## METRICS EXPLAINED

How does ARION measure it?

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: mid-range
• 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.

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.

• below 220 ms: short
• 220ms to 300ms: mid-range
• above 300ms: long

ms- millisecond

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.

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: mid-range
• above 150ms: long

SPM- steps per minute

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.

Swing and stride 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. Faster runners typically have shorter swing times.

• below 400 ms: short
• 400-520 ms: average
• above 520 ms: long

ms- millisecond

Stride time refers to the time of one full step cycle of a foot from the moment the foot contacts the ground to the moment the same foot touches the ground for the second cycle. This includes the contact and swing time for one foot. Faster runners typically have longer stride times.

• below 670 ms: short
• 670-800 ms: average
• above 800 ms: long

ms- millisecond

Footstrike

Footstrike 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 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

Stability

Stability indicates how consistently the foot is placed on the ground. Varying the way your foot contact the ground, decreasing stability, can suggest a lower risk of injury.

Stability X refers to the variation of your landing between steps relative to the width of your foot.

Stability Y refers to the variation of your landing between steps relative to the length of your foot.

• 70% to 90%: mid-range
• 90-95%: high
• above 95%: very high

Varying the way your foot contact the ground, decreasing stability, can suggest a lower risk of injury.
Research has suggested that more variation (lower stability) between steps is associated with a lower risk of injury. Too little variation (too high stability) over longer periods of time is associated with higher risk of injury. Shoe stability can influence variability, and for shot term can bring benefits to certain biomechanical conditions, but reducing stability over time should help improve strength and adaptation to new loadings and reduce injury risk.

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 right 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.

Step and stride length

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

• below 0.6 m: short
• 0.6-1.0 m: average
• above 1.0 m: long

m- meter

The stride length is the distance covered between two consecutive placements of the same foot.

• below 1.3 m: short
• 1.3-2.0 m: average
• above 2.0 m: long

m- meter