Figure 2.

The well organized swing movement in mice requires proprioceptive sensory feedback from the muscle spindles. A, Trajectories of the hindlimb paw of wild-type mice (left) are very stereotyped across animals, whereas more variability in movement is observed in Egr3-KO mice (right). The colored lines are swings from an individual animal, and the bold black line is the pooled average. The average posterior paw position at swing onset and the anterior paw position at swing offset are illustrated as open and closed circles, respectively. B, Histogram representing the distribution of hindlimb paw positions relative to the hip joint at the end of hindlimb swing movement (HL_AP) in wild-type (left) and Egr3-KO (right) mice. C, Histogram showing the distribution of forelimb paw positions relative to hip joint at the end of forelimb stance movement (FL_PP) in wild-type (left) and Egr3-KO (right) mice. D, Histogram presenting the distribution of the distance between HL_AP and FL_PP in wild-type (left) and Egr3-KO (right) mice. E, Diagram illustrating the relationship between the average (±SD) of the HL_AP and FL_PP in wild-type (left) and Egr3-KO (right) mice during unperturbed hindlimb swing movements.