Jump to:

Disease/ Disorder

Definition

Hamstring injuries are common injuries in the athletic population and prone to re-occur. Acute mid-hamstring strains and tears of the myotendinous junction are often seen in explosive sporting events. Overuse injury causing proximal hamstring tendinopathy is seen in athletes, including runners.

Etiology

Mid-hamstring strains and proximal hamstring tears are most commonly seen in athletes who require explosive force, such as with sprinting. These hamstring injuries tend to occur at terminal swing phase, during which the hamstrings are long in length while actively contracting 1. Biceps femoris long head is the most commonly affected hamstring muscle with this mechanism of injury 2. In the general population, hamstring injuries are more commonly ischial tuberosity avulsions as opposed to tears of the muscle belly; these injuries occur primarily in older females and the skeletally immature and tend to occur with excessive lengthening involving combined hip flexion and knee extension 3,4. Chronic proximal hamstring tendinopathy is typically seen in the setting of incomplete healing or altered biomechanics such as inflexibility or weakness.

Epidemiology including risk factors and primary prevention

  • Accounts for 12-29% of all injuries in athletes depending on the sport 5,6
  • Predominately affects the middle-aged population 7
  • No gender predominance – generally males are younger athletes while females athletes are older and endure injuries during everyday activities7,8
  • Acute injuries are usually during competition time, while chronic presentations are likely to arise during training season 9,10
  • Risk factors:
    • Prior hamstring injury – 22-34% reinjury rate 5,6  
    • Neuromuscular fatigue 11-13
    • Reduced flexibility
    • Muscle strength imbalance
    • Poor core stability
    • Poor lumbar posture 14
    • Anterior pelvic tilt
      • Slightly increases tension and length of hamstring tendons from ischial tuberosity to distal attachment 15
    • Leg length inequality
    • Overuse
  • Primary prevention:
    • Education for students and coaches
    • Pre-participation flexibility screening
    • Incorporate proper flexibility training and adequate warm up into an athletic program.16,17
    • Eccentric hamstring strength training, particularly the Nordic Curl hamstrings exercise 18-20
    • Training lumbopelvic hip stability 21
    • Primary prevention strategies focus on providing guidance for gradual activity progression, since symptoms often result from a sudden increase in either intensity or duration of training.
  • Secondary prevention:
    • Allow for adequate healing/rest from the initial injury to prevent an immediate recurrence.
    • Fifty-nine percent of repeat hamstring injuries will occur within the first month of return to play (RTP). Isometric strength tends to return to level of the uninjured leg by about 20 days post-injury, while flexibility returns within about 50 days post-injury. Notably, dynamic strength deficits persist even after RTP 22
    • Increase hamstring flexibility with a graded stretching program 16
    • Eccentric strengthening exercise program may be initiated for tendinopathy and for secondary prevention of hamstring injuries[H1] . 23,24
    • Gradual activity progression, including strengthening, range of motion, and flexibility.

Patho-anatomy/physiology

  • The hamstrings are comprised of three muscles in the posterior thigh:
    • Semitendinosus – originates on the ischial tuberosity and inserts at the pes anserinus
    • Semimembranosus – originates on the ischial tuberosity and inserts at the posterior medial tibia
    • Biceps femoris – Long head originates on the ischial tuberosity and inserts on the head of the fibula; short head originates at the posterolateral femur from the linea aspera.
    • Least common tendon to be injured is the semimembranosus 25
  • Innervation:
    • Semimembranosus, semitendinosus, and long head of the biceps femoris – tibial branch of the sciatic nerve (L5-S2)
    • Short head of the biceps femoris – peroneal branch of the sciatic nerve (L5-S2)24  
  • The hamstrings have a higher proportion of type II muscle fibers compared with other muscles of the lower extremities. This suggests the muscle can generate high intrinsic tension forces. 26  
  • Hamstring function during running 24 
    • At end of forward swing phase: Decelerates knee extension
    • At foot strike: Eccentric hip extension
    • At take-off: Hip extension and knee flexion
  • Mechanism of injury: Stretch-type and Sprint-type 27
    • Stretch-type: Occurs during substantial hip flexion and knee extension maneuvers (i.e. dancing)
      • Commonly affecting the proximal free tendon portion of the semimembranosus 4,28
    • Sprint-type: Usually during eccentric loading during hip flexion and knee extension typically seen in maximal running 29
      • Commonly affecting the long head of the bicep femoris 2,30
      • Key points of hamstring injury typically occur in the late swing and early stance 27
      • Muscle fatigue may promote “Groucho” running pattern27, that along with anterior pelvic tilt, can place the bicep femoris muscle in a vulnerable state for injury 31-33
  • Acute hamstring tears or high-grade strains may involve the sciatic nerve due to compression or inflammation.  Chronic injuries may be associated with fibrosis and scarring.
  • Chronic tendinopathy is characterized by fibrosis with proximal attachment hyaline degeneration in some cases.34  

Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)

  • Acuity:
    • Acute: <6 weeks of symptoms
    • Chronic: >6 weeks of symptoms
  • Muscle Tear Classification 35:
    • Grade I (mild):
      • No appreciable tissue disruption. Minimal or no loss of function or strength (<5%).
    • Grade II (moderate):
      • Tissue damage that reduces strength and function of musculotendinous unit.
    • Grade III (severe):
      • Complete loss of musculotendinous unit, with rupture of muscle and complete loss of function.

Specific secondary or associated conditions and complications

  • Proximal avulsions are typically seen in the pediatric population such as a “hurdler’s fracture” or in water skiers 5,36
  • Progression of a chronic tendinopathy to a tendon rupture is rare but can occur.
  • Associated conditions can include a gait abnormality, leading to dysfunction along the kinetic chain affecting the low back, sacroiliac joint, hip, knee, and ankle joints.
  • Sciatic nerve can become entrapped due to fibrosis and scarring (~5% co-incidence) , particularly in acute tears. This can cause radiating symptoms down the leg with associated pain, weakness, and numbness 7.

Essentials of Assessment

History

  • Acute: Sudden onset of pain or pulling sensation in the posterior gluteal region or thigh (with or without a popping sound or sensation) during strenuous activity. High-grade strain or tear may be associated with ecchymosis. There is typically discomfort with activity such as running and kicking as well as with bending at the hips. Pain is often worse with sitting.
  • Subacute/Chronic: Gradual onset of deep buttock pain, which may be vaguely localized. Can be associated with posterior thigh pain. Often worse with sitting.

Physical examination

  • Assess lumbar spine, hips, and bilateral lower extremities.
  • Assess gait for stiff-leg gait pattern 37
  • Inspection: Ecchymosis at site of injury. Assess pelvic tilt/obliquity.
  • Palpation: Tenderness to palpation, palpable defect. Examine muscle belly with knee flexed to 90 degrees.
  • Range of motion: Reduced flexibility of hamstrings, may be pain-limited. Can assess hamstring flexibility with popliteal angle measurement. Guarding may be seen with hip flexion
  • Neurovascular assessment: Test knee flexion and hip extension strength in prone position. Seated slump test and straight leg raise may be positive.
  • Special tests for chronic proximal hamstring tendinopathy:
    • Puranen-Orava test (Sensitivity 76%, Specificity 82%)- This test consists of the patient actively stretching the hamstring in standing position with the heel of the affected side resting on a support so that the hip is flexed to 90 degrees. Pain at the proximal hamstring indicates a positive test (38).
    • Bent-knee stretch test (Sensitivity 82%, Specificity 87%) (38)- This test is performed in supine. The examiner passively flexes and hip and knee fully and then slowly extends the knee. Pain with passive knee extension in this position is positive for proximal hamstring tightness (24).
    • Modified Bent-knee stretch test (Sensitivity 89%, Specificity 91%)- This test is performed similarly to the bent-knee stretch test except that the examiner extends the knee more rapidly (38).
    • One-legged supine plank test- This test is performed with the patient in supine position, propped on bilateral forearms and heels. The patient then raises the heel of their unaffected leg off the table. Inability to hold proper positioning due to pain or weakness is indicative of a proximal hamstring injury (24).

Functional assessment

A sports-specific assessment may be helpful, including run gait analysis, cycling position, etc. Running assessments such as a treadmill analysis, with video evaluation of proper running technique assessing the entire kinetic chain to include the upper body, spine, pelvis, thigh, leg, and foot, can be helpful. These evaluations can assess for and be helpful in correcting functional deficits. Full pain-free range of motion (ROM) should be achieved before beginning a strengthening program.

