Term
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Definition
The fascia of the palm is continuous with the antebrachial fascia and the fascia of the dorsum of the hand
The palmar aponeurosis, a strong, well-defined part of the deep fascia of the palm, covers the soft tissues and overlies the long flexor tendons.
The fibrous digital sheaths are ligamentous tubes that enclose the synovial sheaths, the superficial and deep flexor tendons, and the tendon of the FPL in their passage along the palmar aspect of their respective fingers
The flexor digital sheaths are composed of five anular and four cruciform (cross-shaped) parts |
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Term
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Definition
A medial fibrous septum extends deeply from the medial border of the palmar aponeurosis to the 5th metacarpal
Medial to this septum is the medial or hypothenar compartment containing the hypothenar muscles.
Similarly, a lateral fibrous septum extends deeply from the lateral border of the palmar aponeurosis to the 3rd metacarpal.
Lateral to this septum is the lateral or thenar compartment containing the thenar muscles
Between the hypothenar and the thenar compartments is the central compartmentcontaining the flexor tendons and their sheaths, the lumbricals, the superficial palmar arterial arch, and the digital vessels and nerves.
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Term
| Dupuytren Contracture of Palmar Fascia |
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Definition
Dupuytren contracture is a disease of the palmar fascia resulting in progressive shortening, thickening, and fibrosis of the palmar fascia and aponeurosis.
The fibrous degeneration of the longitudinal bands of the palmar aponeurosis on the medial side of the hand pulls the 4th and 5th fingers into partial flexion at the metacarpophalangeal and proximal interphalangeal joints
Treatment of Dupuytren contracture usually involves surgical excision of all fibrotic parts of the palmar fascia to free the fingers
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Term
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Definition
Because the palmar fascia is thick and strong, swellings resulting from hand infections appear usually on the dorsum of the hand, where the fascia is thinner.
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Term
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Definition
The intrinsic muscles of the hand are located in five compartments
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Thenar muscles in the thenar compartment: abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis. |
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Adductor pollicis in the adductor compartment. |
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Hypothenar muscles in the hypothenar compartment: abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi. |
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Short muscles of the hand, the lumbricals, are in the central compartment with the long flexor tendons. |
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The interossei lie in separate interosseous compartments between the metacarpals. |
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Term
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Definition
The thenar muscles form the thenar eminence on the lateral surface of the palm and are chiefly responsible for opposition of the thumb.
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Extension: extensor pollicis longus, extensor pollicis brevis, and abductor pollicis longus. |
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flexor pollicis longus and flexor pollicis brevis. |
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Abduction: abductor pollicis longus and abductor pollicis brevis. |
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: adductor pollicis and 1st dorsal interosseous. |
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Opposition: opponens pollicis. This movement occurs at the carpometacarpal joint and results in a “cupping†of the palm. Bringing the tip of the thumb into contact with the 5th finger or any of the other fingers involves considerably more movement than can be produced by the opponens pollicis alone. This complex movement begins with the thumb in the extended position and initially involves abduction and medial rotation of the 1st metacarpal (cupping the palm) produced by the action of the opponens pollicis at the carpometacarpal joint and then flexion at the metacarpophalangeal joint (Fig. 6.51). The reinforcing action of the adductor pollicis and FPL increases the pressure that the opposed thumb can exert on the fingertips. In pulp-to-pulp opposition, movements of the finger opposing the thumb are also involved.
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Term
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Definition
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Term
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Definition
| Origin |
Flexor retinaculum and tubercles of scaphoid and trapezium |
| Insertion |
Lateral side of base of proximal phalanx of thumb |
| Action |
Abducts thumb and helps oppose it |
| Innervation |
Recurrent branch of median nerve (C8 and T1) (C8, T1)
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| Arterial Supply |
Superficial palmar branch of the radial artery |
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The abductor pollicis brevis (APB), the short abductor of the thumb, forms the anterolateral part of the thenar eminence
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Term
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Definition
| Origin |
Flexor retinaculum and tubercles of scaphoid and trapezium |
| Insertion |
Lateral side of base of proximal phalanx of thumb |
| Action |
Flexes thumb |
| Innervation |
The flexor pollicis brevis is mostly innervated by the recurrent branch of the median nerve (C8, T1). The deep part is often innervated by the deep branch of the ulnar nerve.
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| Arterial Supply |
Superficial palmar branch of the radial artery
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The flexor pollicis brevis (FPB), the short flexor of the thumb, is located medial to the APB |
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Term
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Definition
| Origin |
Flexor retinaculum and tubercles of scaphoid and trapezium |
| Insertion |
Lateral side of 1st metacarpal |
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Draws 1st metacarpal laterally to oppose thumb toward center of palm and rotates it medially |
| Innervation |
Recurrent branch of median nerve (C8 and T1) (C8, T1)
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| Arterial Supply |
Superficial palmar branch of the radial artery
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The opponens pollicis opposes the thumb, the most important thumb movement.
