HSE102 – Functional Human Anatomy
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Topic 1. Introduction to Functional Human Anatomy
Basic Functional Anatomy
Planes of Reference
Midsaggital (saggital) Plane:
Separating the body into left and right.
Think about how we move in yoga during sun salutations – very sagital plane dominent.
Where abduction and adduction occur.
Think ‘grabbing a corona’ to the left and right
Separates top and bottom
E.G. The dorsal part of the hand is the back (darker side) because we must always consider that we’re referring to the body in the classic ‘anatomical’ position.
Ipsilateral: Same side of the body
E.G. The right arm is ipsilateral to the right leg, whereas the left arm is contralateral to the right leg.
Contralateral: Opposite side of the body
Practical implication: This becomes important when we discuss rotation of the trunk/neck, e.g. our external obliques does contralateral rotation which mean’s the right external oblique is gonna rotate the body to the left.
Internal & External
Relative distance of a structure from the center of an organ.
Proximal & Distal Clarification
Proximal and distal mean’s ‘relative to something that’s attached’.
E.G. The knee is proximal to the foot because the knee is closer to the original attachment point (the hip) than what the foot is.
E.G.2 The foot is distal to the knee because it’s further away from the attachment point.
Terms Related to Movement
Ventral (anterior) Body Cavities
Dorsal (posterior) Body Cavities
Organisation of Skeletal Muscle Fibers
Parallel Muscles: The fibers are running in the same direction (bicep)
Convergent Muscles: A wide base that converges on a tendon like a fan (pec major)
Pennate Muscles (contain more muscle fibers): Come in on an angle to a tendon.
Unipenate: coming in from ONE direction
Bipennate: Fibers coming in from TWO directions
Multipennate: Fibers coming in from multiple directions
Origins & Insertions
Origin: Is located at the fixed end of a muscle / It’s proximal and less moveable
Insertion: The movable end / It’s distal (further away from the attachment point) and most moveable
General Rule: The insertion moves towards the origin.
Isometric: Muscle contracts/under tension while the limb’s don’t move/the join angle doesn’t change
Concentric: Muscle’s shorten under tension as the join angle usually get’s smaller
Eccentric: Muscle lengthens under tension (gravity or external load) as the joint angle usually get’s larger
Names of Skeletal Muscle
Rectus = ‘straight’ e.g. rectus abdominis and rectus femoris muscle fibers run straight
Transverse = ‘running across the body’ e.g. transverse abdominis
Oblique = ‘running on an angle’ e.g. external oblique
Temporalis = ‘come’s off the temporal bone’ (side of the head)
Spinalis = ‘come’s off the spine’
Adominus = ‘belly region’
Superficialis & externus = superficial)
Profundus & internus = deep
Structure: Number of heads of origin, e.g. ‘bicep femoris’ has 2 heads which we can tell by the ‘bi’ portion, e.g. ‘tricep femoris’ has 3 heads which we can tell by the ‘tri’.
The name of the muscle can often reveal it’s join action. E.G. Flexor Digitorum will flex the fingers.
Teres (long & round)
Topic 2. Bones Of The Axial Skeleton
Functions of the Skeletal System
Support (framework of the body)
Blood Cell Formation (RBC)
Classifications of Bones
Long Bones: Humerus, femur, radius and ulna
Short Bones: Carpals/tarsal
Flat Bones: Cranium, sternum
Irregular Bones: Vertebrae
Sesamoid (formed within a tendon): Patella
Where a bone meet’s another bone.
Condyle: large round knob
Facet: flat articular surface
Head: prominent round head of a bone
Openings in a bone:
Foramen (a hole or opening in a bone)
Fossa: flat shallow surface (a depression in a bone where muscle often sits in)
Bony projections where muscles or ligaments attaches.
Epicondyle: projection adjacent to a condyle
Ramus: flat angular section of a bone
Trochanter: massive bony process found on the femur
Tubercle: small round bony process
Tuberosity: large, roughened process
The Axial Skeleton
Transmites the weight of our upper body into our pelvis and lower limbs.
Forms the vertical axis of the body
Consists of 80 bones
Adjusts the positions of the head, neck & trunk
Performs respiratory motions
Stabilizers & positions the appendicular skeleton
Parietal x 2 (left and right) –Temporal x 2 –Frontal x1 (means there’s only one) –Occipital x 1 –Sphenoid x 1 –Ethmoid x 1
Lateral wall and roof of skull
Articulates (joins) with frontal, occipital, temporal & sphenoid bones
Should be able to identify important landmarks like the temporal line which is where the temporalis origin is which helps the jaw open and close.
