 11 and 25 days after a grade 1 or 2 HSI. However, the high re-injury rates indicate a possible inadequacy of the current RTP criteria. A possible explanation for this could be the neglect of biological healing time. The present review shows that studies indicating time as a possible factor within the RTP-decision are very scarce. However, studies on biological muscle healing showed immature scar tissue and incomplete muscle healing at the average moment of RTP. Twenty-five percent of the re-injuries occur in the first week after RTP and at the exact same location as the index injury. This review supports the statement that functional recovery precedes the biological healing of the muscle. Based on basic science studies on biological muscle healing, we recommend a minimum period of 4 weeks before RTP after a grade 1 or 2 HSI. In conclusion, we advise a comprehensive RTP functional test battery with respect for the natural healing process. Before deciding RTP readiness, clinicians should reflect whether or not it is biologically possible for the injured tissue to have regained enough strength to withstand the sport-specific forces. In an attempt to reduce the detrimental injury-reinjury cycle, it is time to start considering (biological healing) time.

Previous hamstring muscle strain injury alters passive tissue stiffness and vibration sense

BACKGROUND

Hamstring strain is one of the most common among sports injuries. A previous history of this injury is considered a strong predictor of recurrent hamstring strain injury. It has been suggested that fascial tissue alters after muscle strain injury. However, the association between previous hamstring strain injury and tissue stiffness and vibration sense detection has not been investigated.

OBJECTIVES

We aimed to determine whether a previous history of hamstring strain injury affects tissue stiffness and vibration sense in professional soccer players.

METHOD

The stiffness (MyotonPRO®) and vibration disappearance threshold (tuning fork) were measured in eight professional soccer players with previous history of hamstring strain and eight uninjured players. The differences between two groups' means were analyzed. Side-to-side differences between injured and uninjured legs were also analyzed.

RESULTS

The tissue stiffness was higher, and the vibration disappearance threshold was lower, in previously injured players when compared to uninjured players. Similar differences were found between injured and uninjured legs. No significant relationship was detected between the age or body mass index (BMI) for both tissue stiffness and vibration disappearance threshold (all P < 0.05).

CONCLUSIONS

Soccer players with a previous history of hamstring strain injury exhibited higher tissue stiffness and lower vibration sensitivity in the injured leg, regardless of the age and BMI. The results that players who have a previous hamstring strain injury with altered tissue stiffness and vibration sense will be useful and feasible evaluation for chronic muscle strain condition.

Alpha-Actinin-3 Deficiency Might Affect Recovery from Non-Contact Muscle Injuries: Preliminary Findings in a Top-Level Soccer Team

There are recent data suggesting an association between the R577X polymorphism (rs1815739) in the gene encoding α-actinin-3 (ACTN3) and the risk of musculoskeletal injuries. The purpose of this study was to analyze the association of rs1815739 with risk of, and recovery time from non-contact soft-tissue muscle injuries in professional soccer players. Forty-six (22 male and 24 female) players from a top-level professional soccer team were assessed during five consecutive seasons: the genotype distribution was: RR, 41.3%; RX, 47.8%; and XX, 10.9%. There was a trend towards a higher risk of muscle injury associated with the XX genotype (p = 0.092, with no injury-free XX player during the 5-year study period) and a significant genotype effect for the time needed to return to play (p = 0.044, with the highest value shown for the XX genotype, i.e., 36 ± 26 days, vs. 20 ± 10 and 17 ± 12 days for RR and RX, respectively). In conclusion, the XX genotype might be associated not only with a higher risk of non-contact muscle injuries, but also of recovery time from these conditions. However, more research in larger cohorts is needed to confirm this preliminary hypothesis.

Association of the British Athletic Muscle Injury Classification and anatomic location with return to full training and reinjury following hamstring injury in elite football

Background

The relationship between hamstring muscle injuries (HMIs) that involve the intramuscular tendon and prolonged recovery time and increased reinjury rate remains unclear in elite footballers.

Objective

To determine the association of time to return to full training (TRFT) and reinjury of HMIs using the British Athletic Muscle Injury Classification (BAMIC) and specific anatomical injury location in elite-level football players.