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Term
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Definition
| Origin |
Oblique head: bases of 2nd and 3rd metacarpals, capitate, and adjacent carpals; Transverse head: anterior surface of body of 3rd metacarpal |
| Insertion |
Medial side of base of proximal phalanx of thumb |
| Action |
Draws 1st metacarpal laterally to oppose thumb toward center of palm and rotates it medially |
| Innervation |
Deep branch of ulnar nerve (C8 and T1) (C8, T1)
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| Arterial Supply |
Deep palmar arterial arch
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Term
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Definition
The hypothenar muscles (abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi) produce the hypothenar eminenceon the medial side of the palm and move the little finger.
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Term
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Definition
| Origin |
Pisiform |
| Insertion |
Medial side of base of proximal phalanx of little finger |
| Action |
Abducts little (5th) finger |
| Innervation |
Deep branch of ulnar nerve (C8 and T1) (C8, T1)
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| Arterial Supply |
Ulnar artery |
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The abductor digiti minimi is the most superficial of the three muscles forming the hypothenar eminence.
The abductor digiti minimi abducts the 5th finger and helps flex its proximal phalanx.
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Term
| Flexor Digiti Minimi Brevis |
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Definition
| Origin |
Hook of hamate and flexor retinaculum |
| Insertion |
Medial side of base of proximal phalanx of little finger |
| Action |
Flexes proximal phalanx of little (5th) finger |
| Innervation |
Deep branch of ulnar nerve (C8 and T1) (C8, T1)
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| Arterial Supply |
Ulnar artery |
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Term
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Definition
| Origin |
Hook of hamate and flexor retinaculum |
| Insertion |
Medial border of 5th metacarpal |
| Action |
Draws 5th metacarpal anteriorly and rotates it, bringing little finger (5th digit) into opposition with thumb |
| Innervation |
Deep branch of ulnar nerve (C8 and T1) (C8, T1)
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| Arterial Supply |
Ulnar artery
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Like the opponens pollicis, the opponens digiti minimi acts exclusively at the carpometacarpal joint.
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Term
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Definition
| Origin |
FDP tendon [image]
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| Insertion |
Radial lateral band of the extensor expansion (tendon) |
| Action |
Extends PIP and DIP joint. |
| Innervation |
1nd & 2nd lumbricals innervated by median nerve.
3rd & 4th lumbicals innervated by ulnar nerve
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| Arterial Supply |
Palmar 1 - 3: Palmar metacarpal arteries |
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Term
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Definition
| Origin |
Palmar 1 - 3: Palmar surfaces of 2nd, 4th and 5th metacarpals (unipennate muscles) |
| Insertion |
Palmar 1 - 3: Extensor expansions of digits and bases of proximal phalanges of digits 2, 4 and 5 |
| Action |
Palmar 1 - 3: Adduct digits toward axial line and assist lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints |
| Innervation |
Deep branch of ulnar nerve (C8 and T1) (C8, T1)
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| Arterial Supply |
Palmar 1 - 3: Palmar metacarpal arteries |
the three palmar interosseous muscles(palmar interossei) are on the palmar surfaces of the metacarpals in the interosseous compartment of the hand
The four dorsal interossei abduct the fingers, and the three palmar interossei adduct them.
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Term
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Definition
| Origin |
Dorsal 1 - 4: Adjacent sides of two metacarpals (bipennate muscles) |
| Insertion |
Dorsal 1 - 4: Extensor expansions and bases of proximal phalanges of digits 2 - 4 |
| Action |
Dorsal 1 - 4: Abduct digits from axial line and act with lumbricals to flex metacarpophalangeal joints and extend interphalangeal joints |
| Innervation |
Deep branch of ulnar nerve (C8 and T1) (C8, T1)
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| Arterial Supply |
Dorsal 1 - 4: Dorsal and palmar metacarpal arteries |
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Term
| Long Flexor Tendons and Tendon Sheaths in the Hand |
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Definition
The tendons of the FDS and FDP enter the common flexor sheath (ulnar bursa) deep to the flexor retinaculum
The tendons enter the central compartment of the hand and fan out to enter their respective digital synovial sheaths.
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Term
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Definition
Injuries such as a puncture of a finger by a rusty nail can cause infection of the digital synovial sheaths. When inflammation of the tendon and synovial sheath occurs (tenosynovitis)
Because the tendons of the 2nd, 3rd, and 4th fingers nearly always have separate synovial sheaths, the infection is usually confined to the infected finger.
The tendons of the APL and EPB are in the same tendinous sheath on the dorsum of the wrist. Excessive friction of these tendons on their common sheath results in fibrous thickening of the sheath and stenosis of the osseofibrous tunnel. |
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Term
| digital tenovaginitis stenosans (trigger finger or snapping finger). |
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Definition
Thickening of a fibrous digital sheath on the palmar aspect of the digit produces stenosis of the osseofibrous tunnel, the result of repetitive forceful use of the fingers.
If the tendons of the FDS and FDP enlarge proximal to the tunnel, the person is unable to extend the finger.
When the finger is extended passively, a snap is audible. Flexion produces another snap as the thickened tendon moves.
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