Hamstring injuries. Proposed aetiological factors, prevention, and treatment

Injuries to the hamstring muscles can be devastating to the athlete because these injuries frequently heal slowly and have a tendency to recur. It is thought that many of the recurrent injuries to the hamstring musculotendinous unit are the result of inadequate rehabilitation following the initial injury. The severity of hamstring injuries is usually of first or second degree, but occasionally third-degree injuries (complete rupture of the musculotendinous unit) do occur. Most hamstring strain injuries occur while running or sprinting. Several aetiological factors have been proposed as being related to injury of the hamstring musculotendinous unit. They include: poor flexibility, inadequate muscle strength and/or endurance, dyssynergic muscle contraction during running, insufficient warm-up and stretching prior to exercise, awkward running style, and a return to activity before complete rehabilitation following injury. Treatment for hamstring injuries includes rest and immobilisation immediately following injury and then a gradually increasing programme of mobilisation, strengthening, and activity. Permission to return to athletic competition should be withheld until full rehabilitation has been achieved (complete return of muscle strength, endurance, and flexibility in addition to a return of co-ordination and athletic agility). Failure to achieve full rehabilitation will only predispose the athlete to recurrent injury. The best treatment for hamstring injuries is prevention, which should include training to maintain and/or improve strength, flexibility, endurance, co-ordination, and agility.     

Return to sport and beyond following intramuscular tendon hamstring injury: A case report of an English Premier League football player

BackgroundHamstring strain injuries are the most common type of injury in elite football and are associated with a high risk of reinjury, particularly those involving the intramuscular tendon (IMT). Limited information is available regarding the rehabilitation and return to sport (RTS) processes following such injuries. This case study describes the clinical presentation of an elite football player following IMT hamstring injury, their on- and off-pitch rehabilitation alongside performance monitoring throughout RTS and beyond.Case scenarioAn elite football player suffered a grade 2c hamstring injury during an English Premier League (EPL) match. The player underwent early post-injury management, alongside progressive off-pitch physical preparation. The ‘control-chaos continuum’ was used as a framework for on-pitch rehabilitation to prepare the player for a return to full team training and competition. Objective and subjective markers of the player's response to progressive on- and off-pitch loading were monitored throughout RTS and beyond.OutcomesThe player returned to on-pitch rehabilitation after 11 days, to full team training having achieved weekly pre-injury chronic running load outputs after 35 days and played in the EPL 40 days post-injury. The player did not suffer reinjury for the rest of the EPL season.ConclusionAn understanding the unique structural and mechanical properties of the IMT, alongside expected RTS timeframes are important to inform rehabilitation and decision-making processes post-injury. Performance and frequent load-response monitoring throughout RTS and beyond, in conjunction with practitioner experience and effective communication are critical in facilitating effective RTS and reduce risk of reinjury following IMT injury.     

Incidence, risk, and prevention of hamstring muscle injuries in professional rugby union

BACKGROUND: The incidence of hamstring muscle injuries in professional rugby union is high, but evidence-based information on risk factors and injury-prevention strategies in this sport is limited. PURPOSE: To define the incidence, severity, and risk factors associated with hamstring muscle injuries in professional rugby union and to determine whether the use of hamstring strengthening and stretching exercises reduces the incidence and severity of these injuries. STUDY DESIGN: Cohort study (prevention); Level of evidence, 3. METHODS: Team clinicians reported all hamstring muscle injuries on a weekly basis and provided details of the location, diagnosis, severity, and mechanism of each injury; loss of time from training and match play was used as the definition of an injury. Players' match and training exposures were recorded on a weekly basis. RESULTS: The incidence of hamstring muscle injuries was 0.27 per 1000 player training hours and 5.6 per 1000 player match hours. Injuries, on average, resulted in 17 days of lost time, with recurrent injuries (23%) significantly more severe (25 days lost) than new injuries (14 days lost). Second-row forwards sustained the fewest (2.4 injuries/1000 player hours) and the least severe (7 days lost) match injuries. Running activities accounted for 68% of hamstring muscle injuries, but injuries resulting from kicking were the most severe (36 days lost). Players undertaking Nordic hamstring exercises in addition to conventional stretching and strengthening exercises had lower incidences and severities of injury during training and competition. CONCLUSION: The Nordic hamstring strengthening exercise may reduce the incidence and severity of hamstring muscle injuries sustained during training and competition.     

Reconstruction of a chronic quadriceps tendon tear in a body builder

Chronic quadriceps tendon tears are uncommon. We report about a body builder taking a cocktail of anabolic drugs for several years in whom reconstruction of a chronic quadriceps tendon tear was performed using ipsilateral hamstring tendons with good results despite the 7 month delay between injury and surgery. The use of hamstring tendons is a good option for the management of these lesions.     

