MSK anatomy Flashcards
Which muscles are involved in upper limb extension?
posterior deltoid, latissimus dorsi and teres major.
Which muscles are involved in upper limb flexion?
pectoralis major, anterior deltoid and coracobrachialis.
Biceps brachii weakly assists in forward flexion.
Which muscles are involved in upper limb abduction?
0-15 degrees of abduction is supraspinatus.
15-90 degrees middle fibres of the deltoid
Past 90 degrees, the scapula needs to be rotated to achieve abduction – trapezius and serratus anterior.
Which muscles are involved in upper limb adduction?
pectoralis major, latissimus dorsi and teres major.
Which muscles are involved in upper limb external rotation?
infraspinatus and teres minor.
Which muscles are involved in upper limb internal rotation?
subscapularis, pectoralis major, latissimus dorsi, teres major and anterior deltoid.
Where do the shoulder extrinsic muscles originate and attach?
originate from the torso, and attach to the bones of the shoulder
Where do the shoulder intrinsic muscles originate and attach?
originate from the scapula and/or clavicle, and attach to the humerus
What are the two superficial extrinsic muscles in the shoulder?
the trapezius and latissimus dorsi
What are the 3 deep muscles involved in upper limb/shoulder movement?
Rhomboid major and minor
Levator scapulae
Which 4 muscles make up the rotator cuff?
supraspinatus
infraspinatus
subscapularis
teres minor
What is the innervation of the deltoid?
Axillary nerve
What are the actions of the different deltoid fibres?
Anterior fibres – flexion and medial rotation.
Posterior fibres – extension and lateral rotation.
Middle fibres – the major abductor of the arm
What are the 6 muscles that attach scapula to humerus?
Deltoid
supraspinatus
infraspinatus
subscapularis
teres minor
teres major
What are the actions of teres major?
Medial rotator and adductor
Where do supraspinatus, infraspinatus, teres minor originate from and insert?
Posterior surface of scapula and attach to greater tubercle
What space between the teres does the axillary nerve travel through?
Quadrilateral space
Where does subscapularis originate from and attach to?
Originates from anterior surface and inserts onto lesser tubercle of humerus
How does rotator cuff provide stability?
Contraction of RC muscles holds head of humerus in glenoid
RC tendons fuse with capsule of shoulder joint
How do the radius and ulna articulate with humerus?
Trochlea notch of ulna articulates with trochlea of humerus
Radial head articulates with capitellum of humerus
Which movements occur at elbow?
Flexion and extension
Where do radius and ulna articulate with each other?
Radioulnar joints (proximal and distal)
What movements do the radioulnar joints allow?
Pronation and supination
What is the joint called where radius articulates with carpus?
Radiocarpal joint (wrist)
What movements can occur at wrist?
Flexion
Extension
Abduction
Adduction
Which bones form the radiocarpal joint?
Radius
Scaphoid and lunate
Where are the metacarpal bones?
Distal to carpus
Where are the phalanges?
Bones of the digits
3 in fingers
2 in thumb
What bounds the cubital fossa medially?
Pronator teres
What bounds the cubital fossa laterally?
Brachioradialis
What are the 4 superficial muscles of the anterior forearm?
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Which 3 superficial anterior forearm muscles are innervated by median nerve?
Pronator teres
Flexor carpi radialis
Palmaris longus
Which nerve innervates FCU?
Ulnar
How many muscles are in anterior compartment of forearm?
8
Where do the superficial anterior forearm muscles attach proximally?
Medial epicondyle
What movements does pronator teres do?
Pronation of forearm
What movements does FCR do?
Flexion and abduction of wrist
What movements does palmaris longus do?
Flexion of wrist
What movements does FCU do?
Flexion and adduction of wrist
Which muscle is in the middle layer of the anterior forearm?
Flexor digitorum superficialis
What does FDS give rise to?
4 tendons
Which muscles are in the deep layer of the anterior forearm?
Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratus
What is the innervation of flexor digitorum profundus?
Lateral half which gives rise to tendons in index and middle fingers = median
Medial half for tendons in ring and little fingers = ulnar
What forms the floor and roof of carpal tunnel?
Floor = carpal bones
Roof = flexor retinaculum
How many tendons pass through carpal tunnel?
9
Which give rise to tendons that pass through carpal tunnel?
Flexor digitorum superficialis
Flexor digitorum profundus
Flexor pollicis longus
Which nerve travels through carpal tunnel?
Median
Where does the brachial artery bifurcate?
Cubital fossa into radial and ulnar
Which are the two main superficial veins in the upper limb?
Cephalic (laterally) and basilic (medially)
What connects the cephalic and basilic arteries?
Medial cubital vein in cubital fossa
What do the deep veins drain into?
Axillary vein
What does the basilic vein form proximally?
Axillary vein when received input from deep veins
What does the cephalic vein drain into?
Axillary
What forms the radiocarpal joint?
Distal radius articulates with scaphoid and lunate
What is the 1st metacarpal?
Lateral, the thumb
How many phalanges are in each finger?
