|
Correct Answer: flexor pollicis longus.
*p jorge, a 22-year-old male who was injured while playing sports, is experiencing issues related to the muscles in his thumb, specifically concerning the flexion of the distal phalanx at the interphalangeal joint. to understand which muscle is responsible for this action, it is crucial to have a clear understanding of the thumb's muscular anatomy and the functions associated with these muscles.
*p among several muscles that could potentially be involved, the primary candidates include the abductor pollicis longus, flexor pollicis longus, extensor pollicis brevis, and extensor pollicis longus. each of these muscles has distinct roles in thumb movement:
- **abductor pollicis longus**: this muscle primarily abducts the thumb and assists in wrist radial deviation.
- **flexor pollicis longus**: this muscle flexes the distal phalanx of the thumb at the interphalangeal joint. it originates from the middle portion of the anterior surface of the radius and the adjacent interosseous membrane and inserts into the base of the distal phalanx of the thumb.
- **extensor pollicis brevis**: this muscle extends the proximal phalanx of the thumb at the carpometacarpal and metacarpophalangeal joints.
- **extensor pollicis longus**: this muscle extends the distal phalanx of the thumb at the interphalangeal joint.
*p given the specific injury and the action described - flexing the distal phalanx of the thumb at the interphalangeal joint - the correct muscle implicated in jorge's case is the flexor pollicis longus. this muscle, solely responsible for this particular movement, works by contracting and pulling on the distal phalanx, enabling the thumb to flex. the other muscles listed, while important for thumb movement, do not specifically perform this action.
*p in conclusion, for jorge's injury involving the flexion of the distal phalanx of the thumb at the interphalangeal joint, the responsible muscle is the flexor pollicis longus. understanding the specific functions of these muscles can aid in targeted treatments and rehabilitation strategies to restore function and alleviate pain associated with such injuries.
|