Inferior lateral aspect of skull
Articulates with mandible, zygomatic, sphenoid, parietal & occipital bones
Zygomatic process (which is a projection towards the zygomatic bone)
Mandibular fossa (where the head of the mandible sits)
External auditory meatus (allows sound to travel through)
Styloid process (important muscles that support the larynx and the tongue insert off that)
Mastoid process (where the sternocleidomastoid connects)
Forehead and roof of orbits (eye sockets)
Articulates with parietal, sphenoid, ethmoid, nasal, lacrimal, zygomatic, and maxillary bones
Posterior aspect & base of skull
Articulates with parietal, temporal, sphenoid and atlas bones
External occipital protuberance
Foramen (hole/opening) magnum (large) where the spinal cord passes through
Occipital condyles (articulating surface) which meet’s with C1
Keystone of skull
Forms part of base of skull
It unites the cranial bone to the facial bones and articulates with nearly every other bone in your skull
It’s also really important because it has an optic canal where the optic nerve runs through that transmits info from eye to the brain
Most deeply situated bone of skull
Forms bony area between nasal cavity and orbits
Articulates with sphenoid and frontal bones
“The olfactory nerve has a close anatomical relationship with the ethmoid bone. Its numerous nerve fibres pass through the cribriform plate of the ethmoid bone to innervate the nasal cavity with the sense of smell.”
Don’t need to know any landmarks just need to know if their paired or singular.
Nasal x 2 –Maxillae x 2 –Zygomatic (cheek bone) x 2 –Lacrimal x 2 –Palatine x 2 (back of the roof of the mouth) Vomer x 1 –Mandible x 1
Suspended from the temporal bones by ligaments & muscles and doesn’t articulate with any other bone.
Supports the tongue
Attachment site for infrahyoid & suprahyoid musculature
The Vertebral Column
C7 / T12 / L5 / S5 (5 fused vertebrae) / C4 (1-4 fused depending on the person)
Primary & Secondary
Increase strength, help maintain balance in an upright position, absorb shock, protect vertebrae from fracture
Babies develop their spine shape and concave curves as they start crawling and gain the ability to support their head
Characteristics of a Typical Vertebrae
The spinous process is the projection ‘bumpy part’ you feel running your hand down a spine. Many ligaments and muscles attach from the spinous processes.
Where the superior articular facet connects with the inferior articular process is where movement of the spine orginates.
The spinal nerves pass through the interveterbral foramen. Nerve impingement from sciatica pain usually occur within the interveterbral foramen.
A disc actually doesn’t “slip”, instead you get a protrusion of a disc into where the spinal nerves are sitting which can “pinch” the nerve.
There are 2 vertebrae that are a-typical: C1 (atlas) & C2 (axis)
C1 doesn’t have a body or a spinous process.
C2 has a feature called a ‘dens’ which gives a pivot point for C1 to rotate around which is why it’s called axis – this is what helps the head rotate.
How would you distinguish the difference between a cervical, lumbar and thoracic vertebrae?
Cervical vertabrae have holes (foremens) in their transverse process which you don’t find in other areas.
Lumbar are easier to distinguish because they are the largest, typically their spinous process is projecting posterialy straight out the back of the vertabrae.
Whereas the thoracic vertebrae have spinous processes that project downwards.
The sacrum meets the pelvis at the sacroiliac joint where the majority of the weight is transferred from the upper body to lower body.
The ribs and sternum. Role is to protect vital organs.
24 ribs in total: True ribs (first 7) which all have there own cartilage that connects to the sternum
False ribs (8-10) all join 7’s costal cartilage – that’ why their called false ribs, because they don’t have their own seperate costal cartlige.
Floating ribs (11-12) they are still classified as false ribs, but they don’t have any bony attachments anteriorly.
Topic 3. Muscles Moving the Axial Skeleton (Neck & Trunk)
Prac exam: You will be asked to identify things like lateral flexsion of the neck and trunk. Make sure you don’t just state what movement it is but what direction – whether it’s moving to the left or right.
Muscle of the Neck
Originates from the manubrium/medial clavicle inserting to the mastoid process.
Flexion of cervical spine
Contralateral (opposite side of the body) rotation. If I’m rotating to the left the right SCM is on.
Ipsilateral (same side) lateral flexion. So as you bring your neck down to your ear on the right side it’s the right SCM that activates.
Splenius Muscles (cervicis, capitis)
Cervicis – originates from spinous process of T3-T6 inserting at transverse process of C1-C3
Capitis – originates from spinous process C7, T1-T4 inserting at mastoid process and occipital bone
Don’t need to know specific origin and insertion but know where the muscles are.
Ipsilateral rotation & lateral flexion
Anterolateral Abdominal Wall
Muscle of the Trunk
Structure: Bilaterally paired muscles in the anterolateral abdominal wall
3 flat muscles
Transverse abdominis (TVA)
1 vertical muscles
Most superficial of the three lateral muscles
Originates from the ribs and inserts at the pelvis & abdominal aponeurosisto the lineaalba (connective tissue that is often torn during child birth)
Compresses (flexsion) of the abdomen.
Exception to the rule where the origin actually moves towards the insertion instead of the usual other way around.