3
2 in the thumb
What are the 3 phalanges if each finger called?
Proximal, middle, distal
Where are the carpometacarpal joints?
Between distal carpals and proximal base of metacarpala
Where are the metacarpophalangeal joints?
Between distal metacarpals and proximal phalanges
Where are the interphalangeal joints? And how many are there?
Lie between the phalanges
Thumb has 1, fingers have 2 (proximal and distal)
What is the power grip of the hand used for?
Hold or squeeze objects tightly
What is the hook grip of the hand used for?
Carrying objects with handles
What is the precision grip used for?
Hold objects between thumb and index finger
What are the movements of fingers (digits 2-5)?
Flexion
Extension
Abduction
Adduction
What are the movements of the thumb?
Flexion
Extension
Abduction
Adduction
Oppositiion
Where are the extrinsic muscles of the hand?
Anterior and posterior forearm
Where are the intrinsic muscles of the hand?
Within hand
What muscles from the anterior forearm are prime flexors of the wrist?
Flexor carpi radialis
Flexor carpi ulnaris
Palmaris longus
Where do flexor carpi radialis and ulnaris attach in the hand?
FCR inserts onto 2nd metacarpal
FCU inserts onto 5th metacarpal
Where does palmaris longus insert if present?
Palmar fascia
Which anterior compartment muscles flex the digits?
Flexor digitorum superficialis
Flexor digitorum profundus
Flexor pollicis longus
Also cross the wrist so contribute to wrist flexion
What does the tendon of fds flex?
metacarpophalangeal joints and proximal interphalangeal joints of digits 2-5
What does the tendon of fdp flex?
The only muscle capable of flexing distal interphalangeal joints
Also flexes proximal IP and metacarpophalangeals of 2-5
What does the tendon of flexor pollicis longus do?
Inserts onto distal phalanx of thumb and flexes interphalangeal joint
Where does the tendon of fds insert?
Splits into two and inserts either side of the middle phalanx on digits 2-5
Where does the tendon of fdp insert?
Through the slit in fds into palmar aspect of distal phalanx on digits 2-5
Where does the tendon of FPL insert?
Distal phalanx of thumb
What are flexor tendon sheaths?
Fibrous sheaths that enclose long flexor tendons
Maintain position of flexor tendons in the midline of each finger
What does the synovial sheath do in finger tendons?
Within fibrous sheath
Reduces friction
Allows tendons to slide freely within fibrous sheath
What is tenosynovitis
Inflammation of tendon and synovial sheath
What are the four groups of intrinsic muscles in the hand?
Thenar eminence
Hypothenar eminence
Lumbricals
Interossei
Where is the thenar eminence?
Fleshy mass at base of thumb on palm side
What are the three muscles of the thenar eminence and what do they do?
Flexor pollicis brevis- flexes the thumb
Abductor pollicis brevis- abducts the thumb
Opponens pollicis, deep to other two- opposes the thumb
What innervates the muscles of the thenar eminence?
Recurrent branch of median nerve
Where do the 3 muscles of thenar eminence insert?
FPB- proximal phalanx
APB- lateral proximal phalanx
OP- 1st metacarpal
What does adductor pollicis do?
Contraction adducts the thumb
Where does adductor pollicis lie and what is its innervation?
Deep in palm
Attached to 3rd metacarpal an proximal phalanx of thumb
Ulnar nerve
What is the hypothenar eminence?
Fleshy mass on the medial side of the palm of the hand, proximal to little finger
Contains 3 small muscles that act on little finger
What are the 3 muscles in the hypothenar eminence?
Flexor digiti minimi- flexes little finger
Abductor digiti minimi- abducts little finger
Opponens digiti minimi- opposes little finger
Where do the muscles of the hypothenar eminence insert and what is their innervation?
FDM and ADM- insert onto proximal phalanx
ODM- 5th metacarpal
Ulnar nerve
What are the lumbrical muscles?
Arise from the tendons of FDP
Travel along the lateral aspects of digits 2-5 and insert onto dorsal
Flex the metacarpophalangeal joints and extend interphalangeal simultaneously
How many lumbrical muscles are there?
4 one for each finger
What is the innervation of the lumbrical muscles?
Digits 2-3 (lateral) median
Digits 4-5 (medial) ulnar
What are the 2 groups of interossei muscles and where do they lie?
Between metacarpals and insert onto dorsal aspects of digits 2-5
Palmar and dorsal group
What do the palmar interossei do?
Contract to adduct the fingers
What do the dorsal interossei do?
Contract to abduct the fingers (away from middle finger)
Locations of the palmar interossei
1st: arises from medial side of 2nd metacarpal, inserts onto medial aspect of 2nd proximal phalanx
2nd: arises from lateral side of 4th metacarpal, inserts onto lateral 4th proximal phalanx
3rd: arises from lateral 5th metacarpal, inserts onto lateral 5th proximal phalanx
Locations of the 1st and 2nd dorsal interossei
1st: arises from medial side of 1st metacarpal and lateral of 2nd, inserts onto lateral 2nd proximal phalanx
2nd: medial side of 2nd metacarpal and inserts onto lateral 3rd proximal phalanx
Locations of 3rd and 4th dorsal interossei
3rd: medial side of 3rd metacarpal and lateral of 4th to insert onto medial aspect of 3rd proximal phalanx
4th: arises from medial side of 4th metacarpal and lateral side of 5th, inserts onto medial aspect of 4th proximal phalanx
What makes up the carpal tunnel?
