k class 9 muscles of arm 2013

8/10/2019 K Class 9 Muscles of Arm 2013

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Often called theswimmer’s musclebecause of its functionin pulling the body

forward in the waterduring medial rotation,adduction & extension.It is designed forpowerful movementslike rowing & pulling.



O: inferior angle ofthe posteriorscapulaI: bicepital grooveof the humerusEffective only whenthe rhomboidsstabilize thescapula or movethe scapula indownward rotation.



Teres major works as a synergist withlatissimus dorsi in extending the humerus aswell as adduction & medial rotationThis muscle is less frequently injured thanlatissimus dorsi.Teres major will try to compensate forlatissimus dorsi when latissimus dorsi is

injured.



Rotator Cuff Muscles



Group works to keep the head of the humerus inits proper location within the glenoid fossaduring all movements.Group must have adequate strength & muscularendurance to ensure proper functioningespecially in repetitive overhead movementssuch throwing, swimming, & pitching.If weak, fatigued or not properly warmed up, candevelop problems such as tendonitis, tendonosis,or rotator cuff impingement◦ Tendonosis is a breakdown of the collagen fibers within

the tendon◦ Tendonitis is an inflammation of a tendon



O: subscapularis fossa of the anterior scapulaI: lesser tubercle of the humerus.Main concentric action is medial rotation of thehumerus.Works with latissimus dorsi & teres major & all3 muscles form the posterior axillary fold.Most effective when the rhomboids stabilizethe scapula.It is the least powerful of the 3 muscles due toits close proximity to the joint.



It is subject to trigger points & painpatterns when there is little or no ROM ofthe scapula.With lack of movement, such as in AdhesiveCapsulitis, the subscapularis becomes weak

atrophies & adds to the restriction ofnormal ROM.



O: supraspinatus fossa of the posteriorscapulaI: next to the infraspinatus & teres minor onthe greater tubercle of the humerus.Major concentric action is abduction of theshoulder.In a throwing movement, supraspinatus

provides an important dynamic stability forthe head of the humerus in the glenoidfossa.



Most often injured member of the group.Mild to moderate strains or tears oftenoccur with athletic activity with repetitiveoverhead movements such as swimming &throwing.If weak, the athlete tends to use scapulaelevators & upward rotators to obtain

humeral abduction.



O: infraspinatus fossa of the posterior scapulaI: greater tubercle of the humerus.The tendon is often tender at its insertion.Concentric actions are extension, adduction

lateral rotation of shoulderThis muscle, along with teres minor, is mosteffective when the rhomboids stabilize thescapula.

When the humerus is laterally rotated, therhomboids flatten the scapula to the back &stabilize it so that the humerus can be rotated.



Synergists include teres minor & the posteriordeltoid.Clients who have difficulty fastening a seatbelt or placing an arm in a sleeve may have aproblem with infraspinatus.Sports injury or other trauma from hauling awheeled suitcase or excessive poling incross-country skiing, could also contribute toinfraspinatus tendonitis or tendonosis.



O: superior axillary border of the posteriorscapulaI: greater tubercle of the humerusSynergist to as infraspinatus: lateralrotation, adduction, & extensionDoesn’t develop problems unless theinfraspinatus is weakened.Can be included in rotator cuff tendonitis ortendonosis due to its close proximity toinfraspinatus.



Pectoralis Major is a synergist with Latissimusdorsi in shoulder adduction.Teres major is a synergist with Latissimusdorsi in all its functions.Subscapularis is a synergist with Latissimusdorsi Teres major in medial rotation.Teres minor is a synergist with Infraspinatus

in all its functions.



Injuries Overuse Syndrome



Most commonlydislocated joint inthe body.Once the joint hasbeen dislocated,the stretching ofthe collagen in its

ligaments makes iteasier to dislocateagain.



Predisposing factors for dislocation:◦ Small glenoid fossa◦ Anterior tilt of the glenoid fossa◦ Retroversion (turning backwards) of the

humeral head◦ Weakness in the rotator cuff muscles◦ Genetically weaker joint capsule



Dislocations orseparations canhappen withwrestlers footballplayers.