Imaging

  • AP pelvis X-ray: Assess for bony avulsion or bony changes of ischial tuberosity such as enthesophytes or cortical irregularity.
  • Magnetic resonance imaging (MRI): Consider for suspicion of partial or complete tear as well as surgical planning in refractory cases. May see bony edema, muscular tears/avulsions, and peritendinous edema, as well as concomitant lesions in the area.
  • Musculoskeletal ultrasound: Longitudinal and transverse images with high-resolution imaging allow for the dynamic assessment of a tendon tear, muscular edema, or peritendinous edema.
    • In comparison with MRI, ultrasound has been found to have similar sensitivity for identifying acute hamstring injuries 39

Supplemental assessment tools

  • Differential diagnosis 24
    • Lumbar spine discogenic pain or radiculopathy
    • Sacroiliac joint-mediated pain
    • Sacroiliitis associated with spondyloarthropathy
    • Facet-mediated pain
    • Ischial bursitis
    • Apophysitis/bony avulsion – particularly in pediatric population
    • Pelvic stress fracture
    • Pelvic floor pain
    • Piriformis syndrome
    • Obturator internus or gemelli tear
    • Gluteal muscle pain
    • Chronic posterior thigh compartment syndrome
    • Visceral causes, including gastrointestinal and rectal pain
    • Sciatic or posterior femoral cutaneous nerve entrapment

Early predictions of outcomes

Size and extent of hamstring injury can be utilized to some degree to predict RTP. MRI can be used to grade the injury. In a study of professional athletes, RTP occurred at just over two weeks with grade 1 injuries, just over three weeks with grade 2 injuries, and over ten weeks with grade 3 injuries 40.. There is moderate evidence that MRI can predict return to play; lesions closer to the ischial insertion tend to require a longer time to RTP, and patients without hyperintensity on fluid-sensitive sequences tend to have shorter time to RTP 41.

Environmental

Equipment used in sports may play a role. For example, cyclists may benefit from adjustments to the bicycle to off-load the hamstring. Runners may benefit from running gait analysis and appropriate shoe and orthotic insert fitting.

Social role and social support system

Hamstring injuries can be extremely frustrating. The length of recovery and rehabilitation varies widely as in the case of post-operative hamstring repair which can take up to nine months to return to play 29 . This can lead to prolonged absences from athletics. There is often pressure on athletes from coaches, fans and teammates to return to sport prematurely, which can lead to reinjury or a worsening of the original injury.

Professional Issues

Hamstring injuries can also be frustrating to treat from the medical provider’s standpoint as well. Pressures can be present from the injured athlete as well as the coaching staff to return the athlete to play quickly. Unfortunately, there is often risk of reinjury or worsening of the original injury without adequate rehabilitation.

Rehabilitation Management and Treatments

Available or current treatment guidelines

Non-operative Management:

Hamstring strain rehabilitation can be broken into three phases (acute management, strengthening, and return to competition)  6,29

  • Phase I: Focus on protecting the area and start a rehabilitation program
    • Start ROM activities, isometric contractions, and isotonic contractions
  • Phase II: Strengthening the area and prepare the area for sport activity and training
    • Progressing isometric/isotonic exercises and adding linear running, plyometrics, change of direction movements, and sport-specific drills
  • Phase III: Return to competition
    • Prior to progressing to this phase, the athlete must be pain-free with near-to-normal strength
    • Build on phase II exercises and a graded return to play
  • Medications:
    • Non-steroidal anti-inflammatory drugs (NSAIDs) – indicated in the acute setting but not for chronic tendinopathy 37,42
  • Physical therapy 24,43
    • Soft tissue mobilizations to break up adhesions/scar tissue
      • Manual therapy should be applied away from the area of injury during phase I and progressed to the site of injury during phase II and III 29
    • Progressive stretching and muscle energy techniques to improve flexibility
    • Address pelvic tilt, core strength, and neuromuscular control
    • Neuromuscular inhibition may impair rehabilitation and lead to subsequent maladaptation of hamstring44Neural glides, if indicated
    • Progressive (mainly eccentric, particularly swing-phase specific 45) hamstring strengthening exercise program
      • Single/double leg bridge
      • Single/double leg ball curls
      • Single/double leg squats
      • Eccentric single leg squats
      • Eccentric single leg windmill squats – incorporating transverse plane movements
      • Core strengthening exercises
      • Nordic hamstring strengthening – shown to decrease incidence and severity of hamstring injuries in rugby players 46. This exercise preferentially recruits semitendinosis 47.
      • Hip extension exercise tends to activate lateral hamstrings more while knee-flexion exercise tends to recruit more medial hamstrings. 47
      • One study found that athletes whose rehabilitation program including more agility and trunk stabilization had faster RTP and lower reinjury rates (7.7% compared to 70%) when compared to a program focused more on strengthening and flexibility. 48
  • Injections:
    • Controversial and generally unproven
  • Other:
    • May consider orthotics

