The Foot - Intrinsic Muscles Flashcards
(104 cards)
1
Q
Where are the intrinsic muscles of the foot located? What movements are they responsible for?
A
The intrinsic muscles are located within the foot and are responsible for the fine motor actions of the foot, for example movement of individual digits.
2
Q
What 2 groups can the intrinsic muscles of the foot be divided into?
A
Dorsal and plantar aspect
3
Q
Which intrinsic muscles are located in the dorsal aspect of the foot?
A
- Extensor digitorum brevis
- Extensor hallucis brevis
- A group of 4 dorsal interossei (between the metatarsals)
4
Q
Where does EDB lie?
A
Lies deep to EDL
5
Q
Origin and insertion of EDB?
A
Origin: calcaneus
Inserts: proximal phalanges of digits 2-5
6
Q
Action of EDB?
A
Aids the extensor digitorum longus in extending the medial four toes at the metatarsophalangeal and interphalangeal joints.
7
Q
Innervation of EDB?
A
Deep fibular nerve
8
Q
Origin and insertion of EHB?
A
Origin: calcaneus
Inserts: proximal phalanx of big toe
9
Q
Action of EHB?
A
Aids the extensor hallucis longus in extending the great toe at the metatarsophalangeal joint.
10
Q
Innervation of EHB?
A
Deep fibular nerve
11
Q
Where are the 4 dorsal interossei located?
A
Between the metatarsals. Each arises from two metatarsals.
12
Q
Origin and insertion of the dorsal interossei?
A
Originates from the sides of metatarsals one to five. The first muscle attaches to the medial side of the proximal phalanx of the second digit. The second to fourth interossei attach to the lateral sides of the proximal phalanxes of digits two to four.
13
Q
Action of the dorsal interossei?
A
Abduct digits two to four and flex the metatarsophalangeal joints.
14
Q
Innervation of the dorsal interossei?
A
Lateral plantar nerve
15
Q
How are the intrinsic muscles of the plantar aspect of the foot arranged?
A
Arranged in four layers, superficial to deep
16
Q
What muscles are found in the most superficial layer of the plantar aspect?
A
Flexor digitorum brevis, abductor hallucis, abductor digiti minimi
17
Q
What muscles are found in the second most superficial layer of the plantar aspect?
A
The tendons of FHL and FDL (extrinsic muscles), the lumbricals, quadratus plantae
18
Q
What muscles are found in the third most superficial layer of the plantar aspect?
A
Flexor hallucis brevis, flexor digiti minimi and adductor hallucis
19
Q
What muscles are found in the deepest layer of the plantar aspect of the foot?
A
The plantar interossei - there are 3 of these
20
Q
Function of the muscles of the superficial layer of the plantar aspect?
A
- Abductor Hallucis - abducts and flexes the great toe
- Flexor Digitorum Brevis - Flexes the lateral four digits at the proximal interphalangeal joints.
- Abductor Digiti Minimi - Abducts and flexes the 5th digit.
21
Q
Function of the second layer of the muscles of the plantar aspect?
A
- Quadratus Plantae - Assists flexor digitorum longus in flexing the lateral four digits.
- Lumbricals - Flexes at the metatarsophalangeal joints, while extending the interphalangeal joints.
22
Q
Function of the third layer of the muscles of the plantar aspect?
A
- Flexor Hallucis Brevis - Flexes the proximal phalanx of the great toe at the metatarsophalangeal joint.
- Adductor Hallucis - Adduct the great toe. Assists in forming the transverse arch of the foot.
- Flexor Digiti Minimi Brevis - Flexes the proximal phalanx of the fifth digit
23
Q
Function of the deepest layer of muscles of the plantar aspect?
A
Plantar interossei - Adduct digits three to five and flex the metatarsophalangeal joints.
24
Q
Where does flexor hallucis longus insert?
A
Distal phalanx of big toe (sole of foot)
25
Where does fibularis longus insert?
Sole of the foot --\> medial cuneiform and 1st metatarsal
26
Where does extensor digitorum longus insert?
Dorsum of foot --\> distal phalanges of digits 2-5
27
What is being pointed to?
Subtalar joint - between the calcaneum and talus
Eversion and inversion happens here
28
What?
Navicular
29
What?
Cuboid
30
What?
Lateral cuneiform
31
The foot can deform according to what surface it is walking on. What is the purpose of this?
Helps to dissipate the forces --\> shock absorber
32
Normal foot xrays
33
A 50 year old woman presented to her GP with deformity and pain in her feet.
This had been going on for some time, but the pain was now becoming severe and she was finding it painful to wear shoes.
