The Impact of Horizontal vs Vertical Force When Sprinting

The Science of Sprinting: Horizontal and Vertical Forces

If you are here, then you are close to or maybe just as much of a nerd as I am when it comes to sprinting. Questioning all the variables of strength, power, balance, genetics, diet and the list can go on forever and over time you have heard more and more about vertical force in comparison to horizontal force. The goal for me in this article is to provide the information for you in the most unbiased way as possible and at the end give my opinion of which force application is most important for maximal velocity.

At the end of the day we need both vertical and horizontal force when sprinting and the data clearly shows that horizontal force is more prevalent during the acceleration phase while vertical force is much higher the higher the speed. We also know that everyone has certain anatomical strengths and weaknesses so Tyreek Hill who is 5’10” and the fastest player in the NFL, would not and should not run like Usain Bolt who is 6’5″ and has run the fastest recorded speed ever.

Does Height Matter When Sprinting?

This is a common question I receive when working with someone on top speed as if it is the most important factor in determining future success. While the 200m, 400m and 800m are much more dominated by taller athletes with longer legs, the 60m, 100m, 40 yard dash as well as all field sports the height is not a component for predicting speed. In fact, in most of the field sports the smaller players are typically the ones running fast and having the most success.

This is because the importance of acceleration which can most easily be described as change in velocity over time. This is important because horizontal force is commonly calculated as mass times acceleration so the weight of an athlete is easily understood as the mass while the clear definition of acceleration will help as we go through the article.

With that being said, to properly answer the importance of height as it relates to sprinting the distance is an important variable. The shorter the distance and more acceleration is needed then being shorter would be more of an advantage while the longer the sprinting distance the more height is an advantage for the taller athlete. This is simply because shorter athletes usually are able to get to their top speed faster while taller athletes are able to reach higher top speeds. Obviously this is not a 100% truth but typically shorter people are quick while taller people are fast.

Force Velocity Curve

This leads perfectly into the force-velocity curve because this is how we determine your success during your acceleration. Essentially the force-velocity curve is an acceleration graph that shows over a period of time the amount of ground reaction forces created and the corresponding velocity from those horizontal forces. The goal of the force-velocity curve is to maintain higher levels of force production to achieve and reach higher top speed. Or to be said in a more simple way, the longer the acceleration phase, the better.

So how does one achieve a longer acceleration phase? Well that would be by achieving more horizontal forces for a longer period of time. While over time the acceleration begins to lower, not because the athlete is slowing down but because the change in speed is not increasing as much in the first 3-4 seconds as it is at the 7-8 second mark. Therefore, those horizontal forces start becoming vertical force production (mass x acceleration due to gravity) So based on that would you think that horizontal force is more important or vertical force is more important?

Let’s explore further!

The Role of Horizontal Force Production

When we talk about horizontal force production when it comes to speed we have to look at it not only in sprinting in a straight line but in all acceleration and change of direction. When it comes to sports in general and absolutely in sports like tennis and soccer the ability to effectively use horizontal force is a must because most of the actions are quick bursts of speed for short distances. Which means horizontal speed and foot contact become more and more important.

Additionally, it is worth noting that horizontal force and acceleration is a key component of maximum velocity and large vertical force application. However, vertical force production is not nearly as important and could actually be considered a braking forces when an athlete is accelerating. So the technical ability to utilize both vertical and horizontal forces efficiently is the formula to become a world class athlete and fulfill your full sports performance potential.

The Role of Vertical Force Production

Assessing Force Production in Sprinters

Comprehending the interplay between horizontal and vertical forces is vital, but what are the methods to measure this? Enter the world of force plate analysis and motion capture, the cutting-edge techniques that provide a window into the mechanics of sprinting. Force plate analysis utilizes force plates to measure ground reaction forces during sprinting, providing valuable data points on a sprinter’s running performance.

Meanwhile, motion capture and kinematic analysis offer a comprehensive understanding of sprinter’s body mechanics and movement patterns. These methods allow us to quantify the force generated by muscles during sprinting and provide insights into the impact of force production on running performance.

Force Plate Analysis

Force plate analysis serves as a technique to assess and monitor athletes’ movement patterns and responses to load, targeting speed augmentation. It accurately measures the forces exerted onto the ground during movement, including both vertical and horizontal force components, offering a detailed view of the mechanics of force production in sprinting.

This analysis is an integral part of sprint training as it aids in identifying and quantifying accelerations, reactions, athlete imbalances, and evaluating athletes’ responses to load. This aids in refining training protocols and pinpointing areas for enhancement.

Motion Capture and Kinematic Analysis

Motion capture and kinematic analysis provide a more detailed perspective of a sprinter’s mechanics. By placing markers on the athlete’s body and using cameras to capture their motion, these techniques provide comprehensive and precise data on the athlete’s movement. They assess the kinematics and kinetics of sprint running and offer regression equations to accommodate variations in running speed and leg length.

This approach allows for the analysis of:

• Kinematic parameters

• Kinetic features

• Transitions

• Changes in acceleration

• Maximum sprinting speed of an athlete

This contributes to our understanding of force production during sprinting.

Training Techniques for Optimizing Force Production

Training is the juncture where the theoretical meets the practical, where science transforms into action. To optimize force production in sprinting, several techniques come into play, including plyometric exercises, acceleration drills, and strength training. These methods help improve horizontal and vertical force production, leading to improved sprinting performance.

