• Fitness & Health
• Sport & Exercise Science
• Physical Education
• Strength & Conditioning
• Sports Medicine
• Sport Management
• Dance

Countermovement Jump

This is an excerpt from Strength Training for Hockey by NSCA -National Strength & Conditioning Association,Kevin Neeld & Brijesh Patel.

The countermovement jump, also commonly referred to as the vertical jump, is a simple assessment that can provide a large amount of useful information about an athlete’s explosive abilities. Speed and power are key components of elite hockey athletes, and lower body explosiveness is a key performance indicator for hockey performance.

Purpose

By routinely measuring and monitoring the explosive abilities of athletes, the strength and conditioning professional is provided with important feedback on the adaptations achieved by the prescribed training program. The countermovement jump is often used by NHL scouts to serve as a proxy for lower body explosiveness and skating speed potential (5). Put simply, the higher an athlete can jump, the more power the athlete is able to produce. Since explosive hip, knee, and (to some degree) ankle extension are biomechanical features of the skating stride, especially for the first few pushes during acceleration, the countermovement jump provides a biomechanically similar pattern to evaluate explosive power.

Depending on the testing apparatus, jump height may be the only available metric. While yielding beneficial information, the height an athlete jumps may be achieved via different strategies. More complex tools such as force plates can provide insight into these strategies and showcase some of the underlying mechanisms that result in jump height, such as average relative force output, peak power, braking force, reactive strength, left-right asymmetry scores, and many other data points. With these more advanced metrics, the strength and conditioning professional may be able to dig deeper into how the athlete produces force and power, allowing a more nuanced and individualized training program to be developed. In addition, some of the underlying metrics associated with the countermovement jump, such as braking phase duration, countermovement depth, and time to takeoff, may provide valuable insight into the balance between fatigue and neuromuscular readiness.

Equipment

For assessing the countermovement jump, a range of options is available. The most basic version is simply using chalk and having the athlete jump and mark the wall at the highest point. However, more advanced options are arguably more accurate and becoming increasingly accessible to strength and conditioning professionals. For example, the Vertec system is commonplace. This apparatus consists of a tall pole with multiple “vanes”; the athlete jumps and attempts to “knock” a vane to display jump height. A second tool that is relatively affordable and found in many strength and conditioning settings is a contact mat. These pieces of equipment work by measuring the time the athlete is in the air during the jump, and converting this time to a jump height by considering Newton’s law of universal gravitation, which states that time to rise and fall under the influence of gravity is equal. The most advanced tool commonly available to the strength and conditioning professional is a force plate. The force plate measures jump height by calculating mass times takeoff velocity. It should be noted that force plates and contact mats allow the countermovement jump to be performed with or without arm swing, while the other options require arm swing and thus are not able to differentiate between the two variations. Jumping without contribution from an arm swing reduces the height of the jump but provides better information about the power of the lower body. Also, keep in mind that all of these options technically calculate jump height differently, so comparison between the scores from different types of equipment is not advised. Pick one tool and stick to it, if possible. Again, here are the common equipment options:

• Force plate
• Alternatively, contact mat or Vertec
• If using contact mat or Vertec, testing sheets to record data

Setup

Setup for the countermovement jump is similar regardless of testing apparatus. The only difference is the arm position. This depends on whether an arm swing is part of the protocol. If not using an arm swing, then the hands should be placed on and remain on the hips for the duration of the movement. If using an arm swing, then arms should be extended overhead at the initiation of the test. As the countermovement jump is initiated, the athlete descends rapidly into the bottom portion of the loading phase (the “countermovement”) and, at the same time, quickly and in sync with the rest of the body, snaps the arms down toward the floor. Upon reaching the bottom of the movement, the athlete explosively reverses the motion, driving hard off the floor and extending the arms back up overhead. If using a touch-based method such as the Vertec, the athlete reaches as high as possible to mark or brush aside the vane. If using a contact mat or force plates, the start and finish position should be as close as possible to the same spot, and hip, knee, and ankle flexion should be avoided prior to the landing. However, it is important to absorb the landing forces upon contact with the floor, so the athlete should be instructed to land on the heels with the legs straight and knees unlocked but to immediately cushion the landing by flexing the hips, knees, and ankles.

Testing Protocol

In this example, a sequential testing protocol performed on a contact mat or force plates is described.

1. The starting position is on the center of the mat, with the weight evenly distributed on both feet.
2. At a verbal cue, the athlete rapidly descends toward the floor by flexing at the ankles, knees, and hips into the countermovement portion of the jump.
3. Upon self-selected bottom depth, the athlete rapidly reverses motion and initiates the propulsive portion of the jump by extending the ankles, knees, and hips.
4. The athlete leaves the floor during the flight portion of the jump.
5. Upon landing, the athlete absorbs contact with the mat or force plates, allowing for an eccentric braking movement while slowing the downward trajectory and completing the landing portion of the jump.

Coaching Tips

• Fully explain the testing procedure, as well as the intent behind the test.
• Cue the athlete to push explosively and forcefully as hard as possible off of the floor.
• Emphasize an evenly distributed landing.
• Discard any jump with excessive flexion of the lower body prior to landing.

Descriptive Data

See table 3.1 for normative values for a vertical jump using a contact mat and table 3.2 using force plates.

More Excerpts From Strength Training for Hockey

---