Carpal bones and flexor retinaculum
What tendons travel through the carpal tunnel?
Long flexor tendons of FDS, FDP and FPL
What travels over the carpal tunner?
Tendons of flexor carpi radialis and ulnaris and palmaris longus
Radial and ulnar artery
Ulnar nerve
Where in the skin of the hand does the median nerve innervate?
Palmar surface of lateral side and lateral 3 1/2 digits (skin over dorsum of distal phalanges of these digits)
Where in the skin of hand does the ulnar nerve innervate?
Palmar and dorsal surfaces of the medial side of the hand and medial 1.5 digits
Where does the radial nerve innervate in the hand?
Dorsal surface of lateral side of hand
Skin over the dorsum of lateral 3.5 digits as far as the distal IP joint
Why would an injury to the median or ulnar nerves at the wrist not impair sensation to the palm of the hand but would to the fingers?
Cutaneous branches that supply the palm arise in the forearm
The branches that supply the palmar aspect of the corresponding fingers would be impaired as these branches come from distal to wrist
Where are the dermatomes from C4-6?
C4- Upper shoulder
C5- lateral side of anterior and posterior arm
C6- lateral side of anterior and posterior of forearm and palm, both sides of thumb and index
Where are the dermatomes for C7-T1?
C7- anterior and posterior surfaces of the middle finger and middle palm
C8- medial side of anterior and posterior forearm and palm, both sides of digits 4-5
T1- medial side of the arm
Where would you test sensation for C5-T1?
C5: Upper lateral arm
C6: Thumb
C7: Middle finger
C8: Medial border of hand
T1: Medial border of arm
What are the terminal branches of the brachial artery?
Radial and ulnar
What are the 2 palmar arterial arches?
Superficial formed mostly by ulnar
Deep palmar arch formed mostly by radial
What are the 6 superficial muscles of the posterior compartment?
Brachioradialis
Extensor carpi radialis longus and brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris
Where does brachioradialis begin and insert?
Originates on humerus proximal to lateral epicondyle
Inserts on the distal radius
Which nerve innervates the muscles in the posterior compartment of the forearm?
Radial
Actions of brachioradialis and extensor carpi radialis/brevis
Brachioradialis is a weak flexor of the elbow joint
ECRL/B extend and abduct the wrist
What do extensor digitorum, digiti minimi and carpi ulnaris do?
ED: extends digits via 4 long tendons that insert onto dorsal aspects of fingers
EDM: extends little finger
ECU: extends and adducts the wrist by inserting onto 5th metacarpal
What are the deep muscles of the posterior compartment? (upper limb)
Supinator
Abductor pollicis longus
Extensor pollicis brevis and longus
Extensor indicis
Which 3 bones make up the hip bone?
pubic bone, the ilium and ischium, which fuse at the acetabulum
Where do the hip bones articulate?
anteriorly with each other at the pubic symphysis
posteriorly with the sacrum at the sacroiliac joints.
What is the obturator canal?
A small gap in the obturator membrane for vessels and nerves to pass between pelvis and thigh
Describe the femur
The long bone of the thigh
Has a head, neck and shaft
It’s distal end is expanded
What does the head of the femur articulate with?
the acetabulum of the pelvis to form the
hip joint
What are the greater and lesser trochanters of the femur?
2 bony processes distal to the neck
Sites of muscle attachment
Greater is lateral and anterior
Lesser is posteromedial, iliopsoas attachment
Where is the intertrochanteric line?
Between the greater and lesser trochanters on anterior femur
What is the trochanteric fossa?
A small hollow on the medial aspect of the greater trochanter
What is the linea aspera?
A bony vertical ridge on the posterior aspect of the shaft of the femur
Site of muscle attachment
What does the distal end of the femur expand to form?
medial and lateral femoral condyles
What surrounds the thigh?
Fascia lata
What is the iliotibial band?
A thickening of the lateral part of the fascia lata
Attaches to the lateral aspect of the proximal tibia
Important for stabilising the knee joint
What are the muscles of the anterior compartment of the thigh?
Quadriceps femoris (4)
Sartorius
Iliopsoas
Pectineus
What makes up the quadriceps femoris and what does it do?
Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius
Extend the knee
Where do quad femoris run?
converge onto the quadriceps tendon which runs over the patella to insert onto the tibial tuberosity via the patellar ligament
What innervates the muscles of the anterior compartment of the thigh?
Femoral nerve (L2-4)
Where does rectus femoris lie?
Attached to anterior inferior iliac spine proximally
Lies in midline of thigh
Crosses the hip
What actions does rectus femoris help with?
Extension of knee
Flexion of hip
Where does vastus lateralis attach and run?
