Musculoskeletal Flashcards
The pectoral girdle (shoulder girdle) is made up of ?
Scapula
Clavicle
All muscles attached to these (rhomboids, trapezius, subclavian, pec minor, elevator scapularis)
Latissimus dorsi
The rounded contour of the shoulder is made by what muscle and bone?
Deltoid and upper end of humerus
Name the 5 muscles of the back
Latissimus dorsi Levator scapulae Trapezius Rhomboid minor Rhomboid major
Name the 4 muscles which arise from the back of the scapula
supra-spinatus
infra-spinatus
teres minor
teres major
What joint attaches the scapula to the humerus?
glenohumeral joint
Do most clavicular fractures occur in the lateral end, middle or medial end of the clavicle?
What nerve can be damaged by a fractured clavicle and what would the patient experience?
Middle commonly due to a fall onto the shoulder or a fall onto an outstretched hand
Supraclavicular nerves can be damaged in surgery resulting in a numb patch over the upper chest and shoulder
What 3 muscles attach to the coracoid process of the scapula?
- Pectoralis minor
- Corcacobrachialis
- Short head of the biceps brachii
In ‘winging of the scapula’ what nerve is damaged and why does it cause the winged appearance?
Winging of the scapula occurs when the long thoracic nerve which innervates serratus anterior is damaged. As serratus anterior inserts onto the costal surface of the scapula, it usually pulls the scapula against the rib cage.
What does the distal end of the humerus articulate with?
head of radius
trochlear notch of ulnar
Name the 4 rotator cuff muscles and where do they attach on the humerus? (SITS)
Supraspinatus - greater tubercle of humerus
Infraspinatus - greater tubercle of humerus
Teres minor - greater tubercle of humerus
Subscapularis - lesser tubercle of humerus
What muscle runs through the inter tubercular sulcus of the humerus? What is found on either side of the inter tubercular sulcus and what muscles attach onto them?
Long head of biceps
Edges are known as lips and pec major and teres major insert onto the lips of the inter tubercular sulcus.
If a patient falls on an outstretched hand and fractures the surgical neck of the humerus, what key neuromuscular structures might be damaged?
What symptoms would a patient present with if the. nerve is damaged?
Axillary nerve
Posterior circumflex artery
Damage to axillary nerve would cause paralysis of deltoid and teres minor muscles so they would have trouble abducting the affected limb. The nerve also innervates skin over deltoid so sensation in the. regimental badge area would be impaired.
The radial groove runs diagonally down the posterior surface of the humerus, which nerve runs in this groove?
Radial nerve
A mid shaft fracture risks damage to which nerve?
What signs would a patient present with if this nerve was damaged?
Radial
The radial nerve innervates the extensors of the wrist and therefore, damage will result in paralysis of the extensors (unopposed flexion of the wrist ‘wrist droop’) - there might also be sensory loss over posterior surface of the hand
Where do the forearm extensor muscles originate from?
- medial supraepicondylar ridge
- lateral supraepicondylar ridge
- medial epicondyle
- lateral epicondyle
- lateral supraepicondyle ridge is where forearm extensor muscles originate from
Which nerve passes in a groove on the posterior aspect of the medial epicondyle?
Ulnar nerve
What is the purpose of the bursa around the shoulder joint?
Reduce friction in the joint and cushions between tendons and other structures
Where does the deltoid muscle originate and insert?
Originates from clavicle, acromion and spine of scapula and inserts onto deltoid tuberosity at the middle of the humerus
Which nerve innervates deltoid? How can this nerve be damaged? What symptoms would the patient experience?
Axillary nerve
Damaged by posterior dislocation of the shoulder.
- Paralysis of deltoid
- patch of numb skin on lateral arm
Contraction of supraspinatus muscle causes what?
Abduction of the arm
What nerve supplies the extensors of the posterior arm?
Radial nerve
What nerve supplies the extensors of the posterior forearm?
Radial
What nerve supplies the anterior flexors of the arm?
musculocutaneous nerve
what nerves supply the anterior flexors of the forearm?
flexor carpi ulnaris and medial half of flexor digitorum profundus = ulnar nerve
All the other flexors in the forearm = median
What nerves supply the muscles of the hand?
