Standing, sitting or lying supine
Anterior or lateral to the patient.
May I touch your hand? ( or point to the demonstrated area ).
Please bend your elbow and turn your palm up. With your thumb touching your palm and your fingers straight, roll your thumb across your palm (or demonstrate, which is easier). (If needed, hold in this position while I try to move your thumb.)
Guide the patient to bend the elbow and supinate. With the muscle relaxed, palpate the muscle as it attaches to the first metacarpal bone and guide the patient to medially rotate the thumb. Remind the patient to keep the thumb in contact with the palm and the fingers extended. Observe the thumb nail facing laterally initially and then anterolaterally at the end of the movement. With unclear muscle activity, provide added resistance by having the patient ìholdî while you gradually produce a push on the first metacarpal bone of the thumb in the direction of thumb carpometacarpal lateral rotation.
Lifting the thumb away from the palm activates the more superficial abductor pollicis brevis muscle and hides the contraction of the opponens pollicis.
The opponens pollicis is not isolated during the motion of thumb carpometacarpal opposition, as you might think. Opposition of the thumb involves abduction, flexion and medial rotation of the carpometacarpal joint. Contact of the thumb and little finger then involves the adductor pollicis while the abductor pollicis brevis muscle relaxes.
Lifting the thumb away from the palm activates the more superficial abductor pollicis brevis muscle and hides the contraction of the opponens pollicis.
The opponens pollicis is not isolated during the motion of thumb carpometacarpal opposition, as you might think. Opposition of the thumb involves abduction, flexion and medial rotation of the carpometacarpal joint. Contact of the thumb and little finger then involves the adductor pollicis while the abductor pollicis brevis muscle relaxes.
TAKEN OUT:
Note the palpation technique in one video. In the other video, observe the muscle bulge of the opponens pollicis during carpometacarpal medial rotation. VH -
Note the palpation technique in one video. In the other video, observe the muscle bulge of the opponens pollicis during carpometacarpal medial rotation. VH -