bio usa test 1
8. What are the differences in the actions of the three heads of the triceps?
**triceps produce max torque at 90 degrees flexion a. Long head: i. Affected by shoulder position ii. Greatest activity with heavy resistance or quick extension iii. Least effective at full elbow extension and GH hyperextension b. Medial head: i. Not affected by shoulder position ii. Active with non-resisted and resisted extension c. Lateral head i. Active with resisted extension
How would you differentiate between the following muscles: b. flexor pollicis longus and brevis
b. The longus flexes the interphalangeal joint of the thumb and the brevis does not.
Which muscles stabilize the following b. radial side of the wrist when the wrist is in a neutral position
b. ext. carpi radialis longus; flex. carpi radialis;
What muscles produce the following movements: b. wrist flexion and ulnar deviation
b. flex. carpi ulnaris;
2. Give an example of the following types of synovial joints and their degrees of freedom: b. hinge
b. humeroulnar or interphalangeal joints which have 1 degree of freedom
What movements of the clavicle occur at the sternoclavicular and acromioclavicular joints during the following movements:b. clavicular posterior rotation
b. posterior rotation at the sternoclavicular and acromioclavicular joints
9. If you are mobilizing a joint and are applying 5 pounds of compression to the thumb, how much compression force is occurring at each joint of the thumb?
5 pounds of compression force on the thumb will produce 10-15 pounds of force at the IP, 25 - 30 pounds of force at the MCP, and 30 - 60 pounds at the CMC joint.
1. How would you determine the final resultant force and movement of a bone when three different muscles are applying forces (F1, F2, F3) at three different angles to the bone?
By using a parallelogram, the resultant force FR1,2 can be determined for the combined action of F1 and F2 on the bone. After FR1,2 is resolved, this resultant force and F3 can be combined to find the overall resultant force FR1,2,3.
8. What are the movements of the shoulder complex structures during external rotation?
During external rotation with the arm at the side of the body, the humeral head rotates laterally and glides anteriorly, the clavicle translates posteriorly and the scapula retracts.
1. In what way does arthrokinematic abduction and adduction of the carpometacarpal joint of the thumb differ from arthrokinematic movements movements at the other joints of the fingers?
During thumb carpometacarpal abduction and adduction, the direction of rotation and glide are opposite the osteokinematic movement where as at the other joints the direction of rotation and glide are in the same direction as the osteokinematic movement.
5. What is the movement sequence during wrist ulnar deviation?
During ulnar deviation, the distal carpal row moves ulnarly, the proximal row slightly radailly and the scaphoid and lunate move dorsally.
3. What is the movement sequence during wrist extension (dorsiflexion) and where does most of the movement take place?
During wrist extension, the distal carpal row moves dorsally and proximal row moves palmarly. At 60 degrees of extension, the scaphoid of the proximal carpal row and the hamate, capitate and trapezoid of the distal carpal row come into a closed pack position, forming a ridged mass. Palmar movement of this mass at the radiocarpal joint completes wrist extension. Because of the formation of this closed pack position between the proximal and distal carpal rows, 60 -70% of wrist extension occurs at the radiocarpal joint and 30 - 40% at the midcarpal joint.
4. How does the movement sequence during wrist flexion (palmar flexion) differ from that of dorsiflexion?
During wrist flexion, the direction of movement of the proximal and distal carpal rows is opposite that of extension (proximal move dorsally and distal move palmarly). While the scaphoid, hamate, capitate and trapezoid formed a closed packed ridge mass during extension, this formation does not occur during flexion and thus movement of the midcarpal joint is not blocked. In fact, most of the flexion movement that occurs during the last part of flexion is at the midcarpal joint. Because midcapal movement is allow throughout the range of wrist flexion, more flexion (60 %) occurs at the midcarpal joint and less(40%) at the radiocarpal joint which is opposite of that seen during extension where most movement occurs at the radiocarpal joint and less at the midcarpal joint.
1. What scapular and clavicular movements are produced by the upper trapezius?
Elevation of the scapula and clavicle, posterior rotation of the clavicle, upward rotation of the scapula
3. What is the difference between fixed and movable pulleys?
Fixed pulleys change the direction of pull but not the magnitude of the applied force where as movable pulleys change both the direction of pull and decrease the magnitude of the applied force.
What are the muscles producing glenohumeral flexion from 0 - 60 degrees
Flexion for 0 - 60 degrees: the upper trapezuis elevates the clavicle and scapula - the subscapularis, infraspinatus, teres minor produce the inferior glide of the humeral head - the coracobrachialis, anterior deltoid and biceps produce the posterior humeral head rotation.