Laterally flexes the vertebral column
Contralateral rotator of the trunk because it inserts at pelvis and originates off the ribs
Middle layer of the three lateral abdominal muscles
Posterior fibres pass from the anterior trunk to the lumbar spine
Compresses the abdomen & stabilises the spine
Ipsilateral rotator of the trunk because it inserts at the ribs and originates off the pelvis
Deepest of the three lateral abdominal muscles
Passes from the anterior trunk to the lumbar spine
Compresses the abdomen & stabilises the spine
TVA becomes active prior to limb movement
Co-contract with Multifidis
Originates from the pelvis and inserts to the ribs & sternum
RA & lateral fibers of the EO prime movers of trunk flexion (predominantly sagittal plane movements)
Better set up for rapid ballistic movements
Posterior Trunk Muscles
Posterior abdominal wall
Forms an important part of the corset
Originates from the iliac crest of the pelvis and inserts to the 12th rib & lumbar (L1-L4) vertebrae
Actions include ipsilateral lateral flexion and extension of the lumbar spine
Erector Spinae muscles
3 muscles together: iliocostalis, longissimus & spinalis muscles
Originate from iliac crest & sacrum to insertion points up to C2
Main action is trunk and neck extension because the fibers run vertical
Covers a small number of spinal segments
Helps to stiffen and stabilise the spine prior to limb movement
Co-contraction with TVA
It’s an extensor because it’s located on the posterior chain
Because erector spinae and multifidus run all the way up the spine they get nervy supply from pretty much every area their next to.
Measuring Core Stability
Pressure Biofeedback Unit (blood pressure cuff) / Real-time US / Single leg stance (trendelenburgsign) / Single leg squat
This chain that allows us to transfer power from the lower to upper limb and vice versa.
Topic 4. Bones Of The Appendicular Skeleton (Upper Limbs)
Pectoral (Shoulder) Girdle
Connects the upper limb to the axial skeleton.
Includes: Clavicle & Scapula
Role: Position the shoulder join, Help move the upper limb & Provide a base for muscle attachment
Where the sternum meets the clavicle is the only bony attachment site – which is why a fractured clavicle is common when people land on their outstretched arm, because that’s where the force transmutes to.
Articulation points: Where a bone meets another bone.
Acromial end (connects to the scapula is more thin and flat)
Sternal end (the knobby thicker end)
Identify which end is the acromial end and which is the sternal end.
Acromion: where the acromial end of the clavicle meets the acromion
Glenoid fossa: the ball and socket joint of the humerus
Multiple muscle attachment sites
Head, Capitulum, Trochlea
Important muscle attachment sites:
Greater & lesser tubercles, Deltoid tuberosity
Lateral Epicondyle (Capitulum) articulates with the radius
Medial Epicondyle (Trochlea) articulates with the ulna
Why do we feel that sensation when we hit our “funny bone”: the ulna nerves wraps around the medial epicondyle, the ulna nerve is quite superficial which is why its so easy to knock the nerve.
When looking from anatomical position the ulna is medial (pinky side). When in a pronated position the ulna is lateral.
Trochlear notch: where the trochlera sits
Radial notch: where the radius sits
When looking from anatomical position the radius is lateral (thumb side). When in a pronated position the radius is medial.
Articulation for scaphoid & lunate
Important muscle attachment site:
Radial tuberosity: where the bicep brachii inserts
Proximal row: Scaphoid – Lunate -Triquetrum – Pisiform (SLTP)
Distal row: Trapezium (is at the base of the thumb) – Trapezoid – Capitate – Hamate (TTCH)
Sally (Scaphoid) Left (Lunate) The (Triquetrum) Party (Pisiform) To (Trapezium) Take (Trapezoid) Charlie (Capitate) Home (Hamate)
Some lovers try positions that they can’t handle
Metacarpals (Hand) / Phalanges (Fingers)
Each finger has 3 phalanges except the thumb which has 2
Topic 5. Joint Structure & Function
Where bones meet, hold bones together, various degrees of skeletal movement
Generally the more stable a joint the less stability it has and the less stable a joint is the more mobile it is.
Nice practical application
The shoulder joint relies on dynamic stability; the attaching muscles and ligaments to stabilise the joint and keep it in place. Whereas the hip joint has a lot of static stability because the nature of the hip sockets depth and sturdiness.
Synovial (all diarthrosis)
Relates to how much movement will occur at the joint.
Synarthrosis (joined together), Amphiarthrosis (slightly moveable), Diarthrosis (two, freely moveable)
Fibrous joints are connected by dense connective tissue consisting mainly of collagen. These joints are also called fixed or immovable joints because they do not move. Fibrous joints have no joint cavity and are connected via fibrous connective tissue.