Surgical Management

  • Compose of either open primary repair, endoscopic primary repair, or augmentation/reconstruction 5
  • Usually indicated for complete, proximal avulsion fractures or partial avulsions in at least 2 tendons with greater than 2 cm retraction 37  May consider for recalcitrant pain after failure of conservative treatments 49 

Open surgical repair has a complication rate of 23.17% with acute repairs having better functional outcomes

At different disease stages

New onset/acute

  • Control of inflammation/pain and protections of the area (Stage I)
    • POLICE (Protection, optimal loading, ice, compression, elevation)29
    • NSAIDs
    • Physical therapy
      • Focusing on soft tissue treatments, flexibility, neural glides

Subacute

  • Progression of physical therapy regimen to include strengthening, which begins with open chain exercises with a progression to more advanced closed chain exercises, followed by a progressive eccentric strengthening program.
    • Specific focus on eccentric component.
  • Secondary prevention with flexibility and adequate warm-up and gradual return to sport.

Chronic

  • No benefit of NSAIDs at this stage
  • Progression of physical therapy regimen to include strengthening, which begins with open chain exercises with a progression to more advanced closed chain exercises, followed by a progressive eccentric strengthening program.
    • Specific focus on eccentric component.
  • Secondary prevention with flexibility and adequate warm-up, continued eccentric exercise, and gradual return to sport.
  • Surgical management for recalcitrant pain can be considered.

Coordination of care

A multi-disciplinary team approach of treatment professionals is helpful to optimize outcomes. In addition to the physiatrist, physical therapists provide a key role for the recovery of these injuries. Other providers involved may include an athletic trainer, orthotist, sports psychologist, and orthopedic surgeon.

Patient & family education

It is important to have communication between the patient/athlete as well as the coach and parents in order to maximize rehabilitation and activity modification to enhance return to sport.

Emerging/unique Interventions

  • Early incorporation of rehabilitation may provider earlier recovery for an athlete’s return to play 51.
  •  A gradual return to activity depends on multiple factors, including the severity of the injury along with the chronicity of the injury.
    • Maintain aerobic fitness early in treatment with swimming and/or upper body ergometer.
    • Incorporate lower body aerobic activities such as pool running, cycling or elliptical machine when normal pain-free range of motion has been restored.
    • Progress gradually with return of sport/running program.
  • Most athletes make a full recovery, although caution remains due to the risk of recurrence.

Translation into practice: practice “pearls”/performance improvement in practice (PIPs)/changes in clinical practice behaviors and skills

  • Acute hamstring injuries are usually self-limiting and generally respond to proper rest and a progressive rehabilitation protocol with good success and return to sport.
  • Chronic hamstring injuries / tendinopathies require a careful examination to assess for other differential diagnoses and usually a more prolonged rehabilitation protocol.
  • As with most tendon injuries, surgery should be reserved for only those who have truly failed a comprehensive and complete conservative management program, including a progressive eccentric exercise program. The exceptions to this may include an avulsion fracture or complete rupture of tendon with greater than 2 cm of retraction, as described above 37.

Cutting Edge/ Emerging and Unique Concepts and Practice

Cutting edge concepts and practice

Surface electromyography (EMG) has been used to assess maladaptive hamstring activation 52.

Previous studies have incorporated functional MRI (fMRI) to assess metabolic activity during an athletic task through the transient increase of relaxation time of tissue water in T2 imaging 30,47,53-57.

Sciatic nerve hydrodissection may be an alternative method of decompressing the sciatic nerve in cases of scarring.