LLOAF = median nerve
All the other muscles = ulnar
Describe what happens in a ‘frozen shoulder’ to cause pain
Tendon of supraspinatus passes through a tight junction between acromion and humerus and if the tendon becomes inflamed, it can cause pain as it passes through the tight space.
Typically a patient will be able to lift their arm to a certain point and then feel pain as the inflamed tendon passes through the tight space and then the pain goes away once the tendon is through and the arm is raised. It is described as a ‘painful arc’.
Which nerve runs in the spiral groove directly against the humerus which can easily be damaged by a fracture of the humerus or pressure on the humerus (sleeping with arm hooked over sofa)
Radial nerve - radial nerve palsy
When someone hits their ‘funny bone’ what nerve have they hit?
Ulna nerve which runs behind the medial epicondyle of the humerus
What is the innervation to trapezius muscle?
CN XI
What is the action of elevator scapulae?
Elevate the scapula
What is the action of rhomboid minor and major?
Adduct scapula and perform downward rotation
What is the action of latissimus dorsi?
extension, adduction and medial rotation at the shoulder
What are the boundaries of the axilla? (anterior, posterior, lateral, medial, apex and base)
- Anterior wall - pectoralis major and pectoralis minor muscles
- Posterior wall - subscapularis, teres major and latissimus dorsi muscles
- Lateral wall - upper end of the humerus with the biceps brachii and coracobrachialis muscles
- Medial wall - serratus anterior muscle covering ribs and intercostal spaces
- Apex - formed by the first rib medially with the clavicle infront and the scapula behind.
- Base - skin and fascia extending between chest wall and the arm
What does the axilla contain?
- fat and lymph
- axillary artery
- axillary vein
- brachial plexus
- all of the above
All of them
- Fat and lymph nodes
- Axillary artery which is the major artery supplying the upper limb
- Axillary vein which is the major vein draining the arm
- Brachial plexus which is the nerve plexus supplying the limb
Lymph nodes in the axilla drain what part of the body? Which cancer is commonly involved in spread to the axillary lymph nodes?
Upper limb, chest wall and abdominal wall as far as the umbilicus
Breast cancer commonly spread to axillary lymph nodes
What are the 5 divisions of the brachial plexus?
read that damn cadaver book Roots Trunk Divisions Cords Branches
Which spinal nerves make up the brachial plexus?
C5, 6, 7, 8, T1
Are the roots of the brachial plexus made up of the anterior or posterior rami of the spinal cord nerves?
Anterior
Posterior innervates skin and intrinsic muscles of the back
Which roots join to form the superior, middle and inferior trunk of the brachial plexus?
Superior: C5 and C6 combined
Middle: C7 continuation
Inferior: C8 and T1 combined
What happens to each trunk of the brachial plexus within the posterior triangle of the neck?
Each trunk divides into 2 branches (anterior to the front of the body and posterior to the back of the body) which makes 3 anterior and 3 posterior nerve fibres that pass into the axilla.
What happens to the 3 anterior and 3 posterior nerve fibres from the trunks of the brachial plexus once they pass into the axilla?
Once anterior and posterior divisions have entered the axilla, they recombine to form 3 cords. These are named relative to their position to the axillary artery
Lateral cord: anterior division of superior and middle trunk
Posterior cord: posterior division of superior, middle and inferior trunk
Medial cord: anterior division of the inferior trunk
Name the 5 branches which come off the 3 cords of the brachial plexus
Musculocutaneous Axillary Median Radial Ulnar
Which nerve innervates Brachialis, biceps and Coracobrachialis?
Musculocutaneous
Which nerve innervates teres minor and deltoid?
Axillary
Which nerve innervates the flexor muscles in the forearm, thenar muscles and 2 lateral lumbricals in index and middle fingers?
Median nerve
Which nerve innervates the triceps and muscles in posterior compartment of forearm?
Radial nerve
Which nerve innervates the muscles of the hand (except thenar muscles, 2 lateral lumbricals) and flexor carpi ulnaris and medial half of flexor digitorum profundus?
