Hand

flexor pollicis brevis

FLEK-sor POL-ih-sis BREH-vis

This thumb muscle in the thenar eminence flexes the thumb's base, critical for pinching and precision grips like turning keys or holding tools. It's key for hand strength in weightlifting or racket sports. Imbalances lead to thumb weakness.

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Common Pain & Injury

Pain at thumb base or palm, aggravated by pinching. De Quervain's or arthritis common. See doctor for swelling or grinding sensation.

Anatomy & Function

Origin

Flexor retinaculum and trapezium tubercle (wrist ligament and thumb-side wrist bone)

Insertion

Proximal phalanx of thumb (base of thumb bone)

Actions

Metacarpophalangeal joint flexion of thumb (bending thumb base)
Carpometacarpal opposition (thumb to fingers)

Innervation

Median and ulnar nerves

Muscle Relationships

Antagonists

Extensor pollicis longusAbductor pollicis longus

Synergists

Opponens pollicisFlexor pollicis longus

Trigger Points

Thenar base, referring to thumb pad and radial palm.

Stretches

1Thumb opposition stretch

2Finklestein stretch variation

3Thenar palm stretch

Common Conditions

De Quervain's tenosynovitisThumb carpometacarpal osteoarthritis

Anatomical Parts

Superficial head of left flexor pollicis brevisLeft flexor pollicis brevisSuperficial head of right flexor pollicis brevisRight flexor pollicis brevis

FAQ

Flexor pollicis brevis function

Flexes thumb base for pinching and opposition.

Flexor pollicis brevis pain

From repetitive thumb use; rest and thumb stretches help.

Thumb flexor pain

Often flexor pollicis brevis strain; ice and avoid pinching.

Flexor pollicis brevis stretch

Gently pull thumb away from palm.

