Ground Contact Time (GCT)

Ground Contact Time is one of the most common values in running evaluations. It refers to the time duration it takes from the time the foot lands to the time it takeoff the ground when standing phase.

The question that arises when discussing Ground Contact Time is when is "landing" and "takeoff"?

The image above is a series of photos of the moment of landing extracted from the video at about 8ms (120fps). There is a difference of 40ms between the leftmost photo and the rightmost photo, but which moment is the "landing"? The discussion is somewhat easier if there is a force plate, but this definition is very difficult to define with just a photo.

It is even more difficult if there is a difference in the Landing Pattern.

So, for LEOMO devices, all landings and take-offs are defined as "the moment the shoe touches the ground" and "the moment the shoe leaves the ground".

Does Ground Contact Time Matter?

• Ground Contact Time has a great deal of correlation with cadence, although it will inevitably increase as you increase your speed.

• However, it is said that the same cadence and speed can vary from athlete to athlete, but whether this is really the case is a matter of debate.

• LEOMO also has a Heel Pitch, an MPI that analyzes in finer phases than the GCT, so it is important to evaluate it in conjunction with the GCT.

About the value of Ground Contact Time

• The unit is in ms, which measures the time it is grounded in ms.

• The value is greatly correlated with the speed, but it is better to keep it as short as possible and minimize the difference between right and left.

Sensors

• Foot placement

• Use Sensor clip

• Attach to shoes with shoelaces

• Insert it from the heel to the toe (To prevent it from falling)

Real-time data & analysis

GCT can be observed in real-time during the activity.

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