We’ll take the brachial biceps as an example.
The patient is lying down and the practitioner seizes the fleshy part of the biceps between thumb and fingers.
– At first one won’t feel anything. Then gradually, one should feel their fingers spread apart for several seconds. It is important that the pressure exerted by the practitioner be light and as constant as possible*.
– Then, one should feel the volume of the muscle diminish for about 3 seconds, then again an increase in tension for about 3 seconds, so on and so forth. This phenomenon stops as soon as the patient mobilises his or her arm or contracts his or her muscle. It is also the case when the arm is passively mobilised.
Note that during the filling-up phase (dilatation of the muscle), the muscle swells transversally, but also longitudinally, and vice versa during the emptying phase (diminution of the volume of the muscle). The increase and decrease in volume happen on all three planes of space.
Also note that the volume of the muscle diminishes during contraction.
Only a seasoned therapist trained in « subtle » palpation can perceive this motility; one needs to have an « osteopathic » hand to feel such a change in tension or swelling of the muscle.
NB:
The difficult part of this palpation is in perceiving the first emptying phase.
*Any change in the tension or pressure exerted by the practitioner on the muscle, will disrupt the muscle contraction (cf. Afore mentioned instruction to keep the pressure as constant as possible).
For those not familiar with this type of palpation:
Have somebody lie on their back.
Sit next to them so as to face them (photo).
Put your hand on their thigh spreading your fingers so as to take on the shape of the limb, relax your hand and your whole body.
You will then progressively feel your fingers spread apart and tighten back in a rhythmical way. That is the manifestation of the PMM.