Gaps in the Evidence- Based Knowledge

Possible other treatments which are controversial or unproven include the following:

  • Injections:
    • Corticosteroid injection (CSI) for an acute tendinitis – peritendinous – avoid injecting into the tendon with needle guidance 58. 
      • In a study evaluating the efficacy of CSI, it was shown to provide pain relief at 1 month in up to 50% of patients 58
    • Percutaneus needle tenotomy in chronic recalcitrant cases 59,60  
    • Platelet-rich plasma (PRP), dextrose, autologous blood – function as irritants or proinflammatory agents to induce a healing response in chronic injuries
    • Sclerosing polidocanol of the neo-vessels 61
    • Aprotinin 62
  • Other:
    • Dry needling 63
    • Topical nitroglycerin 64
    • Iontophoresis
    • Phonophoresis
    • Therapeutic ultrasound
    • Low-level laser therapy
    • Extracorporeal shock wave therapy 65
    • Kinesiotape
    • Controversies are typically those surrounding injection therapy: Safety profile of corticosteroid injections in weight-bearing tendons is cause for concern, although data suggests that it is beneficial. 66 Few studies have evaluated PRP therapies specifically for hamstring tendon injuries; studies that do exist have shown mixed results 67.
      • A recent systematic review provided only non-statistically significant evidence for PRP injections with or without physical therapy reducing time to return to play or re-injury rate when compared to physical therapy alone or no treatment 68.
  • Numerous studies are investigating newer tendinopathy treatments, but most are not looking at the treatment of tendinopathy with regard specifically to the hamstring.

