Elbow BiomechanicsKyle FlorenceOlivia DurandTom Conlon

Kyle McCrobie

The Joints

● Humero-ulnar: Hinge

● Proximal radio-ulnar: Pivot

● Humeroradial: Hinge, limited ball-and-socket

Anatomy:Ligaments

● Radial Collateral Ligament● Ulnar Collateral Ligament● Annular Ligament

Anatomy:Muscles

● Biceps Brachii● Triceps Brachii● Brachialis● Brachioradialis● Pronator Teres● Anconeus

MotionsMovement Joint Muscles Limiting structures

Extension Humero-ulnarHumeroradial

Triceps brachiiAnconeus

Muscle: FlexorsJoint Capsule: AnteriorlyBones: Olecranon process and fossa

Flexion Humero-ulnarHumeroradial

Biceps brachii (when supinated)BrachialisPronator teres

Muscle: TricepsJoint Capsule: PosteriorlySoft Tissue: Anterior forearm and arm

Pronation HumeroradialProximal radio-ulnarDistal radio-ulnarInterosseous membrane

Anconeus (by abducting ulna)Pronator teresPronator quadratus

Muscle: Supinator, BicepsLigaments: Dorsal inferior radio-ulnar, interosseous membraneBones: Radius on ulna

Supination HumeroradialProximal radio-ulnarDistal radio-ulnar

Biceps brachiiSupinator

Muscle: Pronator teres, Pronator quadratusLigaments: Anterior inferior radio-ulnar, interosseous membrane

The Carrying Angle

● A result of the trochlea extending more distally than the capitulum

● 10°-15° in men● >15° in women

Case Study - Little League Elbow● Common injury in youth baseball pitchers

o Valgus stress on elbow during overhand throw Distraction of medial side of elbow Compression of lateral side

o Medial epiphyseal plate avulsiono Tears in wrist flexor tendons

● Risk factors not entirely known but possibly…o Quick height changeo Between 8-15 years oldo Excessive curve balls thrown

References● Cubitus [Online image]. (n.d.). Pueblo Bone and Joint Clinic. Retrieved from http://www.mypbanj.com● Dwyer, M. (2013). Clay Buchholz [Online image]. Retreived from http://www.concordmonitor.com● Elbow anatomy [Online image]. (2013). Phoenix Shoulder and Knee. Retrieved from

https://phoenixshoulderandknee.com● Golf Swing [Online image]. (n.d.). Retrieved from http://leecarringtongolf.com● Gray, H. (1918). Anatomy of the human body. Philadelphia, PA: Lea & Febiger.● Huang, Y., Wu, T., Learman, K., & Tsai, Y. 2010. A comparison of throwing kinematics between youth baseball

players with and without a history of medial elbow pain. Chinese Journal of Physiology 53(3), 160-166.● Moore, K. L., Agur, M. R., & Dalley, A. F. (2011). Essential clinical anatomy. Baltimore, MD: Lippincott Williams &

Wilkins.