Hamstring strains and tears in the athlete

Hamstring injuries continue to be very common for both elite and amateur athletes. Given their high recurrence rate, the ability to treat these injuries effectively is critical to helping athletes return to their previous level of activity without putting them at risk for future injury. Most hamstring strains can be treated with initial pain control and a course of rehabilitation focused on a gradual return to activity. However, an exact, evidence-based rehabilitation protocol has yet to be studied. Although surgery is rare and reserved for complete hamstring ruptures, results show high patient satisfaction and ability to return to play.     

Deep posterior knee pain caused by a ganglion of the popliteus tendon — a case report

The most common causes of posterior and posterolateral knee pain (besides referred pain) are knee joint effusions, tendinitis of the hamstring tendons, Baker cyst (semimembranous cyst), bursitis, meniscal pathologies such as tears and ganglions and lesions of the anterior cruciate ligament. Less common causes include popliteus and gastrocnemius tendinitis, arthrofibrosis after trauma. posterior cruciate ligament sprains. deep venous thrombosis and/or irritations of the common peroneal nerve. We present one patient with posterolateral knee pain after a minor contusion. Magnetic resonance imaging revealed a degenerated posterfor horn of the lateral meniscus and a somewhat unclear polypoid structure in the intercondylar region. As the posterior component of the pain persisted even after an arthroscopic partial meniscectomy, an operative revision was performed. A small ganglion of the sheath of the popliteus tendon was found and excised. The patient was immediately relieved of his pain after this procedure. To our knowledge this is the first report concerning a ganglion of the sheath of the popliteus tendon causing posterior knee pain. A similar pathology of the popliteus tendon has been described earlier but at a different localisation (in the hiatus), simulating a parameniscal cyst.No benefits in any form have been received from a commercial party related directly or indirectly to the subject of this article. This work has been presented at the Annual Meeting of the Swiss Orthopedic Society in Geneva 1995 It won the second poster prize     

Risk Factors for Hamstring Injuries in Male Soccer Players: A Systematic Review of Prospective Studies

Hamstring injuries are common injuries in soccer players. In view of the high incidence and the serious consequences, identifying risk factors related to hamstring injuries is essential. The aim of this systematic review was therefore to identify risk factors for hamstring injuries in male adult soccer players. PubMed, Embase/Medline, Cumulative Index to Nursing and Allied Health Literature, and SPORTDiscus were systematically searched, and prospective studies investigating risk factors for hamstring injuries in adult male soccer players were included. The methodological quality of the included articles was assessed using a standardized set of predefined criteria. Seven of the 11 studies identified, involving a total of 1775 players and 344 hamstring injuries, met the inclusion criteria. All but one of the included studies met at least five of nine methodological criteria, causing them to be qualified as ‘high quality’. The included studies used univariate as well as multivariate analyses to identify risk factors for hamstring injury. The results from the multivariate analyses suggest that previous hamstring injury is most strongly related to hamstring injury. Conflicting evidence is found for age and hamstring length or flexibility as risk factors for the occurrence of hamstring injuries.     

Hamstring exercises for track and field athletes: injury and exercise biomechanics, and possible implications for exercise selection and primary prevention

Hamstring strain injuries are the most prevalent muscle injuries in track and field (TF). These injuries often cause prolonged symptoms and a high risk of re-injury. Strengthening of the hamstring muscles has been recommended for injury prevention. The authors review the possible role of eccentric training in TF hamstring injury prevention and introduce exercise classification criteria to guide clinicians in designing strengthening programmes adapted to TF. The principles exposed may serve as a foundation for future development and application of new eccentric programmes to decrease the high incidence of this type of injury in other sports.     

Evidence based prevention of hamstring injuries in sport

A common soft tissue injury in sports involving sprinting and jumping is the hamstring strain. A major problem with hamstring strains is the high incidence of reinjury. Muscle injuries can be classified as direct or indirect and are typically grouped into three categories according to severity. A number of potential risk factors have been proposed for hamstring strains. Only a few are evidence based and some are mainly based on theoretical assumptions. There is a lack of clinical research on the effectiveness of rehabilitation programmes for hamstring strains. Although the initial treatment of rest, ice, compression, and elevation is accepted for muscle strains, no consensus exists for their rehabilitation. Not much evidence based research has been carried out on prevention of hamstring strain. To our knowledge only two prospective studies have so far been published. As the injuries are common in football and other sports involving sprinting and jumping, there is a need for further research preferably in the form of randomised controlled trials.     

