Digital video images of the underside of mice were recorded at ˜1

Digital video images of the underside of mice were recorded at ˜150 frames per sec. Each image represents ˜7 msec of locomotion; the paw area indicates the temporal placement of the paw relative to the treadmill belt. The color images were converted to their binary matrix equivalents and the areas of the approaching

or retreating paws relative to the belt and camera were calculated throughout each stride. The plotted area of each digital paw print (paw contact area) imaged sequentially in time provides a dynamic gait signal, representing the temporal record of paw placement Inhibitors,research,lifescience,medical relative to the treadmill belt. Each gait signal for each limb comprises a stride duration that includes the stance duration when the paw of a limb is in contact with the walking

surface, plus the swing duration when the Inhibitors,research,lifescience,medical paw of the same limb is not in contact with the walking surface. Stance duration was further selleck screening library subdivided into braking duration (defined as increasing paw contact area over time) and propulsion duration (defined as decreasing paw contact area over time). Stride frequency was calculated from the number of gait signals (see above) over time (Fig. ​(Fig.2a).2a). Stride length was calculated from the following equation: speed = stride frequency X stride Inhibitors,research,lifescience,medical length. Stance widths and paw placement angles at full stance were obtained by fitting ellipses to the paws and determining the centers, vertices, and major axes of the ellipses. Forelimb and hind limb stance widths were calculated as the perpendicular distance between the major axis of the left and right fore paw images and between the major axis of the

left and right hind paw images during peak stance. Inhibitors,research,lifescience,medical Paw placement angle was calculated as the angle that the long axis of a paw makes with the direction of motion of the animal during peak stance (Fig. Inhibitors,research,lifescience,medical ​(Fig.2b).2b). Gait data were collected and pooled from both the left and right forelimbs, and the left and right hindlimbs. Figure 2 (A) Lateral view of a right hind paw during one stride depicting instances of time in swing and stance. Stance is comprised of braking and propulsion. (B) Paw Placement Angle is measured between the long axis through the hind paw and a line drawn through … Measures of stride-to-stride variability (gait variability) for stride length, stance of width, and paw placement angle were determined as the standard deviation and the coefficient of variation (CV). The standard deviation reflects the dispersion about the average value for a parameter. CV, expressed as a%, was calculated from the following equation: 100× standard deviation/mean value. The maximal rates of change of area with respect to time, during the braking phase (+dA/dtmax) and during the propulsion phase (−dA/dtmin) of stance, were also determined.

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