Lies lateral to RF and attaches to linea aspera on posterior aspect of femoral shaft
Where does vastus medialis lie?
Medial to RF
Attaches to linea aspera
Where does vastus intermedius lie?
Deep to rectus femoris
Attaches to anterior aspect of the femoral shaft
Where does sartorius lie and attach?
Superficially in anterior thigh
Attaches proximally to anterior superior iliac spine
Inserts onto medial proximal tibia
Crosses hip and knee joints
What movements does sartorius do?
Not a prime mover
Contributes to flexing hip and knee, and laterally rotating hip
Which muscles make up iliopsoas?
Psoas major and iliacus
Converge onto lesser trochanter
Where do iliopsoas originate from?
Psoas major- lumber vertebrae
Iliacus- iliac fossa of pelvis
What movement does iliopsoas do?
Flexion of hip joint
Where does pectineus lie?
Originates from the pectineal line of the pubis bone.
Inserts onto the pectineal line on the posterior aspect of the femur, immediately inferior to the lesser trochanter
Innervation of sartorius and pectineus?
Femoral nerve
Innervation of iliopsoas
psoas major is innervated by anterior rami of L1-3
iliacus is innervated by the femoral nerve
What are the muscles of the medial thigh (5)?
Adductor brevis, longus and magnus
Gracilis
Obturator externus
What innervates the muscles in the medial thig?
Obturator (L2-4)
What is the primary movement of the medial thigh muscles?
Adductors of hip
What are the 2 components of adductor magnus?
adductor component and a hamstring component
Attachments of adductor part of AM
Attaches to inferior pubic ramus and linea aspera
Attachments of hamstring part of AM
Attaches to ischial tuberosity and adductor tubercle
Attachments of adductor brevis and longus
AB deep to AL
Attach to pubic bone and linea aspera
Obturator nerve lies inbetween
What is the adductor hiatus?
a gap between the adductor and hamstring attachments of the adductor magnus muscle
femoral artery and veins travel through to enter posterior thigh
Where does gracilis attach?
Most medial
Attaches to pubic bone and medial aspect of tibia
Movements of gracilis?
Weak adductor of hip and flexor of hip and knee
Movement of obturator externus
Stabilises and laterally rotates hip joint
Attachment of obturator externus
Attached to external surface of obturator membrane and inserts near greater trochanter
What is the femoral artery a continuation of ?
External iliac artery
What does femoral artery give rise to?
Profunda femoris which supplies deep thigh
Femoral becomes popliteal in distal posterior thigh
What is the obturator artery a branch of?
Internal iliac artery
What veins are in the thigh?
Femoral and obturator
What innervates skin over the leg?
Saphenous (sensory)
What are the boundaries of the femoral triangle?
Lateral: medial sartorius
Medial: lateral adductor longus
Superior: inguinal ligament
What’s the contents of the femoral triangle?
Femoral artery
Femoral and great saphenous (from fem) vein
Femoral nerve
What type of joint is the hip joint?
Synovial ball and socket
What forms the hip joint?
Articulation between the acetabulum and femoral head
Has a joint capsule that is reinforced by strong ligaments
What is the fibrocartilaginous collar that deepens the acetabulum?
The acetabular labrum
Which 3 ligaments stabilise the hip joint?
Iliofemoral
Pubofemoral
Ischiofemoral
What type of joint is the knee?
Synovial hinge
What forms the knee joint?
Articulation between femoral condyles and tibial condyles
Where does the iliotibial tract attach?
Lateral aspect of the tibia and stabilises the knee
What are the menisci?
C-shaped cartilages that lie on the tibial plateuas
Deepen the tibial condyles for articulation with the femoral condyles
Out of medial and lateral, which menisci is more prone to injury?
Medial as attached to medial collateral ligament so can be twisted
What do the collateral ligaments do?
Support the knee and resist sideways movement of the tibia on the femur
Taut in extension
What does the medial collateral ligament do?
Connects the femur to the tibia
Attached to medial meniscus
What does the lateral collateral ligament do?
Connects femur to fibula
What do the cruciate ligaments do?
Connect tibia to femur
Taut in extension
What does the ACL do?
Attached to anterior intercondylar area of tibia
Attaches to the medial aspect of lateral condyle of femur
Prevents tibia moving anterior to femur
What does the posterior cruciate ligament do?
Attached to posterior intercondylar area of tibia
Attaches to the lateral aspect of medial condyle of femur
Prevents tibia moving posteriorly to femur
Stabilises knee walking downhill
What type of joint is the ankle?
Synovial hinge joint
What makes up the ankle joint?
Articulation between distal tibia, fibula and the talus
Which 3 ligaments support the lateral aspect of the ankle joint?
Anterior talofibular
Posterior talofibular
Calcanefibular
Where do the ligaments of the lateral and medial aspect of ankle joint attach?
Lateral malleolus and medial malleolus
What forms the subtalar joint?
Articulatio of the talus with calcaneum and navicular
What happens at the subtalar joint?
Inversion and eversion of the foot for walking on uneven ground
What do the sacrotuberous and sacrospinous ligaments help form?