Why is the amount of force generated by the deltoid to hold the arm at 90 degrees of abduction so much greater than the weight of the arm? How about the rotator cuff holding the arm in abduction at 60 degrees?
For both the deltoid and rotator cuff muscles, the high forces are associated with the type of lever involved in these actions. These muscles are acting as the force part of a Class III lever and the force arms are short compared to the weight arms. With this arrangement, the amount of force required is always much higher that the amount of weight or resistance.
2. How much wrist movement is needed for most ADLs?
For most ADLs 10 degrees of palmar flexion and 35 degrees of dorsiflexion are needed.
1. Apply Newton's First Law to the movements of the glenohumeral joint:
Force is needed to start movement at the joint and the movement will continue in the same direction unless another force is applied to change the directions of movement. If the shoulder flexors activate flexion at the glenohumeral joint, flexion will continue until another force, say the deltoid, applies an abduction force on the glenohumeral joint. The move direction will then change with the addition of this second force.
6. What are the movements of the shoulder complex structures during flexion?
From 0 - 60 degrees, the scapula and clavicle elevate, the humeral head glides inferiorly and rotates posteriorly. From 60 - 90, the humeral head is seated in the glenoid fossa and rotates posteriorly, the clavicle and scapula continue to elevated but the scapula also begins to upwardly rotate. From 90 - 180, the scapula upwardly rotaes, the clavicle rotates posteriorly, and humeral head rotates posteriorly while still seated in the glenoid fossa.
7. What are the movements of the shoulder complex structures during extension?
From 180 - 90 degrees, the seated humeral head rotates anteriorly, the scapula downwardly rotates, and the clavicle rotates anteriorly. From 90 - 60, the seat humeral head continues to rotate anteriorly, the scapula stops it downward rotation and depresses, and the clavicle stops its anterior rotation and depresses. From 60 - 0, the humeral head rotates anteriorly and glides superiorly, and the scapula and clavicle depress.
4. What are the actions of the deltoid?
Gleonhumeral flexion, extension, abduction, internal rotation, external rotation
1. What is the difference between osteokinematic and arthrokinematic movements?
Osteokinematic are the movements seen by the bone at a joint. These include flexion, extension, abduction and adduction. Arthrokinematic movements are those that are occurring at the articular surfaces of the bone making up the joint. These movements are usually described as a rotation, translation, or a combination of the these or curvilinear.
8. How might fractures or dislocations at the wrist affect movement?
If a fracture of the distal radial occurs, motion at the radiocarpal joint will be affected. Because 60 - 70% of dorsiflexion (extension) occurs here, there will likely be more restriction and problems with wrist dorsiflexion than with wrist palmar flexion. As radial and ulnar deviations occur mainly at the midcarpal joint, there should be little effect on these movements. If the scaphoid or lunate are fractured or dislocated, both the radiocarpal and midcarpal joints would be involved. In this case, dorsiflexion, palmar flexion and radial and ulnar deviations could be affected. If a fracture or dislocation affected mainly the midcarpal joint, then radial and ulnar deviation would be affected. Palmar flexion would most likely be affected more than dorsiflexion as 60% of palmar flexion occurs at the midcarpal joint where as only 30 -40% of dorsiflexion occurs at the midcarpal joint.
7. With a type III lever, what would the Force be if dW=10 cm and dF=2 cm? What if the dW=20 cm and dF=2 cm?
If dW=10 and dF=2, the Force (F) = 5W (Weight). If the dW= 20 and dF=2, the Force (F) = 10W (Weight).
6. With a type I lever, what would the Force be if dW=6 cm and dF=2 cm? What if the dW=3 cm and dF=9 cm?
If dW=6 and dF=2, the Force (F) = 3W (Weight). If dW=3 and dF=9, the Force (F) = 1/3 W (Weight)
2. Apply Newton's Second Law to an exercise for increasing elbow flexion strength.:
If it is necessary to accelerate elbow flexion motion during an exercise than greater force will be needed. If a weight is added to the hand, then the mass increases and this increase in mass will decelerate the motion unless more force is added. Rapid elbow flexion requires more force and if the mass is also increased then even force is required.
