Metrics explained

How does ARION measure movement?

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.

  • \below 150 SPM: low
  • \150-170 SPM: average
  • \above 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.

To discover your running identity

  • abelow 220 ms: short
  • a220ms to 300ms: average
  • aabove 300ms: 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.

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. 

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.

  • *below 85ms: short
  • *85ms to 150ms: average
  • *above 150ms: 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.

  • Abelow 400 ms: short
  • A400-520 ms: average
  • Aabove 520 ms: long

*ms: milliseconds

Faster runners typically have shorter swing times.

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.

Footstrike

 

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 the foot
  • 100%: lateral / outside edge of the foot

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
  • +below 0: lateral biased
  • +0: neutral
  • +above 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.

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.

Balance

 

Balance indicates how much more or less you use 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.

  • ,below 0%: more left foot
  • ,0%: balance between left & right foot
  • ,above 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.

  • Vbelow 0.6 m: short
  • V0.6-1.0 m: average
  • Vabove 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.

Step length

 

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

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.

To discover your running identity

  • )10-30: average range
  • )5-10: low
  • )below 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.