Plyometric exercises, like Jump Squats, Box Jumps, Depth Jumps, Tuck Jumps, Jumping Lunges, Hurdle Hops, and Ankle Jumps, have been shown to enhance sprinting performance by increasing sprint velocity, step length, and overall sprint performance over various distances. Meanwhile, acceleration drills, such as sprints from blocks and the wicket drill, contribute to optimizing force production by emphasizing front-side mechanics and stride frequency. Finally, strength training exercises like loaded and unloaded vertical jumps, half-squats, horizontally-oriented jumps, medicine ball throws, resisted sprints, and plyometric exercises can enhance both horizontal and vertical force production in sprinters.

Plyometric Exercises

Plyometric exercises form a key component of a sprinter’s training regimen. These exercises focus on rapid muscle contractions and movements, helping to:

• Develop explosive power

• Improve force production

• Enhance sprint performance

• Increase jump height

Some of the recommended plyometric exercises for sprinters include:

• Jump Squats

• Box Jumps

• Depth Jumps

• Tuck Jumps

• Jumping Lunges

• Hurdle Hops

• Ankle Jumps

These exercises specifically target the lower-body muscles, including the quadriceps, hamstrings, glutes, and calves, which play a crucial role in sprinting.

Common Mistakes and How to Avoid Them

Even the most proficient sprinters are prone to errors, and it’s necessary to identify and rectify these to boost performance and mitigate injury risk. Two common mistakes in sprinting are overstriding and poor posture, which can lead to inefficient force production and an increased risk of injury.

Overstriding occurs when a sprinter’s foot lands too far in front of their center of mass, reducing horizontal force production and increasing the risk of injury. On the other hand, poor posture during sprinting can lead to inefficient force production and increased risk of injury. Maintaining proper body alignment and mechanics is crucial for optimal sprinting performance.

Overstriding

Overstriding is a frequent error in sprinting that can affect performance and heighten the injury risk. It occurs when the foot lands too far in front of the runner’s center of mass, introducing deceleration to the stride and hindering the ability to land the feet in parallel and underneath the body.

Overstriding can be detected by checking the position of the foot in relation and perpendicular to a vertical line through the torso down to the ground. If the foot lands far in front, with a nearly straight knee and toes pointing upwards, it is likely that the sprinter is overstriding.

Elite athletes exemplify the gold standard in the realm of sprinting. Numerous published studies have demonstrated that male and female elite sprinters at the world-class level can achieve force production levels of 11 and 10 N∙kg-1, respectively.

Case Studies: Elite Sprinters and Their Force Production

Elite sprinters demonstrate a tendency to generate higher levels and magnitude of horizontal forces in comparison to amateur sprinters, a factor that is pivotal in contributing to their superior sprinting performance. Understanding their strategies and the balance they maintain between horizontal and vertical forces can offer valuable insights for other sprinters.

Injury Prevention and Management

Preventing and managing injuries are vital components of any training regimen. For sprinters, for example, this means incorporating proper warm-up and cool-down routines, as well as managing overuse injuries through rest, rehabilitation, and biomechanical analysis.

Warm-up exercises like the modified hurdler’s stretch, heel-toe drills, arabesque to hip lock, and lunge and rotate are crucial for preparing the muscles for the intensity of sprinting. Meanwhile, cool-down routines that involve maintaining a low-level exercise to sustain elevated body temperature and circulation, followed by incorporating static stretching and barefoot skips can promote muscle recovery and minimize the risk of injury.

Managing Overuse Injuries

Overuse injuries frequently afflict sprinters. These can include hamstring strains, stress fractures, and muscle strains in the groin and calf. The primary factors contributing to these injuries include excessive pronation, poor training technique, and rapid increases in mileage.

Managing these injuries involves:

• Rest and rehabilitation

• Rehabilitation focuses on symptom management, recovery, and gradual strength rebuilding

• Rest, including active rest, facilitates healing and aids in injury prevention.

Summary

In the exciting world of sprinting, every step matters. From understanding the science of horizontal and vertical forces to honing technique through targeted training, optimizing force production is a science and an art. By addressing common mistakes like overstriding and poor posture, incorporating effective warm-up and cool-down strategies, and managing overuse injuries, athletes can enhance their performance and reach new speeds. The world of sprinting is a testament to human potential and the fascinating science of speed.

Frequently Asked Questions

Is sprinting vertical or horizontal?

Sprinting is primarily a horizontal activity, with the majority of the force applied being directed in a horizontal (fore-aft) direction. This means that a person with the capability to produce force in sprinting is effective for a specific sprinting task.

What are the 3 forces acting on a sprinter?

When sprinting, the three forces acting on a sprinter are the normal force and friction from the ground surface, and the gravitational force pulling the sprinter downwards. These forces affect the sprinter’s movement and acceleration.

How do you increase vertical force when sprinting?

To increase vertical force when sprinting, focus on electronically timed short sprints like fly 10s and gradually increase to fly 30s by the peak point of the season. This will help develop sprint speed effectively.

What is horizontal force in running?

Horizontal force in running refers to the force required to accelerate in a horizontal direction. This force is highest during the initial steps of a sprint and is a result of mass multiplied by acceleration.

How can force production in sprinters be assessed?

To assess force production in sprinters, use force plate analysis to measure ground reaction forces and motion capture with kinematic analysis to understand body mechanics and movement patterns. This will provide valuable insights into their sprinting performance.