Hamstring Tears: Diagnosis

Like with most musculoskeletal injuries, a patient history and physical exam performed by a qualified clinician can often lead to an accurate diagnosis for acute hamstring injuries.

A clinician may determine the severity of the hamstring tear (grade 1 to 3) according to pain and physical limitations, including weakness and loss of motion.¹Silder A, Heiderscheit B, Thelen D, Enright T, Tuite M. MR observations of long-term musculotendon remodeling following a hamstring strain injury. Skeletal Radiol 2008;37:1101-9.^,2Mason D, Dickens V, Vail A. Rehabilitation for hamstring injuries. Cochrane Database Syst Rev 2012;12:CD004575. These findings may help estimate when a patient can return to activity.¹Silder A, Heiderscheit B, Thelen D, Enright T, Tuite M. MR observations of long-term musculotendon remodeling following a hamstring strain injury. Skeletal Radiol 2008;37:1101-9.^,2Mason D, Dickens V, Vail A. Rehabilitation for hamstring injuries. Cochrane Database Syst Rev 2012;12:CD004575.

Hamstring tears can be graded by severity:

• Grade 1 is a strain of the muscle fibers
• Grade 2 is a partial tear of the muscle
• Grade 3 is a complete tear of the muscle

Grade 3 tears are the most severe and can take months to heal.

The diagnostic process will include a patient interview and physical exam and possibly medical imaging:

Patient interview. A clinician will ask the patient about how the injury happened, the pattern of pain, and how symptoms affect lifestyle and training.

Physical exam. The clinician will use the physical exam to determine the location and severity of the injury.

• A clinician conducting a physical exam may be able to use his or her hands to find where the injury is located; a hamstring tear will often cause a thickening and swelling of soft tissue. While palpation can often pinpoint the injury to either the muscle belly (myotendinous) or the high (proximal) hamstring, the precise location of injury may be difficult to determine without advanced imaging.³Connell D, Schneider-Kolsky M, Hoving J, et al. Longitudinal study comparing sonographic and MRI assessments of acute and healing hamstring injuries. AJR Am J Roentgenol 2004;183:975-84.^,4Slavotinek J, Verrall G, Fon G. Hamstring injury in athletes: using MR imaging measurements to compare extent of muscle injury with amount of time lost from competition. AJR Am J Roentgenol 2002;179:1621-8.^,5Silder A, Heiderscheit B, Thelen D, Enright T, Tuite M. MR observations of long-term musculotendon remodeling following a hamstring strain injury. Skeletal Radiol 2008;37:1101-9.^,6Linklater J, Hamilton B, Carmichael J, Orchard J, Wood D. Hamstring injuries: Anatomy, Imaging, and Intervention. Semin Musculoskelt Radiol 2010;14:131-61.
• The patient may be asked to perform various movements so the practitioner can evaluate strength and range of motion. For example, side-to-side asymmetry of motion, especially with hip flexion with the knee straight, is a common finding on physical examination.⁷Clanton T, Coupe K. Hamstring strains in athletes: diagnosis and treatment. J Am Acad Orthop Surg 1998;6:237-48. Resisted knee flexion is also often limited by pain and functional weakness.⁷Clanton T, Coupe K. Hamstring strains in athletes: diagnosis and treatment. J Am Acad Orthop Surg 1998;6:237-48. Typically testing will be performed on both sides so that a comparison to the uninjured leg can be made to help gauge the severity of the injury.
• Occasionally, the sciatic nerve, which runs down the back of the thigh, may become irritated or entrapped in healing scar tissue, causing sciatica-like symptoms down the leg.⁸Puranen J, Orava S. The hamstring syndrome--a new gluteal sciatica. Ann Chir Gynaecol 1991;80:212-4. In this case, the physician will conduct a thorough musculoskeletal and neurologic examination. This is why it is important to have a physician or qualified clinician perform a complete musculoskeletal and neurologic examination in the setting of hamstring strain.