When a rigidlyoutstretched armsustains the full forceof a full-body fall,either the AC jointseparates or there isa fracture of theclavicle.



A common injury among workers or athletes whoengage in forceful overhead movements thatinvolve abduction or flexion along with medialrotation.

Caused by progressive pressure on the rotatorcuff tendons by the bone & soft tissues.Symptoms include:◦ hypermobility of the anterior shoulder capsule◦

hypomobility of the posterior capsule◦ excessive external rotation◦ limited internal rotation of the humerus◦ lax ligaments of the shoulder joint.



Can result ininflammation of thetendons or bursaor, in severe cases,rupture of a rotatorcuff tendon.Most commonly

affected muscle issupraspinatus



Can cause pain and tenderness in the anterior& superior shoulder regions & sometimesshoulder weakness.Can be caused by:◦ throwing (especially something like a javelin)◦ serving in tennis◦ swimming (especially free style, backstroke &

butterfly)

So common among swimmer’s it is alsoknown as swimmer’s shoulder.



Injuries caused by repeated, forceful rotation ofthe shoulder in throwing, serving in tennis &spiking a volleyball.Injuries can include:◦ Tears of the labrum (ring of connective tissue around the

glenoid fossa),◦ Tears in the rotator cuff muscles◦ Tears in the biceps tendon at its attachment to glenoid

fossaMost tears happen in the anterior-superioraspect of the labrum & in the supraspinatusmuscle.



Normal Labral Tear



Condition thatsometimes occurs withcompetitive volleyballplayers.Is a loss of nervesupply to infraspinatuswith loss of strength inexternal rotation of thehumerus.Associated withrepeated stretching ofthe nerve duringserving.



A pain response duringa part of an active orpassive jointmovement.In the shoulder, paincan occur when theclient abducts thehumerusPain not felt until thearm is about 90degrees abductedthen the pain subsidesas the arm continuesto move in abduction.



Cause is the humerus interacting too closelywith the acromion process.If there is not enough room for the humerusto slide under the acromion process inabduction, it might impinge on parts of therotator cuff muscles.Additionally the subacrominal bursa could beirritated by the close proximity of thehumerus.



A progressive,painful conditionthat starts withlimited ROMprogresses to afrozen stage.Small adhesionsform in the jointcapsule, creating anextremelydebilitatingcondition.



Elbow Radioulnar Joint Muscles



Elbow : ulnaarticulates withthe humerus

Radioulnar:radius pivotsaround the ulna

proximally anddistally



As radioulnar joints go through their ROM, theshoulder & elbow muscles contract to stabilize orassist in the effectiveness of the joints.When we hold a screwdriver in the right hand &

fully tighten a screw , the movement consists ofradioulnar supination, which usually involveslaterally rotation & flexing the shoulder & elbow

joints.

When we loosen a screw , the movement consistsof pronation, which usually involves mediallyrotating & extending the elbow & shoulder joints.



2 headed muscleO: supraglenoid tuberclecoracoid process of the

scapulaI: radial tuberosity

There is no attachmentto the humerus.Coracoid process is alsoan attachment site forcoracobrachialis

pectoralis minor.



Most powerful in flexing the elbow when theradioulnar joint is supinated.Also a strong supinator, especially if theelbow is flexed.Triceps brachii is the main antagonist.Synergists for biceps brachii includebrachialis, brachioradialis and pronator teresfor elbow flexion and the supinator forsupination of the forearm.



The biceps is used so frequently for commonactivities that everyone at some time hasexperienced fatigued anterior arm muscles.Actions such as shoveling snow, performing ahard tennis serve, playing the violin,engaging in heavy lifting – all stress thebiceps repeatedly. Usually the ache is feltsuperficially & can refer down the arm orlaterally.



The long head of the biceps is like a ropestretched over a pulley (the humerus). Thewear & tear on the long-head tendon causesattachment tenderness at its origin.Injury to the long-head tendon can result inbicepital tendonitis , which may involve thetendon in slipping out of the bicepital groovewhich can irritate the tendon.



