The ARION metrics

Learn about the running metrics ARION offers.

Elzemieke avatar
Written by Elzemieke
Updated over a week ago

ARION Metrics

Flight time

Flight time refers to the time neither foot is in contact with the ground between consecutive steps of the left to the right foot or vice versa. From the toe-off of one foot to the moment the other foot touches the ground.

  • <85 ms: short

  • 85-150 ms: average

  • >150 ms: long

*ms: milliseconds

Some research has indicated, and many coaches and runners associate the ratio of flight time and contact time to running efficiency, with relatively longer flight times and shorter contact times associated with higher efficiency.

Flight time is typically longer at higher running speeds. Flight time is often compared to contact time to provide an indication of running efficiency or leg stiffness/elasticity, with shorter contact times and relatively longer flight times often associated with higher efficiency.

Contact time

Contact time refers to the time your foot remains in contact with the ground during each step, the time from the moment your foot touches the ground until toe-off.

  • <220 ms: short

  • 220-300 ms: average

  • >300 ms: long

*ms: milliseconds

Some research studies have established that often shorter contact times at the same speed are associated with higher efficiency.

Shorter contact times at the same running speed are often correlated with a higher running efficiency, provided the gait pattern has not been substantially changed from natural self-selected. Faster runners typically have shorter contact times.

Footstrike X

Footstrike is calculated from the pressure measured with the various sensors in the insole.

Footstrike X refers to the location of the center of pressure (COP) at initial ground contact relative to the foot width on a scale of 0% to 100%, in which 0% is at the medial or inside edge and 100% at lateral or outside edge of the foot. All values in between are possible.

  • 0%: medial / inside edge of the foot

  • 50%: middle of foot

  • 100%: lateral / outside edge of the foot

Footstrike can influence how loading is experienced by the body and how a runner interacts with the shoe, ground and their body. Whilst a lot of research suggests footstrike location is not a clear indication of risk of injury, footstrike can influence where injuries are likely to occur.

Footstrike Y

Footstrike is calculated from the pressure measured with the various sensors in the insole.

Footstrike Y refers to the location of the center of pressure (COP) at initial ground contact relative to the foot length on a scale of 0% to 100%, in which 0% is at the back of the heel and 100% at the tip of to toe. All values in between are possible

  • 0%: back of the heel / rearfoot

  • 50%: middle of the foot / midfoot

  • 100%: front of the toes / forefoot

Footstrike can influence how loading is experienced by the body and how a runner interacts with the shoe, ground and their body. Most runners naturally run with a heel landing when running in conventional running shoes. Whilst a lot of research suggests footstrike location is not a clear indication of risk of injury, footstrike can influence where injuries are likely to occur.

Stability

Stability describes the lateral/medial motion within the shoe. With a positive value, the foot motion is biased more towards the inside of the foot (medial side) which is common with a higher degree of pronation. With a negative value the foot motion is biased more towards the outside of the foot (lateral side) which is more common for a more supinated foot.

  • <0: lateral biased

  • 0: neutral

  • >0: medial biased

Stability is expected to be influenced by the amount of support, stiffness and stability of the shoe, the strength of the foot, the surfaces you run on, your running form, and the mobility of your foot and ankle joints.

Variability

Variability indicates how consistently the foot is placed on the ground. Varying the way your foot contacts the ground can suggest a lower risk of injury.

  • 10 to 30: average range

  • 5-10: low

  • <5: very low

Varying the way your foot contact the ground, can suggest a lower risk of injury.

Research has suggested that more variation between steps is associated with a lower risk of injury. Too little variation over longer periods of time is associated with a higher risk of injury. Shoe stiffness and stability, the surfaces you run on, your running form, and the training you do can influence variability. Increasing variability gradually over time should help improve strength and adaptation to new loadings and reduce injury risk.

Cadence

Cadence is defined as the number of (left and right) steps per minute. Cadence is calculated by counting the number of steps and dividing this by the time in which those steps were taken.

  • <150 spm: low

  • 150-170 spm: average

  • >170 spm: high

*spm: steps per minute

Slight increases in cadence have been shown to help reduce loading and improve running efficiency in some research studies .

Faster and more experienced runners often have a higher cadence. Average ranges for distance runners are between 140 and 180 spm, with many recreational runners falling within 140 to 160 spm. Most elite runners are above 180 spm when running at competition pace.

Small increases from the natural self-selected cadence of any individual can often help reduce loading and improve running efficiency. Large changes are likely to have the opposite effect, increasing injury risk and reducing running efficiency.

Step length

The step length is the distance covered between two consecutive placements of the left to the right foot or vice versa.

  • <0.6 m: short

  • 0.6-1.0 m: average

  • >1.0 m: long

*m: meter

A shorter step length with higher cadence can help reduce loading.

Faster runners typically have longer step lengths. For many runners, running with a slightly shorter step length compared to the natural self-selected step length can often help reduce loading and improve running efficiency, but large changes are likely to increase loading and reduce running efficiency. More experienced stronger runners are likely to be able to achieve longer step lengths without over-striding, whereas less experienced weaker runners have a risk of over-striding when step length is longer.

Balance

Balance indicates to how much more or less you use your one foot over the other. A balance equal to 0% means you use both feet equally. When your balance is negative you use your left foot more and when it is positive you use your right foot more.

  • < 0%: more left foot

  • 0%: balance between left & right foot

  • > 0%: more right foot

Some research studies have suggested that changes in balance over time can indicate developing weakness or injury risk.

Most runners and coaches strive more a more balanced running style, but small imbalances are unlikely to significantly increase injury risk. Changes in balance over time may indicate an increasing risk of injury.

Swing time

Swing time refers to the time one foot remains in the air in between consecutive steps of the same foot from the toe-off of one foot to the moment the same foot touches the ground.

  • <400 ms: short

  • 400-520 ms: average

  • >520 ms: long

*ms: milliseconds

Faster runners typically have shorter swing times.

More metrics coming soon!

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