What If Your Thigh Pain Isn’t a Hamstring Strain and What to Do About It

The title of this post is purposefully reminiscent of one of our most popular articles on plantar foot pain. When Editor-in-Chief Bryon Powell came up with that title, I was at first critical of such an unrefined name. That is, until I realized how such wording helped many ailing, frustrated runners find the article. Indeed, a great number of runners are diagnosed with ‘plantar fasciitis’ yet:

• Their injury doesn’t quite fit the mold of actual plantar-fascial pain; and/or
• Their ‘plantar fasciitis’ fails to improve as a result of conventional treatment.

It was a powerful article and it continues to help folks today because it raised awareness to the notion that you can have pain in your foot from other structures other than the plantar fascia. This concept, called differential diagnosis, simply asks, “What else could it be?”

In that same vein, we now turn our attention to a long-overdue subject, hamstring pain. In this article, we talk about what it is and what else pain in your posterior thigh can be.

Hamstring Pain Defined

The hamstring is a muscle group on the posterior aspect of the thigh comprised of three muscles in parallel. Together they play mostly a supportive role while running, helping to:

• Swing and drive-through a shortened leg when striding forward;
• Slow the foot between the swing-through phase and landing;
• Stabilize the leg during stance phase; amd
• Extend the leg behind upon push-off.

In the efficient state, the hamstring seldom gets overworked, especially among trail and ultrarunners. When it does occur, the muscle can strain. This means that individual muscle fibers (out of many thousands) are torn. Mild strains occur when only a small number are torn. Moderate or severe strains occur when more numerous (or focal) fibers are torn. In severe (and very rare) cases, the entire muscle (across all the fibers) can tear.

A few factors can add excessive load to the hamstring. For trail and ultrarunners, these factors include:

• Overstriding. When the foot swings and lands too far in front of the body’s center of gravity.
• A ‘low-legged swing’: This is a failure to adequately lift the heel during swing through. This keeps the hamstring ‘long’ and tensioned. This often occurs when a trail and ultrarunner begins to ‘shuffle’ with insufficient knee and foot lift.
• Deficient hip extension: If the hip joint (and its primary mover, the glutes) fails to extend efficiently, hamstring overuse may occur, trying to aid in push-off.

[Author’s Note: For a more detailed description of hamstring anatomy, physiology, and function for trail runners, see this article from several years ago.]

In this article, we focus on the other structures that can cause posterior thigh pain. Spoiler alert: there are a lot of structures that can cause pain in the hamstring region, an area that ranges from the posterior pelvis (buttocks) to the back of the knee. The posterior pelvis and thigh are a complex, busy area with many different muscles, tendons, ligaments, bones, joints, and nerves. Each of these groups, if irritated, can cause pain in the area.

Hamstring Pain Versus Something Else

First off, let’s distinguish between hamstring pain and pain from non-hamstring origins:

If your posterior thigh pain falls mostly into the ‘Something Else’ category, it is time to consider what other structures might be in play. But before we do, here are some key concepts to keep in mind about our bodies, in general, and the hip area, specifically:

The ‘Hips’ are a Mechanical System

I use a lot of automobile analogies, and I compare the leg, pelvis, and spine to these parts of a car:

• The tire (leg)
• The wheel or rim (pelvis)
• The axle (sacrum)
• The chassis (vertebral column)

Each part of this mechanical system must move efficiently. Problems arise when one component–or one side of the system–fails to move efficiently.

Posterior thigh pain can come from ‘tire-on-rim,’ ‘rim-on-axle,’ or ‘axle-on-chassis’ issues. So, whether your thigh pain is from a hamstring muscle or something else, the key to getting better is to restore efficiency to this system. Unfortunately, general muscle stretching, strengthening, or rest seldom corrects a mechanical dysfunction. Getting all the parts moving equally is crucial to recovery!

If Your Stride Lacks Efficiency, Anything Can (and Will Continue to) Hurt

Stride inefficiency can cause swing strain or landing stress–whether that occurs to the hamstring muscle; to hip, pelvic, or spinal joints; or to associated connective tissues or nerves. Too much stress and anything can hurt. Removing the source of the stress through stride optimization is paramount for sustained recovery.

Nerves Run from Head to Toe

The sciatic nerve–or all back and leg nerves for that matter–literally runs from head to toe. Our peripheral nerves begin in the brain, run down the entire length of the spine, go into the leg, and continue all the way down to the toes.