O: humerusI: ulnaWorks with the otherelbow flexormuscles, regardlessof supination orpronation.It pulls on the ulna,which does notrotate; making thismuscle is the onlytrue flexor of theelbow.



Synergists include biceps & brachioradialis.Heavy lifting can lead to discomfort in thebrachialis.Is easily strained in elbow flexion, especiallyif the biceps is weak. When injured, thebrachialis is extremely painful.



O: lateral supra-condylar ridge of thehumerusI: styloid process ofthe radius.Its insertion at thestyloid process at thedistal end of theradius makes it astrong elbow flexor.



Acts best as a flexor in a neutral positionbetween supination & pronation.In a supinated forearm position, it tends topronate as it flexes. In a pronated position, ittends to supinate as it flexes.Because of its action of rotating the forearmto a neutral thumb-up position, it is referredto as the ‘hitchhiker muscle,” although it hasno action on the thumb.



Often used a great deal in the neutralposition so worker such as carpenters,roofers & grocery cashiers all canexperience muscle exhaustion.May also be involved in tendonitis ortendonosis of the lateral epicondyle ofhumerus due to its close proximity to theoverused wrist extensors.



O: medialepicondyle of thehumerus ulnaI: radiusRepetitive supine toprone movementstend to put stress

on pronator teresfatigue the forearmmuscles.



Median nerve travelsthrough the pronatorteresRepetitive pronationcan fatigue the muscle& irritate the mediannerve.Symptoms may reflectcarpal tunnelsyndrome.



O: ulnaI: radiusA: pronationCommonly used inturning ascrewdriver or inmovementsrequiring extension

pronation such asthrowing a curveball.



Difficult to workdue to its deeplocation.All the wrist flexortendons pass overthis muscle.



A 3 headed muscleO:◦ long head on the

infraglenoid tubercle

of the scapula◦ lateral & medialheads on humerus

I: olecranon process ofthe ulna.



Typical action oftriceps is shown inpush-ups whenthere is a powerfulextension of theelbow.Used in handbalancing in anypushing movementinvolving the arm.



Long head is animportant extensorof the shoulderjoint. It works withanconeus.Golf tennis swingwould beimpossible withoutthe use of thetriceps.



Long head will often have tenderness at theorigin on the scapula.Because one of its main actions is the forcefulextension of the forearm, fatigue can developfrom overuse activities.A therapist can passively shorten the tricepsby working on the muscle in an overheadposition.



O: lateralepicondyle of thehumerusI: olecranon processof the ulna.Synergist for triceps



Chief function is to pull the synovialmembrane of the elbow joint out of the wayof the olecranon process during elbowextension.

Due to its attachment to the lateral condyle, itcan be involved in tennis elbow.



Radial nerve travelsthrough thismuscle.If the radial nerve isentrapped, it is amedical conditionrequiring surgery tofree up the nerve.



O: humerusulnaI: radiusSupinates whenextension isrequired, as inturning ascrewdriver orthrowing a curveball.



Injuries and Overuse Syndromes



This fractureprohibits the use ofa cast.If casted, the joint

would likely ‘fuse’or severely limitROM as the jointheals.Massage iscontraindicated asthe condition healsvery slowly



A painful conditionwhich requires medicalcare.A dislocation couldconstrict circulation ornerve function locallyas well as distally.Ligaments can also betorn or sprained in adislocation.



Massage should be avoided until:bruising is minimal or goneswelling is significantly reducedcirculation is normalsafe to apply pressure to the soft tissue

When one joint suffers trauma, the rest ofthe body compensates for the injury and

massage can help with the compensationpattern.



Bursitis can occurwith medialepicondylitis.Swelling of thebursa can getbigger than a golfball.

Often requiresmedical treatmentdraining.



Conditions are bothcases of tendonitiscaused by overuse.Tennis elbowincludes:◦ extensor digitorum◦ brachioradialis◦ supinator◦ extensor carpi

radialis◦ brachialis



A somewhat lesscommon problemAssociated with thewrist flexorspronators near theirorigin on themedial epicondyle.



