GENERAL INFORMATION
The Palmaris Longus is a muscle located in the anterior compartment of the forearm. It is a slender muscle that runs along the inner side of the forearm as well as plays a minor role in flexing the wrist as well as tensioning the palmar aponeurosis.
ORIGIN
The Palmaris Longus originates from:
- Medial epicondyle of the humerus: Bony prominence on the inner side of the elbow.
INSERTION POINT
It inserts onto:
- Palmar aponeurosis: A fibrous structure on the palm.
MAJOR ARTERIES
The Palmaris Longus muscle receives its blood supply from branches of the ulnar artery.
NEURAL INNERVATION
This muscle is innervated by the median nerve, which originates from the brachial plexus.
TRIGGER POINT
Trigger points in the Palmaris Longus muscle are relatively rare but may cause localised pain in the forearm as well as refer to pain in the palm.
CONCENTRIC FUNCTION
The concentric function of this muscle involves the contraction of its muscle fibres, also resulting in:
- Flexion of the wrist.
- It assists in tensioning the palmar aponeurosis and provides support to the palm.
ECCENTRIC FUNCTION
The eccentric function of the Palmaris Longus muscle occurs when the muscle fibres lengthen under tension. It aids in:
- Controlling the extension of the wrist.
- They are releasing tension from the palmar aponeurosis.
ISOMETRIC FUNCTION
The isometric function of the Palmaris Longus muscle involves contracting and generating tension without changing its length. This function helps stabilise the wrist joint during activities that require a static hold as well as resistance.
RELATED MUSCLE SCIENTIFIC NAMES
There are no directly related muscle scientific names to list under this category for the Palmaris Longus.
ANTAGONIST MUSCLES
- Extensor Carpi Radialis Longus: Extends and abducts the wrist, opposing the flexion action of the Palmaris Longus.
- Extensor Carpi Radialis Brevis: Extends and abducts the wrist, counteracting the flexor actions of the Palmaris Longus.
COMMON INJURIES
- Palmaris Longus Tendinitis: Inflammation or irritation of this tendon, typically occurring at its insertion point or along the course of the tendon. It may cause pain and reduced wrist function.
- Absence or Variations: The Palmaris Longus muscle is absent in a significant portion of the population without causing functional deficits. However, variations can occasionally lead to diagnostic confusion.
EXERCISES
- Wrist flexion exercises: Hold a dumbbell with the palm facing up and curl the wrist upward to strengthen the Palmaris Longus and other wrist flexors.
- Wrist curls: Use a dumbbell or resistance band to perform wrist curls, targeting the Palmaris Longus and enhancing wrist flexion strength.
- Grip strengthening exercises: Squeeze a grip strengthener or stress ball, focusing on the muscles of the forearm, including the Palmaris Longus, to improve overall grip strength.
- Forearm pronation and supination exercises: Hold a dumbbell and rotate the forearm from palm-up to palm-down and vice versa. They are targeting the pronator and supinator muscles for forearm strength and flexibility.
- Wrist extension exercises: Hold a dumbbell with the palm facing down and curl the wrist upward to engage the wrist extensors, balancing the strength of the forearm muscles.
STRETCHES
- Wrist flexor stretch: Extend the arm forward, palm up, and gently pull the fingers back with the other hand to stretch the wrist flexors. It may include the Palmaris Longus.
- Wrist extensor stretch: Extend the arm with the palm facing down and gently pull the fingers back with the other hand to stretch the wrist extensors.
- Forearm stretch: Extend the arm with the palm facing down and gently pull back on the hand to stretch the forearm muscles.
- Finger and hand stretches: Spread the fingers wide and hold, then bring them together, repeating to increase flexibility and reduce tension in the hand and fingers.
- Palmar aponeurosis stretch: Extend the fingers and palm, then gently press the palm outward with the other hand to stretch the palmar aponeurosis.