4. What is the difference between a loose pack and close pack position of a joint?
In a loose pack position, the joint show minimum congruency between the match joint surfaces, the ligament and capsule are loose and there is maximum joint space. This position is for good for dynamic joint movement and joint mobilization but poor for static load bearing. In the close pack position, the joint shows maximum congruency, tightness of the joint capsule and ligaments, minimal joint space. This is a good position for static load bearing but not for joint mobilization.
8. What is the difference between a tip pinch and a lateral pinch?
In a tip pinch, the tips of the two fingers are used and the forces are greater at the PIP joint than the MCP joint. With a lateral pinch, the palmar aspect of the distal thumb is pressing a object against the distal radial aspect of the index finger and forces at the MCP are greater than the PIP.
5. What muscles produce glenohumeral adduction and internal rotation?
Pectoralis major, latissimus dorsi, teres major, subscapularis (slight adduction)
2. What muscles produce downward rotation of the scapula?
Pectoralis minor, rhomboid major and minor, levator scapulae
What movements and muscle actions are common during glenohumeral extension (180 - 0 degrees) and adduction (180 - 0 degrees)? What are different?
In both extension and adduction, scapular downward rotation is produced by the levator scapulae, rhomboids major and minor and pectoris minor - anterior clavicular rotation by the pectoralis major - subscapularis, infraspinatus, teres minor hold the humeral head seated in the glenoid fossa - pectoralis minor and lower trapezius depress the scapula - pectoralis major and suclavius depress the clavicle. The differences are the direction of humeral head rotation (anterior in extension and lateral in adduction) and the muscles producing these rotations.
9. What movements and muscle actions producing glenohumeral flexion are common to those during glenohumeral abduction? What are different?
In both flexion and abduction, scapular and clavicular elevation are produced by the upper trapezuis - upward scapular rotation is produced by the upper trapezius, lower trapezius, serratus anterior and the rhomboids stabilize the scapula and control upward rotation - the upper trapezius produces posterior clavicular rotation - the subscapularis, infraspinatus and teres minor produce the inferior humeral head glide and hold it (searted) in postion - deltoid acts to rotate the humeral head. The only differences are the medial direction of humeral head abduction and the muscles producing the rotation.
3. Apply Newton's Third Law to gripping and holding an object in your hand:
In flexing the fingers to grasp an object, the force from the finger flexors is greater than the resistance to flexion and so the fingers move in flexion. Once the fingers grasp and hold the object then the flexion force of the fingers is equivalent to the resisting force of the object and motion of the fingers stops. The fingers flexors are still producing a flexion force against the resistance of the object to hold the object. Increased force by the finger flexor at this time may overcome the resistant forces of the object and the object may break.
4. When is phase II of scapular movement and what movements occur during this phase?
Phase II of scapular movement occurs after 90 degrees of shoulder flexion and abduction. During this phase, scapular and clavicular elevation occurring in Phase I stops and the scapula upwardly rotates and the clavicle rotates posteriorly.
2. What are benefits of upward scapular rotation during arm flexion and abduction?
Increases ROM in flexion and abduction, maintenance of the subacromial space, permits the deltoid, supraspinatus and coracobrachialis muscles to function near the top of the length-tension curve so that they can produce high forces over a large portion of the motion.
6. What muscles produce an inferior glide of the humeral head?
Infraspinatus, teres minor, subscapularis
5. What is the difference between loads and stresses?
Loads are external applied to a structure while stress is the force that occurs with in that structure due to the external load.
6. How does radial deviation differ for ulnar deviation?
Movements of the distal and proximal carpal rows and movement of the scaphoid and lunate during ulnar deviation are opposite those occurring during radial deviation.
7. Why are radial and ulnar deviations limited when the wrist is in full extension?
Radial and ulnar deviations require movements between the proximal and distal carpal rows at the midcarpal joint. With the wrist is full extension, the scaphoid, hamate, capitate, and trapezoid form a closed pack ridged mass that blocks movement at the midcarpal joint. With midcarpal movement blocked, radial and ulnar deviations are also blocked and thus very limited or no deviation is permitted.
2. How can the component forces be determined from the line of action of a muscle?
Represent the line of action of a muscle as a vector and then construct a X and a Y axis for that vector. The X axis is always along the bone that is moving and the Y axis will be perpendicular to the X axis. Using the line of action of the muscle as the hypotenuse, the X and Y components of muscle action can be derived. Remember, that as the muscle contracts and the bone moves the line of muscle action usually changes and so do the components.
