Elbow

Upper Extremity Bones humerus ulna radius

Elbow Structures Anterior View coronoid fossa radial fossa lateral epicondyle trochlea capitulum medial epicondyle coronoid process Anterior View

Elbow Structures Posterior View Olecranon process – fills the olecranon fossa of the humerus in full extension Posterior View

Elbow Joints humeroulnar joint humeroradial joint proximal radioulnar 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 radius ulna humerus ulnar (medial) collateral ligament Radial (lateral) collateral ligament annular ligament Anterior view of right elbow joint

Elbow ROM (Range Of Motion) flexion/extension 145º active, 160º passive need 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/pronation 85º supination; 70º pronation need 50º supination & 50º pronation to perform ADL’s

Elbow Flexors biceps brachii Flexors are almost twice as strong as brachialis Flexors are almost twice as strong as the extensors (hampir dua kali sekuat extensor) biceps brachii brachioradialis (serat panjang untuk gerak cepat atau menahan) multi-articular muscle whose effectiveness is dependent on position of shoulder & radioulnar jts (keefektifan tergantung posisi bahu dan radioulnar) Elbow Flexors There are actually 24 muscles that cross the elbow joint. Note: Brachialis is the MOST EFFECTIVE elbow flexor! Biceps brachii is not effective when pronated. Elbow & Wrist

Elbow Extensors Posterior View triceps brachii anconeus long head is bi-articular so its force production dependent on shoulder Position (hasil tekanan tergantung pada posisi bahu) lateral head adalah terkuat walaupun relatif tidak aktif kecuali menahan (is strongest yet is relatively Inactive unless acting against resistance) anconeus medial head adalah “pekerja keras” pada kelompok ini dan aktif dalam segala posisi (is the ‘workhorse’ of this group active in all positions Posterior View

Radioulnar Joints biceps supinator brachii Supination Pronation pronator teres pronator quadratus Figure shows olecranon process on anterior of arm. Elbow & Wrist

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

Lateral Epicondylitis 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. Wrist extensors Elbow & Wrist

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) Wrist flexors Elbow & Wrist