3 Types of Fibrous Joints:
1. Sutures (seam)
Thin layer of dense fibrous connective tissue
Only unites bones of the skull
Their interlocking edges add strength, thus reducing fractures
Functional classification: Immoveable (synarthroses)
2. Syndesmoses (fastening)
Location: between radius and ulna and tibia and fibula to prevent seperation of the two bones
Articulating bones are united either by a ligament or Interosseousmembrane
Interosseousmembrane of the forearm
Functional classification: Slightly moveable (amphiarthroses)
3. Gomphoses (bolt)
Cone shaped peg fits into a socket
Articulations of the roots of the teeth are an example
Functional classification: Immoveable (synarthroses)
2 Types of Cartilaginous Joints:
Joined by hyaline cartilage between 2 bones
Epiphyseal growth plate is made from hyaline cartilage
2. Symphyses (pelvis)
Articulating bones are united by either hyaline cartilage or fibrocartilage
Useful for shock absorbing
Slightly moveable (amphiarthroses)
All diarthrosis (freely moveable)
Structure of Synovial Joints
Articular Capsule comprises of:
Surrounds and encloses the joint
Continuation of the periosteum
Lined with synovial membrane which produces & secretes synovial fluid for joint lubrication
Lines the inside of the capsule
Produces the synovial fluid which acts as a lubricant inside the joint capsule
Is a space between where the two bones meet which contains synovial fluid. Both cartilaginous and fibrous joints don’t have this joint cavity space.
Articular Cartilage (hyaline cartilage)
People with OA (osteoarthritis) damage the articular cartilage causing the joint space to narrow where you begin to get bone against bone instead of cartilage against it.
The problem with articular cartilage is that it’s avascular so it doesn’t get any blood supply and aneural so it doesn’t have nerve supply. So after damaging the cartilage it can’t repair itself unless you get something like stem cell treatment.
Covers the surface of articulating bones
Aneural & Avascular
Poor healing capacity
Thickenings in the fibrous capsule to make it stronger/reinforce the joint
Control & limit excessive joint movements
Occasionally intra-articular ligaments found in some joints
Articular discs / menisci
Fibrocartilage pads are shock absorbers that distribute force across a larger surface area
Found around most synovial joints
Fluid filled sacs that reduce friction
Packing material & Protect the joint
Common in places where’s there’s lots of tendons (hands and feet)
Tendon sheaths are filled with synovial fluid
Reduce friction in joints
Wrap around tendons
Factors Influencing Joint Stability
Joint Congruency: how well two bones come together. A joint that doesn’t have high congruency is usually unstable (shoulder). A joint like this is highly reliant on strong and fluid motor control of the surrounding limbs/muscles.
Shape & fit of the articular surfaces
Ligaments prevent undesirable movements & help to direct joint movement
Tone of the muscles whose tendons cross a joint
Importance of regaining muscle tone & strength post injury
Classified according to structural category (movement)
Uniaxial: Moves in one direction (elbow)
Biaxial: Allow movement on two planes (wrist)
Multiaxial: Moves in multiple planes (knee)
Uniaxial –least mobile
Articulating bones are flat or slightly curved
Found in the intercarpal & intertarsal joints
Convex surface of one bone fits with a concave surface of another bone
Elbow, knee & Interphalangeal joints
Rounded or pointed surface of one bone articulates with a ring formed by another bone & ligament
Proximal Radioulnar Joint that is responsible for rotation of the ulna/radius
Condyloid (ellipsoidal) Joints:
Convex oval shaped projection of one bone fits into the oval shaped depression of another bone
Biaxial (the main difference between a ball and socket and condyloid is that ball & socket is multiaxial whereas condyloid is biaxial).
RadiocarpalJoint (wrist joint)
Carpometacarpal joint of thumb. This joint enables ‘opposition’ movement so we can grasp things.
Hip & shoulder
Topic 6. Joints of the Upper Limb 1: Shoulder Girdle
Know the ligament that support the area, be able to identify and know it’s joint actions.
Comprised of the Clavicle & Scapula
Part of the appendicular skeleton
Attaches the upper limb to the axial skeleton where the sternum attaches to the clavicle
Positions the humorous it can move correctly
Provides the only bony point of connection between the pectoral girdle, upper limb and the trunk/axial skeleton
Articulations of the Sternoclavicularjoint
Enlarged medialend of the clavicle articulates in the shallow socket formed by the manubrium & 1st costalcartilage
The claviculararticular surface tends to be larger than that on the sternum
Thus, the medial end of the clavicle projects above the upper margin of the manubrium sterni, creating poor congruency (how well the two bones come together)
Congruency is helped and provided by an intra-articular fibrocartilaginousdisc which helps increase the contact area between the two bones which results in more stability.
The strong fibrocartilage disc separates the articular surfaces acts as a shock absorber
Is firmly attached to the joint capsule
Holds the medial end of the clavicle against the sternum
Prevents medial displacement –Helps to absorb shock waves transmitted along the clavicle
Ligaments of the SternoclavicularJoint
Strength of the SC joint is dependant on ligamentous support
Anterior & Posterior Sternoclavicular Ligaments
The anterior ligament prevents the clavicle from moving forward and the posterior one prevents the clavicle from moving backwards
Reinforces the joint capsule stability anteriorly & posteriorly
Passes from the clavicle to sternum anteriorly and posteriorly
Runs between the two clavicles.
