What is Trigger Finger?
Trigger Finger refers to inflammation caused by inflammation in
the tendon sheaths in the interphalangeal joints
in the fingers (i.e. the parts of the fingers which allow them
to curl and flex). This inflammation results in
'bumps' in these sheaths (or tenosynovium
prevents them from acting as lubricants for the smooth
application of tendons to open and close the fingers (and grasp
Why is Trigger Finger a Risk Factor?
When an individual is required to press a mouse button or a key
on a keyboard, this is an action which requires the articulation
of the finger and use of tendons to press down on the button or
key. If the tendon sheaths are inflamed, the use of these
tendons will cause them to thicken and the more frequent the
movement, the more serious the risk factor will be.
Unfortunately, repetitive movements are inherent in modern
computer usage of either the keyboard and the mouse, making
trigger finger a very real risk factor for computer users.
How Much Trigger Finger Related Inflammation is 'ok' and not a
For most individuals, once the movement or dexterity of the
fingers is affected, that is an indication that the inflammation
is severe enough to be a cause for concern and worth addressing.
What are the Symptoms of Trigger Finger?
The symptoms of Trigger Finger include pain which is usually
more pronounced during movement (i.e. when one flexes the
fingers). In addition there may be a snap or click-like
sensation as the tendons move around the inflamed areas where
the bumps are located. In severe cases, the symptoms can
mimic arthritis often found in seniors in that the fingers will
become partially or completely immobile in a partially curled,
How can the Choice of Mouse Help to Reduce Trigger Finger?
Mice which reduce or eliminate the amount of force or movement
required to press the buttons will generally provide benefits to
individuals suffering from Trigger Finger. Touchpads
will virtually eliminate movement from the act of mousing, and
eliminate the force required from clicking as one can tap to
click. Other types of pointing devices such as Assistive
take away the possibility of clicking, by using a
different paradigm for mousing and removing the cause (buttons
pressed by the fingers) from the action of mousing.
How can the Choice of Keyboard Help to Reduce Trigger Finger?
Keyboards offer a wide variety of keyswitches and selecting one
which is full travel, tactile and low force is ideal for
individuals suffering from Trigger Finger. Full-travel
tactile keyswitches of 3.5 mm or longer typically provide
'stopping distance' after the point of actuation which prevents
the problem of 'bottoming out' at the end of a keystroke, and
the resulting strain on the joints in the fingers. Tactile
keyswitches provide feedback which allow the user to exert only
as much force as is required to actuate the keyswitch, and not
exert more muscle effort than is required. Low force
keyswitches also assist in reducing the amount of effort
associated with typing.
What Other Strategies can be used to Reduce Trigger Finger?
An excellent strategy which will assist in Load
would be to use Footswitches
to move repetitive tasks from the fingers to the feet.