Methods

The electronic medical records of all players at an English Premier League club were reviewed over eight consecutive seasons. All players who sustained an acute HMI were included. Two experienced musculoskeletal radiologists independently graded each muscle using the BAMIC, categorised each injury location area (proximal vs middle vs distal third and proximal vs distal tendon) and reported second muscle involvement. TRFT and reinjury were recorded.

Results

Out of 61 HMIs, the intramuscular tendon (BAMIC ‘c’) was involved in 13 (21.3%). HMI involving the intramuscular tendon (‘c’) had a mean rank TRFT of 36 days compared with 24 days without involvement (p=0.013). There were 10 (16.4%) reinjuries with a significant difference of 38.5% reinjury rate in the group with intramuscular tendon injury (‘c’) and 12.5% in the group without (p=0.031). TRFT and reinjury involving a second muscle was statistically significantly higher than without. Most of the HMIs to the biceps femoris with reinjury (5 out of 9) were in the distal third section related to the distal tendon site involving both the long and short head.

Conclusion

TRFT in HMI involving the intramuscular tendon (‘c’) of the Biceps femoris is significantly longer with significantly higher reinjury rate compared with injuries without, in elite football players. The finding that most reinjures of the biceps femoris occurring in the distal third muscle at the distal tendon site, involving both the long and short head, merits further investigation.

Is Pre-season Eccentric Strength Testing During the Nordic Hamstring Exercise Associated with Future Hamstring Strain Injury? A Systematic Review and Meta-analysis

BACKGROUND

Interventions utilising the Nordic hamstring exercise (NHE) have resulted in reductions in the incidence of hamstring strain injury (HSI). Subsequently, quantifying eccentric knee flexor strength during performance of the NHE to identify an association with the occurrence of future HSI has become increasingly common; however, the data to date are equivocal.

OBJECTIVE

To systematically review the association between pre-season eccentric knee flexor strength quantified during performance of the NHE and the occurrence of future HSI.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

CINAHL, Cochrane Library, Medline Complete, Embase, Web of Science and SPORTDiscus databases were searched from January 2013 to January 10, 2020.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Prospective cohort studies which assessed the association between pre-season eccentric knee flexor strength quantified during performance of the NHE and the occurrence of future HSI.

METHODS

Following database search, article retrieval and title and abstract screening, articles were assessed for eligibility against pre-defined criteria then assessed for risk of bias. Meta-analysis was used to pool data across studies, with meta-regression utilised where possible.

RESULTS

A total of six articles were included in the meta-analysis, encompassing 1100 participants. Comparison of eccentric knee flexor strength during performance of the NHE in 156 injured participants and the 944 uninjured participants revealed no significant differences, regardless of whether strength was expressed as absolute (N), relative to body mass (N kg^-1) or between-limb asymmetry (%). Meta-regression analysis revealed that the observed effect sizes were generally not moderated by age, mass, height, strength, or sport played.

CONCLUSION

Eccentric knee flexor strength quantified during performance of the NHE during pre-season provides limited information about the occurrence of a future HSI.

Tears of Biceps Femoris, Semimembranosus, And Semitendinosus are Not Equal-A New Individual Muscle-Tendon Concept in Athletes

Objectives:

Hamstring injuries are common and can now be accurately diagnosed. In addition, novel surgical indications have been introduced. However, evidence-based guidelines on the hamstring injuries in management of top-level athletes are missing.

Methods:

The management methods and outcomes of treatment are classically based on relatively small case series. We discuss a novel concept based on the fact that each tendon of the hamstrings muscle should be managed in an individual fashion. Furthermore, suitable indications for hamstring surgery in athletes are introduced.

Results:

The present study introduces modern treatment principles for hamstring injury management. Typical clinical and imagining findings as well as surgical treatment are presented based on a critical review of the available literature and personal experience.

Conclusions:

Hamstring injuries should not be considered to be all equal given the complexity of this anatomical region: The three separate tendons are different, and this impacts greatly on the decision-making process and outcomes in athletes.

