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Tight Hamstrings? Maybe Not...

Updated: May 1, 2020

My hamstrings are tight, I need to stretch ”

How many times have you heard or even said this yourself? It has to be true because when you bend forward to touch your toes or you lift your leg up to stretch you feel that pull down the back of your leg. Right?


In my experience working with elite athletes and active adults the hamstrings are frequently complained of and often need attention but are not always the real reason for that feeling of tightness. The extent of the possibilities would be impractical to cover here, but I will go over one aspect of the core that can contribute to tightness during running or when doing a stretch.

Anterior Tilt

“An anterior tilt is the forward rotation of the pelvis with an increase in lumbar lordosis. It is believed to be associated with a number of common musculoskeletal conditions such as low back pain, ACL deficiencies, and a loss of core stability. The degree of pelvic tilt has been used to assess core strength” (Preece et al) Fig. 1.

Figure 1

When running, stability of the core enables the extremities to generate ground force (Seagrave et al), move effectively and reduce injury. Together the muscles of the core and hips work to stabilize the pelvis, spine, kinetic chain, and abdomen as the pelvis moves during running (Nicola & Jewison).

Common causes of running injuries:

• Too much anterior tilt

• Too much lateral tilt

• Asymmetric hip movement

• Abnormal pelvic mechanics

“When pelvic asymmetry is present and uncorrected, running will more than likely lead to overuse injuries, which can improve if the pelvic asymmetry is corrected” (Nicola & Jewison)

The scope of this article doesn’t allow us to analyze running mechanics and injuries, but instead will present how one aspect of having an anteriorly tilted pelvis changes your stride and can often feel like tight hamstrings.

In Figure 2 you can see what happens when there is an anterior pelvic tilt. This can cause the runner to loose hip height which compromises mechanics and can create leg drag on the contralateral leg (drive leg) during high speeds (Seagrave et al).

Figure 2

Tight Hamstrings?

The inability to hold the pelvis in place can feel like the hamstrings are tight and thus preventing the hip from achieving full ROM as it is flexed. This can be observed while running or felt when checking hamstring flexibility with a straight leg raise (Fig. 3,4).

Figure 3

Figure 4

Fig. 3 is an example of good hamstring flexibility and Fig. 4 shows a limitation. The limitation is usually experienced as a feeling of tightness in the hamstrings.

But do the hamstrings really restrict the motion?

Not Tight Hamstrings:

If you look closer, the hip has reached 90° of flexion…in both images!

The limitation was at the core where is was unable to hold the weight of the lifted leg and sagged under the load giving the impression of less flexibility (Figures 5,6).

Figure 5

Figure 6

Core Control

When there is an inability to control the pelvis, it drops and is unable to hold position while running or lifting the leg. This can occur on one side or bilaterally depending on core stability. So limitations observed in hip flexion can often be caused by core weakness. Not tight hamstrings!

When running with this weakness, one compensation is for people to round their backs (image on the right Fig. 7). There can be many different reasons such as a local issue with the core as described above or perhaps an issue with the back muscles and opposite hip extension. Hip extension works as a force couple with the abdominals to keep the pelvis in place (subject for another blog).

Figure 7

What to Do?

Strengthen the core!

Core strengthening can help reposition the pelvis so when you stretch or run the hamstrings won’t feel as tight. Seagrave et al. discuss how body position is one of the first factors that should be addressed in the correction of running mechanics.

Core exercises that emphasize leg lifting have a big focus on hip flexors and rely on the core as an anchor. However IF the core is already weak, it can sometimes be counterproductive or even increase chance of injury to the groin or hips from overuse.

Core exercise using hip flexors the most

Ideally, leg lifting exercises should be progressed to after you strengthen the core by itself. Isolated core exercises that do not use the hips or legs can be a better way to start.

Core Exercises without active hip flexion movements:

• Controlled crunches

• Planks

• Banded core exercises

• Abdominal machines that fit your body and fitness level

What if you want MORE core? (instead of cowbell...I know, only a few will get that..sigh)

For some people using a band, a machine, or getting on the floor for a plank are not an option. The reasons vary and can include: shoulder injury, back pain, access to machines, a missing limb or the continued overuse of the limb instead of the core for the exercise.

If you would like to explore a way to train the core without using your arms or legs, the Ki-RO Core Trainer was designed with this in mind. Below is an exercise focusing on anterior core muscles as an active rotation exercise or which can be adapted as an anti-rotation exercise. Video below shows rotation facing away from resistance so that the anterior muscles are emphasized.

Trunk Rotation: Abdominal emphasis

What about dynamic stability?

After you achieve static core stability/strength, start to integrate it into motion or while running for dynamic core stability/strength. Dynamic Strength is "the ability to produce Force when the body limbs are moving at high speeds" (Mann &Murphy). Training this can be a challenge depending on equipment available. The Ki-RO Core Trainer has sliding rings which enables you to not only challenge the core while seated, but even while sprinting or doing drills. Pete Bommarito of Bommarito Performance has been using it with his athletes and says that it has been “The best invention this industry has seen in 25 years”. He uses it both in the weight room and on the field.

Below is a picture using a sled with a rotational resistance on the body. This set up will help train the different forces from the ground up during running. To use the Ki-RO as part of an acceleration series, click here for a video by Advanced Athletic Development and Seth Forman.

Ki-RO Sled Sprints with rotational resistance on the core

Having a strong and stable core is important and can be a key factor in the prevention and rehab of injuries or other issues. There are countless ways to approach core training and we encourage you to find the safest way possible for your individual body and fitness levels.

If you would like to hear more about this topic, listen to the online discussion between Coach Willis of Willis Performance Training and Kika Mela here.

Reminder: Always check with your doctor or exercise professional before engaging in an exercise program or adding anything new to your current work out program. Be safe! In addition, also contact your local MAT Specialist here for an assessment to see about muscle imbalances.

Please check us out and sign up for our email list to get our latest blog posts that discuss core concepts. Send any questions to or DM us @kirocore on Instagram.

I hope you have benefited from this information!

Kika Mela, BSE, LMT, MATCSm

Ki-RO Core Trainer photographs courtesy of @sarah_jaquemet and modeled by @malcolmsolomon

Sleds used:

Resistance tube used: Kayezen Vectors


Preece, Stephen J., Willan, Peter, Nester, Chris J., Graham-Smith, Philip, Herrington, Lee, Bowker, Peter. Variation In Pelvic Morphology May Prevent The Identification Of Anterior Pelvic Tilt. The Journal Of Manual & Manipulative Therapy. 2008; 16: 113-117

Seagrave, Loren, Mouchbahani, Ralph, O'Donnell,Kevin. Neuro-biomechanics of maximum velocity sprinting. International Association of Athletics Federation's Publication New Studies in Athletics. 2009; 1

Nicola, Terry L. & Jewison, David J. The anatomy and biomechanics of running. Clinical Sports Medicine. 2012; 31:187-201

Mann, Ralph & Murphy, Ann. The Mechanics of Sprinting and Hurdling. Las Vegas, NV: Dr. Ralph Mann, 2018: 22.

Kika Mela is Co-Owner of Mela Therapeutics, Inc. and the creator of the Ki-RO Core Trainer. She is a Master Level MAT Specialist, MAT Rx Specialist, and has been a Licensed Massage Therapist for 25 yrs. She has worked extensively with professional and elite athletes and is a contributor to the training process at Bommarito Performance Systems as part of their medical team.

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