Avulsion of the common hamstring tendon origin in an active duty airman

Hamstring injuries are common in active athletic populations, such as military service members. Ruptures of the hamstring origin from the ischial tuberosity are rare injuries and missed if not considered in the differential diagnosis of ischial pain. Unlike other hamstring injuries, complete hamstring avulsions must be treated surgically. Results of untreated hamstring avulsions are poor. The purpose of this article is to describe the case of an active duty airman who presented for an unrelated complaint and was discovered to have a 5-week-old hamstring avulsion. Surgical repair of the hamstring avulsion 6 weeks after injury yielded an excellent result and return to full duty. Hamstring avulsions recognized early by history and physical examination and diagnostic imaging permits early and effective treatment. Early surgical repair of the tendon to bone can result in return to full duty.     

Imaging in the diagnosis, prognostication, and management of lower limb muscle injury

Muscle injuries of the lower extremity are extremely common among athletes leading to significant morbidity and time out from competition. Furthermore, increasing athletic activity in the general population has resulted in lower limb muscle injuries becoming commonplace. It is therefore vital for the musculoskeletal radiologist to be familiar with the imaging findings of lower limb muscle injuries and to be aware of the role of imaging in the prognostication and management of these injuries. The most commonly injured lower limb muscles are the quadriceps, the hamstring complex, and the gastrocnemius muscles. This article reviews the biomechanical and imaging features of common acute muscle injuries of the lower extremity and evaluates the role of imaging in the prognosis of these sport injuries.     

Histochemical correlates of hamstring injuries

This study reports the histochemical fiber type composition of the human hamstring muscles. Muscle specimens from necropsy specimens were obtained from seven locations in the hamstring, four locations in the quadriceps, and one location in the adductor magnus. The hamstring muscles are shown to have a relatively high proportion of Type II fibers. Type II fibers are more involved with exercise of higher intensity and force production and it is postulated that the hamstrings are capable of high intrinsic force production. The hamstrings are two-joint muscles and are, therefore, subject to increased stretch and force production extrinsically by motion at the hip and knee. It is proposed that high levels of tension in the hamstrings produced by intrinsic force production and extrinsic stretch may make them prone to injury in periods of intense muscular activity. This proposal is also relevant to other frequent athletic muscle injuries.     

Randomized prospective study of ACL reconstruction with interference screw fixation in patellar tendon autografts versus femoral metal plate suspension and tibial post fixation in hamstring tendon autografts: 5-year clinical and radiological follow-up results

Patellar tendon graft has been the most frequently used material in anterior cruciate ligament (ACL) reconstruction, but the hamstring tendons have been increasingly used as well; however, which graft is to be preferred is not adequately supported by existing clinical studies. In this prospective randomized clinical trial, the study hypothesis was that the hamstring tendons are equally good graft material as the patellar tendon in ACL reconstruction. Ninety-nine patients with laxity due to a torn ACL underwent arthroscopically assisted reconstruction with graft randomization according to their birth year to either patellar tendon with metal interference screw fixation or double looped semitendinosus and gracilis tendons with fixation similar to the Endobutton technique using a titanium metal plate suspension proximally and screw-washer postdistally. Excluding preoperative Lysholm knee score, there were no significant differences between the two groups in the preoperative and operative data. A standard rehabilitation regimen was used for all the patients, including immediate postoperative mobilization without a knee brace, protected weight bearing for 2 weeks, and return to full activity at 6–12 months postoperatively. Forty patients in the patellar tendon group and 39 patients in the hamstring tendon group were available for clinical evaluation at median 5 years after surgery (ranges 3 years 11 months–6 years 7 months). The results revealed no statistically significant differences with respect to clinical and instrumented laxity testing, isokinetic muscle torque measurements, International Knee Documentation Committee ratings, Lysholm (knee score), Tegner (activity level) and Kujala patellofemoral knee scores. There was an enlargement of the drill tunnels, statistically more in the hamstring tendon group, but no increase from 2 to 5 years in either group. Narrowing of the joint spaces (IKDC measurement method) from 2 to 5 years postoperatively was seen in both the groups, however, without difference between the two groups.     