Strengthens the capsule superiorly to stop the clavicle moving upwards
Extends from the sternal end of one clavicle to the other
In between it attaches to the superior border of the manubrium
Runs from the costal cartilage (joins the ribs to the sternum)
Anchors the inferior surface of the sternal end of the clavicle to the 1st rib
Primary restraint for elevation of the pectoral girdle
Stability is primarily dependant upon the strength & integrity of its ligaments, particularly the Costoclavicular ligament
Elevation / Depression
When we take our arm overhead the distal end of the clavicle is elevating relative to where the manubrium is.
Protraction / Retraction
The distal end of the clavicle moving relative to the SCJ (sternoclavicular joint) / whether your shoulder is moving forward or backward
Passive movement (i.e., no muscle involvement)
Produced by scapular rotation
When our scapula internally or externally rotates our clavicle rotates with it.
Acromioclavicular Joint (AC)
Where the clavicle meets the acromium of the scapula
Plane type of synovial joint
Not to be confused with the glenohumeral joint
Located between the lateral end of the clavicle & the acromion of the scapula
Clavicle tends to override & project over acromion
Acromial end of clavicle articulates with the acromion of the scapula
Articular surfaces are covered with fibrocartilage
An incomplete wedge-shaped articular disc separates the articular surfaces, thus adding some congruency to the joint
Is quite weak and loose, however it’s strengthened superiorly by the trapezius and acromioclavicular ligament therefore it’s going to rely my on ligament stability predomintly and some muscles that cross over the joint.
The fibrous capsule attaches to the margins of the articular surfaces
A synovial membrane lines the fibrous layer
3 Ligaments of the AC Joint
Joint is stabilized by 3 ligaments
1. Acromioclavicular Ligament
Fibrous band that extends from the acromion to the clavicle
Strengthens joint superiorly
Thickening of the joint capsule
2. Coracoclavicular Ligament
This joint gives stability
Strong pair of fibrous bands called the conoid (medial) ligament and the trapezoid (lateral) ligament that unite the Coracoid process of the scapula to the clavicle
You don’t need to be able to distinguish which one is which.
The 2 parts of this ligament are set so as to restrain opposite movements of the scapula with respect to the clavicle
The conoid ligament limits forward movement of the scapula
The trapezoid ligament limits backward movement
3. Coracoacromial Ligament
Runs from caracoid process to the acromium.
It actually does NOT help join the clavicle to the acromium at all and does NOT help stabalise the AC joint because its not joining the clavicle to the acromium.
Is essentially provided by the Coracoclavicular ligament
Upper fibres of the trapezius and deltoid will provide some dynamic stability in a healthy injury free AC joint
However, both muscles can create further damage to the AC joint during periods of injury if the muscles are contracting because they where their attachment points are.
Movements of the AC Joint
The acromion of the scapula rotates on the acromial end of the clavicle
These movements are associated with motions of the scapulothoracic joint
Anterior / posterior gliding of the acromion relative to the clavicle (e.g. protraction/retraction of shoulder blade)
Superior / inferior migration of the acromion when you elevate and depress your shoulders
Note: There are no direct muscles that move the AC joint. The axioappendicular muscles that attach and move the scapula cause the acromion to move on the clavicle
AC Joint Pathology
G1: Torn some fibers / G2: Ruptured ligament but the coracoclavicular ligament is still in tact so the clavicle wont ride up / G3: Complete rupture which is when the clavicle rides up
Ability of the scapula to glide & upwardly and downwardly rotate relative to the posterior aspect of the rib cage
Out of the 180 degrees of abduction our shoulder joint gets: 120 comes from the GH joint and 60 degrees comes from the scapula movement. (2:1 ratio). So if the scapula isn’t movement correctly your shoulder ROM will be limited.
Along with the Acromioclavicular & Sternoclavicular joints, scapulothoracic gliding enables the glenoid fossa to follow the head of the humerus
Helps to maintain maximum contact between the articular surfaces of the true shoulder joint
Muscles Controlling Scapular Upward/Downward Rotation
The below muscles origins are on the axial skeleton and their insertions are on the scapula. Therefore if insertions on the scapula this means those muscles are going to move the scapula because their always moving insertion relative to the origin.
Trapezius (all 3 portions)
Serratus anterior (upper & lower portions)
Pectoralis minor to a lesser extent
Vital component of normal shoulder joint function
If a back muscle is above the scapula it’s typically going to move the scapula upwards (elevation). If it’s origin is medial to the scapula it’s going to retract the scapula towards the midline. If it’s origin is inferior to the scapula it’s going to depress the scapula.
Topic 7. Muscles Moving the Shoulder Girdle (Scapula)
Upward rotators obviously rotate our scapula up, but when we come down it’s still our upward rotators working eccentrically to control that downward rotations as the muscle lengthens (so it’s not our downward rotators responsible for the joint action).