3. What is scapular rhythm?
Scapular rhythm is the ratio of glenohumeral motion to scapular motion. This ratio is commonly given at 2:1 (2 degrees of glenohumeral to 1 degree of scapular motion) but it is variable. Using the 2:1 ratio, 90 degrees of osteokinematic flexion or abduction is the result of 60 degrees of glenohumeral movement and 30 degrees of scapular movement.
8. What is the difference between stress and strain?
Stresses are internal forces with in a structure while strain is the deformation of the structure due to these tensile stresses.
5. What can decrease the size of the subacromial space?
Subacromial bursitis, calcium deposits in the subacromial bursa, thichening of the coracoacromial ligament, inflammation of the rotator cuff or the tendon of the long head of the biceps, thickening or hooking for the acromion process.
7. What muscle is the main glenohumeral abductor from 0 - 60 degrees? What about abduction over 90 degrees?
Supraspinatus is the main abductor for 0 - 60 degrees and the deltoid is the main abductor above 90 degrees.
6. How does the extensor assembly extend the PIP and DIP?
Tension applied to the extensor hood by the extensor digitorum (ext. indicis and digiti minimi), lumbricles and interossei is transmitted to the central slip and the lateral bands. Tension of the central slip produced extension of the PIP. Tension on the lateral bands is transmitted to the terminal tendon to extend the DIP.
4. What muscles are needed to fully extend a finger and why are multiple muscles needed for this action?
The extensor digitorum, ext. indicis (specific to index finger), ext. digiti minimi (specific to little finger), lumbricles, palmar and dorsal interossei are the muscles needed for full extension of the finger. Because of the strength of the flexor digitorum superficialis and profundus and the lack of strength of the extensors, the lumbricles and interossei are needed.
5. What are the two main functions of the flexor tendon sheath?
The flexor sheath 1) maintains the proper position of the tendon to the axis of the joint so that there is smooth distal to proximal flexion of the fingers and thus preventing bow stringing of tendon which gives the tendon a mechanical advantage at the joint (increasing the force arm) and produces premature bending of the joint and 2) minimizes the amount a tendon needs to move to produce flexion and thus the amount of muscle shortening so the muscle can work near the top of its length- tension curve.
What are the two strongest groups of shoulder muscles? What are the two weakest groups? How does this relate to muscle testing?
The strongest groups are the adductors and internal rotators awhile the weakest groups are the abductors and external rotators. Because of these normal differences in strength, comparisons of strength based on the amount of resistance applied during a movement may be misleading and not provide an accurate measure of function. It is important to remember that some muscles and muscle group are more powerful than others and that relative weakness between these is not necessarily a sign of dysfunction.
7. What is the difference between a power grip and a precision grip?
The thumb is adducted in a power grip but abducted in a precision grip.
9. What muscles produce the following movements: a. wrist extension,
a. ext. carpi radialis longus and brevis, ext. carpi ulnaris, ext. digitorum, ext indicis, ext. digiti minimi;
1. What are the roles of the intrinsic and extrinsic ligaments of the wrist?
These ligaments provide stability for the radiocarpal, ulnocarpal, midcarpal and intercarpal joints. They also resist movements by tightening and allow movements by loosening. This combination of ligament tightening and loosing allows certain bones to move while at the same time restricts other bones from moving. The results are wrist flexion (palmar flexion), extension (dorsiflexion), radial and ulnar deviation.
5. What is torque and how is it calculated?
Torque is a rotational force and is calculate by multiplying the Force or Weight by the perpendicular distance of the Force or Weight from the center of rotation.
4. What is the difference between total and unit force?
Total force is the total amount of force being applied to a surface while unit force is the force being applied per unit area on the surface. So if there is a total force of 100 Newtons on a surface with an area of 100 mm2 then the unit force would be 100 N divided by 100 MM2 or 1N per mm2.
4. What is the difference between type I and type III levers?
Type I lever has a central fulcrum with the weight side of the lever on one side of the fulcrum and the force side of the lever on the opposite side of the fulcrum. With a type III lever, the fulcrum is at one end and the weight at the opposite end of the lever. The force lies between the fulcrum and the weight end. In this lever, the weight arm is always longer than the force arm.