Any sort of tension or ‘pinch’ can cause a nerve to become painful. That pain can be localized to the pinch or it can radiate that pain up or down its length. Moreover, there can be multiple ‘pinch points’–areas of tension or motion restriction–that, when combined, break the threshold to create nerve pain. Lastly, nerve pain is often ‘sub-clinical’ to imaging, meaning that diagnostic imaging (x-rays or even MRIs) will fail to see any abnormality. A nerve can be tight and painful without being visibly pinched (let alone strained or torn).

As such, we runners and medical folk need to ‘think like a plumber or an electrician’ and recognize that a problem anywhere along the cord can cause an issue along its length. Thus, if you’re experiencing posterior thigh pain (and you think it could be nerve pain), then you or your medical provider must consider any dysfunctions from head (neck/cervical spine) to toe.

Common Sources of Posterior Thigh Pain

This is not an exhaustive list nor is this a complete how-to for diagnosing (let alone treating!) these conditions. The intent of this list is to merely generate awareness of what other structures can cause pain in the hamstring area. They are listed in order of what I find most commonly at my clinic.

Whole Hamstring Pain

These symptoms tend to affect large areas or lengths of the posterior thigh (which is often a key to differential diagnosis from a proper hamstring strain). The most frequent problem areas are:

1. Sacroiliac joint dysfunction. The sacroiliac (SI) joint is where the rim meets the axle. It is a tough, stable area yet it also has to ‘spin.’ (Really, it rotates a small amount both in flexion and extension.) Pain can radiate from this area if this joint fails to move, or if it moves too much (because the opposite side fails to move). Here are some examples of what referred SI joint pain feels like. Severe SI joint pain often radiates down the entire posterior thigh. In some cases, it can also refer into the lateral calf.
2. Sciatica. This is a blanket term for tension and irritation of the sciatic nerve, the large nerve that supplies the entire backside of the leg from the pelvis to the toes. Sciatica can result from any nerve-mobility problem in the spine or in the pelvis (and not necessarily due to compression by the piriformis muscle, a deep hip rotator that runs adjacent this nerve). Sciatic-nerve tension or irritation is generally experienced throughout the posterior leg and often has symptoms at rest, namely sitting (but sometimes also lying flat). Sciatic-nerve tension can be assessed by nerve mobility testing, which generally worsens if adding either foot or spine motion.

Upper Hamstring Pain

For more focal pain in the ‘hip,’ ‘butt,’ or ‘sit bone’ areas, the most frequent problem areas include:

1. Sacroiliac joint dysfunction. The SI joint can refer pain focally to the upper hamstring and lower pelvis area, especially when the joint irritation is milder.
2. Lumbar facet joint referral. This is more like ‘axle-on-chassis’ mechanics. The joints of the lumbar spine (chassis) and sacrum bone (axle) can cause referred joint pain. While sciatica (see below) tends to refer a great length down the leg, referred pain can mimic buttock or upper hamstring pain.
3. Posterior hip impingement. This is a ‘tire-on-rim’ issue, where the back side of the ball-and-socket hip joint ‘pinches’ the joint capsule or other structures. This can cause hamstring-like referred pain.
4. Obturator nerve or obturator internus muscle pain. Only recently have these structures–and their propensity for dysfunction–appeared on my clinical radar. The obturator nerve is a small branch nerve that comes from the lower spine. It innervates deep into the hip and pelvis as well as the medial thigh. When strained or irritated, both the obturator nerve and its namesake muscle, the obturator internus, can cause pain in the hamstring area.
5. Honorable mentions: piriformis syndrome (another that is widely over-diagnosed) and cluneal nerve pain.

Lower Hamstring Pain

For focal pain at the bottom of the hamstring, where it attaches at the knee joint and lower leg, the most frequent problem areas are:

1. Tibiofemoral (knee) joint pain. The knee joint is the articulation of the tibia (lower leg) and femur (thigh) bones. Significant irritation to this joint can refer pain to any side of the joint: front, inside, outside, and the back. Posterior joint pain can refer to the area behind the knee, around where the hamstrings attach to the knee and lower leg area.
2. Others: pes anserine bursitis, popliteus, or plantaris muscle strain.

Conclusion

Being an effective medical professional doesn’t necessarily require a deep knowledge of orthopedics and sports medicine, precision hands-on skill, scientific protocol, or high-tech gadgetry. Instead, it lies in the accurate diagnosis of what is actually creating the pain. More often than not, such a discovery begins with the question of, “What else can it be?”

If you experience pain in your hamstring area, yet it fails to respond to conventional hamstring muscle treatment or is taking an inordinately long time to improve, it’s important to ask that all-important question and to consider these other structures.

Call for Comments

Have you experienced posterior thigh pain that you–and other medical professionals–thought was your hamstring, but it turned out to be something else? If so, what was your experience and treatment approach?