Intra and inter-tester reliability of a novel device to assess gluteal muscle strength in professional football players

The aim of this study is to investigate inter-tester and intra-tester reliability of a novel clam test (CLAMT) for the measurement of gluteal muscle strength and to detect possible differences between CLAMT values in football players with and without a history of groin injuries. Twenty male football players participated in the test-retest and sixty-two male professional football players participated in the case-control study. Hip abductor maximal muscle strength was evaluated either using CLAMT or in a supine position with the hip in a neutral pose. For CLAMT, intraclass correlation coefficient (ICC) for inter-tester-intra-day reliability was 0.80 (95% CI: 0.60-0.90), with a standard error of measurement of 34.2 N. The intra-tester-intra-day ICC was 0.92 (95% CI: 0.87-0.95), with a standard error of measurement of 23.6 N. The inter-week ICC was 0.96 (95% CI: 0.92-0.98), with a standard error of measurement of 18.9 N. CLAMT showed lower (but not significant) strength values in football players with a history of groin injuries to non-injured players. CLAMT showed good to excellent levels of reliability, intraday and inter-week, with low standard errors of measurement while it was effective (possible) to identify residual weakness in players with previous groin injuries.

Recurrent and Subsequent Injuries in Professional and Elite Sport: a Systematic Review

BACKGROUND

Injury surveillance in professional sport categorises injuries as either "new" or "recurrent". In an attempt to make categorisation more specific, subsequent injury categorisation models have been developed, but it is not known how often these models are used. The aim was to assess how recurrent and subsequent injuries are reported within professional and elite sport.

METHODS

Online databases were searched using a search strategy. Studies needed to prospectively report injury rates within professional or elite sports that have published consensus statements for injury surveillance.

RESULTS

A total of 1322 titles and abstract were identified and screened. One hundred and ninety-nine studies were screened at full text resulting in 81 eligible studies. Thirty studies did not report recurrent injuries and were excluded from data extraction. Within the studies that reported recurrent injuries, 21 reported the number and percentage; 13 reported only the proportion within all injuries; three reported only the number; five reported the number, percentage and incidence; and two only reported the incidence. Seven studies used subsequent injury terminology, with three reporting subsequent injury following concussion, one using an amended subsequent injury model and three using specific subsequent injury categorisation models. The majority of subsequent injuries (ranging from 51 to 80%) were categorised as different and unrelated to the index injury. The proportion of recurrent injuries (exact same body area and nature related to index injury) ranged from 5 to 21%.

CONCLUSIONS

Reporting recurrent or subsequent injuries remains inconsistent, and few studies have utilised subsequent injury models. There is limited understanding of subsequent injury risk, which may affect the development of injury prevention strategies.

TRIAL REGISTRATION

CRD42019119264.

Ultrasound-Guided Percutaneous Needle Electrolysis and Rehab and Reconditioning Program for Rectus Femoris Muscle Injuries: A Cohort Study with Professional Soccer Players and a 20-Week Follow-Up

Rectus femoris muscle strains are one of the most common injuries occurring in sports such as soccer. The purpose of this study was to describe the safety and feasibility of a combination of percutaneous needle electrolysis (PNE) and a specific rehab and reconditioning program (RRP) following an injury to the rectus femoris in professional soccer players. Thirteen professional soccer players received PNE treatment 48 h after a grade II rectus femoris muscle injury, followed by a the RRP 24 h later. Assessment of recovery from injury was done by registering the days taken to return to train (RTT), return to play (RTP), and structural and functional progress of the injured muscle was registered through ultrasound imaging and match-GPS parameters. Also, adverse events and reinjuries were recorded in the follow up period of twenty weeks. The RTT registered was 15.62 ± 1.80 days and RTP was 20.15 ± 2.79 days. After fourteen days, the ultrasound image showed optimal repair. Match-GPS parameters were similar before and after injury. There were no relapses nor were any serious adverse effects reported during the 20-week follow-up after the RTP. A combination of PNE and a specific RRP facilitated a faster RTP in previously injured professional soccer players enabling them to sustain performance and avoid reinjuries.