3. What muscles produce upward rotation of the scapula?
Upper trapezius, lower trapezius, serratus anterior
3. How much elbow movement is needed for most ADLs?
a. flexion/ extension= 20-130 degrees b. pronation= 50 degrees c. supination= 50 degress
2. Give an example of the following types of synovial joints and their degrees of freedom: a. plane,
a. intercarpal joints which can have 1, 2 or 3 degrees of freedom
3. What is the concave/convex rule?
When a convex surface is moving on a fixed concave surface, arthrokinematic joint translation (glide) is opposite to the direction of osteokinematic movement. However, when a concave surface is moving on a fixed convex surface, arthrokinematic joint translation (glide) is in the same direction a the osteokinematic movement.
10. What strains occur when a long bone is bending?
When a long bone bends, the concave side of the bend shows compressive stress and strain and the convex side show tension stress and strain. The forces for both are greatest at the periphery and decrease as the neutral axis in the center of the bone is reached.
9. What strains occur at a tendon when a tensile load is applied?
When a tensile load is applied to a tendon, the tensile stresses produce tensile strain (elongation) of the tendon. At the same time, the resisting compressive stresses in the tendon produce compressive strain (contraction, squeezing) in the tendon and these two stresses produce shear stresses which produces shear strain (cutting, tearing) in the tendon. The relative magnitude of the stresses determines what the overall strain is on the structure. If the tensile stresses are greater than the compressive stresses than the structure will elongate.
7. What are the stresses occurring in a vertebral disc when a compression load is applied by the vertebral bodies?
With a compression load on a vertebral disc, there are compressive stresses being transmitted in the disc, tensile stresses resisting the compression stresses, abd shear stresses resulting for the tensile - compression forces.
8. How does movement of the force arm only a short distance affect muscle contraction force?
With a short Force arm and a long Weight arm, small movement at the force end of the lever produces a large movement at the weight end. Because the movement of the force end is small, the shorten (contraction) of the muscle is also small. This small shortening keeps the muscle near the top of its length-tension curve so force production by the muscle is high. .
6. What are the stresses occurring in a tendon when a tensile load is applied by the contraction of a muscle?
With a tensile (tension) load on the tendon, there are tensile stresses being transmitted with in the tendon, compressive stresses with in the tendon resisting the tensile stresses and shear stresses resulting from the tensile - compression forces.
11. What is the difference between work and power?
Work is a function of the amount of force times the distance over which that force is applied. Work has no time component. However, Power is work divided by time. Unlike Work, as the time interval changes the amount of power changes.
2. What joints are flexed by contraction of the flexor digitorum superficialis?
Wrist, carpometacarpal, metacapophalangeal, proximal interphalangeal
9. What is the main pronator of the forearm and why?
a. **Pronator quadratus i. Active during non-resisted and resisted movement ii. Active during slow and rapid pronation b. Pronator teres i. Active with rapid pronation and with resisted movement ii. Maintains position of radial head relative to capitellum iii. Elbow extension to strengthen because its across the anterior elbow
10. What is the main supinator of the forearm and why?
a. **Supinator i. Active with non-resisted and resisted supination ii. Active during slow and rapid supination iii. Maintains radial head relative to capitellum b. Biceps i. Active during resisted supination ii. Active during rapid supination iii. Needs elbow extension to work bicep during supination
7. What is the main flexor of the elbow and why?
a. Brachialis i. Largest in strength and work capacity ii. ** active at all positions and speeds of movement; don't need to worry about the position of the shoulder iii. ** active with non-resisted and resisted movemen
4. What arthrokinematic movements are common at the humeroulnar and humeroradial joints during flexion? What movements are not common?
a. Common during HR and HU flexion: i. Anterior rotation ii. Anterior translation (glide) b. HU flexion: i. Ulna adducts b/c of the trochlear ridge of the ulna follows the titled trochlear groove of the humerus c. HR flexion: i. Radius glides anteriorly on capitulum ii. Radius moves cranially on the ulna
10. Which muscles stabilize the following: a. ulnar side of the wrist when the wrist is in a neutral position
a. Flex. carpi ulnaris; ext. carpi ulnaris;
2. What is the best way to test the medial collateral ligament and the joint capsule of the elbow joint?
a. MCL: 78% With the elbow bent at 90 degrees flexion, with a downward force b. Joint Capsule: 85% With elbow at 0 degrees flexion, with a posterior force
1. Why is the medial collateral ligament of the elbow more developed than lateral collateral ligament and what movements do the medial collateral ligament resists.
