When only one leg is affected it is usually "dragged" in much the manner of individuals suffering from other forms of paralysis. But when the other leg begins to succumb to the ravages of Parkinsonism a curious type of gait develops which is known medically as a "festinating" or "hurrying" gait. This gait is an exceedingly complex technical affair, when one considers that three hundred muscles are utilized in the "simple" act of walking, but reduced to its simplest terms it may be said to be composed of part shuffle and part loss of balance.
The average person may never have noticed the relative positions of his arms and legs when he walks. If his gait is normal, he will find that when his left leg advances, his left arms swings in a backward arc, and vice versa. A comparable situation exists on the opposite side. It is not difficult to comprehend Nature's reason for this system—it is to provide balance for the act of walking.
Let us consider, as an elementary example, a patient who decides to walk from one room to another. First comes the intention, which in a normally healthy person would be translated into a forward step at once. Not so with the Parkinson patient.
He attempts to advance one foot, but finds it rooted to the spot. In anticipation of making this step, however, his body already has begun to move forward. A critical split-second occurs. Will the feet move to "catch up" with the body, or will the feet remain rooted and the body pitch headlong? If the patient is having a "good" day the former will occur, but if he happens to be experiencing a "bad" day he is very likely to fall flat.
The patient who succeeds in taking the first crucial steps cannot yet enjoy a feeling of security. His feet, even though they have some mobility, move sluggishly and are relatively unresponsive, while his body, with its associated center of gravity, tends to hurry onward. The inevitable result is the festinating gait—the hurrying gait—the feet shuffling desperately after the trunk.