Axioscapular & Axioclavicular Muscles
Axioscapular means the muscle attaches to the axial skeleton as well as the scapula
Position the scapula and clavicle by moving the Sternoclavicular and Scapulothoracic joints
Muscles involved work as a group to hold the scapula stable as it moves on the thorax
Trapezius (force couple, force in opposing direction) – Serratus Anterior – Levator Scapulae – Rhomboids Major & Minor – Pectoralis Minor
Large muscle which can be separated according to fibres (sections)
Origin: Occipital bone, ligamentum nuchae, spinous process C7-T12
Insertion: clavicle, acromion, spine of scapula
Actions: Upper fibres (Upper trap): Elevation & upward rotation / Middle fibres (middle trap): Retraction (adduction), elevation / Lower fibres (lower trap): Depression
If a muscle is ABOVE the scapula it’s going to upwardly rotate/elevate.
If a muscle sits medial to the scapula it will retract it.
If a muscle is below the scapula it will depress/downardlly rotate.
If a muscle is more anterior to the scapula it will protract it.
Is important role in scapulothoracic stability and keeping the medial border of the scapula flat on the thoracic cage (back). Which is a really important mechanical function to not allow scapula winging, which is when the medial border come up.
Origin: anterior margin ribs 1-9
Insertion: medial border of scapula
Action: Protraction (abduction) & upward rotation
Common site for neck discomfort. People who sit a lot at a desk usually get tight levator scapulae’s – their scapula might be slightly elevated which shortens the LS and tightens it.
Origin: Transverse process C1-C4
Insertion: Superior medial border of scapula
Action: Elevation, downward rotation
Deep to trapezius
Origin: Spinous process C7-T5
Insertion: Medial border of scapula
Action: Retraction (adduction), downward rotation, elevation
Can become tight with activities in front of the body (upper cross sydrome) / Sits deep compared to pec major
Origin: Anterior surface ribs 3-5
Insertion: Coracoid process
Action: Protraction (abduction), downward rotation, assists in depression
Joint Actions Summary
Superior rotators = upward rotation / inferior rotators = downard rotation.
Synchronous scapula and humeral movement – 2:1 ratio = when we take our arm overhead we get 180 degrees of flexsion (abduction) = 120 degrees is coming from the glenohumeral joint and 60 is coming from the scapula. Practical Implication: People who can’t raise their arms full above their head.
If you don’t have healthy shoulder mechanics (rotator cuff and scapula rhythm) you can decrease the subacromial space and end up impinging the soft tissue against the bone causing inflammation and/or burisits.
Topic 8. Joints of the Upper Limb: Glenohumeral Joint
Where the glenoid cavity meets the humerus.
Allows a wide range of movement
Mobility is gained at the expense of stability. The GH joint is most at risk in abduction and externally rotated positions (single arm throwing)
Agonists (prime-movers) of the shoulder are able to generate large forces
Counterbalanced by smaller less powerful stabilisers
Articulations of the Glenohumeral Joint
Poorly matched (poor congruency)
Glenoid cavity accepts little more than 1/3rd of the large humeral head which is one reason why it’s not a very stable joint but quite mobile
A ring of fibrocartilage that wraps around the glenoid cavity to help deepen the socket – so it creates more contact between the humeral head and the glenoid
Slightly deepens & enlarges the Glenoid fossa
Helps decrease stress (force/area) on the glenoid fossa (the more contact area the less stress when force is being applied)
Also is the fibrous attachment of the glenohumeral ligaments and capsule to the glenoid rim
Articular Capsule of the GHJ
The loose capsule is attached proximally to the labrum and glenoid rim
Distally it attaches to the articular margins of the head of humerus
Posteriorly and inferiorly, the capsular insertion is directly onto the labrum
Inferioraly the capsule is quite loose/lax which decreases it’s stability but also helps increase its mobility enabling us to life our arm up.
Superiorly, the capsule is attached to the glenoid rim at the base of the labrum, and includes the origin of long head of biceps tendon
The capsule is reinforced by the tendons of the rotator cuff, and the tendon of long head of triceps below
Ligamentous Support of the GHJ
Ligaments of the Joint Capsule
Strengthened on its anterior surface by 3 capsular ligaments
Superior, Middle & Inferior Glenohumeral ligaments
Joint stability is largely maintained by the 4 rotator cuff muscles
Superior Glenohumeral Ligament (SGL)
Smallest of the glenohumeral capsular structures
It arises from the upper part of the glenoid margin and labrum
It inserts just superior to the lesser tuberosity in the region of the bicipital groove
Contributes to superior stabilization
SGL Prevents posterior and inferior translation of the humeral head
SGL represents the primary capsuloligamentousrestraint to inferior translation of the unloaded, abducted shoulder joint
Middle Glenohumeral Ligament (MGL)
It arises inferior to the SGL
Attaches to the humerus on the front of the lesser tubercle inferior to the insertion of subscapularis
Stabilizes the shoulder joint from 0º to 45º of abduction
In the lower and mid-ranges of abduction, it limits external rotation
Limits inferior translation when the shoulder is abducted and externally rotated (throwing)
Inferior Glenohumeral Ligament (IGL)
Arises from the margin of the glenoid fossa and the anterior border of the glenoid labrum
It descends obliquely to attach to the anatomical neck of the humerus
Is lax in adduction
Tightens with increasing abduction
IGL is the primary restraint for anterior and posterior dislocations at 90º of abduction
Stability of the GHJ
Shoulder joint stability is largely maintained by the rotator cuff muscles. They’re really important for keeping the humerus centered in the glenoid cavity.