What’s the diagnosis?
Bunions - 'hallux valgus'
34
How would you describe the abnormalities seen? What are some causative factors?
* Deformities at the MTP joints of both feet
* Bony protrustion is the head of the first metatarsal
* Causative factors:
* High heels
* Poorly fitting shoes over a long period of time
* Genetic element
35
A 48 year old man presented to his GP with with sudden onset severe pain, swelling and redness of his left foot, as shown. The patient was hobbling and wearing a flip-flop, as it was too painful for him to put on a shoe or sock.
What’s the diagnosis?
* Gout
* Typically first attack in 1st MTP joint
* Sudden onset of pain
36
How would you describe the abnormalities seen in this X-ray?
What’s happening inside the affected joints?
* X-ray of gout
* Joint erosion
37
This patient had a history of pain and swelling in his right foot.
How would you describe the abnormalities seen?
* X-ray of gout
* Long term chronic gout can cause **tophi** --\> nodular masses of monosodium **urate crystals** deposited in the soft tissues of the body
* Punched out regions
38
This patient had a history of chronic left foot pain and previous episodes of gout.
How would you describe the abnormalities seen?
* Erosions at 1st MTPJ
39
A 26 year old man presented to A&E one evening with severe pain in his right heel. Earlier that day he had fallen about 2m from scaffolding at work, but had landed on his feet. His foot was painful immediately after but he thought it would get better. The pain however is worsening and he can’t walk on that foot because of pain.
* What’s the diagnosis?
* What action should be taken now?
* 2 radiolucent lines in the calcaneum --\> fracture of the calcaneum
* Need to examine lower limbs, joints, pelvis, vertebral column
* Large forces required to break calcaneum
40
On a Radiology placement the registrar asks you what you think about this X-ray.
* How would you describe the abnormalities in this X-ray?
* Which joints are affected? What has happened to them?
* What’s the diagnosis?
* Rheumatoid arthritis
* Predominantly affects the MTP joints and PIP joints
41
The intrinsic muscles in the sole of the foot are innervated by which nerves?
* Lateral and medial plantar nerves
42
What is this?
Plantar aponeurosis - a flat band of fibrous tissue that lies deep to the skin
43
Where does pain from plantar fascitis tend to present?
Heel pain which radiates forward into the sole of the foot
44
What is this?
Abductor hallucis --\> tendon travels up on medial aspect of big toe
45
What is this?
Abductor digiti minimi --\> tendon runs up on lateral aspect of 5th digitis
46
What is this?
Flexor digitorum brevis --\> 4 tendons that run to each tendon, assists flexor digitorum longus in flexing the toes
47
What is characteristic of the 2nd layer of the sole of the foot?
Tendon of flexor digitorum longus (running through middle towards toes)
48
Which malleolus does flexor digitorum longus pass to get into the foot?
Its tendon passes behind the **medial malleolus** of the ankle, and enters the sole in its medial side.
49
Which muscles arise from the tendons of FDL?
Lumbricals
50
What is this? What is its action?
Quadratus plantae --\> inserts onto tendon of FDL and assists FDL in flexing the toes
51
What nerve is this?
Medial plantar nerve
52
What nerve is this?
Lateral plantar nerve
53
What are the medial and lateral plantar nerves the terminal branches of?
The tibial nerve
54
How does the tibial nerve enter the foot?
Passes down posterior aspect of leg and behind the medial malleolus into the sole of the foot
55
What do the medial and plantar nerves innervate?
The muscles of the sole of the foot
56
What is this tendon?
Tendon of flexor hallucis longus
57
How does the tendon of FHL enter the foot?
Down posterior leg and behind the medial malleolus
58
What is this fleshy muscle directly deep to FHL tendon? What layer of the sole of the foot is this found in?
Flexor hallucis brevis muscle - found in 3rd layer
59
Flexor hallucis brevis is mirrored on the opposite side. What fleshy muscle is this? What layer of the sole of the foot is this found in?
Flexor digiti minimi --\> found in 3rd layer of the foot
60
What muscle is found alongside FHB and FDM in the 3rd layer?
Adductor hallucis
61
What is this?
Abductor hallucis
62
What is this?
Abductor digiti minimi
63
What is this?
Flexor digitorum brevis
64
What is this?
Quadratus plantae
65
What is this?
Tendons of FDL
66
What are these? What are they attached to?
Lumbricals - attached to tendons of FDL
67
What is this?
Tendon of FHL
68
What is this?
Muscle of FHB
69
What is this?
FDM
70
What are the muscles of the 3rd layer of the foot?
