By: Taylor Peckham
Often when people think of Parkinson’s disease, they think of the typical, commonly talked about symptoms such as tremor, slowness of movement (bradykinesia), muscle rigidity and impaired balance. While these are the most universal and well-known symptoms, Parkinson’s disease may look different for everyone, and many individuals will experience a variety of different or additional symptoms to the main four mentioned above.
Freezing of gait (FOG) is one of the most debilitating yet least understood symptoms of Parkinson’s disease. It is a gait disorder which is characterized by the inability to continue locomotion (Okuma, 2006). The best way to understand this feeling is to imagine trying to take a step forward but your leg will not move. It feels as though your foot is stuck to the ground even though you feel like you are telling it to lift and move forward. As you can probably imagine, this is often a very frustrating and impairing sensation for people with Parkinson’s disease. Although moving one foot in front of the other is a voluntary movement that we can control, it becomes second nature to us, and does not often take a lot of concentration or cognitive effort in a person who isn’t experiencing FOG. While walking is a simple movement that most of us take for granted, the inability to control your voluntary movements (termed akinesia) can be very disabling for individuals with Parkinson’s disease (Okuma, 2006). One reason that this symptom is so disabling for people with Parkinson’s disease is that it is a major cause of falls. Since the individual’s feet will suddenly get “stuck” in place, the momentum that the individual had while walking often causes their upper body to keep moving forwards. Without the ability to move their feet underneath them to readjust their centre of gravity, they inevitably fall. This is especially dangerous for people with Parkinson’s disease as not only does it put them at higher risk for sprains and fractures, but since people with Parkinson’s disease also often experience muscle weakness and rigidity, it makes it very difficult for them to get back up or readjust themselves if they fall in an uncomfortable or dangerous position.
When does this freezing of gait occur, and what can you do to unfreeze it? As mentioned earlier, Parkinson’s symptoms are unique to each individual so one person may have more severe or frequent freezing of gait than others. It most often occurs in more advanced stages of Parkinson’s Disease and is also a very common symptom in Parkinson’s related disorders such as progressive supranuclear palsy and vascular parkinsonism (Okuma, 2006). FOG can occur in many different situations; however, it is most common when turning corners, passing through a narrow space (tight corners hesitation), starting walking after stopping for a bit (start hesitation), or just before reaching a destination (destination hesitation) (Okuma, 2006). It is also often observed when the individual is in a stressful situation where time is limited such as crossing a busy street before the light changes (Okuma, 2006).
There are a few strategies that can be used to try to prevent this from happening or unfreeze the gait and get the individual to start walking forward again. One strategy is to use auditory cues to help keep a steady walking rhythm, similar to a marching command (Okuma, 2006). Another common one is to use visual cues such as stepping over an object or a line drawn on the ground (Okuma, 2006). One interesting product on the market for breaking the freeze state, is a laser device that can be attached to a cane or walker (Jovanov, et al., 2009). This provides a visual cue, so the individual has a steady point to follow while walking.
Overall, freezing gait is still not very well understood or managed, but knowledge on this phenomenon has been continuing to accumulate more recently, and new advancements in ways to treat it are being studied continuously.
Jovanov, E., Wang, E., Verhagen, L., Fredrickson, M., & Fratangelo, R. (2009) "deFOG — A real time system for detection and unfreezing of gait of Parkinson’s patients," 2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2009, pp. 5151-5154, doi: 10.1109/IEMBS.2009.5334257.
Okuma, Y. (2006) Freezing of gait in Parkinson’s disease. J Neurol. 253, 27–32. https://doi.org/10.1007/s00415-006-7007-2