Key areas for locomotion and medical students

1. Surface anatomy:
Quadrangular space – axillarynerve andposteriorcircumflex arteriespassthroughhere andaround
the surgical neckof the humerus. Borders:above:subscapularisandteresminor;below:teres
major;medially:longheadof triceps brachii;laterally:surgical neckof the humerus.
Triangular interval – radial nerve andprofundaarterytravel throughhere on wayto spiral groove.
Borders:above:teresmajor;lateral:humerus;medial:tricepsbrachiilonghead
Triangular space – circumflex scapularartery. Borders:notinthe lecture slides
Triangle of auscultation – sitsmedial tothe inferiorangle of the scapula. Borders:trapezius,
rhomboidmajor,latissimusdorsi
Axilla– fat-filledregionsuperiortounderarmskin. Contains:axillaryartery,distal partsof the
brachial plexus,fat,lymphnodes(humeral,subscapular,pectoral all drainintocentral,whichdrains
intoapical). Borders:anterior:pectoralismajorandminor;posterior:latissimusdorsi,teresmajor,
subscapularis andscapula;medial:serratusanteriorandlateral thoracicwall;lateral:intertubercular
groove.
Cubital fossa – triangularregionanteriortothe elbow. Containsthe bicepsbrachii tendon,the
brachial arteryand the mediannerve. Borders:superior: inter-epicondylarline;lateral:medial
borderof brachioradialis;medial:lateral borderof pronatorteres.
Anconeustriangle – regionforelbowaspiration/injection. Borders:radial head,lateral epicondyle,
olecranon.
Anatomical snuffbox – contains:radial artery(palpable pulse),radial styloidprocess,scaphoid,
trapezium,base of 1st
metacarpal. Cephalic(houseman’s) veinpassesoverit,alongside radial nerve
and superficialtoradial artery. Borders:(1) tendonof the EPL, (2) tendonsof the EPB and APL.
Carpal tunnel – contains:flexordigitorumprofundus(x4),flexordigitorumsuperficialis(x4),flexor
pollicislongus,mediannerve. Attachmentpoints:scaphoidtubercule,trapeziumtubercule,hookof
hamate,pisiform.
Greatersciatic foramen – dividedintwobythe piriformismuscle. Upperhalf (suprapiriform)
containsthe superiorgluteal nerve(L4,L5) whichsuppliesthe gluteusmediusandgluteusminimus
muscles. Itsweaknesscanbe seeninthe Trendelenburgsign. Lowerhalf (infrapiriform) contains
the inferiorgluteal nerve (L5,S1),whichsuppliesthe gluteusmaximusmuscle,andthe sciaticnerve,
whichsuppliesthe posteriorupper-legcompartmentandmostof the lowerleg. The greatersciatic
foramenisitself borderedinferiorlybythe sacrospinousligament.
Gluteal IM injection– method#1: Findthe highestpointof the iliaccrest,go straightdown. Halfway
betweenhere andthe ischial tuberosity,draw ahorizontal line. The upperquadrantisthe safe
space for injection. Method#2: Draw anothervertical line downfromthe iliaccrest. Draw a line
fromthe PSISto the greatertrochanter. Anywhere inthe upperquadrantissafe toinject.
Adductor hiatus – gap betweenthe adductormagnusmuscle andthe femurthroughwhichthe
femoral arterypasses tobecome the poplitealarter
Femoral triangle – contains(fromlateral tomedial):femoralnerve,femoral artery,femoral vein.
Femoral arterycan be palpatedbyfindingthe midpointof the inguinal ligamentandfollowingdown
1.5 cm. Borders:superior:inguinal ligament;lateral:medialborderof sartoriusmuscle;medial:
medial borderof adductorlongusmuscle

2. Popliteal fossa– contains(fromdeeptosuperficial):popliteal artery,popliteal vein,tibial nerve.
Commonfibularnerve passesalongthe superiolateral edge. Borders:superiomedial:
semimembranosusandsemitendinosismuscles;superiolateral:bicepsfemoris;inferior:medial and
lateral headsof the gastrocnemiusmuscle
Tarsal tunnel – coveredbythe flexorretinaculum. Three thingstoremember:flexor,posteriorand
tibial. Contains:tibialisposteriormuscle (Tom),flexordigitorumlongusmuscle (Dick),posterior
tibial artery(And),posteriortibialvein(Very),tibial nerve(Nervous),flexorhallucislongus(Harry)