1. Flexor hallucis brevis
2. Flexor digiti minimi
3. Adductor hallucis
71
What is this?
Oblique part of adductor hallucis (N.B. also has a transverse head but this has been removed)
72
What is this?
Tendon of FHL
73
What are these?
The plantar interossei (3 of them)
74
Sensory innervation of the sole of the foot
75
What is the saphenous nerve a branch of?
The terminal cutaneous branch of the **femoral nerve.** It travels through the adductor canal (accompanied by the femoral artery and vein) and exits prior to the adductor hiatus.
76
What skin of the sole of the foot does the medial plantar nerve innervate?
Medial 3 1/2 toes
77
What skin of the sole of the foot does the lateral plantar nerve innervate?
Lateral 1 1/2 toes
78
What skin of the sole of the foot does the tibial nerve innervate?
Sole of foot near heel
79
What supplies the majority of the sensory innervation of the sole of the foot?
The tibial nerve or its branches
80
What supplies the majority of the sensory innervation of the dorsum of the foot?
Superficial fibular nerve
81
Innervation of dorsum of the foot
82
What is this a tendon of?
Tibialis anterior
83
What is this?
The 1st dorsal interosseus
84
What is this vessel? What is it a continuation of?
Dorsalis pedis artery - continuation of the anterior tibial artery
85
What runs alongside dorsalis pedis?
2 deep veins (on either side)
86
What is this very fine structure? How does it enter the foot? What happens when it approaches the toes?
The **deep fibular nerve** - passes down anterior aspect of leg (innervating anterior muscles), over the dorsum and then divides into 2 branches as it approaches the toes
87
What sensory innervation does the deep fibular nerve provide in the dorsum of the foot?
1st web space (between 1st and 2nd toe)
88
What is this muscle? What is it innervated by?
Extensor digitorum brevis --\> innervated by the deep fibular nerve
89
What is this the tendon of?
Extensor hallucis longus
90
What are these the tendons of?
Extensor hallucis longus
91
What is this small muscle on the lateral aspect of the foot?
Extensor digitorum brevis
92
What tendon is this? What is this a part of?
Extensor hallucis brevis (a part of extensor digitorum brevis)
93
Function of EDB?
Sends very thin tendons to digits 2, 3 and 4 - assists EDL in extension of the toes
94
What does the deep fibular nerve innervate in the dorsum of the foot?
EDB and EHB
95
Where can you palpate the dorsalis pedis artery?
Just lateral to tendon of EHL
96
In the dorsum of the foot, where does the dorsalis pedis artery divide?
at the proximal part of the first intermetatarsal space, where it divides into two branches, the first dorsal metatarsal artery and the **deep plantar artery.**
97
What does the deep plantar artery go on to anastamose with?
Travels deep into the foot and anastamoses with branches of the plantar aspect (medial and lateral plantar arteries)
98
This 35 year old man presented to the ED with pain in his second toe after accidentally kicking something.
Can you describe the injury?
* Fracture of the proximal phalanx of the 2nd toe
99
What is a sesamoid bone?
A sesamoid bone is a bone that is inside a tendon where the tendon passes over a joint (e.g. patella)
Can be seen in this xray in big toe
100
This 40 year old man presented with on-going pain after a heavy object fell onto his left foot several days ago.
Can you describe the injury?
* 3rd metatarsal oblique fracture
101
This 60 year old woman presented to her GP with chronic pain in the medial side of her left foot for over 1 year. There was no history of trauma. Her foot appeared normal on examination, but was tender on the medial aspect.
Can you see anything that would explain the patient’s pain?
* A foreign body --\> very white line (radiopaque)
* A thin metallic object in the foot
102
An man was taken to hospital by his daughter, who was concerned about **swelling and deformity** in his right foot.
The patient’s foot wasn’t painful, and was not tender on examination, but it was clearly very swollen.
The patient’s PMH included a diagnosis of **leprosy** many years ago.
* What is the term for this abnormality?
* Why isn’t the patient’s foot painful?
* What is the cause of this abnormality in this patient?
* Not painful as a result of peripheral neuropathy
* Limited sensation in the foot
* Appearance of foot in x-ray: **Charcot joint** (often Charcot foot)
* Progressive degeneration of a weight bearing joint, a process marked by bony destruction, bone resorption, and eventual deformity due to **loss of sensation**
103
What is Charcot foot?
The progressive degeneration of a weight bearing joint, a process marked by bony destruction, bone resorption, and eventual deformity due to loss of sensation
104
What other disease, except leprosy, can lead to Charcot's foot?
Diabetes (uncontrolled)