Greater and lesser sciatic foramina
What does the sacrospinous ligament attach to?
Ischial spine
Which bit of the pelvis do we sit on?
Ischial tuberosity
Where is the gluteal tuberosity?
Inferior to the trochanters on posterior femur
What are the 4 superficial gluteal muscles?
Gluteus maximus, medius and minimus
Tensor fascia latae
What does gluteus maximus do?
Extends hip
Important for standing from sitting
Laterally rotates hip
Inserts into iliotibial tract to help stabilise knee
What do gluteus medius and minimus do?
Abduct and medially rotate the hip
Contract to keep the pelvis level when walking
Normal gait
What does tensor fascia latae do?
Contraction tenses the fascia lata and iliotibial band
Stabilises the knee when extended
Flexes the hip
Not a prime mover
What innervates gluteus maximus?
Inferior gluteal nerve
What innervates gluteus medius, minimus and tensor fascia latae?
Superior gluteal nerve
What are the deep gluteal muscles?
Piriformis
Superior and inferior gemelli
Obturator internus
Quadratus femoris
Where do the deep gluteal muscles insert?
Onto or close to the greater trochanter
Where does piriformis pass through?
Greater sciatic foramen
What are the 4 muscles of the posterior compartment of the thigh?
Semimembranosus
Semitendinosus
Biceps femoris
Hamstring part of adductor magnus
What makes up the hamstrings?
Semimembranosus
Semitendinous
Long head of biceps femoris
What do the hamstrings attach to?
Ischial tuberosity
What is the innervation of the hamstrings?
Tibial nerve
What movements do the hamstrings do?
Extend hip
Flex knee
Where do semimembranosus and semitendinosus insert and what is their innervation?
Medial proximal tibia
Tibial nerve
What is the innervation of biceps femoris?
Long head- tibial nerve
Short head- common peroneal nerve
What movements does biceps femoris do?
Long head: extends hip and flexes knee
Short head: flexes knee
What arteries supply the gluteal muscles and where do they pass through?
Superior and inferior gluteal arteries
Leave pelvis via greater sciatic foramen
What arteries supplies the hamstring muscles?
Perofrating arteries of the profunda femoris
What supplies the lower thigh?
Femoral artery travels through adductor hiatus to reach popliteal fossa and become the politeal artery
What veins drain the posterior thigh?
Superior and inferior gluteal veins
Popliteal veins
What fibres make up the sciatic nerve?
L4-S3
What are the 2 nerves in the sciatic?
Tibial and common peroneal
What innervates the gluteal muscles?
Superior and inferior gluteal nerves
What does the tibial nerve innervate?
Posterior thigh and leg muscles
What does the common peroneal nerve innervate?
Muscles of anterior and lateral leg
Where is the popliteal fossa?
Diamond shaped depression behind knee
What are the boundaries of the popliteal fossa?
Semimembranosus and semitendinosus medially
Biceps femoris laterally
Gastrocnemius inferiorly
What is in the popliteal fossa?
Popliteal artery and vein
Tibial and common peroneal nerves
What does the tibia articulate with?
Femur to form knee joint (proximally)
Talus and fibula distally
Where are the medial and lateral tibial condyles and what do they articulate with?
Proximal part of tibia
They are flattened to form plateaus which articulate with the femoral condyles
Where do the intercondylar tubercles lie?
Between tibial plateaus
What inserts at the tibial tuberosity?
Patellar ligament
Where is the tibial tuberosity?
Upper anterior surface of tibia
Palpable
What is the soleal line?
An oblique ridge of bone on the posterior surface of tibia
Where is the medial malleolus and what does it form?
Projects medially on distal tibia and forms part of socket for talus
Does the fibula contribute to the knee joint?
No
What are the 4 parts of the fibula?
Proximal head
Neck distal to head
Shaft
Lateral malleolus
Where is the lateral malleosus and what does it form?
Projects distally and forms part of socket for talus
What are the tarsal bones?
Talus
Calcaneus
Navicular
Cuboid
3 cuneiforms
What comprises the fore foot?
Metatarsals
Phalanges
How many phalanges are in each toe?
3 in toes 2-5 (proximal, middle, distal)
2 in big toe
Where are the metatarsophalangeal joints?
Between the metatarsals and the proximal phalanges
Where are the interphalangeal joints?
Between phalanges
What is the foot adapted for?
Weightbearing and bipedal gait
How can the foot move?
Dorsiflexion
Plantarflexion
Inversion
Eversion
What is dorsiflexion of foot?
at ankle joint
toes point upwards
What is plantarflexion of foot?
at ankle joint
toes point downwards
What is inversion of the foot?
At subtalar joint
Brings sole of foot medially
What is eversion of foot?
At subtalar joint
Brings sole and lateral border laterally
What forms the subtalar joint?
Articulation of talus with the calcaneum and navicular
How can the toes move?
Flexion
Extension
Abduction
Adduction
What surrounds the leg?
Deep fascia
In leg, where do intermuscular septa extend from and what do they do?
