Walk Run Froude Screen

Screen a gait-speed Froude number against a caller-selected transition value.

Description

A Froude number normalizes gait speed squared by gravity and leg length.

A Froude number normalizes gait speed squared by gravity and leg length. The transition value is a caller-defined comparison rather than a universal gait switch.^[1]

Screen a gait-speed Froude number against a caller-selected transition value.

When to use Walk Run Froude Screen

Use this tool to screen a gait-speed Froude number against a caller-selected transition value.

Prepare the measured movement, timing, load or preassigned score requested. Keep protocols, units, paired measurements and caller-selected thresholds consistent.

How to use Walk Run Froude Screen and understand its results

Prepare the measured movement, timing, load or preassigned score requested. Keep protocols, units, paired measurements and caller-selected thresholds consistent.
Enter walkingSpeedMps, legLengthM, gravityMps2, transitionFroude using the field table and calculation rules, then run the tool.
Read froudeNumber, atOrAboveTransition. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
walkingSpeedMps	Walking speed mps	number	Required
legLengthM	Leg length m	number	Required
gravityMps2	Gravity mps 2	number	Required
transitionFroude	Transition froude	number	Required

Enter nonnegative speed/threshold and positive length/gravity. Return dimensionless Fr and inclusive ≥transition flag.

Fr=speed²/(gravity×legLength)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
froudeNumber	Froude number	number
atOrAboveTransition	At or above transition	boolean

json

{
  "input": {
    "walkingSpeedMps": 2,
    "legLengthM": 0.8,
    "gravityMps2": 10,
    "transitionFroude": 0.5
  },
  "output": {
    "froudeNumber": 0.5,
    "atOrAboveTransition": true
  }
}

Limitations and assumptions

No gait observation, physiological diagnosis or individualized transition speed is fitted.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use Cadence Stride Speed Solver: Solve one missing gait speed, step cadence, or step length from the other two. For a complementary task, use Gait Duty Factor: Calculate stance duty factor and compare against a supplied walking cutoff.

References

Walk Run Froude Screen — tool.io

Similar or alternative tools

Cadence Stride Speed Solver
Solve one missing gait speed, step cadence, or step length from the other two.
Gait Duty Factor
Calculate stance duty factor and compare against a supplied walking cutoff.