Effects of muscular injuries on the technical and physical performance of professional soccer players

Introduction: The aim of this study was to determine the effects of muscular injuries in the lower limbs on the technical and physical performance of professional soccer players when they return to the league competition. Methods: Seventy-six muscular injuries incurred by Spanish male professional soccer players (Age: 27.5 ± 3.5 years) were analyzed during two consecutive competitive seasons: 2014-2015 and 2015-2016. The players' performance was studied during Spanish First Division competitive matches using a multi-camera computerized tracking system (Mediacoach Desktop). Results: After muscular injury relative total distance covered in sprints decreased by 8.6 ± 30.2% (P = 0.013) in the first half and 7.7 ± 36.6% (P = 0.038) in the second half. Similarly, maximal running speed decreased by 2.78 ± 6.91 km.h^-1 (pre: 27.3 ± 6.4 km.h^-1vs. post: 24.5 ± 6.6 km.h^-1, P = 0.013) in the first half, and 1.50 ± 5.68 km.h^-1 (29.1 ± 3.9 km.h^-1vs. 27.6 ± 5.3 km.h^-1, P = 0.043) in the second half. Muscle injury also affected technical performance significantly decreasing successful passes (P = 0.045). There were no differences in the number of possession gains (P = 0.277), and possession losses (P = 0.178). Conclusions: After a moderate or severe muscular injury (causing >8 days lay off), player performance is significantly lower in high-intensity efforts and technical skills such as sprints, maximal running speed, or successful passes.

Effect of Nordic Hamstring Exercise Training on Knee Flexors Eccentric Strength and Fascicle Length: A Systematic Review and Meta-Analysis

CONTEXT

Nordic hamstring exercise (NHE) has been widely employed to prevent hamstring strain injuries. However, it is still not clear which adaptations are responsible for the NHE preventive effects.

OBJECTIVES

The aim of this study was to investigate the effects of NHE on knee flexors eccentric strength and fascicle length.

EVIDENCE ACQUISITION

The search strategy included MEDLINE, PEDro, and Cochrane CENTRAL from inception to April 2020. Randomized clinical trials that have analyzed the effects of NHE training on hamstring eccentric strength and/or fascicle length were included.

EVIDENCE SYNTHESIS

From the 1932 studies identified, 12 were included in the systematic review, and 9 studies presented suitable data for the meta-analysis. All studies demonstrated strength increments in response to NHE training (10%-15% and 16%-26% in tests performed on the isokinetic dynamometer and on the NHE device, respectively), as well as significant enhancement of biceps femoris long head fascicle length (12%-22%). Meta-analysis showed NHE training was effective to increase knee flexors eccentric strength assessed with both isokinetic tests (0.68; 95% confidence interval, 0.29 to 1.06) and NHE tests (1.11; 95% confidence interval, 0.62 to 1.61). NHE training was also effective to increase fascicle length (0.97; 95% confidence interval, 0.46 to 1.48).

CONCLUSIONS

NHE training has the potential of increasing both knee flexors eccentric strength and biceps femoris long head fascicle length.

Inertial flywheel knee- and hip-dominant hamstring strength exercises in professional soccer players: Muscle use and velocity-based (mechanical) eccentric overload

The primary aim of the present study was to analyze mechanical responses during inertial knee- and hip-dominant hamstring strengthening exercises (flywheel leg-curl and hip-extension in conic-pulley), and the secondary aim was to measure and compare regional muscle use using functional magnetic resonance imaging. Mean power, peak power, mean velocity, peak velocity and time in the concentric (CON) and eccentric (ECC) phases were measured. The transverse relaxation time (T2) shift from pre- to post-exercise were calculated for the biceps femoris long (BFl) and short (BFs) heads, semitendinosus (ST) and semimembranosus (SM) muscles at proximal, middle and distal areas of the muscle length. Peak and mean power in flywheel leg-curl were higher during the CON than the ECC phase (p<0.01). ECC peak power was higher than CON phase (p<0.01) in conic-pulley hip-extension exercise, while mean power was higher during the CON than ECC phase (p<0.01). Flywheel leg-curl showed a higher T2 values in ST and BFs and BFl (p<0.05), while the conic-pulley hip-extension had a higher T2 values in the proximal region of the ST and BFl (p<0.05). In conclusion, ECC overload was only observed in peak power during the conic-pulley hip-extension exercise. Flywheel leg-curl involved a greater overall use of the 4 muscle bellies, more specifically in the ST and BFs, with a selective augmented activity (compared with the conic-pulley) in the 3 regions of the BFs, while conic-pulley hip-extension exercise selectively targeted the proximal and medial regions of the BFl. Physiotherapists and strength and conditioning coaches should consider this when optimizing the training and recovery process for hamstring muscles, especially after injury.