Ulnar nerve
Describe the sensory innervation to the hand
Palmar:
- lateral 2 1/2 fingers and thumb = median nerve
- medial 1/2 fingers = ulnar nerve
Dorsal:
- lateral 1/2 = ulnar
- back of hand on inner surface = radial
median nerve provides sensation to the tips of thumb, and 2 1/2 fingers.
In the cubital fossa, what artery and nerve lie medial to the tendon of biceps?
Brachial artery
Median nerve
The cubital fossa is bounded laterally and medially by which muscles?
Laterally by brachioradialis
Medially by pronator teres
What actions do biceps and Brachialis perform?
Flexion at the elbow joint
Biceps is also a strong supinator of the forearm.
What type of palsy can occur due to injury to the upper roots of the brachial plexus caused commonly by stretching injuries or difficult vaginal deliveries? What distinct position do you see of the hands?
Erbs palsy
Forearm is pronated and wrist is flexed.
What type of palsy can you get due to injury of the lower roots of the brachial plexus?
Klumpke’s palsy where muscles of the hand are affected causing a clawed hand appearance
What syndrome can result from damage to T1 nerve foot? What are the characteristic signs of this syndrome?
Horners syndrome Drooping of eyelid Lack of sweating on the face Constricted pupil This is because it affects sympathetic fibres running to the face.
Function of gluteus maximus, medius and minimus?
Gluteus maximus: extensor of hip and lateral rotation of the thigh
Gluteus medius and minimus: abduction and medial rotation of the hip - works to stabilise the pelvis during walking to prevent pelvis drop.
What forms the greater and lesser sciatic foramen?
Sacrotuberous ligament and sacrospinous ligament which run between the sacrum and ischial spine
Sciatic nerve roots?
L5, S1-S4
Why is it safe to inject IM into the upper outer quadrant of the buttocks?
Avoids damage to sciatic nerve and vessels which run in the inner lower quadrant of the buttocks
Nerve supply of the posterior compartment of the thigh
Sciatic
Nerve supply of the hamstrings?
Tibial branch of the sciatic nerve
Function of the hamstrings?
Flexion of knee and extension of the hip
What are the 3 compartments of the leg?
Anterior
Posterior (calf)
Lateral
Arterial and nervous supply of the anterior compartment of the leg? Function of this compartment?
Anterior tibial artery
Deep peroneal nerve
Function: dorsiflexion and inversion of foot.
Arterial and nervous supply of the posterior compartment of the leg? Function of this compartment?
Posterior tibial artery
Tibial nerve
Function: plantar flexion, inversion of foot
Arterial and nervous supply of the lateral compartment of the leg? Function of this compartment?
Peroneal artery
Superficial peroneal nerve
Function: Eversion of the foot
If someone suffers a fracture of the tibia at the distal end, it can damage the fibula at the proximal end and can damage which nerve? What would the effect be?
Common peroneal nerve
This nerve supplies all the muscles which lift the foot and toes so if it is damaged = foot drop.
Where can you find the 4 pulses of the lower limb?
Femoral - groin
Popliteal - back of knee when flexed
Posterior tibial - behind medial malleolus
Dorsalis pedis - between 1st and 2nd metatarsal
Which blood vessel can be found between extensor hallucis longus and extensor digitorum?
Dorsalis pedis
What are the 7 muscles in the posterior compartment of the leg? (superficial and deep)
Superficial
- Gastrocnemius
- Plantaris
- Soleus
Deep
- Popliteus
- Flexor digitorum longus
- Tibialis posterior
- Flexor hallucis longus
Which nerve runs next to biceps femoris and around the head of the fibula?
Common peroneal nerve
In the popliteal fossa, which nerve, vein and artery can we find?
Tibial nerve
Popliteal vein
Popliteal artery
Gastrocneumius is the most superficial muscle on the posterior compartment of the calf. It has 2 heads which attach where?
Contraction of this muscle will cause what?
Condyles of femur -> Achilles tendon
Contraction = flex the knee and plantar flex foot.
Soleus muscle has its origin on the fibula and tibia and attaches onto the deep surface of achilles and inserts onto the calcaneum. What is its action?
