Maximize transfer of dynamic stability training for running

Part 1: The determining factors for dynamic stability in running

Over the past two decades, there has been a growing interest in core training to improve pelvic stability. However, it’s not a straightforward process to get the optimal transfer needed in running technique with the traditional core exercises we know. While these exercises certainly play a fundamental role in your training program, it’s important to understand that they are just one piece of the puzzle when it comes to achieving better stability. If you want to take your stability training to the next level, it’s time to go beyond the basics of core training and focus on a more holistic approach that takes into account all the factors that contribute to dynamic stability.

Throughout the dynamic stability training series, we will offer various posts on ways to optimize your transfer of dynamic stability training. In part 1, we’ll explain the most important determining factors that influence dynamic stability. 

What is dynamic stability, and why is it important?

Before we dive deeper into the influencing factors, it’s important to understand how we measure dynamic stability. It’s the side-to-side movement of the Center of Mass (CoM) and reflects the ability to control the pelvis during the stance phase of running gait. Increased side-to-side movements will increase the demand on the stabilizing muscles which leads to reduced running efficiency and increases the injury risk (Schütte et al. 2017; Pla et al. 2021).

*Illustration of the side-to-side movement of COM during the stance phase of gait

Determining factors for an optimal dynamic stability

1. smooth body torsion

Torsion refers to the rotational interplay between the upper and lower body, where they move in opposite directions. For example, when you bring your left- leg and left side of your pelvis forward, your right arm and shoulder move forward. This pattern creates a stretch through our oblique sling, which becomes shortened when transitioning to the opposite side. This coordinated pattern creates a stable, forward-propelling body CoM.
 
To understand the importance of torsion, try running forward without moving your arms and shoulders. You’ll quickly notice how challenging it is to generate speed and maintain control over your pelvis. This is because the coordinated movement of the upper and lower body plays a crucial role in generating movement.

Poor/asymmetrical upper-body coordination can be a consequence of poor control of the pelvis. Don’t force it to change!

2. Adequate hip mobility

Did you know that hip mobility and flexibility deficits can disturb how we can maintain dynamic stability during running? Especially our hip joint’s extension range of motion (ROM), which is limited to +-20-30°, plays a vital role. This is where it creates a challenge when running, as we need to be able to extend our legs. To achieve the required ROM, we have to rotate and tilt, and that’s great. But, with our busy working hours and sitting for too long, we have to rely more on this support. 
 
While increasing our pelvic tilt can have its benefits, it also comes with a price. When we tilt our pelvis anteriorly, we may inadvertently loosen up the tightened anterior muscle groups that have stored energy to move our leg forward. This can result in a leg that doesn’t move as quickly as it should. It impacts our ability to properly place our foot during the first contact phase of our stride.

Do you notice a long ground contact time and a low cadence? Try to cue on smaller steps to improve dynamic stability

*Illustration of the ‘modified thomas test‘ to assess hip flexibility

3. Ability to control the pelvis

In order to achieve good dynamic stability, we should be able to keep our pelvis under control. While the forces exerted on the body are high, it is not just the maximal muscle force that determines this control, but also the timing of muscle activation. Impact duration, the time when the peak impact reaches our pelvis, can be very short (15-150ms) which makes it difficult for the muscles to react in time. To address this, we must rely on muscle pre-activation, where the muscles are already active before the foot hits the ground. Even if we have good hip muscle strength, proper timing is crucial, and must be trained appropriately.

Be aware that injury can cause delayed muscle activation in stabilizing hip muscles (Willson et al. 2011)

Maintaining good control of our pelvis becomes even more challenging when we are starting to fatigue. The images above show an example runner from the paper of Schutte et al., (2014) who moves his pelvis with more side-to-side displacements (Figure B fatigued vs. Figure A fresh) and with higher, less controlled, side-to-side accelerations (Figure D fatigued vs. Figure C fresh). This highlights the importance of being able to maintain good control of our pelvis throughout a longer or more intensive run minimize movement energy wastage. 

4. Foot proprioception & ankle control

These days, we tend to wear more cushioned shoes. This can be beneficial to absorb the impact, but also reduce the ability to sense the ground beneath our feet, known as proprioception. Therefore it’s important to properly activate our stabilizing muscles before initial contact because we have limited time to react appropriately. Whether you run with a forefoot, midfoot, or rearfoot strike, actively dorsiflexing your foot is crucial to reducing slack in your calf muscles and engaging the anterior muscles of your ankle. This can improve the first shock absorption in the foot and ankle (really important!) and control the joints to improve the energy storage within the tendinous tissue for a better energy return.

*Muscles around the foot & ankle are long and highly tendinous, which makes them suitable for energy storage and release while running.

Is there a framework to enhancing pelvic control in running?

While dynamic stability is an important biomechanical parameter to reduce injury risk and improve movement efficiency, several determining factors can influence this parameter. But, how can we now become better at propelling our CoM through training?  In Part 2 we’ll propose a training framework to enhance dynamic stability in running.

Picture of Written by Philip Cortvriendt

Written by Philip Cortvriendt

Philip achieved a master’s degree in physiotherapy & rehabilitation sciences and has core expertise in the field of running, working with both recreational and elite runners. Philip has the unique role of educating Runeasi physiotherapists and helping them translate biomechanical insights into targeted strength and conditioning exercises- specifically on how they can improve their client care using scientifically validated biomechanical insights from our Runeasi analytics.

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