Chronic Hamstring Tendinopathy Review
The hamstring complex is made up of the long and short head of the biceps femoris, semitendinosus, and the semimembranosus (2). The three hamstring muscles originate from the ischial tuberosity. Most medial is the semitendinosus and biceps femoris complex (2). The most lateral muscle is the origination of the semitendinosus (2). The role of the hamstring complex is to extend the hip and flex the knee (1). Chronic hamstring tendinopathy typically occurs just proximal or distal to the myotendinous junction of the long head the bicep (1). Chronic overload of the hamstring origin during running can cause tendinopathy and partial proximal hamstring tears (1). Histologic samples of the hamstring tendon origin in patients diagnosed with chronic hamstring tendinopathy showed collagen disintegration, increased tendon vascularity, and no inflammatory cells (5).
Patients with hamstring tendinopathy complain of pain localized to the ischial tuberosity that can worsen with prolonged sitting or running (4). Commonly confused with proximal hamstring tendinopathy is sciatic neuritis (7).
Physical exam involves palpation of the ischial tuberosity for point tenderness (6). There are also special tests that aim at stretching the hamstring. For example, providers can flex the hips to maximal flexion and then have the patient extend their knee (6). The tibia can be internally and externally rotated to better isolate each hamstring muscle during this maneuver(6). A positive test is pain at the ischial tuberosity. However, providers should be aware that these maneuvers can also stretch neural tissue and be positive from lumbar nerve impingement as well.
Imaging studies can also aid in diagnosis. Both MRI and ultrasound can be used to evaluate the common hamstring origin. The typical ultrasound findings of tendinopathy in the hamstring are tendon thickening, calcifications, and peritendinous fluid (8). With an MRI, tendons are typically dark and hypointense (12). A sign of tendinopathy in the hamstring origin is intratendinous signal (12).
Primary treatment for chronic hamstring tendinopathy is typically conservative (1). This involves a combination of activity modification, physical therapy, NSAIDs, and possible corticosteroid injection. Expert opinion regarding physical therapy for chronic hamstring tendinopathy involves the progression from low load to high load exercises that load the musculotendon unit (7). Physiotherapists will increase the amount of hip flexion as therapy progresses and then introduce faster movements (7).
PRP has also been studied as a possible treatment option for chronic hamstring tendinopathy. In a study published in the Journal of Ultrasound Medicine, they injected one group with PRP and the other with whole blood and compared pain outcomes in patients (1). They found that compared to whole blood, PRP had better Hip Outcome Score at 6 month follow up (1). Another study done by Fader showed that 80% of patients who had chronic hamstring tendinopathy who failed PT had improvement in their pain score after hamstring origin PRP injection (3).
Shockwave therapy has also been studied as an adjuvant to treatment for hamstring tendinopathy. In a study published in the American Journal of Sports Medicine, they compared shockwave therapy to the hamstring origin to a group that was given rest, NSAIDs, and PT (10). They found that the group who received shockwave therapy had statistically significant improvements in pain at the 1 week, 6 months, and 12 month follow up (10).
Proximal hamstring tendinopathy is found commonly in athletes and is frequently described as buttocks pain with exertion. Diagnosis can be made clinically or with imaging studies such as MRI and ultrasound. Treatment typically involves conservative treatment such as PT and injection.
1) Davenport, Kathleen L., et al. “Ultrasound-Guided Intratendinous Injections With Platelet-Rich Plasma or Autologous Whole Blood for Treatment of Proximal Hamstring Tendinopathy: A Double-Blind Randomized Controlled Trial.” Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine, vol. 34, no. 8, Aug. 2015, pp. 1455–63. PubMed, https://doi.org/10.7863/ultra.34.8.1455.
2) Arner, Justin W., et al. “Hamstring Injuries in Athletes: Evidence-Based Treatment.” The Journal of the American Academy of Orthopaedic Surgeons, vol. 27, no. 23, Dec. 2019, pp. 868–77. PubMed, https://doi.org/10.5435/JAAOS-D-18-00741.
3) Fader, Ryan R., et al. “Platelet-Rich Plasma Treatment Improves Outcomes for Chronic Proximal Hamstring Injuries in an Athletic Population.” Muscles, Ligaments and Tendons Journal, vol. 4, no. 4, Dec. 2014, pp. 461–66.
4) Bowman, Karl F., et al. “Operative Management of Partial-Thickness Tears of the Proximal Hamstring Muscles in Athletes.” The American Journal of Sports Medicine, vol. 41, no. 6, June 2013, pp. 1363–71. PubMed, https://doi.org/10.1177/0363546513482717.
5) Lempainen, Lasse, et al. “Proximal Hamstring Tendinopathy: Results of Surgical Management and Histopathologic Findings.” The American Journal of Sports Medicine, vol. 37, no. 4, Apr. 2009, pp. 727–34. PubMed, https://doi.org/10.1177/0363546508330129.
6) Hunter, David Glenn, and Cathy A. Speed. “The Assessment and Management of Chronic Hamstring/Posterior Thigh Pain.” Best Practice & Research. Clinical Rheumatology, vol. 21, no. 2, Apr. 2007, pp. 261–77. PubMed, https://doi.org/10.1016/j.berh.2006.12.002.
7) Nasser, Anthony M., et al. “Proximal Hamstring Tendinopathy; Expert Physiotherapists’ Perspectives on Diagnosis, Management and Prevention.” Physical Therapy in Sport: Official Journal of the Association of Chartered Physiotherapists in Sports Medicine, vol. 48, Mar. 2021, pp. 67–75. PubMed, https://doi.org/10.1016/j.ptsp.2020.12.008.
8) Fee, C., et al. “Ultrasound Assessment of the Hamstrings Complex of Athletes with MRI Correlation.” Clinical Radiology, vol. 77, no. 5, May 2022, pp. 337–44. PubMed, https://doi.org/10.1016/j.crad.2022.01.049.
9) Cacchio, Angelo, et al. “Shockwave Therapy for the Treatment of Chronic Proximal Hamstring Tendinopathy in Professional Athletes.” The American Journal of Sports Medicine, vol. 39, no. 1, Jan. 2011, pp. 146–53. PubMed, https://doi.org/10.1177/0363546510379324.
10) De Paulis, F., et al. “Sports Injuries in the Pelvis and Hip: Diagnostic Imaging.” European Journal of Radiology, vol. 27 Suppl 1, May 1998, pp. S49-59. PubMed, https://doi.org/10.1016/s0720-048x(98)00043-6.
11) Beltran, Luis, et al. “The Proximal Hamstring Muscle-Tendon-Bone Unit: A Review of the Normal Anatomy, Biomechanics, and Pathophysiology.” European Journal of Radiology, vol. 81, no. 12, Dec. 2012, pp. 3772–79. PubMed, https://doi.org/10.1016/j.ejrad.2011.03.099.
12) De Grove, Veerle, et al. “MR of Tendons about the Hip: A Study in Asymptomatic Volunteers.” European Journal of Radiology, vol. 143, Oct. 2021, p. 109876. PubMed, https://doi.org/10.1016/j.ejrad.2021.109876.
By Gregory Rubin, DO