Preoperative testing revealed that protraction, retraction, and control animals demonstrated symmetrical right and left whisking, with relative amplitudes (SEs) of 1.0 (0.023), 1.0 (0.030), and 0.9 (0.191), respectively. Animals had complete absence of whisking function on postoperative week 1 and measureable whisking recovery by postoperative week 4 in both the protraction and retraction groups. This was significantly greater than the recovery observed without mechanical stimulation in our normative data set (unpublished data). There were statistically significant differences in relative amplitude between the protraction group and our normative data set (P = .01, P = .04, P = .01, P = .04, and P = .046 at weeks 4, 5, 6, 7, and 8, respectively; 1-tailed t test) and the retraction group and our normative data set (P = .005, P = .02, and P = .045 at weeks 4, 6, and 7, respectively; 1-tailed t test) at multiple time points (Figure 2). In addition, there were statistically significant differences in relative velocity (protraction vs normative data: P = .03 at 4 weeks and P = .01 at 7 weeks, 1-tailed t test) (retraction vs normative data, P = .02 at 7 weeks, 1-tailed t test) and acceleration (protraction vs normative data, P < .001 at 7 weeks and P = .03 at 15 weeks, 1-tailed t test) (retraction vs normative data, P = .01 at 15 weeks, 1-tailed t test) between the protraction and the retraction groups and our normative data at multiple time points (Table). At 7 weeks the protraction group demonstrated a significant improvement in acceleration compared with the retraction group (P < .001). For all other time points and kinematic measures the protraction group (n = 15-18) trended toward improved functional recovery compared with the retraction group (n = 18); however, no statistical significance was demonstrated between the experimental groups (Table).