Treatment of proximal hamstring ruptures - a systematic review

Proximal hamstring ruptures are increasingly treated surgically, despite little high-level supporting evidence. We sought to determine whether there are differences in clinical outcome after surgical vs. non-surgical treatment of proximal hamstring tendinous avulsions/ruptures and acute vs. chronic surgical repair of tendinous avulsions. Multiple medical databases were searched for Level I-IV evidence. 18 studies were included. 298 subjects (300 proximal hamstring injuries) were analyzed with mean age of 39.7 years. 286 injuries were managed with surgical repair vs. 14 non-operative. 95 surgical cases were performed within 4 weeks of the injury (acute), while 191 were performed beyond 4 weeks (chronic). 292 injuries were tendinous avulsions while 8 were bony tuberosity avulsions. Surgical repair resulted in significantly (p < 0.05) better subjective outcomes, greater rate of return to pre-injury level of sport, and greater strength/endurance than non-surgical management. Similarly, acute surgical repair had significantly better patient satisfaction, subjective outcomes, pain relief, strength/endurance, and higher rate of return to pre-injury level of sport than chronic repair (p < 0.001) with reduced risk of complications and re-rupture (p < 0.05). Chronic surgical repair also improves outcomes, strength and endurance, and return-to-sport, but not as well as acute repair. Non-operative treatment results in reduced patient satisfaction, with significantly lower rates of return to pre-injury level of sport and reduced hamstring muscle strength.     

The prognostic value of the hamstring outcome score to predict the risk of hamstring injuries

ObjectivesHamstring injuries are common among soccer players. The hamstring outcome score (HaOS) might be useful to identify amateur players at risk of hamstring injury. Therefore the aims of this study were: To determine the association between the HaOS and prior and new hamstring injuries in amateur soccer players, and to determine the prognostic value of the HaOS for identifying players with or without previous hamstring injuries at risk of future injury.DesignCohort study.MethodsHaOS scores and information about previous injuries were collected at baseline and new injuries were prospectively registered during a cluster-randomized controlled trial involving 400 amateur soccer players. Analysis of variance and t-tests were used to determine the association between the HaOS and previous and new hamstring injury, respectively. Logistic regression analysis indicated the prognostic value of the HaOS for predicting new hamstring injuries.ResultsAnalysis of data of 356 players indicated that lower HaOS scores were associated with more previous hamstring injuries (F = 17.4; p = 0.000) and that players with lower HaOS scores sustained more new hamstring injuries (T = 3.59, df = 67.23, p = 0.001). With a conventional HaOS score cut-off of 80%, logistic regression models yielded a probability of hamstring injuries of 11%, 18%, and 28% for players with 0,1, or 2 hamstring injuries in the previous season, respectively.ConclusionsThe HaOS is associated with previous and future hamstring injury and might be a useful tool to provide players with insight into their risk of sustaining a new hamstring injury risk when used in combination with previous injuries.     

Prospective and randomized evaluation of ACL reconstruction with three techniques: a clinical and radiographic evaluation at 5 years follow-up

A variety of graft sources have been used for ACL reconstruction to improve functions and kinematics in ACL deficient knees. The two most commonly used autogenous grafts are the central third of the patellar tendon and the hamstring tendon constructs. The choice of different grafts and different construct influence the final clinical outcome of ACL reconstruction. The 3 groups, of 25 patients each, were generated by choosing the technique (PT tendon, 4 strand hamstring, and single hamstring plus extraarticular plasty) to utilize and followed for 5 years, with an alternate systematic sampling. Our comparison has shown significant kneeling pain in the patellar tendon with respect to the groups with hamstrings techniques. Single hamstring plus extraarticular plasty achieved subjective score significantly higher with respect to the other two groups as well as for the time to resume sport. The study confirms that patellar tendon and hamstring can be equivalent options for ACL reconstruction. This study demonstrated that a superior outcome as far as subjective clinical findings were concerned, was obtained in group III. Patients in the latter group were also able to return to sports sooner than those in the bone-patellar tendon graft group and the four-strand hamstring group.     

Practice patterns for the treatment of acute proximal hamstring ruptures

ABSTRACT

Objective: Proximal ischial hamstring avulsion injuries are relatively uncommon. As such, the management of these injuries is often highly variable. Consensus agreement is lacking for the indications for repair, along with the operative technique, and post-operative rehabilitation. The purpose of this study was to survey surgeons who treat proximal hamstring avulsion injuries to identify current trends in the management of this injury.

Methods: After IRB approval, a 46-question cross-sectional survey was distributed using a secure electronic survey portal. The survey sought to determine surgeon experience, diagnostic preferences, treatment patterns, surgical indications/technique, perceived patient outcomes, surgical complications, as well as post-operative management and rehab protocols. Surveys were completed electronically and anonymously, with invitations distributed to members of the American Orthopedic Society for Sports Medicine (AOSSM) and Arthroscopy Association of Canada (AAC).

