Effect of early compensation of distal motor deficiency by the Chignon ankle-foot orthosis on gait in hemiplegic patients: a randomized pilot study

Objective: To compare the effect of the Chignon ankle-foot orthosis on gait versus a standard ankle-foot orthosis. Method: A multicentre randomized study was conducted in seven rehabilitation centres. Hemiplegic patients were recruited after unilateral stroke lasting less than six months. Exclusion criteria were: impossibility to stand for 10 seconds; ankle passive dorsiflexion <5 degrees with knee flexed to 90 degrees; triceps spasticity >= 3/4 on the Ashworth modified scale; diseases that might impair active participation in the study. Thirteen patients were randomized to the Chignon group and 15 to the control group. Included patients were given a standard ankle-foot orthosis or Chignon ankle-foot orthosis. The Chignon ankle-foot orthosis is an articulated double-stopped custom-made orthosis with elements to assist dorsiflexion and plantar flexion. Gait speed improvement (ten-metre test), kinematic assessment, and functional scales were assessed. Results: Gain ratio of walking speed with the orthosis increased significantly more in the Chignon group than in the control group at day 0 (27.2 +/- 36% versus -0.8 +/- 17%; P=0.006), day 30 (39.9 +/- 19% versus 7.5 +/- 17%; P=0.0004) and day 90 (44.6 +/- 27% versus 17.1 +/- 0.3%; P=0.04). There was also a significant improvement in kinematic parameters and spasticity in the Chignon group. Conclusion: Early compensation of distal motor deficiency by the Chignon ankle-foot orthosis improves the immediate gait of hemiplegics more than the standard ankle-foot orthosis and seems to modify motor recovery processes in the legs after stroke.