Extend from deep fascia
Separates leg into anterior, lateral and posterior compartments
Where do the muscles in the anterior compartment of the leg arise from?
Tibia, fibula, interosseous membrane
What are the actions of the muscles in the anterior compartment of the leg?
Primarily dorsiflexors of foot at ankle joint and extensors of toes
What innervates the muscles in the anterior compartment of leg?
Deep peroneal nerve
What are the 3 muscles in anterior compartment of leg?
Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
What is the path of tibialis anterior and its action?
Crosses over anterior aspect of ankle and inserts onto medial cuneiform
Dorsiflexes and inverts foot
What is the path of extensor hallucis longus and what does it do?
Its tendon crosses the anterior aspect of the ankle and inserts onto the distal phalanx of big toe
Extends big toe and dorsiflexes foot at angle
What is the pathway of 4 tendons of extensor digitorum longus + their actions?
Cross anterior ankle and insert onto distal phalanges of toes 2-5
Extend toes
Dorsiflex foot at ankle
What innervates 2 muscles in lateral leg?
Superficial peroneal nerve
What are the 2 muscles of lateral leg and where do they insert?
Peroneus longus- more superficial, inserts onto plantar surface of medial cuneiform
Peroneus brevis- deeper, inserts onto base of 5th metatarsal
Tendons of both posterior to lateral malleolus
What do the 2 muscles of lateral leg?
Evert foot at subtalar joint
What does the popliteal artery bifurcate into?
Anterior and posterior tibial arteries
What does the anterior tibial artery become?
Dorsalis pedis artery on dorsum of foot
What does anterior tibial artery supply?
Anterior compartment of leg
What supplies lateral aspect of leg?
Fibular artery (branch of posterior tibial)
What are the 2 main superficial veins that drain the leg?
Great saphenous (medial malleolus to femoral triangle)
Small saphenous (lateral malleolus to popliteal vein in fossa)
What are the 2 branches of the common peroneal nerve that innervate leg and what parts do they innervate?
Superficial peroneal nerve innervates muscles of lateral leg
Deep peroneal nerve innervates muscles of anterior leg
Both innervate skin
Where is extensor digitorum brevis and what is its innervation?
Dorsum of foot, lateral
Gives rise to 4 slender tendons that insert into toes 2-5
Innervated by deep peroneal nerve
What innervates the muscles in the posterior compartment of the leg?
Tibial nerve
What are the superficial muscles of the posterior leg?
Gastrocnemius
Soleus
Plantaris
Where do the muscles of the posterior compartment of the leg insert into?
Calcaneus via calcaneal (achilles) tendon
Where does gastrocnemius attach and what does it do?
Most superficial muscle in leg
Attaches via 2 heads to distal femur
Flexes the knee and plantarflexes ankle
Where does soleus lie and what does it do?
Lies deep to gastocnemius
Attaches to the soleal line
Contraction compresses deep veins of leg and is important for venous return
Where is plantaris and what does it do?
Very small muscle close to politeal fossa
Gives rise to thin tendon which merges into achilles
What are the 4 deep muscles of the posterior leg?
Popliteus
Tibialis posterior
Flexor hallucis longus
Flexor digitorum longus
Where does popliteus lie and what does it do?
In popliteal fossa
Attached to tibia and femur
Slightly rotates knee before flexion when extension
What does tibialis posterior do?
Plantarflexes and inverts the foot
Tendon attaches to multiple bones in the foot
What does flexor hallucis longus do?
Flexes big toe via insertion into distal phalanx
Plantarflexes foot
What does flexor digitorum longus do?
Gives rise to 4 tendons that insert into distal phalanges of toes 2-5
Flexes toes, can also plantarflex foot
What do the muscles on the sole of foot do?
Abductors of big and little toes
Flexors of toes
Adductor of big toe
Work as a group to support foot
What artery supplies the sole of the foot?
Posterior tibial artery
PT bifurcates into medial and lateral plantar arteries which supply the foot
Deep plantar arch formed by lateral plantar and branch of dorsalis pedis
What is the arterial supply to toes and forefoot?
Metatarsal and digital arteries
What is the venous drainage of the dorsal foot?
Dorsal venous network
What does tibial nerve innervate?
All of muscles in posterior compartment of leg and plantar surface of foot
Divides into medial and lateral plantar nerves
Which nerves innervate the skin of the feet?
Tibial nerve innervates most of skin on plantar surface of foot
Common peroneal nerve innervates skin over anterolateral leg and dorsum of foot
Which skin territory does femoral nerve supply?
Anterior thigh and anteromedial leg via saphenous
Which skin territory does obturator nerve supply?
Medial thigh
Which skin territory does common peroneal supply?
Anterolateral leg and dorsum of foot
- superficial lower AL leg and most of dorsum
- deep between big toe and 2nd
Which skin territory does tibial nerve supply?
Sole of foot
What does dermatome L1 cover?
Region over inguinal ligament
What does dermatome L2 cover?
Upper half of anterior thigh
What does dermatome L3 cover?
Lower anterior thigh and medial aspect of knee
What does dermatome L5 cover?