Clinimetric properties of the one-leg sit-to-stand test in examining unilateral lower limb muscle strength among young adults

BACKGROUND

One-leg sit-to-stand (one-leg STS) test is a new clinical test developed to measure the unilateral lower limb (LE) muscle strength among young adults. This study examined the test-retest reliability and the criterion-concurrent validity of the one-leg STS.

METHODS

Forty young adults (mean age ± SD, 28.07 ± 5.39 years) participated in the study. The one-leg STS test was administered in two separate assessment sessions to examine test-retest reliability. Two-leg STS test was administered and the performance time was measured. The concentric peak strength of hip flexors/extensors, knee flexors/extensors and ankle dorsi-flexors/plantar-flexors were determined using an isokinetic dynamometer. An intraclass correlation coefficient (ICC) was used to examine the test-retest reliability of one-leg STS test. The criterion validity of the one-leg STS test was evaluated against the performance of the two-leg STS test using an independent sample t test. The concurrent validity of the one-leg STS test was evaluated by investigating the relationships between STS performance time and LE muscle strength using Pearson correlation coefficients.

RESULTS

 The reliability analysis showed that one-leg STS performance time had excellent test-retest reliability (ICC_3,1  = 0.960, P < .001). Also, the one-leg STS performance time was not different between the first and second sessions, t (39) = 0.672, P = .506. The performance time of the one-leg STS test was significantly greater than the two-leg STS test (t (39) = 20.63, P < .001). The performance time of the one-leg STS test significantly correlated with the concentric peak strength of all LE muscles (P < .05).

CONCLUSIONS

The one-leg STS test demonstrated excellent reliability and criterion-concurrent validity against the two-leg STS and the LE muscle strength. The one-leg STS test was simple to administer and could be beneficial for the assessment of unilateral LE muscle strength of young adults in clinical settings.

Evaluation of Muscle Injuries in Professional Football Players: Does Coach Replacement Affect the Injury Rate?

OBJECTIVES

To assess the incidence and characteristics of muscle injuries in professional football players and to assess if coach dismissal may be related with muscle injuries within 1-month period from the dismissal.

DESIGN

Prospective cohort study during 3 consecutive seasons.

SETTING

Turkish Super League football teams.

PARTICIPANTS

One hundred eighteen male football players.

MAIN OUTCOME MEASURES

Data on time-loss muscle injuries confirmed using magnetic resonance imaging were recorded, including type, body part, duration, and lay-off time, and training session and match exposure times. The muscle injury rate was evaluated at 2 weeks and 30 days after coach dismissal.

RESULTS

In total, 124 muscle injuries were recorded, with injury incidences of 2.3 muscle injuries per 1000 hours of exposure overall, 1.2 in training sessions, and 13.6 in matches. Injury time loss ranged from 3 to 67 days (median, 13 days). Eighteen percent of the injuries (n = 23) were recurrent; no association was found between recurrence rate and the player's age or position (P = 0.15, P = 0.27, respectively). Recurrent injuries caused more severe injuries (26.1%, P = 0.02) and longer median lay-off time (P = 0.01). During the study, teams A and B replaced 7 and 3 coaches, respectively. The injury incidence increased to 5.3 per 1000 hours of exposure in the 2 weeks after the coach dismissal, and decreased to 4.5 within 1 month of coach dismissal.

CONCLUSION

Given the link between coach dismissal and increased rates of muscle strain injuries, increased attentiveness to preventing muscle injuries during coaching transitions and to the impact of new training regimens is required by trainers and medical teams.

