humerus

ulna

radius

Upper Extremity Bones

coronoid fossa

trochlea

capitulum

lateral epicondyle

medial epicondyle

Anterior View

coronoid process

radial fossa

Elbow Structures

Olecranon process – fills the olecranon fossa of the humerus in full extension

Posterior View

Elbow Structures

proximal radioulnar joint

humeroulnar joint

humeroradial joint

Elbow Joints

Video

Elbow Ligaments• radial and ulnar collateral ligaments: as names imply they provide

support for the sides of the joint

• annular ligament: holds the proximal radioulnar joint together

Anterior view of right elbow joint

radiusulna

humerus

ulnar (medial) collateral ligament

Radial (lateral) collateral ligament

annular ligament

flexion/extension145º active, 160º passiveneed 100-140º to perform ADL’s(e.g., reach back of head to comb hair need 140º

only 15º needed to tie a shoe)(contoh menyisir rambut perlu 1400 dan hanya 150 mengikat sepatu)

supination/pronation85º supination; 70º pronationneed 50º supination & 50º pronation to perform ADL’s

Elbow ROM (Range Of Motion)

Note: Brachialis is the MOST EFFECTIVE elbow flexor! Biceps brachii is not effective when pronated.

biceps brachii

brachioradialis(serat panjang untuk gerak cepat atau menahan)

multi-articular musclewhose effectivenessis dependent onposition of shoulder& radioulnar jts(keefektifan tergantung posisi bahu dan radioulnar)

brachialis

Flexors are almosttwice as strongtwice as strong asthe extensors(hampir dua kali sekuat extensor)

Elbow Flexors

triceps brachii

anconeus

long head is bi-articularso its force productiondependent on shoulderPosition (hasil tekanan tergantung pada posisi bahu)

medial head adalah “pekerjakeras” pada kelompok ini dan aktif dalam segala posisi (is the‘workhorse’ of this groupactive in all positions

lateral head adalah terkuatwalaupun relatif tidak aktifkecuali menahan (is strongest yet is relatively Inactive unlessacting against resistance)

Posterior View

Elbow Extensors

pronatorteres pronator

quadratus

supinator biceps brachii Supination Pronation

Radioulnar Joints

Beban pada Siku (Loads on the Elbow)

• non-weight bearing joint– Masih bertekanan besar (still large forces)– 1700 N ketika berdiri dari kursi (when rising

from a chair)– 45% BW ketika melakukan pushup (when

performing pushup)– gymnastics elbow becomes a weightbearing

joint

Cedera Siku (Elbow Injuries)

• dislocations – tidak umum tapi dapat terjadi ketika berolahraga (not prevalent but can occur in sporting situations)

• overuse injuries – cedera berpengaruh kedua (2nd most affected joint for this injury)

Attachments

• AKA tennis elbow-inflammation/microdamage to tissues on the lateral side of the humerus, 30%-40% of tennis players will develop some amount of this injury (kerusakan mikro pada jaringan di sisi lateral dari humerus, 30%-40% pemain tenis akan menghasilkan sejumlah cedera ini)

• Penyebab termasuk teknik dan alat yang buruk.– Contoh : backhand, off-center shots and

rackets strung too tightly• Sakit ini diperparah oleh kegiatan yang

melibatkan tekanan extension pergelangan tangan. Meliputi pengangkatan koper atau ember, bersalamanan tangan, memutar gagang pintu,dll.

Lateral Epicondylitis

Medial Epicondylitis

• AKA little leaguer’s elbow (or golfers elbow)– medial strain imparted during the initial forward phase of throw as hand and elbow

lag behind trunk and shoulder(tekanan medial diberikan selama awal fasa lemparan ketika tangan dan siku

dibelakang tubuh dan bahu)– curveball pitching will magnify this medial strain throughout pitch and therefore is

not recommended for young pitchers(Lemparan bola berbelok akan meningkatkan tekanan medial ke setiap lemparan dan

tidak dianjurkan pada pitcher muda)