Teres minor, Infraspinatus, Supraspinatus, Subscapularis (TISS)
(Smallest to largest)
The Directional Pull Of The Rotator Cuff Muscles
Subscapularus, teres minor and infraspinatus (horizontal red arrows) directional pull is trying to suck that humeral head against the glenoid cavity to it doesn’t dislocate.
The deltoid (red vertical line) wants to pull the humeral head upwards/superioly translate. If the deltoid becomes too active/over in the presence of under active/tight rotator cuff muscles it can pull the humeral head to far vertically impinging on the bursa sac. That’s why having good control and strength in the rotator cuff mucsles is important to counter act to much superior translation.
Join the scapula to the humerus
Prevent the head of the humerus from moving superiorly when the arm is raised
Work as a group to counteract the action of the deltoid muscle
Have their own actions & assist other muscles that move the shoulder joint & shoulder girdle
Formed superiorly (the roof) by the…
Formed inferiorly (the floor) by the…
Greater tubercle of humerus and the head of humerus
Prevents superior displacement of the humeral head from the glenoid cavity
Bursaeof the Glenohumeral Joint
Between the tendon of the Subscapularis & the neck of the scapula
Between the deltoid, tendon of Supraspinatus & shoulder joint capsule
Kinematics of the Glenohumeral Joint
Normal shoulder function requires the smooth integrated movement of the…
Abnormal Scapulohumeral rhythm predisposes the shoulder joint to injury
Topic 9. Muscles Moving the Glenohumeral Joint
Movements of the GH Joint
Muscles Moving the GH Joint
Function: Provide motion and dynamic stabilization to the Glenohumeral joint
Muscles include: Deltoid, Teres Major, Rotator Cuff for stabilisation
Include the Pectoralis Major and Latissimus Dorsi
They attach to the thorax and the humerus
Function: Due to their CSA (cross sectional area) they are involved in providing additional strength to the movements of the shoulder
Remember: Latisimus dorsi and teres major often act synergistically. They both come in and have the same insertion point, the fibers run in a similar direction and they have similar actions.
Glenohumeral Joint Anatomy
Functionally divided into three parts
Common insertion point: deltoid tuberosity of humerus
All heads to abduction.
Origin: Lateral 1/3 of clavicle
Action: Abduction, flexion, internal rotation, horizontal adduction
Middle Fibres Origin:
Origin: Spine of scapula
Action: Abduction, extension, external rotation, horizontal abduction
Forms posterior wall of axilla
Close association with latissiumus dorsi
Provides dynamic inferior stabilisation to GH joint
Origin: lateral border of scapula
Insertion: Intertubercular groove of humerus
Action: Extension, adduction, internal rotation
Rotator Cuff Muscles (TISS)
Smallest to largest: Teres Minor, Infrapsinatus, Supraspinatus, Subscapularis
Note: All 3 posterior rotator cuff muscles (teres minor, supraspinatus and infraspinatus all insert on the greater tubercle of the humerus)
Function: Provide dynamic stabilisation to the glenohumeral joint
Origin: Medial 2/3 of supraspinous fossa
Insertion: Superiorly on greater tubercle of humerus
Action: Initiates abduction, prevents superior translation of humeral head during abduction greater than 200, braces head of humerus against glenoid
Origin: Medial aspect of infraspinatus fossa
Insertion: Posteriorly on greater tubercle of humerus
Actions: External rotation
Origin: Upper/middle lateral scapula border
Insertion: Posteriorly on greater tubercle of humerus
Actions: External rotation
Is the only anterior muscle of the rotator cuff
Origin: Subscapular fossa
Insertion: Lesser tubercle of humerus
Action: Internal rotation, adduction.
Large muscle of anterior thorax
Two distinct bellies
Smaller Clavicular portion (proximal)
Larger Sternocostal portion (proximal)
Common insertion point: Intertubercular groove of humerus
Origin: Medial half of clavicle
Action: Internal rotation, horizontal adduction, flexion, abduction (above 90° of abduction)
Origin: Costal cartilages of ribs 1-6 and adjoining portion of sternum
Action: Internal rotation, horizontal adduction, adduction & extension (from a flexed position to anatomical position
Extensive attachment to spine and pelvis
Capable of producing large forces
Has link with contralateral gluteus maximus via thoracolumbar fascia (posterior sling)
We’re able to transfer power from our lower to upper body (and vice versa) via the posterior sling. Because the lats AND glutes connect to the same thoracolumbar fascia tension within these muscles can transfer diagonally across the body to produce force, e.g. a shot put.