Chronic, painful repetitive injuries often havespells of subacute flare-ups which are a responseto a chronic injury that is not allowed to rest.Using the forearm & arm muscles repeatedly can

cause sore, fatigued & hypertonic muscles.The origins & insertions of tendons are oftentender at the attachment sites.If the muscles continue to be used, the tendons

can start to tear which can be the beginning oftendonitis or tendonosis.



Nerve Complaints



The cubital tunnel of elbow is between themedial condyle & the olecranon process.The ulnar nerve resides in the cubital tunnel& compression of this nerve can occur whenthe nerve doesn’t have enough room in thetunnel, usually from the placement of theelbow joint.

One solution is to surgically move the ulnarnerve to avoid compression.



The radial nerveruns through anumber of armforearm musclesbefore it endsdistally in the hand.Entrapment of thenerve can occur inthe triceps orsupinator.



This disorder can include:◦ Carpal tunnel syndrome◦ Pronator teres syndrome◦ Double-crush syndrome

Can result from median nerve entrapmentfrom the brachial plexus to the wrist.◦ Pectoralis minor can entrap the brachial

plexus in thoracic outlet syndrome.◦ Pronator teres can entrap the median

nerve & cause pronator teres syndrome.



Pectoralis Minor Thoracic OutletSyndrome



Repetitive pronationwith the arm in frontof the body with thescapula abducted can

create an entrapmentenvironment bypectoralis minor andpronator teres known

as the double-crushsyndrome.



Median nerve sitson top of thetendons justbelow the flexorretinaculum.Inflammation ofthe nerve results

in carpal tunnelsyndrome.



Upper trapezius and levator often will shortento elevate the scapula while the rest of thearm tries to protect the injury site.Pain in the elbow joint can subconsciouslyprevent a person from trying to move thearm.Relaxing the shoulder girdle muscles can beof benefit in releasing the compensationpattern.Best to first work the muscles related to the

joint above the injury site



Wrist and Hand Muscles



O: medialepicondyle of thehumerusI: radial side of thewrist at the base ofthe 2 nd 3 rd metacarpals.



This muscle along with flexor carpi ulnarisare the most powerful of the wrist flexors.Tendon travels through the carpal tunnel sorepetitive actions of hyperflexion or

hyperextension can lead to symptoms ofcarpal tunnel.Can also be tenderness at the medialepicondyle area & at its attachments at the2 nd and 3 rd metacarpals.



O: medialepicondyle of thehumerus runsdown the ulnar side

of the forearmI: base of the 5 th metacarpal.Its tendon does notgo through thecarpal tunnel.



Important in wrist flexion.Can be strained by repetitive wrist actions.Besides massage therapists working withhyperextended wrists, other overusemovements are using a trowel on cement,painting with a brush, or scrubbing a floor.Tenderness can appear at its attachments orat the extensor insertions at the wrist.



O: medialepicondyle of thehumerusI: into the palm ofthe handWeak helper withwrist flexion

Does not travelthrough the carpaltunnel



Superficial Wrist Extensors



O: lateralepicondyle of thehumerusI: base of the 2 nd

metacarpal on thedorsal side of thehand.Important in any

sports activity thatrequires powerfulextensions.



Because its origin is so close tobrachioradialis & other lateral epicondyletendons, this muscle is involved in tenniselbow.

Carpenters, musicians, massage therapists, &keyboard operators can also develop it.



O: lateralepicondyle of thehumerus runsdown the ulnar side

of the forearmI: base of the 5 th metacarpal on thedorsal side of thehand.



O: lateralepicondyle of thehumerusI: distal phalanges

of the 4 fingers onthe dorsal side ofthe hand.Only muscle

involved inextension of all 4fingers.



For computer programmers & pianists,stretching the little finger to its maximumlength can be a repetitive action that resultsin hand pain & discomfort.

A combination of little finger extension &abduction contributes to an overusecondition for massage therapists.It can be involved in lateral epicondylitis dueits origin at the lateral epicondyle.



A variety of soft-tissue and bony injuries canhappen to the hand and wrist.Carpenters, manual laborers, fishermen,cooks and chefs can all injure their hands &

wrists in multiple ways including tendonlacerations or repetitive use conditions.Lacerations require surgical repair.Athletic injuries, falls, car accidents are otherways injuries can occur.