Exercises for flexor pollicis brevis

20

Bottoms-Up Clean From The Hang Position position 1

Bottoms-Up Clean From The Hang Position position 2

Bottoms-Up Clean From The Hang Position

intermediate·kettlebells

Cable Wrist Curl position 1

Cable Wrist Curl position 2

Cable Wrist Curl

beginner·cable

Dumbbell Lying Pronation position 1

Dumbbell Lying Pronation position 2

Dumbbell Lying Pronation

intermediate·dumbbell

Dumbbell Lying Supination position 1

Dumbbell Lying Supination position 2

Dumbbell Lying Supination

intermediate·dumbbell

Farmer's Walk position 1

Farmer's Walk position 2

Farmer's Walk

intermediate·other

Finger Curls position 1

Finger Curls position 2

Finger Curls

beginner·barbell

Kneeling Forearm Stretch position 1

Kneeling Forearm Stretch position 2

Kneeling Forearm Stretch

Palms-Down Dumbbell Wrist Curl Over A Bench position 1

Palms-Down Dumbbell Wrist Curl Over A Bench position 2

Palms-Down Dumbbell Wrist Curl Over A Bench

beginner·dumbbell

Palms-Down Wrist Curl Over A Bench position 1

Palms-Down Wrist Curl Over A Bench position 2

Palms-Down Wrist Curl Over A Bench

beginner·barbell

Palms-Up Barbell Wrist Curl Over A Bench position 1

Palms-Up Barbell Wrist Curl Over A Bench position 2

Palms-Up Barbell Wrist Curl Over A Bench

beginner·barbell

Palms-Up Dumbbell Wrist Curl Over A Bench position 1

Palms-Up Dumbbell Wrist Curl Over A Bench position 2

Palms-Up Dumbbell Wrist Curl Over A Bench

beginner·dumbbell

Plate Pinch position 1

Plate Pinch position 2

Plate Pinch

intermediate·other

Rickshaw Carry position 1

Rickshaw Carry position 2

Rickshaw Carry

intermediate·other

Seated Dumbbell Palms-Down Wrist Curl position 1

Seated Dumbbell Palms-Down Wrist Curl position 2

Seated Dumbbell Palms-Down Wrist Curl

beginner·dumbbell

Seated Dumbbell Palms-Up Wrist Curl position 1

Seated Dumbbell Palms-Up Wrist Curl position 2

Seated Dumbbell Palms-Up Wrist Curl

beginner·dumbbell

Seated One-Arm Dumbbell Palms-Down Wrist Curl position 1

Seated One-Arm Dumbbell Palms-Down Wrist Curl position 2

Seated One-Arm Dumbbell Palms-Down Wrist Curl

intermediate·dumbbell

Seated One-Arm Dumbbell Palms-Up Wrist Curl position 1

Seated One-Arm Dumbbell Palms-Up Wrist Curl position 2

Seated One-Arm Dumbbell Palms-Up Wrist Curl

beginner·dumbbell

Seated Palm-Up Barbell Wrist Curl position 1

Seated Palm-Up Barbell Wrist Curl position 2

Seated Palm-Up Barbell Wrist Curl

beginner·barbell

Seated Palms-Down Barbell Wrist Curl position 1

Seated Palms-Down Barbell Wrist Curl position 2

Seated Palms-Down Barbell Wrist Curl

beginner·barbell

Seated Two-Arm Palms-Up Low-Pulley Wrist Curl position 1

Seated Two-Arm Palms-Up Low-Pulley Wrist Curl position 2

Seated Two-Arm Palms-Up Low-Pulley Wrist Curl

beginner·cable

Also Works flexor pollicis brevis

10

Alternate Hammer Curl position 1

Alternate Hammer Curl position 2

Alternate Hammer Curl

beginner·dumbbell

Alternate Incline Dumbbell Curl position 1

Alternate Incline Dumbbell Curl position 2

Alternate Incline Dumbbell Curl

beginner·dumbbell

Alternating Hang Clean position 1

Alternating Hang Clean position 2

Alternating Hang Clean

intermediate·kettlebells

Atlas Stone Trainer position 1

Atlas Stone Trainer position 2

Atlas Stone Trainer

intermediate·other

Atlas Stones position 1

Atlas Stones position 2

Atlas Stones

Axle Deadlift position 1

Axle Deadlift position 2

Axle Deadlift

intermediate·other

Backward Drag position 1

Backward Drag position 2

Backward Drag

beginner·other

Band Assisted Pull-Up position 1

Band Assisted Pull-Up position 2

Band Assisted Pull-Up

beginner·other

Barbell Curl position 1

Barbell Curl position 2

Barbell Curl

beginner·barbell

Barbell Deadlift position 1

Barbell Deadlift position 2

Barbell Deadlift

intermediate·barbell

Related Hand Muscles

Abductor digiti minimi of left hand

Located in the pinky side of the left palm, this muscle fans out the little finger for grip adjustments in sports or tools. It supports fine motor control and power grip stability. Climbers and grip athletes rely on it for pinky strength.

Abductor digiti minimi of right hand

In the right hand's hypothenar area, this muscle abducts the pinky finger, enhancing grip width for tools or sports. Crucial for musicians and weightlifters needing precise finger spread. Builds hand endurance.

abductor pollicis brevis

The thenar muscle at the thumb base abducts the thumb for pinch grips and opposition. Essential for fine tasks like texting or tools. Thumb trainers value it for dexterity.

adductor pollicis

Deep thumb adductor pulls thumb toward palm for key pinch strength. Vital for gripping keys or tools. Handstrength pros train it hard.

Flexor digiti minimi brevis of left hand

In the left hand's hypothenar eminence, this muscle flexes the pinky finger at its base for power grips. Key for musicians and rock climbers needing pinky strength. Enhances grip variety in fitness.

Flexor digiti minimi brevis of right hand

Right hand hypothenar muscle flexing pinky MCP joint for grip power. Essential for right-handed tools.

Flexor retinaculum of left wrist

The flexor retinaculum (transverse carpal ligament) is a thick band across the palmar wrist forming the carpal tunnel roof. It holds flexor tendons in place during wrist motion, vital for grip strength in fitness. Imbalances affect hand endurance.

Flexor retinaculum of right wrist

The right wrist's flexor retinaculum secures flexor tendons through the carpal tunnel, enabling smooth wrist flexion in daily and athletic tasks. It supports grip integrity during pulls and presses. Dysfunction leads to hand fatigue.

Hand Pain Guide

Common causes and relief

Activities & Sports

See which activities use flexor pollicis brevis