Speed is king in sports, and the more tools that a coach has at his disposal for improving an athlete’s running mechanics and speed, the better. “Sport is the art of movement. Our job is to improve movement.”

In fact, of all the various things that we do coaching our athletes, the essence of our work consists of increasing the efficiency of human movement or, more precisely, the movements that constitute the competitive activity. There are two proven ways to improve and perfect athletic abilities and overall performance (1):

  • Improve the athlete's technique used in his sport
  • Develop the physical abilities (strength, power, speed) as it relates to the techniques needed in the athlete's sport

Biomechanics for running is finite. However, there is a certain individualization to everyone’s running form. How, where, and when certain muscles are used during each portion of running remains the same. For instance, how and where the hip flexors are used and how and where the hamstrings are used doesn’t change regardless of the person, sport, or position. The way that this information is then applied practically for the coach’s use is part of the art of our profession.

Dr. Yuri Verkhoshansky used Dr. Nikolia Bernstein's work on biomechanics to identify what he called “key movements,” which he describes as being important for not only obtaining the goal of the competition exercise but also for increasing the power output of competition exercise, which, in substance, constitutes the sport result. It is from identifying key movements that the criteria for selecting specialized exercises and the Principle of Dynamic Correspondence was proposed, as outlined in my articles on specialized exercises.

With his doctorate in biomechanics from the Central Institute of Physical Culture in Russia, Dr. Vladimir Zatsiorsky describes the idea of “accentuation” as training “strength only in the range of the main sport movement where the demand for high force production is maximal” (4). Dr. Zatsiorsky describes accentuation as a popular exercise strategy because it satisfies the requirements for exercise specificity.

For years, coaches have studied, written about, and applied many of the methods written by Dr. Verkhoshansky and Dr. Zatsiorsky. Two of their publications are considered the “bibles” of strength and conditioning—Supertraining and Science and Practice of Sports Training. In the published works of both men, there is a common example of an exercise shown in which the hip flexors are developed specifically for running. This particular exercise is demonstrated in the Special Strength Training Manual for Coaches as an example of selecting special strength training means with multiple examples of how to perform the exercise. Dr. Zatsiorsky uses this same example to illustrate his point on “accentuation” on page 122 in his book, showing where the range of motion of the hip flexors contract. This exercise is seldom spoken about or used outside a small circle of coaches and the work done by Dr. Yessis, in which he calls it “knee drive.”

 

The knee drive is the action of the thigh driving forward from behind the body. “The knee drive is a key force producing action that contributes to great speed” (2). Being able to identify this key movement is one thing, but understanding what muscles are involved and how they are involved allows the expert to properly set up and execute this exercise.

Most coaches use exercises that strengthen the hip flexors driven up in front of the body, which is a great way to strengthen them in general. However, kinesiology of the hip flexors in running  will show that they, along with the lower abdominals, concentrically contract from behind the body and drive the thigh forward until the thigh passes underneath the body. Once the thigh passes under, they cease contracting and it is momentum that carries them forward. The more powerful the contraction behind the body, the higher the thigh will move in front of the body (2). How these muscles are contracted is based on how they are used in the particular sport. "If the training objective is to increase the dynamic strength of the hip flexor muscles to improve velocity of the swing movement, there isn't any reason to increase the strength of the muscles in a range beyond the range this activity requires” (4).

The importance of using this exercise is also brought out in an article from the Soviet Sports Review titled “Fatigue Induced Changes in Sprinting Technique.” The authors looked at what fatigue-induced changes there were in sprinting technique in class II and Olympic sprinters. The authors found that stride frequency of the athletes decreased from reduced push-off forces. This was seen with smaller thigh separation angles and longer ground contact time at push-off. “Also, a survey of runners showed that they could not explain the changes in their leg movement…their answers centered on feelings of general fatigue and local leg muscle fatigue (especially the thigh flexors)”(3).

Practicality

When the subject of specialized exercises comes up, coaches immediately think that they're for high level athletes, which is what they were originally intended for. However, since the fall of the former Soviet countries, the advent of modern technology, and the ideas of Dr. Michael Yessis, advancements have been made in the area of specialized exercises. The original depiction of the exercise, shown in the books of Dr. Zatsiorsky and Dr. Verkhoshansky, is a very cumbersome exercise to execute. However, with the use of Dr. Yessis’s various sized rubber tubing, a four-way hip machine, or a cable pulley machine, this exercise is much easier to perform. You can change the overload of the movement to be as much or as little as necessary without the cumbersome set up. This can allow athletes of various levels to apply this exercise.

The use of different resistances allows the athletes to develop physical qualities in the hips for improving running performance and develop a feel of driving the knee forward. From a motor learning standpoint, not everyone is taught how to run properly, so developing a feel for the action becomes especially important. Athletes are often times taught to pick their knees up. From a biodynamic standpoint, this is incorrect because the hip flexors are used behind the body to drive the thigh forward. Another problem is that some athletes have a tendency to not fold up their thighs and shins as they drive the thigh forward. Instead, their shin remains at an obtuse angle. This creates a longer lever and is inefficient for driving the thigh forward because you want the shortest (quickest) lever possible to get it in front of the body.

There are various other ways that this exercise can be modified and performed. Based on the type of motor quality that you're looking to develop, this exercise can be performed eccentrically (plyometric), iso-dynamically, or explosively to develop the local muscular endurance of the hip musculature.

In the YouTube video below, I demonstrate this exercise with the use of active cords. I also show before and after shots of a couple athletes and how the use of this exercise has helped to improve their running mechanics.

As a coach, the more tools that you can have at your disposal, the better. It's even more efficient if some of your tools can help improve physical qualities as well as develop motor skills simultaneously. As Henk Kraaijenhof has said, “Train them as much as necessary, not as much as possible.”

References

  1. www.doctoryessis.com
  2. Yessis Michael (2011) Explosive Running. Second ed. Ultimate Athlete Concepts.
  3. Tupa VV, Guesinov FA, Mironenko IN (1991) "Fatigue-Induced Changes in Sprinting Technique.” Soviet Sports Review 26(4).
  4. Zatsiorsky Vladimir (2006) Science and Practice of Strength Training. Second ed. Human Kinetics, pg. 122.