Exposure to radial extracorporeal shockwaves induces muscle regeneration after muscle injury in a surgical rat model

The leading cause of training interruption in sport is a muscle injury, for which the standard treatment is nonsteroidal anti-inflammatory drugs (NSAIDs). To find alternative treatments, we investigated whether the radial extracorporeal shockwave application (rESWT) could stimulate muscle regeneration. A lesion with complete rupture (grade III muscle tear) was set in the musculus rectus femoris of 12-week-old Wistar rats, and the NSAID diclofenac, rESWT, or a combined therapy were applied on day 0, 3, and 5 directly following the surgery. Rats were euthanized at 2, 4, and 7 days after surgery and the area of muscle lesion was excised for histological and gene expression analysis to determine the progress in the healing of damaged fibers and tissue regeneration. The best effect on muscle regeneration was observed in the group treated with rESWT alone. Monotherapy by diclofenac showed a smaller but still positive effect and lowest effects were detected when both therapies were applied. rESWT alone demonstrated a significant upregulation of the muscle markers MyoD and myosin. The presence of myosin gene expression indicated newly formed muscle fibers, which was confirmed by hematoxylin and eosin staining. Seven days after injury the amount of mononucleated cell decreased and regenerating fibers could be detected. This effect is most pronounced in the group treated with rESWT alone. In our study, shockwaves demonstrated the best effect on muscle regeneration. Therefore, we recommend prospective clinical studies to analyze the effect of rESWT after sports trauma to improve muscle regeneration and to shorten the rehabilitation.

THE USE OF THERMOGRAPHY AND ITS CONTROL VARIABLES: A SYSTEMATIC REVIEW

ABSTRACT Introduction: Muscle injuries are the most frequent cause of physical disability in sports, representing a large percentage of all sports injuries. In high-performance sports in particular, there is great interest in optimizing the process of diagnosis and rehabilitation of muscle injuries in order to reduce the amount of time taken off by athletes due to their injuries. Infrared thermography, or cutaneous thermometry, is a technique used for complementary investigation of pain. It provides thermal imaging with an infrared camera, to measure the surface temperature of the body. Objective: To conduct a systematic review of the use of thermography as a functional evaluation for the identification and prevention of muscle injuries, and of the control variables used in its applicability. Methods: A systematic review was conducted in the MEDLINE, ResearchGate and Scielo databases, using the search terms: “thermography”, “muscle injury”, “rehabilitation” and “diagnosis”, searching on articles published from 2000 to 2017, in Portuguese, English and Spanish. The eligibility criteria for the studies was the use of thermography as an outcome, and the reporting of standards for evaluating skin temperature variation in athletes. Results: Following the systematic review, 94 studies were retrieved. Of these, only 12 met the criteria for inclusion in the study. Conclusion: Thermography is a suitable tool for the evaluation and prevention of muscle injuries in athletes, and care should be taken with the control variables during its use. The most efficient variables for capturing the thermographic image appear to be an environment with a temperature of between 18 and 25°C, for 15 minutes for acclimatization, and with the individual placed in a pre-determined position, depending on the body segment being evaluated, without contact with another object. Level of evidence I; Systematic review.

Effects of low-level laser therapy on hamstring strain injury rehabilitation: A randomized controlled trial

OBJECTIVES

To evaluate the effects of low-level laser therapy (LLLT) on functional rehabilitation following hamstring strain injury (HSI) in amateur athletes treated with an exercise-based rehabilitation program.

DESIGN

Randomized controlled trial.

METHODS

Male athletes (18-40 years old) who sustained HSI were randomized in LLLT or placebo groups. All patients were engaged in the same exercise-based rehabilitation program until they met specific criteria to return to sport. Hamstring muscles were treated with LLLT or placebo immediately after each rehabilitation session. The primary outcome was time-to-return to sport. Secondary outcomes were the number of rehabilitation sessions, hamstring flexibility, hamstring strength, and re-injury rate.

RESULTS

Twenty-four athletes began rehabilitation, and 22 (11 per group) completed the study schedule. Participants of LLLT and placebo groups had similar age, body size, injury characteristics, and baseline levels of hamstring flexibility and strength. The two groups increased flexibility and strength similarly throughout the rehabilitation program. Time-to-return to sport was the same for athletes treated with LLLT (23 ± 9 days) and placebo (24 ± 13 days). There were no re-injuries within 6 months after return to sport.

CONCLUSION

LLLT, as used in this study, did not optimize functional rehabilitation following HSI in amateur athletes treated with an exercise-based rehabilitation program.

