What is freezing of gait?
Freezing and Freezing of gait (FOG) is a term of often used in Parkinson Disease. It is clinically defined as “a short, episodic absence or noticeable reduction of forward progression of the feet when trying to walk”. This is most often described as having your feet stuck to the ground and looks like you are taking lots of short, shuffly fast steps before being able to step out normally again. This phenomenon is due to several deficits and not just a motor problem.
FOG is a common problem/symptom in PD and can affect up to 50% of the population. Unfortunately as the disease progresses up to 80% of people with PD in the advance stages will have issues with FOG. FOG has significant affects on mobility and can cause falling, people cannot move their feet on initiation and the body continues forwards causing a loss of balance out off the base of support. This impact on mobility can dramatically reduce your independence and hence quality of life.
There are several activities and environments that can trigger FOG, the most frequent are;
- Turning – especially on the spot or turning to sit down.
- When trying to start walking.
- Passing through doorways, crowed spaces or change of surface on the floor.
- Negotiating obstacles and narrow spaces.
- Dual tasking – trying to walk and do something else, talk, rushing to answer the phone.
- Emotional factors also can contribute for example stress and anxiety
All of the above involve a change/adaptation of the gait pattern which in turn has a higher demand on your attention levels. There has been significant research now confirming that cognitive decline is very closely correlated to FOG. On further examination it is apparent that global cognitive decline is pronounced in freezers much more than in people with PD who don’t freeze. Several domains of executive functioning have been found to be affected. This is why people with FOG can’t just change their walking with simple commands or increased concentration.
The risk of freezing increases significantly with activities that involve duel tasking, or doing more than one thing at the same time. This may be trying to find coins in your pocket or trying to have a conversation with someone when you walk. Many of the above factors are of cognitive origin and this demonstrates the increased demand on cognition.
Freezing does not only occur in gait, there may also be motor blocks that resemble freezing in the upper limbs. This confirms that FOG is generic in nature which has implications on the timing and amplitude of repetitive movements in both lower and upper limbs.
Research Evidence – Can Physiotherapy Help?
FOG is only assisted by PD medications (dopaminergic) up to a certain point and then there seems to be no further improvements. Gait rehabilitation aims to use alternative neural circuits to maintain / improve gait by several different strategies;
- External cues – markers on the floor, metronome
- Internal cues – Think Big
- Gait rehab – amplitude training, forced use
The aim is to change your automotive motor control to an external / attention demanding control. There is supporting research that physiotherapy can reduce FOG with cueing, although there is a risk that people can become dependent on cueing.
However consolidation and appropriate fast retrieval of these strategies is needed to see an improvement in day to day life. Which means a sufficient cognitive function is required to lean and perform. As discussed earlier people with FOG can have impaired cognition and executive function which means retrieval of methods/strategies may not work when required.
If you have Parkinson’s and not been assessed by our team please contact us for an appointment, the earlier you learn how to effectively use the above strategies, retrieval may be much easier if FOG becomes a symptom.
Cognitive aspects of freezing of gait in Parkinson’s disease: a challenge for rehabilitation. 2013. Heremans, E., et al. Journal of Neural Transmission