Metrics

General parameters

Dynamic 3D model - real simulation of foot movement mode, intuitive and easy to observe the movement of the foot, can rotate 360 degrees to observe the movement of each direction.
All foot motions in three planes(Sagittal plane,Frontal plane,Transverse plane) of each steps are integrated into one gait cycle then refect in three curve graphs. A grey band in the background represents a reference range that is calculated for each percent in the gait cycle. gait curves > Anteversion and retroversion are the motions that occur parallel in sagittal plane.Pitch angle is formed by the ground and the sole of the shoe.
  •  Inversion and eversion are the motions that occur parallel in frontal plane . Rool angle is formed by the ground and the sole of the shoe on frontal plane.
  •  Adduction and abduction are the motions that occur parallel in horizontal plane . The yaw angle is the angle between the foot axis and advance direction.
What to look: Combine with 3D view and temporal parameters of the report to observe the movements of the foot to evaluate the gait patterns and muscle conditions.
  • Normally the curves in midstance period should be within(±2), if curves are below the gray band, it may caused by the higher heel of shoes, please try to wear flat shoes if possible.
gait evaluate Symmetry: Symmetry is an important assessment of the balance of the overall muscle force and the coordination of the movement, and many chronic pain syndromes are related to the imbalance of muscle strength. The poor gait symmetry often reflects one side of the body cannot effectively load weight and cannot have normal movement, resulting a tendency to transfer the weight of the body to the other side in the walking process . Runners can use symmetry to:
  • Identify areas of concern which could be addressed through physical therapy or corrected using orthotics
  • Assess the impact of injury on mechanics
  • Track progress in injury recovery
Standard Index: The standard index of the left foot refers to the consistency of the left foot’s data with average standard. The smaller the standard degree, the greater the gap, and the greater the risk of the problem of the motion mode.

Swing analysis

swing analysis Step hight: The step height is the maximum height when the foot pedal is lifted.The ground height is generally 10~30cm The excessive ground height often causes the body center of gravity fluctuating wildly.The too low ground height is often with short stride and short swing time. Low ground height is often due to weak knee and hip flexion function.

Step length: Distance from initial contact of one foot to the following initial contact of the same foot.Stride length is about 1-1.6m while normal walking, amateur runners’ stride length is about 1.5-2m.

WHAT WE KNOW From the view of improving the running speed, it is more effective to increase the stride length than to increase the cadence. Increasing the stride length will also reduce the energy consumption at the same rate, but the increase in the stride length also requires more powerful muscle strength. The greatly changed stride length causes big change of loading angle and then produces the braking effect. It may not only affect the running efficiency, but also will have the impact damage easily. What to Look: In a Run Does your overall strategy change as you go from a slow to a medium speed compared to going from medium speed to a sprint? As you increase in pace, does your stride length or your step rate increase more? As you get tired during a run, how do you maintain pace? Do you notice an increase in stride length or step rate What to Look: Over Time As you get faster, look to see whether you’re increasing your Step Rate, Stride Length, or a combination of both.
Swing velocity The swing velocity is the maximum speed of the foot in the forward direction.Generally, swing velocity during walking is about 3-5m/s, swing velocity during running is about 5-8m/s. The swing velocity is a sensitive parameter, when the swing velocity of the left and right foot are significantly different, it is often caused by the side of the lower velocity that cannot support body effectively, which indicates that the balance ability of the body is decreasing. Swing width The swing width is the maximum width of the foot moving outwards while running. The greater the lateral shift of the body's center of gravity, the more the body needs to raise more muscles to maintain balance. This is not only slow but more strenuous. It is often a compensatory performance of the body caused by weak knee and hip flexion function , such as the circle gait of a hemiplegia patient.

Stance parameters

The green line is simulated Standard  center track of plantar pressure. The red line is user’s COP line. The point is foot strike position and impact.The green circle on top of Standard COP line stands for pushing off through the big toe, when the red poly line is long to reach the center of big toe stands for pushing off through the lateral part of big toe. cop tracking line What We Know Types of injuries tend to differ between the groups. Heel strike of lateral heel normally happens in walking. Over impact heel strikers tend to have more knee and hip injuries Over impact forefoot strikers tend to have more Achilles and calf strains and metatarsal injuries Over impact midfoot strikers will have characteristics in common with the both, often moving between the heel and forefoot strike patterns.   What to look: If Foot Strike Type changes over a period of time (weeks or months) and it is not due to a specific training program aimed at changing foot strike patterns, it is probably due to a change in footwear. Minimalist and low heel drop shoes tend to encourage mid and forefoot striking patterns. If you have more that one pair of shoes, tag each run with a particular pair of shoes and see if there is a relationship to your footstrike patterns.  

Temporal parameters

A gait cycle can be divided into the support phase (the period of time which the foot contacts the ground) and the swing phase (the period of time which the foot leaves the ground).The support phase of gait is 62-66%, the swing phase occupies 34-38%, while the support phase is 45-55% and the swing phase occupies 45-55% when jogging.
 The gait (walking) cycle
Phase of the cycle Period Comment
Stance phase Contact (orange bar) From heel strike to foot flat Foot unlocks to act as a shock absorber and adapt to irregularities in the ground surface
Midstance (green bar) From foot flat to heel lift The total weight-bearing surface of the foot is in contact with the walking surface
Propulsion (red bar) From heel lift to toe off Foot is a rigid and stable lever
Swing phase (40%) (blue bar) From toe off limb 1 to heel strike (limb 1) Body mass transfers from limb 1 to limb 2
WHAT TO LOOK: When contact period is short, users might have week tibialis anterior. When there is a large difference of midstance period,  users might have leg length discrepancy, the longer limb tend to have longer midstance period.When midstance period of both limb are short, users might wear a high-heel shoe or walk fast. When propulsion is long , users might have triceps surae muscle tension. When leg length discrepancy is more than 5cm, users might have triceps surae muscle tension on shorter limb. When swing phase discrepancy is more than 2%, users might have leg length discrepancy.

Motions

Strike pitch angle(Heel-strike angle):Pitch angle at foot strike. Strike-pitch velocity:Strike pitch velocity=Pitch excursion/contact time.Pitch excursion=Pitch angle at foot strike- Pitch angle at foot flat.
Strike rool angle(Strike-inversion angle):Roll angle at foot strike. Pronation excursion(Eversion excursion):Pronation excursion is measured between foot strike and the point of maximum pronation.   Pronation has been labeled as a potential indicator for overuse injuries while running. However, it is a natural movement and is an effective means of shock absorption at footstrike. When pronation excursion is subpar, users might have limited movement in ankle joint, while exceeding, users might have flat foot ar arch collapse. Max Pronation Velocity(Maximum Eversion Velocity) is The maximum angular rate at which the foot pronates between footstrike and the point of maximum pronation. What We Know Values range between 200 and more than 500 deg/sec(walking) Max pronation velocity is influenced by a number of factors including: running speed, terrain, Footstrike Type and footwear. Research is not conclusive, but it is believed that max Pronation Velocity is related to increased injury risk.      
Toe-off angle:Pitch angle at toe off.  
Toe-out angle:Walking with a toe-out gait.With the foot externally rotated with respect to the direction of progression.