a. Most ADL's inc valgus strain at the elbow because of the outward movement of the forearm relative to the humerus (carrying angle) i. Valgus strain at the elbow tenses the MCL and medial tissues of the elbow, puts traction on the humeroulnar joint, compresses the humeroradial joint, slackens the lateral tissues of the elbow b. Actions: i. Superior fibers of anterior band- slack in flexion but taut in extension ii. Inferior fibers of anterior band- taut in flexion but slack in extension iii. Posterior band- taut after 90 degrees flexion iv. Transverse band
6. If the musculocutaneous nerve is damaged, what muscles could still flex the elbow?
a. Musculocutaneous N. innervates the biceps, brachialis b. Other elbow flexors that would be unaffected: ** all attach to the common flexor tendon i. brachioradialis ii. ECRL iii. Pronator teres iv. FCU v. FCR Elbow Flexion Brachialis Musculocutaneous Biceps Musculocutaneous Brachioradialis Radial FCRL Median Pronator teres Median FCU Ulnar FCR Median FDS Median i. FDS
5. What arthrokinematics movements occur at the proximal radioulnar joint during pronation of the forearm?
a. Pronation: radius rotates medially, and glides lateraly b. Supination: radius rotates laterally, glides laterally
3. How would you differentiate between the following muscles: a. flexor digitorum superficialis and profundus;
a. The profundus flexes the distal interphalangeal joint but the superficialis does not.
1. What movements of the clavicle occur at the sternoclavicular and acromioclavicular joints during the following movements: a. clavicular elevation
a. elevation at the acromioclavicular joint and depression at the sternoclavicular joint
How would you differentiate between the following muscles: c. extensor pollicis longus and brevis?
c. The longus extends the interphalangeal joint of the thumb and the brevis does not.
What movements of the clavicle occur at the sternoclavicular and acromioclavicular joints during the following movements:c. clavicular protraction
c. anterior translation of the clavicle at the sternoclavicular and acromioclavicular joints.
What muscles produce the following movements c. wrist flexion,
c. flex. carpi radialis, flex. carpi ulnaris, flex. digitorum superficialis, palmaris, longus;
Which muscles stabilize the following c. ulnar side of the wrist when the wrist is in extension?
c. flex. carpi ulnaris
2. Give an example of the following types of synovial joints and their degrees of freedom: c. condyloid
c. radiocarpal or metacarpophalangeal joints which have 2 degrees of freedom
2. Give an example of the following types of synovial joints and their degrees of freedom: d. saddle
d. carpometacarpal joint of the thumb which has 2 degrees of freedom or the sternoclavicular joint which ahs 3 degrees of freedom.
What muscles produce the following movements d. wrist extension and radial deviation
d. ext. carpi radialis longus; ext. carpi radialis brevis (slight radial deviation)
Downward scapular rotation (all three act together to form a force couple to produce this movement)
o levator scapulae o rhomboids major and minor o pectoralis minor
Scapular adduction (retraction)
o middle trapezius o rhomboids major and minor
Anterior clavicular rotation and translation
o pectoralis major
Scapular abduction (protraction)
o serratus anterior
Upward scapular rotation (all three act together to form a force couple to produce this movement)
o upper trapezius o lower trapezius o serratus anterior
Posterior clavicular rotation and translation
o upper trapezius o sternocleidomastoid
What are the muscles producing glenohumeral flexion from 90 - 180 degrees?
the upper trapezius, lower trapezius and serratus anterior produce the upward scapular rotation - the rhomboids stabilize the scapula and control upward scapular rotation - the upper trapezius produces the posterior clavicular rotation - the subscapularis, infraspinatus and teres minor hold the humeral head seated in the glenoid fossa - coracobrachialis, anterior deltoid, biceps produce the posterior rotation of the humeral head.
gh Vertical abduction
● Anterior, middle, posterior deltoid ● Supraspinatus ● Long head of biceps with arm externally rotated
gh Flexion
● Coracobrachialis ● Anterior deltoid ● Long and short heads of the biceps ● Pectoralis major when arm hyperextended
Scapular depression
● Lower trapezius ● Pectoralis minor ● Latissimus dorsi
gh Vertical adduction
● Pectoralis major ● Latissimus dorsi ● Teres major ● Subscapularis ● Infraspinatus ● Long head of triceps
gh Extension
● Posterior deltoid ● Latissimus dorsi ● Teres major ● Long head of triceps
GH Hyperextension
● Posterior deltoid ● Long head of triceps
Clavicular depression
● Subclavius ● Pectoralis major
Scapular elevation
● Upper trapezius ● Levator scapulae ● Rhomboids major and minor
Clavicular elevation
● Upper trapezius ● Sternocleidomastoid
