GENERAL INFORMATION
The flexor pollicis brevis is a short muscle located in the palm. It contributes to the movement and flexion of the thumb, enabling various gripping and pinching actions.
ORIGIN
This muscle originates from the flexor retinaculum, which is a band of connective tissue in the wrist, as well as the tubercles of the trapezium and scaphoid bones.
INSERTION POINT
The flexor pollicis brevis inserts onto the base of the proximal phalanx of the thumb.
MAJOR ARTERIES
This muscle receives its blood supply from branches of the radial artery, such as the princeps pollicis artery. These arteries provide oxygenated blood to the muscle for its proper function.
NEURAL INNERVATION
The recurrent branch of the median nerve innervates this muscle. The median nerve arises from the brachial plexus and provides motor innervation to the muscle.
TRIGGER POINT
Trigger points in this muscle may develop due to muscle tension or overuse. These trigger points can cause localised pain, tenderness, or referred pain patterns in the hand and thumb.
CONCENTRIC FUNCTION
The concentric function of the flexor pollicis brevis involves the contraction of the muscle fibres, resulting in the flexion of the thumb. This contraction allows for gripping and pinching actions.
ECCENTRIC FUNCTION
The eccentric function of this muscle occurs when the muscle fibres lengthen under tension. This function assists in controlled extension and release of the thumb.
ISOMETRIC FUNCTION
The isometric function of this muscle involves contracting and generating tension without changing the length of the muscle. This function aids in stabilising the thumb during activities that require a static hold or resistance.
RELATED MUSCLE SCIENTIFIC NAMES
Its scientific name is also known as the flexor pollicis brevis:
- Musculus flexor pollicis brevis: This muscle is crucial for the flexion of the thumb, aiding in movements such as gripping and pinching.
ANTAGONIST MUSCLES
The antagonist muscles to the flexor pollicis brevis include the extensor muscles located on the posterior side of the forearm. These muscles work in opposition to this muscle, allowing for coordinated movements of the hand and thumb.
COMMON INJURIES
Common injuries associated with the flexor pollicis brevis may include:
- Tendinitis: Inflammation or irritation of the tendon of the flexor pollicis brevis due to repetitive use or strain.
- Muscle Strain: Overexertion or sudden traumatic events can lead to strain or tears in this muscle.
EXERCISES
Exercises that target and strengthen the flexor pollicis brevis include:
- Thumb flexion exercises: Perform thumb flexion movements using resistance bands or small weights.
- Thumb opposition exercises: Touch the thumb to each fingertip to enhance skill and strength.
- Grip strengthening exercises: Squeeze a hand gripper or therapy ball to improve overall grip strength.
STRETCHES
Stretching the flexor pollicis brevis can help improve flexibility and prevent stiffness. Some stretches that target this muscle include:
- Thumb extension stretch: Extend the thumb backwards and hold the position to stretch the muscle.
- Thumb adduction stretch: Gently pull the thumb towards the palm with the opposite hand.
- Wrist flexion stretches: Flex the wrist while keeping the fingers straight to stretch the muscles in the thumb and hand.