by Jennie Hansen, QT2systems

Ed. Note—injury is a frustrating reality for many athletes, and many of us will deal with being injured at some point in our careers. How we handle the setback, though, will either accelerate or delay our return to regular training and competition. Professional triathlete Jennie Hansen of QT2 Systems joins us this week to talk about a particularly intractable affliction.

For endurance athletes of all types, any injury is a figurative pain in the butt! Some, though, are quite literally that, and high hamstring tendinopathy is one of them. Although not as prevalent as some more common tendinopathies in the leg (the Achilles tendon in the heel, for example, or patellar tendon in the knee), high hamstring tendinopathies are notoriously stubborn and frustrating to athletes and health practitioners alike, something I can personally attest to, having been on both sides of that equation. So, what exactly is high hamstring tendinopathy? What leads to this issue? What can we do about it?

Anatomy and Function

The hamstrings consist of three muscles that run down the back of the thigh: the semimembranosus, semitendinosus, and biceps femoris. Higher up, the muscles attach to the pelvis via a tendon at the ischial tuberosity, more commonly known as the “sit bones” of the pelvis. Running close to the tendon is the sciatic nerve, which we’ll get into later. The hamstrings cross two joints (hip and knee), and act to bend the knee, and to assist the gluteals in extending the hip. What does that mean for how we use the hamstrings for triathlon-specific activities? During the stance phase while running (the time from which a foot hits the ground to when toe-off occurs) the hamstrings help the glutes first counteract gravity and then assist them in pushing off into hip extension.  During the swing phase (while the foot is off the ground), the hamstrings bend the knee, allowing your foot to clear the ground. Finally, just before the stance phase begins again, the hamstring stops the knee from extending too far forward. This moment, right before the foot lands, is when peak forces act upon your hamstring.

Visual of run gait phases, with reference to the right leg. Source: https://andrewsacksperformance.com/2013/05/11/hamstring-training-for-sprinting-speed/

What about during cycling? The hamstrings don’t play as large of a role as they do while running, but they are involved to some degree. At the bottom of the pedal stroke the hamstrings, along with the calves, help to pull the foot back up, although the opposite leg’s downstroke tends to be the more powerful contributor to this motion. During the downstroke, the hamstrings assist the quadriceps and gluteals in producing power as the hip and knee extend, especially towards the bottom of the pedal stroke.

Symptoms, Diagnosis, and Pathology

As with most overuse injuries, high hamstring tendinopathy tends to come on gradually. Pain occurs deep in the buttocks area, can radiate down the back of the thigh, and is often described as a tightness or cramping feeling.  Running, leaning forward, and prolonged sitting all can increase symptoms. In the earlier stages, pain tends to decrease after a warm up period and then returns after activity; as the condition progresses, pain persists throughout activity, and permeates throughout daily life.  Because of its proximity to the tendon, sciatic nerve irritation may also be present, and pain may radiate further down the leg. Tenderness over the sit bone is common, and several clinical tests that involve placing the hamstring in stretched positions or activating it against resistance at different angles can implicate the tendon as the source of pain. Gluteal muscle strains, adductor tendon issues, pelvic stress fractures, certain hip and pelvic impingement conditions, arthritis, bursitis, and lower back issues (particularly involving the sciatic nerve) can present similarly to high hamstring tendinopathy, so these tests can help differentiate between the conditions. MRIs may show tendon thickening, increased signal around the tendon, and edema within the bone at the tendon’s attachment.

For those who are into this type of thing-MRI image of my own high hamstring tendinopathy/possible partial tearing in early 2019 (imagine this as a cross-section looking down on the body). The white strip that the arrow refers to is some reactive edema in the bone, and the rest is what my doctor referred to as ”this junk," i.e., the tendon not looking like it should.

The pathology of high hamstring tendinopathy has become better understood in recent years. Tendons are pretty darn good at withstanding tensile (pulling) forces, but not so great when they’re compressed. This compression happens to the hamstring attachment when it gets wrapped around the ischial tuberosity in flexed positions—think of a cable being wrapped around a pulley. Early on, the tendinopathy may be more reactive or inflammatory, but more chronic tendon conditions progress into tendon disrepair and degeneration. Collagen, which is the building block of tendons, breaks down and loses its normal neat architecture. Additionally, changes occur to pain sensitization, and the body tries to compensate.

What Causes High Hamstring Tendinopathy?

High hamstring tendons are not a fan of compressive forces, which occur when the hip is flexed. That’s why that late swing phase of the run gait referenced above, where the hamstring goes through a stretch/shortening cycle while the hip is the most flexed that it gets while running, is thought to be where the point of greatest vulnerability. Certain run training and gait factors are thought to increase this risk. As with any running injury, history of previous injury, and increasing volume or intensity too quickly tend to be strong predictors of future injury-no surprises there. High hamstring tendons are especially vulnerable to increases in speed work, hill running, or exercises such as lunges and squats, which tend to put the hip into greater degrees of flexion while increasing hamstring force. In terms of run gait, over-striding, which increases the overall pull on the hamstring, increases risk. A forward trunk lean and decreased hip extension with running also is often seen, although it can be debated if these are causes or compensatory effects of high hamstring tendinopathy.