Radial fracture

Landing on the handwith the full weight ofthe body can cause:◦ Fractures of the

radius & ulna at thewrist

◦ Dislocations &

fractures fingers,metacarpals &carpals

◦ Tears or avulsions ofligaments

◦ Strains & sprains



Tendonosis

Breakdown ofcollagen fibers inthe tissue andtendons can beginto ‘fray’ whichcauses the tendonto lose strengthresulting in chronicpain and soreness.



Can be tears intendons due tooveruse conditions.In the healing

process there canbe the developmentof scar tissue andadhesions.



Inflammation of atendonIn the worst cases,can include a

tearing theperiosteum awayfrom the bone.



Inflammation of thetendon sheath,plastic wrap-likeconnective tissue

structures thatsurround groups offlexor and extensortendons.

Sheaths can becomeinflamed due tooveruse conditions.



A cyst (lump) on the dorsal side of the wristSometimes comes from the tendon sheathor the joint capsule.Annoying and sometimes painful growths

that sometimes impair normal ROM.Treatment is draining the fluid contained inthe cyst.Ganglions should not be massaged directly.

The area around the growth can be workedif there is no inflammation.



Debilitating hand condition that can inhibit normalhand and finger function.Condition involves the Palmaris longus muscle, thepalmar aponeurosis or fasciaNodules develop in the fibrous tissue & cause a

permanent flexion mostly the 4th

& 5th

fingers inone or both hands.Condition may be hereditaryAlso common in clam diggers & lobster fishermenwhose hands are submerged in cold water in flexedpositions doing repetitive actions & in carpenterswho use tools that press into the palm.



Swelling oftendons infingers due tooveruse



Entrapment bythe triceps canlead to aninability to applypressurebetween thethumb and littlefinger andpainfulsensations .



Entrapment in arm andflexor carpi ulnaris cancause weakness anddiscomfort in the 4 th and5 th fingers.Can also be compressedin the cubital tunnelleading to dropping ofobjects and weakness ofgrip.Clients with pain felt inpassive movementsshould be referred totheir doctor



The space in the carpaltunnel can be reducedby:

small tumorsa ganglion cyst

fluid retention duringpregnancydepressed carpal bonestenosynovitis of flexordigitorum superficialisand profundus



Hands in a flexedposition Elevation of upper arm

This position cancompress median nerve.Sleepers can on wakingexperience numbness,tingling or pins-and-needles sensations in thehands.Propping a pillow underthe hand & forearm canhelp prevent abductionof the scapula & helpprevent hyperflexionduring sleep.

This position helpspectoralis minor entrapbrachial plexus &possibly impede bloodsupply to the hand &wrist.Sleepers tend to wakewith a numb arm & haveto use the other arm tomove the arm back to

anatomical position.



Fetal sleepingposition contributesto roundedshoulders and

entrapping brachialplexus

Rounded shoulders:this posture withthe repetitivepronated forearm

which engages thepronator teres canlead to entrapmentof the median nerve



Compression ofnerves at thecervical level canlead to these

conditions.Arthritis:inflammation ofjoints is commonin the agingprocess.



More common in the cervical and lumbar spine.A degenerative joint disease that can add bonygrowths (bone spurs) to individual vertebra andfray the edges in a jagged manner.Bone spurs can occur on the side of the vertebra

and result in linking vertebra together in what iscalled ‘kissing spurs’.The additional growth inhibits neck movementsand innervation. The inhibited nerves can result inmuscle atrophy and twitching.Osteoarthritis has no cure and can also occur inbones and joints that have had previous injuries.



Common joints affectedby osteoarthritis



Degenerative disk

Often present in personswith osteoarthritis.Results in the loss of diskspace between vertebra &the disk itselfdegenerates & reduces insize.Disks are needed toseparate the vertebra &to allow space for nervesto travel safely out of thearea.

Gilding joints of thecervical region that areslightly ajar.Pain, numbness andtingling with passive

movement can helpidentify problems inthe cervical region.If present, refer client

to their physician.

k class 9 muscles of arm 2013

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