References

  1. Chumanov ES, Heiderscheit BC, Thelen DG. Hamstring musculotendon dynamics during stance and swing phases of high-speed running. Med Sci Sports Exerc 2011; 43(3): 525-32.
  2. Askling CM, Tengvar M, Saartok T, Thorstensson A. Acute first-time hamstring strains during high-speed running: a longitudinal study including clinical and magnetic resonance imaging findings. Am J Sports Med 2007; 35(2): 197-206.
  3. Kuske B, Hamilton DF, Pattle SB, Simpson AH. Patterns of Hamstring Muscle Tears in the General Population: A Systematic Review. PLoS One 2016; 11(5): e0152855.
  4. Askling CM, Tengvar M, Saartok T, Thorstensson A. Acute first-time hamstring strains during slow-speed stretching: clinical, magnetic resonance imaging, and recovery characteristics. Am J Sports Med 2007; 35(10): 1716-24.
  5. Fletcher AN, Cheah JW, Nho SJ, Mather RC, 3rd. Proximal Hamstring Injuries. Clin Sports Med 2021; 40(2): 339-61.
  6. Schmitt B, Tim T, McHugh M. Hamstring injury rehabilitation and prevention of reinjury using lengthened state eccentric training: a new concept. Int J Sports Phys Ther 2012; 7(3): 333-41.
  7. Irger M, Willinger L, Lacheta L, Pogorzelski J, Imhoff AB, Feucht MJ. Proximal hamstring tendon avulsion injuries occur predominately in middle-aged patients with distinct gender differences: epidemiologic analysis of 263 surgically treated cases. Knee Surg Sports Traumatol Arthrosc 2020; 28(4): 1221-9.
  8. Edouard P, Branco P, Alonso JM. Muscle injury is the principal injury type and hamstring muscle injury is the first injury diagnosis during top-level international athletics championships between 2007 and 2015. Br J Sports Med 2016; 50(10): 619-30.
  9. Waldén M, Hägglund M, Ekstrand J. UEFA Champions League study: a prospective study of injuries in professional football during the 2001–2002 season. British Journal of Sports Medicine 2005; 39(8): 542-6.
  10. Jones A, Jones G, Greig N, et al. Epidemiology of injury in English Professional Football players: A cohort study. Phys Ther Sport 2019; 35: 18-22.
  11. Timmins RG, Opar DA, Williams MD, Schache AG, Dear NM, Shield AJ. Reduced biceps femoris myoelectrical activity influences eccentric knee flexor weakness after repeat sprint running. Scandinavian Journal of Medicine & Science in Sports 2014; 24(4): e299-e305.
  12. Marshall PW, Lovell R, Jeppesen GK, Andersen K, Siegler JC. Hamstring muscle fatigue and central motor output during a simulated soccer match. PLoS One 2014; 9(7): e102753.
  13. Opar DA, Williams MD, Shield AJ. Hamstring Strain Injuries. Sports Medicine 2012; 42(3): 209-26.
  14. Hennessey L, Watson AW. Flexibility and posture assessment in relation to hamstring injury. British Journal of Sports Medicine 1993; 27(4): 243-6.
  15. Worrell TW. Factors associated with hamstring injuries. An approach to treatment and preventative measures. Sports Med 1994; 17(5): 338-45.
  16. Petersen J, Hölmich P. Evidence based prevention of hamstring injuries in sport. Br J Sports Med 2005; 39(6): 319-23.
  17. Hartig DE, Henderson JM. Increasing hamstring flexibility decreases lower extremity overuse injuries in military basic trainees. Am J Sports Med 1999; 27(2): 173-6.
  18. Goode AP, Reiman MP, Harris L, et al. Eccentric training for prevention of hamstring injuries may depend on intervention compliance: a systematic review and meta-analysis. British Journal of Sports Medicine 2015; 49(6): 349-56.
  19. Petersen J, Thorborg K, Nielsen MB, Budtz-Jørgensen E, Hölmich P. Preventive Effect of Eccentric Training on Acute Hamstring Injuries in Men’s Soccer: A Cluster-Randomized Controlled Trial. The American Journal of Sports Medicine 2011; 39(11): 2296-303.
  20. Tyler TF, Schmitt BM, Nicholas SJ, McHugh MP. Rehabilitation After Hamstring-Strain Injury Emphasizing Eccentric Strengthening at Long Muscle Lengths: Results of Long-Term Follow-Up. Journal of Sport Rehabilitation 2017; 26(2): 131.
  21. Buckthorpe M, Wright S, Bruce-Low S, et al. Recommendations for hamstring injury prevention in elite football: translating research into practice. British Journal of Sports Medicine 2019; 53(7): 449-56.
  22. Maniar N, Shield AJ, Williams MD, Timmins RG, Opar DA. Hamstring strength and flexibility after hamstring strain injury: a systematic review and meta-analysis. Br J Sports Med 2016; 50(15): 909-20.
  23. Gambetta V, Benton D. A systematic approach to hamstring prevention and rehabilitation. Sports Coach 2006; 28(4): 1-6.