Medical imaging. Medical imaging tests are not needed in all cases. However, if the injury is severe, the diagnosis is uncertain, or a precise location for the injury is needed, imaging tests can be advantageous.³Connell D, Schneider-Kolsky M, Hoving J, et al. Longitudinal study comparing sonographic and MRI assessments of acute and healing hamstring injuries. AJR Am J Roentgenol 2004;183:975-84.^,4Slavotinek J, Verrall G, Fon G. Hamstring injury in athletes: using MR imaging measurements to compare extent of muscle injury with amount of time lost from competition. AJR Am J Roentgenol 2002;179:1621-8.^,5Silder A, Heiderscheit B, Thelen D, Enright T, Tuite M. MR observations of long-term musculotendon remodeling following a hamstring strain injury. Skeletal Radiol 2008;37:1101-9.^,6Linklater J, Hamilton B, Carmichael J, Orchard J, Wood D. Hamstring injuries: Anatomy, Imaging, and Intervention. Semin Musculoskelt Radiol 2010;14:131-61. Furthermore, in cases where there is significant loss of function, it is important to determine the extent of injury to help guide treatment and possibly predict return to activity.⁹Rettig A, Meyers S, Kersey P, Ballard G, Oneacre K, Hunker P. Categorization of Hamstring Strain Injuries by MRI and PLaying Time Lost in Professional Football Players. NATA 2008:29-32.^,10Schneider-Kolsky M, Hoving J, Warren P, Connell D. A comparison between clinical assessment and magnetic resonance imaging of acute hamstring injuries. Am J Sports Med 2006;34:1008-15.

There are several available imaging techniques for both acute and chronic hamstring injuries.

• X-rays of the hip and knee are often normal (negative) in patients with hamstring injuries unless there is an avulsion of the ischial tuberosity or in pediatric patients, the growth plate. ⁷Clanton T, Coupe K. Hamstring strains in athletes: diagnosis and treatment. J Am Acad Orthop Surg 1998;6:237-48.^,11Caine D, Nassar L. Gymnastics injuries. Med Sport Sci 2005;48:18-58.^,12Ali K, Leland J. Hamstring strains and tears in the athlete. Clin Sports Med 2012;31:263-72.32. Orchard J. Biomechanics of muscle strain injury. N Z J Sports Med 2002;30:92-8.
• Advanced imaging with MRI or dynamic ultrasound imaging (sonography) may be required to determine the level and severity of injury.³Connell D, Schneider-Kolsky M, Hoving J, et al. Longitudinal study comparing sonographic and MRI assessments of acute and healing hamstring injuries. AJR Am J Roentgenol 2004;183:975-84.^,4Slavotinek J, Verrall G, Fon G. Hamstring injury in athletes: using MR imaging measurements to compare extent of muscle injury with amount of time lost from competition. AJR Am J Roentgenol 2002;179:1621-8.^,9Rettig A, Meyers S, Kersey P, Ballard G, Oneacre K, Hunker P. Categorization of Hamstring Strain Injuries by MRI and PLaying Time Lost in Professional Football Players. NATA 2008:29-32.^,13Mariani C, Caldera F, Kim W. Ultrasound versus magnetic resonance imaging in the diagnosis of an acute hamstring tear. PM R 2012;4:154-5.^,14Lin J, Jacobson J, Fessell D, Weadock W, Hayes C. An illustrated tutorial of musculoskeletal sonography: part 4, musculoskeletal masses, sonographically guided interventions, and miscellaneous topics. AJR Am J Roentgenol 2000;175:1711-9.

While MRI has been the gold standard for diagnostic imaging of hamstring injuries, musculoskeletal ultrasound can provide several advantages over X-ray, CT, and MRI tests, including decreased cost, portability, lack of ionizing radiation, and exquisite soft tissue imaging.¹⁵Smith J, Finnoff J. Diagnostic and interventional musculoskeletal ultrasound: part 1. Fundamentals. PM R 2009;1:64-75.^,16Smith J, Finnoff J. Diagnostic and interventional musculoskeletal ultrasound: part 2. Clinical applications. PM R 2009;1:162-77. Ultrasound imaging also allows medical professionals to dynamically test the tissues—view how the hamstring changes during movement in real time—to rule out other diagnoses or determine severity. In addition, ultrasound imaging been found to be extremely accurate and precise at determining the location and extent of a hamstring injury.¹²Ali K, Leland J. Hamstring strains and tears in the athlete. Clin Sports Med 2012;31:263-72.32. Orchard J. Biomechanics of muscle strain injury. N Z J Sports Med 2002;30:92-8.^,13Mariani C, Caldera F, Kim W. Ultrasound versus magnetic resonance imaging in the diagnosis of an acute hamstring tear. PM R 2012;4:154-5.