Palm of Hand and Sole of Foot Flashcards
Which property of the palm of the hand enabled gripping ?
The skin is firmly bound to the underlying palmar aponeurosis, which contains a series of potential spaces and layers of fascia and muscle (including thenar and hypothenar muscles)
What is the PALMAR APONEUROSIS ?
Triangular condensation of deep fascia
Where do vessels, nerves, and long flexor tendons lie, relative to the palmar aponeurosis ?
Deep to it
Describe more features of the palmar aponeurosis.
- Thickens as 4 longitudinal bands (with connections) that continue with the fibrous flexor sheaths
- Sends septae to the 3rd and 5th metacarpals to create compartments and potential spaces (e.g. midpalmar space, thenar space.
How is the midpalmar space continuous with the forearm ?
Via the carpal tunnel.
What are the thenar muscles ?
Where are they located ?
How are they innervated ?
- Abductor pollicis brevis (median nerve)
- Opponens pollicis (median nerve)
- Flexor pollicis brevis (median and ulnar nerve)
- Adductor pollicis (ulnar nerve)
Located around the thumb
What are the hypothenar muscles ?
Where are they located ?
How are they innervated ?
- Abductor digiti minimi
- Flexor digiti minimi brevis
- Opponens digiti minimi
- Palmaris brevis
Located around the 5th finger
All supplied by the ulnar nerve
Are thenar and hypothenar muscles intrinsic or extrinsic ?
Intrisinc
How does the thenar muscles help movements of the thumb ?
Thenar muscles give precision to thumb movements, esp. for opposition
How many lumbrical muscles are there in one hand ?
How many interosseal muscles ?
4 3 (palmar interossei) + 4 (dorsal interossei) = 7
What is the origin and insertion of lumbrical muscles ?
Origin: tendons of deep flexors
Insertion: extensor expansions
What is the origin and insertion of palmar interosseal muscles ?
Origin: metacarpals
Insertion: extensor expansions
What is the origin and insertion of dorsal interosseal muscles ?
Origin: metacarpals
Insertion: extensor expansions
What movements are performed by the palmar interosseal muscles ?
Adduction of fingers (PAD)
Flexion of MCP joint
Extension of IP joint
What movements are performed by the dorsal interosseal muscles ?
Abduction of fingers (DAB)
Flexion of MCP joint
Extension of IP joint
What are the lumbrical, palmar interosseal, and dorsal interosseal muscles respectively innervated by ?
Lumbrical: Lateral 2 by Median nerve, medial 2 by Ulnar Nerve
Palmar Interosseal: Ulnar nerve
Dorsal Interosseal: Ulnar nerve
Acting together, what movements can lumbricals and interosseal muscles bring about ?
Flexion of MCP joint
Extension of IP joint
Which root supplies the small muscles of the hand ?
T1 (through either ulnar and/or median)
Describe the location of the extensor retinaculum, relative to surrounding structures.
Between radius, styloid process of ulna, triquetrum and pisiform
What is the function of the extensor retinaculum ?
Holds the extensor tendons in place, in synovial sheaths against the posterior aspects of the radius and ulna.
How many synovial canals run under the extensor retinaculum?
Name the muscles going through each synovial canal under the extensor retinaculum, lateral to medial.
6
- Abductor Pollicis Longus with Extensor Pollicis Brevis
- Extensor Carpi Radialis Longus and Brevis
- Extensor Pollicis Longus
- Extensor Digitorum and Extensor Indicis
- Extensor Digiti Minimi
- Extensor Carpi Ulnaris
What is the flexor retinaculum ? Describe its layers.
A band of antebrachial fascia
Superficial palmar carpal ligament and Deep transverse carpal ligament
Describe the location of the ligaments making up flexor retinaculum, relative to surrounding structures. Are they attached to each other ?
Superficial palmar carpal ligament: Extends between styloid processes of radius and ulna
Deep transvers carpal ligament: Extends between pisiform, hook of hamate, scaphoid and trapezium
Yes, except where ulnar nerve and artery pass

What forms the roof and floor of the carpal tunnel ?
Floor: Proximal row carpal bones
Roof: Flexor retinaculum
What is the main function of the carpal tunnel ?
Transmits median nerve and the tendons of superficial and deep flexors of the fingers
Where does the ulnar nerve pass, relative to the carpal tunnel ?
Anterior/superficial to it, in Guyon’s Canal
What is the anatomical snuff box ? What does it contain ?
A triangular depression found on the lateral aspect of the dorsum of the hand.
Contains Radial Artery and branches of the Radial Nerve, the Cephalic Vein
Which bones form the base of the anatomical snuff box ?
Scaphoid and trapezium
Describe the arrangement of the tendons of Flexor Digitorum Superficialis and Profundus.
Tendons of Flexor Digitorum Superficialis and Profundus pass behind the Flexor Retinaculum in a common, synovial sheath, which ends in the palm – except for the little finger
The tendons of Flexor Digitorum Superficialis split and attach to the middle phalanx
The tendons of Flexor Digitorum Profundus pass through the split tendons of Superficialis and attach to the distal phalanx
Describe the function and structural features of the plantar aponeurosis.
