What is the flexor carpi ulnaris muscle?
The flexor carpi ulnaris is a muscle in the forearm that is responsible for bending the wrist towards the direction of the little finger as well as turning the hand palm down.
It is one of several muscles (pronator teres, palmaris longus, flexor digitorum superficialis and flexor carpi radialis) that work together to control the movement of the wrist and hand. When this muscle contracts, it pulls on the bones in the wrist, causing the wrist to bend. This muscle is often used in activities such as typing, playing musical instruments and weightlifting. (1)
Origin, insertion and function
Origin
- The flexor carpi ulnaris muscle originates from the medial epicondyle of the humerus (the inner bump on the elbow) and the adjacent supinator crest of the ulna (one of the bones in the forearm).
Insertion
- The muscle then runs down the forearm and inserts on the pisiform, the hamate bone and the base of the 5th metacarpal bone (the bone in the hand that connects to the little finger).
Function
- The main function of the flexor carpi ulnaris is to bend the wrist towards the little finger side (i.e. flexion) and also helps in turning the hand palm down (i.e. pronation).
- It also helps in stabilizing the wrist and gripping objects.
- This muscle works in conjunction with other muscles in the forearm to control the movement of the wrist and hand.
- The flexor carpi ulnaris muscle is often used in activities such as typing, playing musical instruments and weightlifting.
![flexor carpi ulnaris muscle](https://upload.wikimedia.org/wikipedia/commons/7/75/Flexor_carpi_ulnaris.png)
Common signs of weak flexor carpi ulnaris muscles
Common signs of a weak flexor carpi ulnaris muscle include:
- Difficulty or inability to flex the wrist towards the little finger side
- Weak grip strength
- Wrist instability
- Pain or discomfort in the inner forearm, especially during activities that involve gripping or wrist flexion
- Reduced range of motion in the wrist
- Clumsiness or difficulty performing fine motor tasks
- Difficulty in playing musical instruments
- Weakness in pronation of the hand
- Tendency to drop objects
- Loss of muscle mass on the inner side of the forearm.
Exercises to help strengthen the flexor carpi ulnaris
Here are a few exercises that can help to strengthen the flexor carpi ulnaris muscle:
Wrist flexion with a resistance band:
- Sit or stand with your arm extended in front of you, palm facing down.
- Hold one end of a resistance band in your hand and wrap the other end around a fixed object.
- Slowly flex your wrist towards your little finger as far as you can, then return to the starting position.
- Repeat this movement for 2-3 sets of 10-15 reps, using a light to moderate resistance band.
Reverse wrist curl with a dumbbell:
- Sit at a table or bench with your forearms resting on the surface, palms facing down and holding a dumbbell.
- Slowly raise your hand by flexing your wrist, then lower it back down.
- Repeat for 2-3 sets of 10-15 reps, using a light to moderate weight.
Wrist extension with a resistance band:
- Sit or stand with your arm extended in front of you, palm facing up.
- Hold one end of a resistance band in your hand and wrap the other end around a fixed object.
- Slowly extend your wrist as far as you can, then return to the starting position.
- Repeat this movement for 2-3 sets of 10-15 reps, using a light to moderate resistance band.
Pronation and supination with a weight:
- Sit or stand with your arm extended in front of you, holding a weight such as a can or bottle.
- Slowly rotate your hand so your palm is facing down (pronation), then rotate it back so your palm is facing up (supination).
- Repeat this movement for 2-3 sets of 10-15 reps, using a light weight
It’s important to note that before starting any exercise program, it’s always best to consult with a healthcare professional to ensure that the exercises are appropriate for you and that you perform them correctly to avoid any injury.
References:
- Lung BE, Siwiec RM. Anatomy, Shoulder and Upper Limb, Forearm Flexor Carpi Ulnaris Muscle. [Updated 2022 Jun 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526051/