Flexor Digiti Minimi Brevis
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Description[edit | edit source]
The word "thenar" means fleshy mounds. There are two fleshy mounds located in the palmar surface of the hand. These thenar mounds are called the thenar eminence and the hypothenar eminence. The thenar eminence is the fleshy mound at the base of the thumb. The hypothenar eminence is the mound located at the base of the fifth digit (little finger). The muscles located in the thenar eminence function primarily to control the thumb.The hypothenar eminence is on the medial side of the hand. This group of muscles is considered intrinsic muscles of the hand. The muscles present in the hypothenar eminence will contract and manifest motion through the little finger.
The hypothenar eminence is made up of four muscles. The four muscles are
- The abductor digiti minimi muscle,
- The flexor digiti minimi brevis muscle,
- The opponens digiti minimi muscle, and
- The palmaris brevis muscle. These muscles contract and create specific movements to the little finger.[1]
Origin[edit | edit source]
The muscle originates from the hook of hamate and flexor retinaculum (Transverse carpal ligament) .This muscle lies laterally to the abductor digiti minimi.[2]
Insertion[edit | edit source]
It inserts into the medial side of base of the proximal phalanx of the little finger.
Nerve[edit | edit source]
Deep branch of Ulnar nerve
Artery[edit | edit source]
Ulnar artery
Function[edit | edit source]
Flexes the Metacarpophalangeal joint of the little finger.
Clinical relevance[edit | edit source]
As the ulnar nerve passes between the hook of the hamate and pisiform bone (Guyon's canal), it can become compressed. Individuals that apply direct pressure to the Guyon canal such as cyclists can damage the ulnar nerve. Damage to the ulnar nerve will manifest as atrophy, numbness, tingling, and pain in the hypothenar eminence along with the fourth and fifth digits. This condition is the same as "carpal tunnel syndrome," but it affects the ulnar nerve.[3]
The hypothenar eminence can become damaged if the ulnar artery is compromised, and there is insufficient collateral blood flow. This condition is called the "hypothenar hammer syndrome: This condition tends to affect individuals that work with tools that need tight gripping and repetitive pounding of the tool. The tight grip and pounding of tools will cause a recoil impact on the vascular blood supply in the hypothenar eminence. If the blood supply becomes compromised, there will be necrosis of the hypothenar eminence.[4][5]
Resources[edit | edit source]
- ↑ https://www.ncbi.nlm.nih.gov/books/NBK546622/
- ↑ https://teachmeanatomy.info/upper-limb/muscles/hand/
- ↑ Ramage JL, Varacallo M. StatPearls [Internet]. StatPearls Publishing; Treasure Island (FL): Sep 8, 2020. Anatomy, Shoulder and Upper Limb, Hand Guyon Canal.
- ↑ Kitzinger HB, van Schoonhoven J, Schmitt R, Hacker S, Karle B. Hypothenar Hammer Syndrome: Long-Term Results After Vascular Reconstruction. Ann Plast Surg. 2016 Jan;76(1):40-5.
- ↑ Zhang F, Weerakkody Y, Tosenovsky P. Hypothenar hammer syndrome in an office worker. J Med Imaging Radiat Oncol. 2017 Dec;61(6):774-776.