Plantar aponeurosis
- Function: grip and weight bearing
- Structure: thickens as 5 longitudinal bands that
continue with the fibrous flexor sheaths. Sends septae to the metatarsals to create compartments and potential spaces
What are the roles of plantar muscles (besides the actions implied by their names) ?
Arch support, adjustment of balance and gait
How are the plantar muscles innervated ?
By lateral or medial plantar nerves
How many layers of plantar muscles are there ?
5
Identify the muscle in the first layer of plantar muscle.
Determine whether each one if innervated by lateral or medial plantar nerve.
LAYER 1
Abductor digiti minimi (L)
Flexor Digitorum Brevi (M)
Abductor hallis (M)
Identify the muscle in the second layer of plantar muscle.
Determine whether each one if innervated by lateral or medial plantar nerve.
LAYER 2 Lumbricals 1 (M), 2-4 (L) Quadratus plantae (M)
Identify the muscle in the third layer of plantar muscle.
Determine whether each one if innervated by lateral or medial plantar nerve.
LAYER 3
Flexor digiti minimi brevis (L)
Adductor hallucis (L)
Flexor hallucis brevis (M)
Identify the muscle in the fourth layer of plantar muscle.
Determine whether each one if innervated by lateral or medial plantar nerve.
LAYER 4 Plantar Interosseal (L) Dorsal Interosseal (L)
What is the fundamental difference between interosseals of the hand and of the foot ?
Palmar interossei bones of the hand are attached to the index, ring, and little fingers
Plantar interossei bones of the foot are attached to the 3rd through 5th toe
What is the difference between the RETINACULA around the ANKLE and those around the wrist ?
3 around the ankle
2 around the wrist
Identify the 3 retinacula around the ankle, along with the function of each.
- Extensor (keeps tendons in place)
- Fibular (keeps fibular tendons in place)
- Flexor
Describe the content of the tarsal tunnel.
4 channels
3 of them synovial sheaths with the tendons of tibialis posterior (first channel), flexor digitorum longus (second channel), and flexor hallucis longus (fourth channel)
1 of them contains arteries, veins, and tibial nerve
Describe the boundaties of the tarsal tunnel.
Roof: flexor retinaculum
Floor: medial surfaces of the tibia (medial malleolus), talus, calcaneus, Inferior surface of the sustentaculum tali
How many plantar arches are there ? What is their name ?
Three total 2 Longitudinal (Medial and Lateral) and a Transverse
What is the function of plantar arches ?
Weight bearing/distribution; shock absorption; resilience
How are the arches supported ?
- Shape of bones
- Ligaments: Passive support
- Muscles: Dynamic (Active) support
What are some of the supports of the arches of the foot (specific bones, ligaments, and muscles) ?
LIGAMENTS:
Short and Long Plantar ligaments
Spring Ligament
Plantar Aponeurosis
MUSCLES: Fibularis Longus Tibialis Anterior Tibialis Posterior Flexor Hallucis (and Digitorum) Longus Intrinsic muscles of the Foot
BONES:
1st Cuneiform
Navicular
Sustentaculum Tali
What is present in Guyon’s canal ?
Ulnar nerve
Which muscles are responsible for inversion ?
Main: Tibialis anterior and tibilias posterior
Which muscles are responsible for eversion ?
Main: Fibularis [peroneus] longus and Fibularis [peroneus] brevis
What is the origin and insertion of the inverters of the foot ?
TIBIALIS ANTERIOR
Origin: Lateral condyle and superior-lateral surface of tibia and interosseous membrane
Insertion: medial cuneiform and base of 1st metatarsal
TIBIALIS POSTERIOR
Origin: Interosseous membrane, posterior surface of tibia inferior to soleal line, and posterior surface of fibula
Insertion: Tuberosity of navicular, medial cuneiform
What is the origin and insertion of the everters of the foot ?
FIBULARIS PERONEUS LONGUS
Origin: Fibula and intermuscular septum
Insertion: Medial cuneiform and 1st metatarsal
FIBULARIS PERONEUS BREVIS
Origin: Fibula and intermuscular septum
Insertion: 5th metatarsal
How are the inverters of the foot innervated ?
Tibialis anterior by deep peroneal nerve
Tibilias posterior by tibial nerve
How are the everters of the foot innervated ?
Superficial fibular [peroneal] nerve
What are other functions of fibularis peroneus longus, besides eversion of the foot ?
Supports the lateral longitudinal plantar arch and allows standing on one leg
What are other functions of fibularis peroneus brevis, besides eversion of the foot ?
Acts against transverse plantar arch
Where do tendons of fibular muscles pass, relative to the lateral malleolus
Behind the lateral malleolus
What movements are performed by lumbrical muscles ?
Flexion of Metacarpophalangeal joint (MCP)
Extension of Interphalangeal joints (IP)