Origin: Posterior iliac crest, sacrum, spinousprocess of T6-12 & L1-5
Insertion: Intertubercular groove of humerus
Action: Extension, adduction, internal rotation
Topic 10. Joints & Muscles of the Elbow & Radioulnar
Elbow Joint Structure
Where the humerus meets the ulna (hinge joint): humeraulna joint.
Complex synovial hinge joint
Located 2-3 cm inferior to the epicondyles of the humerus
Involves the distal end of the humerus and proximal ends of the radius & ulna
Distal region of the humerus has two important articular surfaces
Trochlea (articulates with the ulna) & capitulum (articulates with the radius)
Anatomical structures make it a stable joint
Articular surfaces are well matched anatomically
Articulations of the Humeroulnar Joint
Largest and strongest articulation at the elbow
Trochlea of humerus articulates with Trochlea notch of ulna
Joint capsule completely encloses the joint
Radial head articulates with the capitulum of the humerus
Not part of the true hinge joint
Articulations of the Superior Radioulnar Joint
Head of radius articulates with radial notch of the ulna
Allows movement of the head of the radius on the ulna (pivot joint)
The radial head is held in place by the annular ligament of the radius – which is a really strong ligament that wraps around the head
Articular Capsule of the Elbow Joints
Anteriorly the joint capsule attaches to:
Upper margins of the coronoid and radial fossae;
To the front of the medial and lateral epicondyles AND; inferiorly to the margin of the coronoid process
Posteriorly the joint capsule attaches to
The superior margins of the olecrannon fossae AND; inferiorly to the upper margins and sides of the olecranon process
Ligamentous Support of the Elbow
The collateral ligaments of the elbow joint are strong fibrous bands
They are thickenings of the joint capsule called Radial (lateral) collateral and Ulnar (medial) collateral ligaments
Annular ligament which wraps around the radial head
Strong triangular band that attaches to the lateral epicondyle, deep to the common extensor tendon
Below, it attaches to the annular ligament which surrounds the radial head
Function: Prevents the radius separating from the humerus
Fans out from the medial epicondyle & attaches to the coronoid process & olecranon
Consists of a thick anterior and posterior band
Intermediate (oblique) band unites anterior & posterior bands
Anterior band is intimately associated with the common flexor tendon
Thus, prone to injury. Especially with young baseballers when they reach back and throw which stretches the distance between your humerus and your ulna which gets irritated after so many reps under high velocity.
Function: Medial stability
Function: Hold radial head against ulna and provides pivot point for it to rotate over the top of the ulna (pronation)
Attaches to the radial notch anteriorly and ulna posteriorly
Anchors the radial head
This allows the radius to rotate
Inferior Radioulnar Joint Structure
Head of the ulna articulates with the ulnar notch of the radius – remember the radius is bigger at the distal end
Elbow Joint Musculature
Movements at superior radioulnar joint
Pronationand supination (via pivot joint)
4 main muscles: Pronator teres, Pronator quadratus, Supinator, Biceps Brachii
Anterior Compartment of Arm: Flexor Compartment
Contains Biceps Brachii
Coracobrachialis (actually moves the shoulder not the elbow)
All anterior muscles supplied by the: Musculocutaneous Nerve which is a terminal branch of the brachial plexus
Bicep = 2 heads (2 origins)
Fusiform (spindle) muscle with bilateral head
Activity of this muscle affects Glenohumeral, humeroulnar and radioulnar articulations
Long head from superior lip of glenoid fossa
Short head from coracoid process
Insertion: radial tuberosity
Action: elbow flexion, forearm supination, shoulder flexion (because it attached at the glenoid)
Deep to biceps on distal humerus
Is monoarticular (affecting only one joint of the body) – Actions only occur at the elbow
Sole action is elbow flexion
Works eccentrically to control the speed of extension
Origin: Distal anterior humerus
Insertion: Coronoid process of ulna
Action: elbow flexion (because it’s only attached onto the ulna)
Makes up bulk of the arm
Crosses the shoulder joint
Acts only at shoulder
Origin: Coracoid process
Insertion: Medial humeral shaft
Action: Flexion & adduction of glenohumeral joint
Makes up bulk of forarm and seperates the extensors and flexors of the wrist
Superficial muscle of lateral forearm
Origin: Lateral supracondylar ridge of humerus
Insertion: Radial styloid process
Action: elbow flexion
Posterior Compartment of Arm: Extensor Compartment
Principal Elbow Extensor
Constitutes the entire mass on the posterior aspect of the arm
Has three heads (origins)
Origin: Long head from infraglenoid tubercle of scapula; lateral head from posterior shaft of humerus; medial head from humeral shaft
Insertion: Olecranon process
Action: Chief elbow extensor
A small muscle that assists triceps in extending the forearm
Synergist muscle (not a prime mover)
Origin: Lateral epicondyle of humerus
Insertion: Olecranon process
Action: elbow extension
Both insert onto the radius
Origin: medical epicondyle of humerus
Insertion: Lateral radius
Origin: Distal anterior ulna
Insertion: Distal anterior radius
Origin: Lateral epicondyle of humerus
Insertion: Proxmial radius