This unedited video of a full lunging session shows physiologically correct movement, (natural cadence), verses fast forward motion. At the walk, trot, and canter, correct movement is point out while incorrect movement, when it happens, is underlined and explained. The lunging technique, the choice of body language instead of voice commands, the easy to teach cues which allow sound education are also explained. This is not a demonstration abundantly edited to accredit preconceived opinion. This video is a non-edited lunging session showing good and bad moments and how bad moments are analyzed and converted into sound gymnastic for the horse.
The two elements that are minimizing the side effects of lunging are for one, adding as many straight lines as possible and for two, maintaining the horse at his natural cadence. Cues and voice commands are useful as long as they are reduced to the minimum.
Decarpentry's technique works well if the horse has been trained to give a very light contact on the bit. By contrast, the technique may rapidly over-bend the horse's neck if the horse is leaning heavily on the bit or the trainer is maintaining a strong contact on the lunge line.