Cycling can also contribute to high hamstring tendinopathy. In the quest for saddle comfort, it’s often considered preferable to get us sitting on our sit bones—right on our hamstring attachments! Sitting on a wide, couch-like seat isn’t going to be the best for power transfer, but seats that are the wrong width (usually too narrow), or too hard can do a number on our hamstring attachments. As anyone who’s ever tried to get into a relatively aggressive position knows, decreased hamstring flexibility can be a limiter.  It follows that riding in the aerobars in high degrees of hip flexion without adequate hamstring length will put quite a bit of stress on that attachment—especially if the seat is too high. Weight distribution is another potential factor-less weight through the arms equals more on the rear. 

Some factors outside of our control are also associated with high hamstring tendinopathy risk. Age, hormonal changes (particularly menopause), metabolic imbalances, and certain genetic codes for collagen have all been implicated as possible culprits, as have certain medications. On a day to day basis, prolonged sitting (right on the tendon) can be less than ideal. Also implicated is a postural change known as an anterior pelvic tilt. I see this commonly in triathletes, especially those with desk jobs-long periods of sitting at work and on bikes shorten the hip flexors and weaken the glutes, causing the pelvis to essentially “tip” forward, compressing the hamstring tendon at its attachment.

Treatment and Return

High hamstring tendinopathy is, unfortunately, a notoriously recalcitrant injury; many examples exist of frustrated athletes sharing experiences and treatments over various online platforms. While no one size fits all approach exists (does it ever?), some concepts and treatments can be applied to treat the injury.  Because high hamstring issues tend to be chronic and longer-standing prior to diagnosis, as athletes *might* have tendencies to train through the early stages (including yours truly), compensatory movement patterns and other dysfunctions often exist in conjunction with the tendon damage. Treatment, then, needs to identify and address these issues from the ground up, with physical therapy being a great place to start. Activity modification (as in...rest from training, everyone’s favorite) does need to happen here to give the tendon a shot at healing, but that doesn’t mean that complete inactivity is indicated (this can sometimes just serve to weaken the tendon), and focusing on rehabilitation can help the mental aspects, as well. Goals should include initially decreasing pain, correcting postural imbalances (especially anterior pelvic tilts), improving hip and core strength and control, increasing the tendon’s tolerance to loading, and improving tissue mobility. That all sounds like a bunch of generalized PT talk-so, how do we actually go about accomplishing that? The review by Beatty et al (reference below) outlines a four phased approach, summed up as follows. We'll return in two weeks to finish this article with some suggested movements and exercises.

Phase 1

Decrease pain through methods such as relative rest; improve soft tissue mobility via manual therapies or techniques such as Graston, cupping, or dry needling; initiate non-provocative core strengthening; begin gluteal and hamstring isometrics (exercises that contract muscles without moving them-such as digging the heel into the ground or squeezing the buttcheeks).

Phase 2

This begins when isometrics can be done without pain, and some walking/jogging/cycling is being tolerated. Add concentrics (exercises where muscles shorten as they contract-glute bridges, hamstring curls, etc). Some pain during or afterwards is considered normal in this stage, but should not last more than a few hours, or up to a day for more difficult exercises (for example, lunges).

Phase 3

This phase consists of progressing concentric exercises into higher degrees of hip flexion, and adding eccentric exercises every other day (more on that shortly!). Gluteal power, strength, and endurance should also be emphasized in this phase to decrease load on the hamstrings.

Phase 4

Plyometrics and exercises that challenge pelvic control in a variety of planes are added here. Increasing power and emphasizing quality movement are goals, and it is appropriate to reassess run form. Flat ground running should be emphasized, with hills only gradually added as able.

OK! That's enough for today, we're guessing. Do YOU think you have a high hamstring tendinopathy? It's more common in triathletes than you think, and it can be a real pain in the rear. We'll be back in two weeks with part two, addressing some specific exercises you can perform to improve your outcomes.

References: 

  1. Beatty NR, Felix I, Hettler J, Moley PJ, Wyss JF. Rehabilitation and Prevention of Proximal
    Hamstring Tendinopathy. Current Sports Medicine Reports. 2017;16:162-171.
  2. Chapman AR, Vicenzino B, Blanch P, Knox JJ, Dowlan S, Hodges PW. The influence of body position on leg kinematics
    and muscle recruitment during cycling. Journal of Science and Medicine in Sport. 2008;11:8.
  3. Chu SK, Rho ME. Hamstring Injuries in the Athlete: Diagnosis, Treatment, and Return to Play. Current Sports Medicine Reports. 2016;15:184-190.
  4. Chumanov ES, Heiderscheit BC, Thelen DG. Hamstring Musculotendon Dynamics during Stance and Swing Phases of High Speed Running. Medicine and Science in Sports and Exercise. 2011;43:525-532.
  5. Degen RM. Proximal Hamstring Injuries: Management of Tendinopathy and Avulsion Injuries. Current Reviews in Musculoskeletal Medicine. 2019;12:138-146.
  6. Kotler DH, Babu AN, Robidoux G. Prevention, Evaluation, and Rehabilitation of Cycling-Related Injury. Current Sports Medicine Reports. 2016;15:199-206.
  7. Schultz M. The Primary Muscles Used for Cycling and How to Train Them. Coach Blog: TrainingPeaks; 2015.