Flexes the ankle
Name the bones of the foot
Calcaneus Talus Navicular Cuboid Cuneiforms
Which 2 bones of the foot are most commonly fractured? How are they usually fractured?
Talus and Calcaneus
Fracture of talus can lead to avascular necrosis of bone (neck of talus fractures from dorsiflexion, body of talus fracture from jumping from a height) Calcaneus is also commonly fractured from falling from a height.
What 2 things prevent the lateral displacement of the patella?
lower fibres of vests medals and depth of the patella grove (lateral femoral condyle is taller)
Which is the bone you sit on?
Ischial tuberosity
What is trendelenburgs test?
Gluteus medius and minimus both abduct the hip joint. During normal walking when one leg is lifted off the ground, the opposite gluteus muscles contract to support the pelvis in a horizontal position. If the superior gluteal nerve is damaged (supplies gluteus medius and minimus) then the opposite side of the pelvis will drop when the leg is raised on that side (left damaged will lead to right pelvis drop)
Where do bones receive their blood supply from?
Muscles that attach to them
Why can a fractured tibia take a long time to heal?
The lower 1/3rd of the tibia has no muscle attachments and if it is injured it has difficulty healing due to the limitation in blood supply.
Tibia also lays just underneath the skin so if it is damaged and bone breaks through skin, infection is much more likely to occur and is difficult to treat as abx do not penetrate bone well.
what is clergyman knee?
around the knee there are bursa which allow tissue to slide freely over each other. A bursa is a pocket of synovial which produces synovial fluid. If there is a bursa over the infra patellar tendon, when a clergyman prays, it can become damaged and inflamed. The bursa will swell and lead to a limitation and painful flexion of the knee.
What is compartment syndrome?
Compartments are enclosed in fascia. If there is damage to the structures, there could be swelling causing an increase in pressure in the compartment and can stop blood flow leading to the compartment dying.
Describe what happens in common peroneal palsy. What clinical sign can we see?
The common peroneal (fibular) nerve passes round the head of the fibula and damage here will de-nervate all the anterior and lateral compartment muscles. These are the muscles which dorsiflex the ankle so the foot ‘drops’ down when lifted off the floor, foot drop.
When playing a sport which requires a rapid change in direction, what tendon can rupture?
Achilles tendon
Where do the anterior and posterior cruciate ligaments attach to?
Anterior cruciate to anterior of tibia
Posterior cruciate to posterior of tibia
Describe what can happen in a fractured neck of femur?
Fracture can interrupt the blood supply to the head of the femur which comes from the circumflex femoral arteries in adults. This can lead to avascular necrosis of the femur head.
Describe how a cruciate ligament tear can occur
The ligaments of the knee are all ‘loose’ when the knee is bent to 90 degrees and all tight when the knee is extended/straight. However, at 30 degrees of flexion, there is only 1 ligament which is taught, the anterior cruciate. If an abnormal force is experienced by the knee in this position, the anterior cruciate ligament might not be strong enough and it will rupture.
Describe how a medial meniscal tear can occur
The lateral meniscus is attached to the tibia at the 2 ends of the meniscus which means it can move when a rotating force is experienced by the knee.
The medial meniscus is attached to the capsule of the knee all the way around its perimeter so the medial meniscus cannot move web an abnormal twisting force is experienced and it may get torn.
Explain how an ankle sprain happens
If the ankle is subject to a forced eversion or inversion, medial and 3 lateral ligaments can tear leading to an ankle sprain
boundaries of the femoral triangle
The borders of the femoral triangle are composed of
- the inguinal ligament superiorly
- the adductor longus muscle medially
- the sartorius muscle laterally.
pulsation of femoral artery?
midinguinal point in groin
What is the femoral artery a continuation of?
external iliac artery
Which nerve roots make up the femoral nerve and obturator nerve?
Femoral L2-L4
Obturator L2-L4
which 3 bones fuse in adolescence to form the pelvis? What’s the point where the fuse called?
Ilium
Ischium
Pubis
Fuse at the acetabulum which articulates with the head of femur
what surrounds the hip joint to deepen it?
labrum.