Calf muscle strain injuries in elite Australian Football players: A descriptive epidemiological evaluation

BACKGROUND

Calf muscle strain injuries (CMSI) show consistent rates of prevalence and re-injury in elite Australian Football players. An epidemiological evaluation is warranted to better understand the clinical presentation and recovery of CMSI.

PURPOSE

First, to describe the epidemiology of CMSI in elite Australian Football players. Second, to determine if recovery following injury is different according to: (a) injury type (index vs re-injury); (b) muscle injured (soleus vs gastrocnemius); and (c) mechanism of injury (running-related activity vs non running-related activity).

STUDY DESIGN

Descriptive epidemiological.

METHODS

Data retrieved from the Soft Tissue injury Registry of the Australian Football League were analyzed. Sixteen clubs submitted data on CMSI from 2014 to 2017. Data included: player characteristics, training and match history at the time of injury, MRI, and the time to reach recovery milestones.

RESULTS

One hundred and eighty-four CMSI were included (149 index injuries; 35 re-injuries). Soleus injuries were most prevalent (84.6%). Soleus injuries took 25.4 ± 16.2 days to return to play, whereas gastrocnemius injuries took 19.1 ± 14.1 days (P = .097). CMSI sustained during running-related activities took approximately 12 days longer to recover than injuries sustained during non running-related activities (P = .001). Compared to index injuries, re-injuries involved older players (P = .03) and significantly more time was taken to run at >90% of maximum speed, return to full training, and return to play (P ≤ .001). Almost all of the observed re-injuries involved soleus (91.4%).

CONCLUSION

Soleus injuries are more prevalent than gastrocnemius injuries in elite Australian Football players. Prognosis appears to be influenced by clinical factors, with CMSI sustained during running-related activities and re-injuries needing more time to recover.

Healing Process of Gastrocnemius Muscle Injury on Ultrasonography Using B-Mode Imaging, Power Doppler Imaging, and Shear Wave Elastography

OBJECTIVES

Muscle injury often occurs in sports activity. To avoid reinjury, it is important to determine the appropriate period until return to play after injury. The purpose of this study was to evaluate characteristics of the healing process for gastrocnemius muscle injury by B-mode imaging, power Doppler (PD) imaging, and shear wave elastography (SWE).

METHODS

Twenty patients with acute calf musculotendinous injury were enrolled. Scar thickness on B-mode imaging, new vessels according to PD grades, and SWE values in the muscle, musculotendinous junction, and tendon of the medial head of gastrocnemius were measured at 4, 8, and 12 weeks after injury.

RESULTS

Scar thickness was significantly larger at 8 and 12 weeks compared with 4 weeks (P < .01 for both). Power Doppler grades at 4 and 8 weeks were significantly higher compared with 12 weeks (P < .01 for both). Shear wave elastographic values in the muscle on the injury side were significantly higher at 8 and 12 weeks compared with 4 weeks (P < .01 for both), whereas those in the musculotendinous junction on the injury side were significantly higher at 12 weeks compared with 4 and 8 weeks (P < .01; P = .01, respectively).

CONCLUSIONS

B-mode imaging, PD imaging, and SWE can measure the healing process after musculotendinous injury of the gastrocnemius medial head.

Italian consensus statement (2020) on return to play after lower limb muscle injury in football (soccer)

Return to play (RTP) decisions in football are currently based on expert opinion. No consensus guideline has been published to demonstrate an evidence-based decision-making process in football (soccer). Our aim was to provide a framework for evidence-based decision-making in RTP following lower limb muscle injuries sustained in football. A 1-day consensus meeting was held in Milan, on 31 August 2018, involving 66 national and international experts from various academic backgrounds. A narrative review of the current evidence for RTP decision-making in football was provided to delegates. Assembled experts came to a consensus on the best practice for managing RTP following lower limb muscle injuries via the Delphi process. Consensus was reached on (1) the definitions of 'return to training' and 'return to play' in football. We agreed on 'return to training' and RTP in football, the appropriate use of clinical and imaging assessments, and laboratory and field tests for return to training following lower limb muscle injury, and identified objective criteria for RTP based on global positioning system technology. Level of evidence IV, grade of recommendation D.

