This article is incomplete.
Falling is both more likely and more dangerous for an individual with ALS when compared to the wider population.
Lower limb weakness or a sudden loss of strength in the lower limbs may create enough instability to cause a fall. The fall may cause the trunk to go straight down, collapsing the lower limbs and putting significant pressure on the feet and knees.
Upper limb weakness makes it far more difficult to break a fall.
I was walking along flat ground with a cane, when suddenly my legs shook, and then collapsed. Instead of falling forward, backward, or to one side, my whole upper body went straight down toward the ground. All of my body weight went onto my left foot, which caused it to sprain and swell. The swelling took months to go away.
— ALS patient
I was walking toward the toilet and leaning very gently on a towel rack to provide a little stability. I was hardly putting any weight on it at all. Still, I managed to put enough load on it that it broke into several pieces. The minor change in my balance caused by that was enough to make me fall straight forward, like a domino.
— ALS patient
I was walking up the stairs at a friends house. I was gripping the railing with both hands, but when I got to the second step from the top, there was no more railing ahead of me to grip on. I tried to use my legs more, but my right leg gave out, and I fell backwards. Fortunately, my friend was standing behind me and managed to catch me. If he hadn't, I would have hit my head on concrete from a height of about 6 feet (180 cm) and likely would have been badly injured.
— ALS patient