Why does stride length measurement matter for target validation?

Stride length quantifies step distance and reflects changes in motor coordination, enabling objective assessment of therapeutic effects on locomotor function in mice.

How does isolating fore- and hindlimb base width support discovery pipeline decisions?

Base width measurements assess stance stability and limb coordination, providing independent variables that help isolate specific motor deficits linked to target modulation.

What does footprint overlap measurement enable in motor coordination analysis?

Overlap distance between fore and hind prints evaluates interlimb coupling and gait symmetry, offering a quantitative dependent variable for detecting subtle coordination impairments.

Why do replication requirements matter for cross-functional collaboration in footprint testing?

Replication ensures measurement consistency across operators and studies, which is essential for reliable data sharing between discovery, screening, and preclinical teams.

What statistical analysis capabilities are required before implementing footprint analysis in screening workflows?

Teams must be able to compare stride length, base width, and overlap across groups using appropriate variance tests to determine significant motor phenotype shifts.

Assessing Gait by Footprint Analysis: A Method to Test Motor Coordination in Mice

JoVE Encyclopedia of Experiments

Biology

0 views • 2:49 min • April 30th, 2023

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The footprint test is performed on a flat surface covered with a white sheet of paper, like a runway, ending in a dark gold box and an escape hole. The runway is restricted on each side to prevent subjects from leaving the test area.

A mouse will avoid the bright setting by walking across the runway to enter the escape hole. After the mouse has learned to perform the task, paint its front paws in red and its back paws in black with non-toxic paints. As the mouse walks on the white paper, it will now leave color-labeled footprints.

To describe the animal's gait and motor coordination, measure the distance of the fore- and hindlimbs' stride length, fore- and hindlimb base width, as well as the distance of their overlap.

When all of the mice have been tested, place a 9.9 by 42 centimeter piece of white paper onto the lab bench and place a dark goal box at the distal end of the paper. Place other boxes approximately the same length as the paper on both sides of the runway to prevent escape and add black and red ink to separate 35-millimeter Petri dishes. To train the mice for the analysis, place a mouse at the proximal end of the paper facing the goal box and let the mouse walk from the proximal end of the paper to the goal box.

When the mouse reaches the box, gently scruff the animal tucking the back and tail between the ball of the thumb and the other fingers to limit the movement of the hindlimbs and immerse the bottoms of the forelimbs in red ink and the bottom of the hindlimbs in black ink. Then, immediately place the mouse back onto the proximal end of the paper facing the goal box and let the mouse walk from the proximal end to the goal box. After air drying the foot-printed paper, use a ruler to obtain three measurements of the stride length by measuring the distances between the same parts of the paw prints.

Of the front base width, by drawing a line between consecutive same side front footprints and measuring the length of the vertical line from the pad of the front footprint to the line drawn between the footprints, and of the hind base width, by drawing a line between consecutive right hind footprints and measuring the length of the vertical line from the pad of the left hind footprint to the line drawn between the other right footprints. For overlap, measure the distance between the pads of the front and hind footprints.