  24. Fredericson M, Moore W, Guillet M, Beaulieu C. High hamstring tendinopathy in runners: meeting the challenges of diagnosis, treatment, and rehabilitation. Phys Sportsmed 2005; 33(5): 32-43.
  25. De Smet AA, Blankenbaker DG, Alsheik NH, Lindstrom MJ. MRI Appearance of the Proximal Hamstring Tendons in Patients With and Without Symptomatic Proximal Hamstring Tendinopathy. American Journal of Roentgenology 2012; 198(2): 418-22.
  26. Garrett WE, Jr., Califf JC, Bassett FH, 3rd. Histochemical correlates of hamstring injuries. Am J Sports Med 1984; 12(2): 98-103.
  27. Huygaerts S, Cos F, Cohen DD, et al. Mechanisms of Hamstring Strain Injury: Interactions between Fatigue, Muscle Activation and Function. Sports (Basel) 2020; 8(5).
  28. Askling C, Saartok T, Thorstensson A. Type of acute hamstring strain affects flexibility, strength, and time to return to pre-injury level. Br J Sports Med 2006; 40(1): 40-4.
  29. Hammond KE, Kneer L, Cicinelli P. Rehabilitation of Soft Tissue Injuries of the Hip and Pelvis. Clin Sports Med 2021; 40(2): 409-28.
  30. Koulouris G, Connell D. Evaluation of the hamstring muscle complex following acute injury. Skeletal Radiol 2003; 32(10): 582-9.
  31. Schuermans J, Danneels L, Van Tiggelen D, Palmans T, Witvrouw E. Proximal Neuromuscular Control Protects Against Hamstring Injuries in Male Soccer Players: A Prospective Study With Electromyography Time-Series Analysis During Maximal Sprinting. The American Journal of Sports Medicine 2017; 45(6): 1315-25.
  32. Schuermans J, Van Tiggelen D, Danneels L, Witvrouw E. Susceptibility to Hamstring Injuries in Soccer: A Prospective Study Using Muscle Functional Magnetic Resonance Imaging. Am J Sports Med 2016; 44(5): 1276-85.
  33. Schuermans J, Van Tiggelen D, Palmans T, Danneels L, Witvrouw E. Deviating running kinematics and hamstring injury susceptibility in male soccer players: Cause or consequence? Gait Posture 2017; 57: 270-7.
  34. Puranen J, Orava S. The hamstring syndrome. A new diagnosis of gluteal sciatic pain. Am J Sports Med 1988; 16(5): 517-21.
  35. Rachun A. Standard nomenclature of athletic injuries: American Medical Association; 1966.
  36. Sallay PI, Friedman RL, Coogan PG, Garrett WE. Hamstring muscle injuries among water skiers. Functional outcome and prevention. Am J Sports Med 1996; 24(2): 130-6.
  37. Cohen S, Bradley J. Acute Proximal Hamstring Rupture. JAAOS – Journal of the American Academy of Orthopaedic Surgeons 2007; 15(6): 350-5.
  38. Cacchio A, Borra F, Severini G, et al. Reliability and validity of three pain provocation tests used for the diagnosis of chronic proximal hamstring tendinopathy. Br J Sports Med 2012; 46(12): 883-7.
  39. Connell DA, Schneider-Kolsky ME, Hoving JL, et al. Longitudinal study comparing sonographic and MRI assessments of acute and healing hamstring injuries. AJR Am J Roentgenol 2004; 183(4): 975-84.
  40. Ekstrand J, Healy JC, Waldén M, Lee JC, English B, Hägglund M. Hamstring muscle injuries in professional football: the correlation of MRI findings with return to play. British Journal of Sports Medicine 2012; 46(2): 112-7.
  41. Reurink G, Brilman EG, de Vos RJ, et al. Magnetic resonance imaging in acute hamstring injury: can we provide a return to play prognosis? Sports Med 2015; 45(1): 133-46.
  42. Arner JW, McClincy MP, Bradley JP. Hamstring Injuries in Athletes: Evidence-based Treatment. J Am Acad Orthop Surg 2019; 27(23): 868-77.
  43. Heiderscheit BC, Sherry MA, Silder A, Chumanov ES, Thelen DG. Hamstring strain injuries: recommendations for diagnosis, rehabilitation, and injury prevention. The Journal of orthopaedic and sports physical therapy 2010; 40(2): 67-81.
  44. Fyfe JJ, Opar DA, Williams MD, Shield AJ. The role of neuromuscular inhibition in hamstring strain injury recurrence. J Electromyogr Kinesiol 2013; 23(3): 523-30.
  45. Guex KJ, Lugrin V, Borloz S, Millet GP. Influence on Strength and Flexibility of a Swing Phase-Specific Hamstring Eccentric Program in Sprinters’ General Preparation. J Strength Cond Res 2016; 30(2): 525-32.
  46. Brooks JH, Fuller CW, Kemp SP, Reddin DB. Incidence, risk, and prevention of hamstring muscle injuries in professional rugby union. Am J Sports Med 2006; 34(8): 1297-306.
  47. Bourne MN, Williams MD, Opar DA, Al Najjar A, Kerr GK, Shield AJ. Impact of exercise selection on hamstring muscle activation. Br J Sports Med 2017; 51(13): 1021-8.
  48. Sherry MA, Best TM. A comparison of 2 rehabilitation programs in the treatment of acute hamstring strains. J Orthop Sports Phys Ther 2004; 34(3): 116-25.
