It is sometimes said that the Alexander Technique has no side effects, but there are several things that can go wrong. Still, it is good to remember that Alexander Technique is clearly an exceptionally safe activity. Some of the potential problem areas are analysed below:
Spasms and Tremors
Some people who practise the technique experience involuntary movements (muscle spasms and tremors). These can be anything from simple movements, for example arm suddenly rising up, to shakes that involve the whole body. These movements can have a lot of force; sometimes the whole body may even jump up if first there is a movement that results in knee flexion, and then suddenly the quadriceps contract. While some people find this uncomfortable, embarrassing or even frightening, it doesn't seem to be particularly dangerous. The only slightly dangerous aspect of this is collisions, for example standing close to a wall when arms suddenly move sideways and one of them hits the wall. Also, this shouldn't be too embarrassing as these experiences are most likely to occur when people are feeling quite relaxed, and so it probably wouldn't happen when they are surrounded by a lot of strangers.
There are probably at least two reasons why spasms and tremors occur when people practise the Alexander Technique:
1. Muscle spindle sensitivity varies. This is what determines the level of habitual muscle tone. As we practise the technique, muscles sometimes suddenly lengthen beyond what muscle spindles currently regard as normal, and this triggers the stretch reflex.
2. Skeletal muscles can be seen as a complex network. To maintain posture and create movement all the edges of the network are in a balanced relationship to each other. Alexander Technique temporarily disturbs this balance, and the network has to seek for a new equilibrium.
Seeing Colors
Possibly the most bizarre side effect of the Alexander Technique is that some people start seeing flowing and vibrating colours in places where there shouldn't be any colours. So far there is no explanation why this happens and what it means. It is hard to make sense of it at least for the following reasons:
1. Lighting conditions and backgrounds change what is seen.
2. The state of mind also has an influence.
3. Poor three-dimensional vision: colours nearby overlap more distant colours.
4. Subjectivity of it.
This problem doesn't seem to be dangerous in any way. It can be slightly irritating if for instance you are reading a book and there are colours between your eyes and the page. Activities like driving a car could potentially be dangerous, but in practice this is unlikely to become such a serious problem.
Fainting
Fainting (syncope) when practising the Alexander Technique is rare and occurs almost exclusively during Alexander lessons. Nevertheless, when it does happen it disrupts the lesson and may frighten or alienate people. It makes sense then to discuss this matter briefly here.
The basic reason why people faint is because not enough blood is flowing to the brain. Why this may happen during a lesson is likely to be a combination of longer term and shorter term causes. The first group includes causes like feeling slightly nervous about having an Alexander lesson and not eating properly before the lesson. The second group includes causes like changes in muscle tone, standing for long periods and in particular moving from sitting to standing.
In most cases fainting during an Alexander lesson is easy to prevent. People should be aware of this risk and prepared to warn the teacher if they start feeling weak. Also, the teacher may notice some early warning signs, such as abnormal paleness, and guide their client to sit or even lie down.