Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company CHAPTER 6 Elbow Complex

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company Introduction  Is composed of three synovial joints surrounded by one capsule  Humeroulnar (“true elbow”)  Humeroradial  Proximal radio-ulnar  Only part of the “complex” because of proximity

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company Joints  Humeroulnar and humeroradial  Humeroulnar articulation is “primary”  Why?  Functional classification = ginglymus  Modified because of “carrying” angle  See next slide

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company Carrying angle

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company Joints  Radioulnar articulations  Include proximal, medial, & distal joints—one degree of freedom (pivot/trochoid)  supination/pronation (mostly at proximal joint)  Motion occurs in transverse plane  During open kinematic chain (OKC)—radius pivots around ulna

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company Muscles  Elbow flexors  Brachialis – only crosses elbow – always a participant in flexion  Biceps brachii – secondary action at shoulder (long head)  Works better with supination  Brachioradialis (works better in pronation)

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company Muscles  Elbow extensors  Triceps – has secondary action at shoulder  Anconeus (initiates elbow extension but provides little force)

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company Functional Movement of the Elbow and Forearm  One and multijoint muscles  Single joint muscles recruited before multijoint.  Brachialis recruited with all elbow flexion activities.  Strength capability of multijoint muscles is influenced by position of other joints it crosses.  Active insufficiency of multijoint muscles is typically avoided by body.

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company Functional Movement of the Elbow and Forearm  Typical muscular function—elbow flexion  Brachialis—recruited for all elbow flexion activities  Biceps—activated versus large resistance  Brachialis and biceps—have favorable moment arms  Brachioradialis—is a weak elbow flexor

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company Functional Movement of the Elbow and Forearm  Typical muscular function—extension  Anconeus  Small cross-sectional area  Uniaxial—likely active with all elbow extension motions  Triceps  Recruited against larger forces  Medial head first followed by lateral and then long head

Brunnstrom’s Clinical Kinesiology Sixth Edition Copyright © 2012 F.A. Davis Company Muscle Activity during Functional Movements  Pulling  Closed kinematic chain—pull-up  Biceps and brachialis flex elbow concentrically and control extension eccentrically.  Supinator and biceps provide supination force.  Open kinematic chain—pull-down