  49. Lempainen L, Sarimo J, Mattila K, Vaittinen S, Orava S. Proximal hamstring tendinopathy: results of surgical management and histopathologic findings. Am J Sports Med 2009; 37(4): 727-34.
  50. Bodendorfer BM, Curley AJ, Kotler JA, et al. Outcomes After Operative and Nonoperative Treatment of Proximal Hamstring Avulsions: A Systematic Review and Meta-analysis. Am J Sports Med 2018; 46(11): 2798-808.
  51. Bayer ML, Magnusson SP, Kjaer M. Early versus Delayed Rehabilitation after Acute Muscle Injury. New England Journal of Medicine 2017; 377(13): 1300-1.
  52. Bourne MN, Timmins RG, Opar DA, et al. An Evidence-Based Framework for Strengthening Exercises to Prevent Hamstring Injury. Sports Med 2018; 48(2): 251-67.
  53. Ono T, Okuwaki T, Fukubayashi T. Differences in activation patterns of knee flexor muscles during concentric and eccentric exercises. Res Sports Med 2010; 18(3): 188-98.
  54. Ono T, Higashihara A, Fukubayashi T. Hamstring functions during hip-extension exercise assessed with electromyography and magnetic resonance imaging. Res Sports Med 2011; 19(1): 42-52.
  55. Mendiguchia J, Arcos AL, Garrues MA, Myer GD, Yanci J, Idoate F. The use of MRI to evaluate posterior thigh muscle activity and damage during nordic hamstring exercise. J Strength Cond Res 2013; 27(12): 3426-35.
  56. Mendiguchia J, Garrues MA, Cronin JB, et al. Nonuniform changes in MRI measurements of the thigh muscles after two hamstring strengthening exercises. J Strength Cond Res 2013; 27(3): 574-81.
  57. Bourne MN, Opar DA, Williams MD, Al Najjar A, Shield AJ. Muscle activation patterns in the Nordic hamstring exercise: Impact of prior strain injury. Scand J Med Sci Sports 2016; 26(6): 666-74.
  58. Zissen MH, Wallace G, Stevens KJ, Fredericson M, Beaulieu CF. High hamstring tendinopathy: MRI and ultrasound imaging and therapeutic efficacy of percutaneous corticosteroid injection. AJR Am J Roentgenol 2010; 195(4): 993-8.
  59. Housner JA, Jacobson JA, Misko R. Sonographically guided percutaneous needle tenotomy for the treatment of chronic tendinosis. J Ultrasound Med 2009; 28(9): 1187-92.
  60. Kirschner J, Cheng J, Hurwitz N, et al. Ultrasound-guided percutaneous needle tenotomy (PNT) alone vs. PNT plus platelet-rich plasma injection for the treatment of chronic tendinosis: a randomized controlled trial. PM R 2021.
  61. Alfredson H, Lorentzon R. Sclerosing polidocanol injections of small vessels to treat the chronic painful tendon. Cardiovasc Hematol Agents Med Chem 2007; 5(2): 97-100.
  62. Orchard J, Massey A, Brown R, Cardon-Dunbar A, Hofmann J. Successful management of tendinopathy with injections of the MMP-inhibitor aprotinin. Clin Orthop Relat Res 2008; 466(7): 1625-32.
  63. Jayaseelan DJ, Moats N, Ricardo CR. Rehabilitation of Proximal Hamstring Tendinopathy Utilizing Eccentric Training, Lumbopelvic Stabilization, and Trigger Point Dry Needling: 2 Case Reports. Journal of Orthopaedic & Sports Physical Therapy 2014; 44(3): 198-205.
  64. Gambito ED, Gonzalez-Suarez CB, Oquiñena TI, Agbayani RB. Evidence on the effectiveness of topical nitroglycerin in the treatment of tendinopathies: a systematic review and meta-analysis. Arch Phys Med Rehabil 2010; 91(8): 1291-305.
  65. Cacchio A, Rompe JD, Furia JP, Susi P, Santilli V, De Paulis F. Shockwave Therapy for the Treatment of Chronic Proximal Hamstring Tendinopathy in Professional Athletes. The American Journal of Sports Medicine 2010; 39(1): 146-53.
  66. Levine WN, Bergfeld JA, Tessendorf W, Moorman CT, 3rd. Intramuscular corticosteroid injection for hamstring injuries. A 13-year experience in the National Football League. Am J Sports Med 2000; 28(3): 297-300.
  67. Chu SK, Rho ME. Hamstring Injuries in the Athlete: Diagnosis, Treatment, and Return to Play. Curr Sports Med Rep 2016; 15(3): 184-90.
  68. Seow D, Shimozono Y, Tengku Yusof TNB, Yasui Y, Massey A, Kennedy JG. Platelet-Rich Plasma Injection for the Treatment of Hamstring Injuries: A Systematic Review and Meta-analysis With Best-Worst Case Analysis. Am J Sports Med 2021; 49(2): 529-37.

Original Version of the Topic

John E. Tobey, MD. Proximal and mid-hamstring strain/tendon tear. 1/9/2013.

Previous Revision(s) of the Topic

Daniel C. Herman, MD, Justin Weppner DO, and Sara Raiser MD. Proximal and mid-hamstring strain/tendon tear. 4/28/2017

Author Disclosures

Sara Raiser, MD
Nothing to Disclose

Daniel C. Herman, MD PhD
Nothing to Disclose

Justin Weppner, DO
Nothing to Disclose

Giorgio Negron, MD
Nothing to Disclose