On anterior surface of lower limb, obliquely excluding ankle, middle of dorsum foot, toes 2-4, corresponding on sole
Posterior upper leg to bum
What does dermatome L4 cover?
anterior lateral lower thigh, knee and upper leg, anteromedial leg, skin over dorsum and big toe
What does dermatome S1 cover?
Posterior middle of thigh to lateral sole of foot
What does dermatome S2 cover?
Posterior medial thigh to sole of foot
Where does the clavicle articulate?
Sternum at medial end (sternocalvicular)
Scapula at lateral end (acromioclavicular)
What type of joints are those of the clavicle?
Synovial
What does the clavicle do?
Keep limb from trunk so it can move freely
Where is the spine of scapula?
Posterior surface
Where is the acromion?
Articulates with lateral end of clavicle
Lateral end of scapula spine
What comprises the pectoral girdle?
Clavicle
Scapula
Attached muscles
Where is the glenoid fossa and what does it articulate with?
Shallow fossa on lateral aspect of scapula
Articulates with proximal humerus to form glenohumeral joint
Bad fit for humerus
What does the shallow glenoid fossa mean?
Bad fit for humerus
Increases range of movement
Compromises stability
What is the shoulder joint called?
Glenohumeral
Where are the supraglenoid and infragleoid tubercles?
Above and below glenoid fossa
2 small projections
What attaches to the greater tubercle?
Supraspinatus
Infraspinatus
Teres minor
What attaches to the lesser tubercle?
Subscapularis
Why is the surgical neck clinically important?
Commonly fractured in a fall
Axillary nerve runs close and con be injured by fractures or dislocation
Where is the deltoid tuberosity?
Upper lateral aspect of humeral shaft
Site of attachment of deltoid
What does the radial groove mark?
Path of the radial nerve over posterior aspect of the upper humeral shaft
Radial nerve can be injured in mid shaft fractures
What makes up the elbow?
Humerus
head of radius
Trochlear notch of ulnar
What is protraction?
Extrends upper limb
E.g. to open a door
Where does trapezius originate and attach?
Originates: Skull, C and T vertebrae
Attaches: Clavicle, spine of scapula and acromion
What innervates trapezius?
Accessory nerve (CN 11)
C3-4
What are the actions of trapezius?
On scapula: elevates, retracts, depresses, rotates
Abduction past 90 degrees
Where does latissimus dorsi attach?
Anterior aspect of proximal humerus
Moves shoulder joint not scapula
Innervation of lattissimus dorsi?
Thoracodorsal
Action of latissimus dorsi
Humerus: extends, adducts, medially rotates
What are the muscles in the posterior pectoral girdle?
Trapezius
Latissimus dorsi
Rhomboids
Levator scapulae
Where does levator scapulae originate?
Upper C vertebrae
Where does rhomboid minor originate?
C7 and T1
Where does rhomboid major originate?
T vertebrae
Where do levator scapulae and the rhomboids attach?
Medial border of scapula
What does deltoid attach?
Humerus to lateral clavicle and spine of scapula
Where does deltoid insert?
Deltoid tuberosity
What can injury of axillary nerve lead to?
Atrophy and weakness of deltoid
No deltoid actions, like abduction
Where does teres major insert?
Anterior aspect of humerus
Which muscle travels under the acromion?
Supraspinatus
Tendon can be inflamed and pinched between acromion and humerus
Which muscle impingement gives a painful arc?
Supraspinatus
What structures other than the rotator cuff help provide stability to the shoulder?
Glenoid labrum deepens fossa
Ligaments
Tendon of biceps brachii
What muscle lies in the posterior compartment of the arm?
Triceps brachii
Where do the 3 heads of triceps brachii converge and insert onto?
Converge onto common tendon and insert onto olecranon of ulna
What does contraction of biceps brachii cause?
Extension of elbow
Where do the different heads of triceps brachii originate from?
Long head: infraglenoid tubercle, msot medial
Lateral head: proximal to radial groove on posterior humerus
Medial head: distal to radial groove on posterior humerus
What does the long head of triceps brachii contribute to?
Shoulder extension
What innervates triceps brachii?
Radial nerve
Boundaries of the axilla
Anterior: pecs
Posterior: subscapularis, teres major, lati d
Lateral: humerus
Medial: serratus anterior and chest wall
Apex: first rib, clavicle, scapula
Base: skin, fascia
What does the axilla contain?
Fat
Lymph nodes
Axillary artery and vein
Cords and branches of brachial plexus
What is the axillary artery a continuation of?
Subclavian (travels under clavicle into axilla)
What does the axillary artery become when it crosses the inferior border of teres major?
Brachial artery
What is the axillary vein a continuation of?
Subclavian vein
What spinal nerves from the brachial plexus? (roots)
C5-T1
What are the 5 segments of brachial plexus?
Roots
Trunks
Divisions
Cords
Branches
What are the trunks of the brachial plexus?
C5-6: superior trunk
C7: middle trunk
C8-T1: inferior trunk
Where are the roots and trunks of brachial plexus?
