The rationale of 'ThoppukkaraNam' is known from the Super Brain yoga.
Similarly some research can be done on the counting of the japa-mala (rosary) on whether the constant movement of the beads in a particular fashion has an effect on activating some nerve centres, as happens in acupressure.
Usually, the thumb and the middle finger are used in rotating the beads.
The knowledge of acupressure centers that we know as of now, is that the top phalange of the thumb is connected to brain and that of the middle finger to the nose.
Some people do the japa by sliding the mala on the base of fingers.
The base of the fingers has relevance to the eye and ear centres.
It must be researched how these centres are activated when japa is done using the japa-mala.
Of all the japas, Gayathri manthra japa is considered as supreme.
No japa-mala is used in gayathri japa.
Counting the mantra is done by the thumb moving over the parts of other fingers.
This method has all the trappings acu-pressure in activating some important centres of the body and brain.
In Gayathri japa, the thumb presses certain phalanges of the other fingers in a particlular sequence.
This is also one area of research to ascertain whether any activation of internal power centres is happening by doing like this.
The gayathri manthra is aimed at Enlightenment.
Perhaps the counting activity is an additional feature to buttress the effect of mental awakening.
Another activity that seems to have some curious connection to acupressure is the way achamanam is done.
The 12 names of Bhagawan are recited by touching different body parts in different ways.
The thumb and the fingers and the divisons of the fingers come into contact in a specific fashion while touching the various body parts.
For example it is done like this for 'Keshava'. The index finger touches the second phalange of the thumb while the thumb touches the cheek bone.
Other achamanam pics can be seen here:-
Hope to hear some research on these.