Abduction: Movement of the thumb away from the second metacarpal. (
What causes adduction of the thumb?
Infections of the thenar space, the tendon sheaths of the thumb, index and middle fingers and the first lumbrical space have resulted in adduction contracture. Ischemia of the hand may also be a cause.
What is thumb adduction?
While adduction of the thumb (bringing it back into the plane of the palm of the hand from its previously abducted position) is mainly produced by the adductor pollicis, it can also bring the thumb to the side of the palm and index finger and the flexor pollicis brevis and the opponens pollicis help in thumb adduction.
What nerve does thumb abduction?
The median nerve supplies the abductor pollicis brevis (APB) muscle at the lateral border of the thenar eminence which abducts the thumb at right angles to the palm.
What causes ape hand?
Ape hand is usually the result of median nerve palsy, which is commonly caused by deep injury to the wrist or forearm. This can impair the function of the thenar muscles.
What is Palmaris longus?
The palmaris longus (PL) is a narrow, fusiform muscle of the superficial anterior compartment of the forearm [1,2,3,4,5,6]. The muscle originates at the medial epicondyle of the humerus and the antebrachial fascia, with the muscle belly partially fused with the adjacent muscles [3, 4].
Can the thumb do Circumduction?
Circumduction of the thumb is an essential motion for hand function. Thumb rotation is required to achieve pulp–pulp contact, which is essential for two- or three-finger pinch [13].
What is adduction and abduction?
Abduction and adduction are terms that refer to certain body motions or movements. Abduction is the opposite of adduction. With abduction, limbs (arms, legs or fingers) are moved away from your body’s midline. Adduction, however, refers to moving your limbs closer to the midline.
What movement is adduction?
Adduction is the movement of a body part toward the body’s midline. So, if a person has their arms straight out at the shoulders and brings them down to their sides, it is adduction. For fingers or toes, adduction brings the digits toward the center of the hand or foot.
What is thumb extension?
The thumb’s MP and CMC joints flex and extend in a plane parallel to the palm. Some therapists refer to extension as “radial abduction,” because the thumb moves toward the hand’s radial side. Why do we name CMC movements in this manner? The CMC joint is biaxial, not triaxial.
What motion occurs at the thumb?
Purpose. The movements at each thumb joint are flexion and extension (called radial abduction in the CMCJ) and additional movements of anteposition, retroposition and opposition at the CMCJ, due to the saddle shape of the articulation.
Which 2 muscles make up the anatomical snuffbox?
The tendons of two of the outcropping muscles make up the lateral border of the anatomical snuffbox; they are the abductor pollicis longus and extensor pollicis brevis. The medial border of the snuffbox is made up of the remaining outcropping muscle, the extensor pollicis longus.
What is palmaris brevis?
The palmaris brevis (PB) is a small muscle of variant morphology originating from the palmar aponeurosis to insert in the skin and fascia of the medial palm (Przystasz, 1977). The PB is uniquely innervated by the only motor component of the superficial branch of the ulnar nerve.
What causes pain in the abductor pollicis brevis?
Injury to the abductor pollicis brevis can be caused by repetitive motion or a direct trauma. The most common causes would be overuse, perhaps caused by repetitive actions such as typing, heavy lifting, and sports; or a direct impact, such as a fall to the ground or punching something.
