Method sensitivity is critical for evaluation of poststroke motor function. Skilled walking was assessed in horizontal, upward, and downward rung ladder walking to compare the demands of the tasks and test sensitivity. The complete step sequence of a walk was subjected to analysis aimed at demonstrating the walking pattern, step sequence, step cycle, limb coordination, and limb interaction to complement the foot fault scoring system. Rats (males, ) underwent unilateral photothrombotic lesion of the motor cortex of the forelimb and hind limb areas. Locomotion was video recorded before the insult and at postischemic days 7 and 28. Analysis of walking was performed frame-by-frame. Walking along the rung ladder revealed different results that were dependent on ladder inclination. Horizontal walking was found to discriminate lesion-related motor deficits in forelimb, whereas downward walking demonstrates hind limb use most sensitively. A more frequent use of the impaired forelimb that possibly supported poststroke motor learning in rats was shown. The present study provides a novel system for a detailed analysis of the complete walking sequence and will help to provide a better understanding of how rats deal with motor impairments. 1. Introduction Stroke survivors commonly retain motor disabilities for years or even decades. Improvement of chronic poststroke motor dysfunction can be facilitated by special training [1, 2], medication [3, 4], and multisensory stimulation methods (for review, see [5, 6]). Moreover, recent evidence suggests that improvement of motor performance can be achieved over a prolonged time window [1, 2, 7–10]. In this context and for purposes of experimental studies, it is of special interest to have skilled motor tasks at one’s disposal to evaluate postlesion motor performance in detail, particularly the level of impairment and functional recovery [11, 12]. In the present study, we modified the ladder rung walking test originally introduced by Metz and Whishaw [13] to analyse locomotion of rats across a horizontal rung ladder. In the above test, operations of all 4 paws are rated according to a qualitative score, and a mean value for each paw reflects the overall accuracy of paw use. Another option for locomotion assessment with the test represents calculating the percentage of errors in relation to the number of steps [13]. The ladder rung walking test has been shown to be sensitive to age-related motor deficits [13] and to different models of motor dysfunction [13–17]. We hypothesized that crossing an inclined rung ladder placed at
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