Neck
What forms the divisions of the brachial plexus?
Each trunk divides into anterior and posterior
What are the cords of the brachial plexus?
Anterior divisons of superior and middle trunks form lateral cord
Posterior divisions of all trunks form posterior cord
Anterior division of inferior trunk continues as medial cord
What are the branches of the brachial plexus?
Musculocutaneous: branch from lateral cord
Axillary: branch from posterior cord
Radial: continuation of posterio cord
Median: formed by branches from lateral and medial cords
Ulnar: branch from medial cord
Where are the branches of the brachial plexus?
Axilla
Where does the thoracodorsal branch come off?
Posterior cord
What does the axillary nerve innervate?
Deltoid and teres minor
Upper lateral arm skin
Where does the axillary nerve come from?
Branch of posterior cord
Fibres from C5-6
What does the radial nerve innervate?
Triceps
All muscles in posterior compartment of forearm
Where does the radial nerve come from?
Posterior cord
Fibres from C5-T1
Where does the musculocutaneous nerve come from and what does it innervate?
Lateral cord from C5-C7
Innervates 3 muscles in anterior arm
Sensory to region of skin over forearm
What forms the median nerve?
Parts of lateral and medial cords
Fibres from c6-t1
What does the median nerve innervate?
Most of the muscles of anterior forearm
Flexors of the wrist and digits
Small muscles of the thumb
Where is median most vulnerable?
In arm as it crosses cubital fossa
What forms the ulnar nerve?
Continuation of medial cord after median nerve
c8-t1
What does the ulnar nerve innervate?
Most small muscles in hand
Vital for fine movements of the digits
Skin over medial aspect of hand and medial digits
Where is the ulnar nerve most vulnerable?
Behind medial epicondyle
What muscles are in the anterior compartment of the arm? (BBC)
Biceps brachii
Brachialis
Coracobrachialis
Where does biceps brachii originated and attach?
Long head: supraglenoid tubercle
Short head: coracoid process
Converge via a common tendon onto radial tuberosity
What does biceps do?
Contract to flex elbow
Shoulder flexion
Supinator of forearm when elbow is flexed
Where does brachialis lie?
Deep to biceps
Anterior lower shaft of humerus
Crosses elbow to insert upon ulna tuberosity
What does brachialis do?
Flex elbow
Where does coracobrachialis attach?
Coracoid process of scapula and distally to medial aspect of middle part of humerus
What does coracobrachialis do?
Weak flexor of shoulder
What forms the borders of the cubital fossa?
Lateral: brachioradialis
Medial: pronator teres
Superior (base): line between medial and lateral epicondyles of humerus
What does the cubital fossa contain?
Tendon of biceps brachii
Bicipital aponeurosis
Brachial artery medial to biceps tendon
Median (medial to BA) and radial (lateral, deep to brachioradialis) nerves
Where does the brachial artery bifurcate into radial and ulnar arteries?
In cubital fossa
What is the bicipital aponeurosis?
Fasical extension of biceps tendon
Separates superficial veins from BA and median nerve
What are the superficial veins in the cubital fossa clinically used for?
Venepuncture
IV access
What does flexor pollicis longus do?
Flexes thumb
What does pronator quadratus do?
Pronates distal radioulnar joint
What do the radial and ulnar arteries do?
Anastamose with each other to give rise to palmar archers
These ensure hand remains perfused
What innervates brachioradialis?
Radial nerve
What does supinator do?
Supinates forearm and hand
What does abductor pollicis longus do?
Abducts the thumb
What do extensor pollicis brevis and extensor poliicis longus do?
Extend the thumb
EPB extends the MCP joint
EPL extends the interphalangeal joint
What does extensor indicis do?
Inserts onto dorsum of the index finger to allow independent movement
What innervates the posterior forearm muscles?
Radial nerve
What muscles are seen on the dorsum of the hand?
4 Dorsal interossei
Where does the dorsal venous network from the dorsum of the hand drain?
Cephalic vein laterally and basilic vein medially
What is the extensor expansion?
Fibrous structure
Overlies the dorsal aspect of the digits
Attached at base of proximal phalanx
Has a central slip and 2 marginal slips
What forms the boundaries of the anatomical snuffbox?
Extensor pollicis longus medially
Extensor pollicis brevis laterally
Abductor pollicis longus laterally
What artery travels through the anatomical snuffbox?
Radial
What vein arises in the anatomical snuffbox?
Cephalic
What nerves runs over the anatomical snuff box?
Superficial branch of radial
What supplies the posterior forearm compartment?
Ulnar artery
Cephalic and basilic veins
What type of joint is the shoulder?
Synovial ball and socket
What type of joint is the elbow?
Synovial hinge formed by articulations between trochlea of humerus, trochlear notch of ulna, capitellum of humerus and radial head
What reinforces the elbow joint capsule?
Medial and lateral collateral ligaments
What type of joints are the radioulnar joints?
Synovial pivot
What does the anular ligament do?
Holds the radial head in place during rotation
Attaches to the ulna
What type of joint is the wrist?
Condyloid synovial