Hip-related groin pain, patient characteristics and patient-reported outcomes in patients referred to tertiary care due to longstanding hip and groin pain: a cross-sectional study

BACKGROUND

Due to advances in hip arthroscopy, the number of surgical procedures has increased dramatically. The diagnostic challenge in patients with longstanding hip and groin pain, as well as the increasing number of hip arthroscopies, may lead to a higher number of patients referred to tertiary care for consideration for surgery. Therefore, the aims were: 1) to describe the prevalence of hip-related groin pain in patients referred to tertiary care due to longstanding hip and groin pain; and 2) to compare patient characteristics and patient-reported outcomes for patients categorized as having hip-related groin pain and those with non-hip-related groin pain.

METHODS

Eighty-one patients referred to the Department of Orthopedics at Skåne University Hospital for longstanding hip and groin pain were consecutively included and categorized into hip-related groin pain or non-hip-related groin pain using diagnostic criteria based on current best evidence (clinical examination, radiological examination and intra-articular block injection). Patient characteristics (gender (%), age (years), BMI (kg/m²)), results from the Hip Sports Activity Scale (HSAS), the SF-36, the Copenhagen Hip and Groin Outcome Score (HAGOS), and pain distribution (pain manikin) were collected. Parametric and non-parametric statistics were used as appropriate for between-group analysis.

RESULTS

Thirty-three (47%) patients, (30% women, 70% men, p < 0.01), were categorized as having hip-related groin pain. The hip-related groin pain group had a higher activity level during adolescence (p = 0.013), and a higher pre-injury activity level (p = 0.034), compared to the non-hip-related groin pain group. No differences (mean difference (95% CI)) between hip-related groin pain and non-hip-related groin pain were observed for age (0 (- 4; 4)), BMI (- 1.75 (- 3.61; 0.12)), any HAGOS subscales (p ≥ 0.318), any SF-36 subscales (p ≥ 0.142) or pain distribution (p ≥ 0.201).

CONCLUSIONS

Only half of the patients referred to tertiary care for long-standing hip and groin pain, who were predominantly men with a high activity level, had hip-related groin pain. Self-reported pain localization and distribution did not differ between patients with hip-related groin pain and those with non-hip-related groin pain, and both patient groups had poor perceived general health, and hip-related symptoms and function.

Proximal hamstring tendon avulsion treatment choice depends on a combination of clinical and imaging-related factors: a worldwide survey on current clinical practice and decision-making

Objectives

To evaluate current practice in the treatment of proximal hamstring tendon avulsions and identify decision-making preferences.

Methods

An invitation to an anonymous e-survey containing 32 questions was sent to 3475 members of the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS) and the European College of Sports and Exercise Physicians (ECOSEP).

Results

We received 403 (12%) unique responses with a completion rate of 79%. Participants were orthopaedic/trauma surgeons (90%), sports medicine physicians (7%) or physical therapists (2%). For 83% of the participants, the preferred treatment (ie, surgical or non-operative) depends on the individual case. Participants base their decision-making process on patient- and injury-related factors (decision modifiers). The five most frequently selected decision modifiers that support the choice for surgical treatment were diminished function (84%), neurological symptoms (74%), involved tendons (82%), tendon retraction on MRI (84%) and patient preference for surgery (78%). The majority prefer early surgical repair (<2 weeks after injury) to achieve highest functional outcome (63%) and ensure a low complication risk (61%). Suture anchors are used by 93% of the participants for tendon reattachment. Estimated recovery duration (ie, time to return to sports) was a median 12 weeks (IQR: 12–20) for non-operative treatment and 17 weeks (IQR: 12–24) for surgical treatment. Estimated reinjury risk was a median 25% (IQR: 10–31.5) and 10% (IQR: 5–20), respectively.

Conclusion

This survey among experienced medical professionals has summarised current practice and identified treatment decision-making preferences. The typical surgical patient has a retracted (>2 cm) two-tendon avulsion (ie, common tendon and semimembranosus tendon), is unable to engage in sports or activities of daily life, reports sciatic symptoms and prefers surgical treatment. Surgery is thought to prolong recovery and decrease reinjury risk compared with non-operative treatment and is preferably performed early.

Level of evidence

Level V.