Results: A total of 108 surgeons who manage proximal hamstring injuries completed the survey. Most respondents (77%) treat one to five of these injuries per year. MRI was the preferred imaging modality to confirm diagnosis. Despite 98% of respondents indicating that there was a role for surgical management of proximal hamstring avulsions, operative treatment was reportedly undertaken in only 50% of cases seen by each respondent. The top three reported surgical indications were: number of tendons involved (most important factor = 42%, second most = 26%, third most = 13%), amount of tendon retraction (28%, 41%, 16%), and patient activity level (16%, 18%, 24%).

Conclusion: Based on the practice patterns of the surgeons who completed the survey, there is continued disparity in the management of proximal hamstring avulsions. A lack of agreement exists with regards to surgical indications, operative technique, and post-operative protocols. Most striking is the rate of non-operative treatment and perceived rate of poor outcomes within this cohort. Future research should focus on objective evaluation of non-operative management, and additional variables involved in surgical treatment and post-operative rehabilitation.     

Comparison of anterior cruciate ligament reconstruction in male and female athletes using the patellar tendon and hamstring autografts

Despite the higher incidence of anterior cruciate ligament (ACL) injuries in female than in male athletes few authors have studied the effects of gender on the outcome of ACL reconstruction. This prospective study compared the results of ACL reconstruction using the patellar tendon and hamstring techniques in men and women. We prospectively followed 80 comparable athletes (46 males, 32 females) from a population of 287 patients operated on at our institution for ACL reconstruction using either patellar tendon or hamstring graft. There were 26 males and 14 females in the patellar tendon group, and 22 males and 18 females in the hamstring group. All patients were operated on by the same surgeon within 6 months from injury and underwent the same rehabilitation program at the same center. After an average of 36 months the patients were assessed by clinical evaluation, computerized knee laxity analysis, and isokinetic and functional strength tests; standard knee scores were also used. Among patellar tendon patients there were no significant differences between males and females regarding knee evaluation form, laxity, or isokinetic and functional tests. Females in the hamstring group had significantly greater laxity, and isokinetic tests at 1 year revealed a significantly higher deficit of peak torque at 60°/s in flexion and extension. We suggest further studies on the clinical significance of these findings particularly on their possible ramifications in the areas of return to sports and rehabilitation of female athletes     

Nerve Injuries in Athletes

In brief: Nerve injuries in athletes may be serious and may delay or prevent an athlete's return to his or her sport. Over a two-year period, the authors evaluated the condition of 65 patients who had entrapments of a nerve or nerve root, documented with electromyography. They describe four case histories: Two patients had radial nerve entrapments, one caused by baseball pitching and the other by kayaking; one football player had combined suprascapular neuropathy and upper trunk brachial plexopathy; and one patient had carpal tunnel syndrome of a median nerve secondary to rowing. Sports-related peripheral nerve lesions of the lower extremity were not seen during the study period. Based on a literature review, the nerve injuries discussed represent the spectrum of nerve entrapments likely to be seen in US clinics. The authors conclude that peripheral nerve lesions should be considered in the differential diagnosis of sports injuries, particularly at the shoulder, elbow, and wrist.     

Diagnostic and prognostic value of clinical findings in 83 athletes with posterior thigh injury: comparison of clinical findings with magnetic resonance imaging documentation of hamstring muscle strain

BACKGROUND: Little is known about the clinical features of posterior thigh injuries and their contribution to accurate diagnosis and prognostic assessment of hamstring muscle strain injury. HYPOTHESES: The clinical features of posterior thigh injury can be used to diagnose hamstring muscle strain and to predict duration of absence from competition. STUDY DESIGN: Prospective clinical study. METHODS: For two playing seasons, the clinical features of posterior thigh injury, timing of injury, and playing days lost were recorded for Australian Rules football players. Magnetic resonance imaging was used to confirm hamstring muscle injury. RESULTS: Posterior thigh injuries associated with pain and tenderness were recorded for 83 players, with magnetic resonance imaging confirming hamstring injury in 68 (82%). Most of the hamstring injuries were sudden onset (62; 91%) and occurred after a significant warm-up period (57; 84%). Of the patients whose injuries were sudden onset and occurred after the warm-up period (N = 59), 57 (97%) had hamstring muscle strain detected on magnetic resonance imaging. Hamstring muscle injury confirmed by magnetic resonance imaging was associated with a longer absence from competition (mean, 27 days) than injuries where no hamstring injury was detected (mean, 16 days). CONCLUSIONS: The clinical features of hamstring injury typically include sudden onset, pain, and tenderness, although exceptions do occur. Muscle fatigue may be important in the pathogenesis of hamstring injury.