Are these exercises safe?
No, maybe not.
In general, yoga is a powerful tool for change that must be used
In the case of finger stretching, there are several reasons to
Firstly, there is no particularly good reason to think that
many of our ancestors did much finger stretching. Intensive finger
stretching is probably strange and unusual passtime. This probably
means that any dangerous areas may not be well protected with pain
Secondly, the wrist is a known mechanical weak point, where tendons
pass curve over bones. Applying force to the tendons while they
are curved may drag them sideways into the surrounding tissues - where
they may cause problems.
Lastly - and perhaps most importantly - the flexor tendons are
surrounded by subsynovial connective tissue (SSCT). This tissue is delicate
and prone to damage. On the basis of mechanical considerations, flexor
over-extension is a likely cause of SSCT
damage. If damage is sufficiently severe the tissue catastrophic
collapse - and is then very difficult to heal. Collapse of
the SSCT may eventually lead to carpal tunnel
At the time of writing there is no known epidemological
link between flexor stretching and the onset of carpal tunnel
syndrome. However no studies appear to have investigated the issue.
Details about the hypothesised role of subsynovial connective tissue
in the pathogenesis of carpal tunnel syndrome are available
Stretching is commonly recommended by many as a therapy for
carpal tunnel syndrome. However, there is little or no evidence to
indicate that it is beneficial - and it may well frequently cause more
harm than good. Sometimes it is argued by analogy with tendon
disorders in other parts of the body that stretching may be theraputic
- but the micro-anatomy of the carpal tunnel tendons is very
different from any other part of the body, so such arguments are
Even the relatively mild finger flexor stretches in conventional
hatha yoga poses may cause damage.
Prospective finger stretchers should investigate these issues for
My assessment of the moral of this is not that you should not stretch
your finger flexors. Stretching these is important to their long-term
health. However, it does suggest reasons to stretch these tissues
extremely gently and carefully.