Stance Vertical Oscillation Ratio / Stance Displacement

Stance Vertical Oscillation Ratio (SVOR) is the ratio of Stance Displacement, which is the magnitude of vertical movement during the stance phase, to Vertical Oscillation, which is the magnitude of vertical movement throughout the run.

Stance Vertical Oscillation Ratio and Stance Displacement are unique Motion Performance Indicator (MPI), available only with LEOMO products.

 

Overview

Stance Vertical Oscillation Ratio is an MPI related to Vertical Oscillation. Running, a movement in which a person alternates between the left and right foot, creates a "vertical movement" of the center of gravity compared to a wheeled movement such as a bicycle. Vertical Oscillation indicates the magnitude of vertical movement during running (stance phase and flight phase), while Stance Displacement indicates the vertical movement during stance phase. Stance Vertical Oscillation Ratio is the ratio between Stance Displacement and Vertical Oscillation.

If the ratio of vertical movement during running is large during the stance phase, the flexion of the lower leg tends to increase from the ground contact to the takeoff, and it is considered that there is unnecessary movement. Thus, running form with a large Stance Vertical Oscillation Ratio is considered to be less efficient. A lower Stance Displacement compared to Vertical Oscillation will result in a stiffer run. Generally, there is a tendency for the ratio to decrease as the stride increases. Advanced runners tend to be smaller than novice runners.

		Stance Displacement	Vertical Oscillation
Period	Stance Phase	◯	◯
	Flight Phase		◯
Parameter	Vertical Movement	◯	◯

Do Stance Vertical Oscillation Ratio and Stance Displacement matter?

The vertical movement of the pelvis during running moves from top to bottom and from bottom to top between the time the foot lands and the time the foot takes off. The movement of the pelvis from top to bottom is almost the same as the movement of the center of gravity of the body from top to bottom. Then, by the time the foot takes off the ground, the center of gravity shifted downward needs to be reversed upward, which generally requires a force at least twice the body weight. Since running is an exercise that moves the body forward rather than up and down (shifting the center of gravity forward), excessive up-and-down center-of-gravity movements are considered inefficient. Stance Vertical Oscillation Ratio shows the ratio of Vertical Oscillation during the stance phase, with smaller values indicating less vertical movement of the center of gravity during the stance phase.

About the value of Stance Displacement

• The amount of center of gravity movement during stance phase, expressed in [cm]

Stance Displacement (cm)	Interpretation
2.0 - 2.8	Very Low
2.8 - 3.6	Average (at high speed)
3.6 - 4.4	Average
4.4 - 5.2	Higher than average
5.2 - 6.0	Very High

 

About the value of Stance Vertical Oscillation Ratio

• The amount of center of gravity movement during the stance phase is expressed as a percentage of the total vertical movement during running. (0-100%)

Stance Vertical Oscillation Ratio	Interpretation
< 39%	Very Low
39 - 45%	Average (at high speed)
45 - 51%	Average
51 - 57%	Higher than average
57% <	Very High

In general, an advanced runner will have a value of less than 0.53, while a novice runner will have a value of 53% or more.

Advanced runner	< 53%
Novice runner	>= 53%

 

 

Sensors

• Sacrum placement

• Use Adhesive tape

• Attach at the Sacrum. (The largest bone at the base of the spine.)

  • See: https://en.wikipedia.org/wiki/Sacrum

• Proper placement (as seen in the image above) orients the LED in the upper left position. 

Real-time data & analysis

Stance Vertical Oscillation Ratio can be observed in real-time during the activity.

Coaches can also access the scores in real-time, with the LEOMO LVS.