a. Elbow Joint Bones

The Ulna is the elbow joint bone of interest. Ulnas articulate with humeral trochleas. Ulna's coranoid processes and humerus' coranoid fossas limit elbow joints' flexion motion ranges. Ulna's olecranon processes and humerus' olecranon fossas limit elbow joints' extension motion ranges. Three-part ulnar collateral ligaments medially secure ulnas' proximal ends to humerus' distal surfaces. Anterior surfaces of ulnar olecranon processes have trochlear ridges that slide in grooves of humerus' distal ends. Anterior surfaces of ulnar olecranon processes have radial notche on lateral sides where radial heads rest and rotate. Because ulnas only move anteriorly and posteriorly, elbow joints only flex and extend.

1. Ulna

a) Anterior Surface

Ulnas' anterior surfaces have two bony landmarks, two tendon attachments and two areas from which primary pitching muscles arise. Brachialis tendons attach to coranoid processes. Flexor digitorum profundus muscles arise from ulnas' proximal two-thirds. Pronator quadratus muscles arise from lines on ulnas' distal one-quarters.

b) Posterior Surface

Ulnas' posterior surfaces have one bony landmark, two tendon attachments and one area from which a primary pitching muscle arises. Triceps brachiis' three heads combine into common tendons that attach to ulnas' olecranon processes. Anconeus tendons attach to ulnas' proximal one-fifths. Supinator muscles arise from medial surfaces of ulnas' proximal ends.

b. Elbow Kinesiological Joint Actions

Elbow joint movements involve ulna movements relative to humeruses. Kinesiologists generally include forearm joint actions with elbow joint actions. However, muscles that attach to radiuses can only indirectly influence ulna movements. Therefore, I separte forearm and elbow joint actions. Ulnas only move toward or away from humerus' anterior surfaces.

1. Extensions occur when elbow joint muscles contract to move ulnas' anterior surfaces away from humerus' anterior surfaces. Ulnas' olecranon processes and humerus' olecranon fossas move closer together.

2. Flexions occur when elbow joint muscles contract to move the ulnas' anterior surfaces closer to humerus' anterior surfaces. Ulnas' coranoid processes and humerus' coranoid fossas move closer together.

However, when humeruses rotate when ulnas flex or extend, then elbow joint movements combine shoulder joint, elbow and wrist movements. To explain these combinations, I created four more elbow joint actions.

3. Lateral Extensions occur when elbow joint muscles contract to move ulnas' anterior surfaces laterally away from humerus' anterior surfaces.

4. Medial Extensions occur when elbow joint muscles contract to move ulnas' anterior surfaces medially away from humerus' anterior surfaces.

5. Lateral Flexions occur when elbow joint muscles contract to move ulnas' anterior surfaces laterally closer to humerus' anterior surfaces.

6. Medial Flexions occur when elbow joint muscles contract to move ulnas' anterior surfaces medially closer to humerus' anterior surfaces.

c. Elbow Joint Muscles

Elbow joint muscles attach to ulnas and directly influence elbow joint actions.

1. Brachialis

Brachialis muscles attach to ulnas' coranoid processes and to anterior surfaces of humerus' distal one-halves. When brachialis muscles contract, ulnas' coranoid processes and humerus' anterior surfaces move closer together. Brachialis muscles flex, laterally flex and medially flex ulnas. During decelerations, brachialis muscles laterally flex elbow joints.

Ulnas' coranoid processes and humerus' coranoid fossas limit elbow joint flexion motion ranges. Brachialis muscles attach to ulnas' coranoid processes. Horizontal pitching arm actions cause forearms to centripetally fly out horizontally. To prevent ulnas' olecranon processes from colliding with humerus' olecranon fossas, brachialis muscles centrifugally fight these fly out forces. Brachialis muscles' coranoid processes physiologically adapt to cope with these fly out forces. Ulnas' coranoid processes enlarge. Enlarged ulna coranoid processes decrease elbow joint motion ranges.

2. Anconeus

Anconeus muscles attach to lateral surfaces of ulnas' olecranon processes and to posterior surfaces of humerus' lateral epicondyles. When anconeus muscles contract, ulnas' olecranon processes and humerus' posterior surfaces move closer together. Anconeus muscles extend, laterally extend and medially extend ulnas. During forearm accelerations, anconeus muscles medially extend elbow joints.

3. Triceps Brachii I

Triceps brachii I muscles attach to ulnas' olecranon processes and to scapulas' infraglenoid fossas. When triceps brachii I muscles contract, ulnas' olecranon processes and humerus' infraglenoid fossas move closer together. Triceps brachii I muscles operate across two joints, shoulder and elbow joints. Triceps brachii I muscles indirectly extend shoulder joints and horizontally extend humeruses. Triceps brachii I muscles extend ulnas. Two-joint muscles cannot have both joints simultaneously changing joint angles. Therefore, shoulder joints isoanglosly fix at single joint angles when triceps brachii I muscles mioanglosly decrease elbow joint angles. During forearm accelerations, triceps brachii I muscles extend elbow joints.

Incorrect curve pitching techniques place elbow joints at risk. If triceps brachii I muscles incorrectly powerfully extend elbow joints, ulnas' olecranon processes can slam into humerus' olecranon fossas. Continued olecranon process/fossa slammings eventually injure elbow joints. Olecranon process tips break off. Olecranon fossas calcify. Extension elbow joint motion ranges decrease. Correct curve pitching techniques move olecranon processes and fossas lateral to elbow joint extensions.

4. Triceps Brachii II

Triceps brachii II muscles attach to ulnas' olecranon processes, distal three-quarters of humerus' posterior surfaces and proximal one-thirds of humerus' lateral surfaces. When triceps brachii II muscles contract, humerus' olecranon processes and humerus' posterior/lateral surfaces move closer together. Triceps brachii II muscles are pure elbow joint muscles. Triceps brachii II muscles directly extend ulnas. During forearm accelerations, triceps brachii II muscles combine with medial epicondyle muscles to medially extend elbow joints.

Elbow joint muscles master complicated force application patterns or suffer centrifugal acceleration injuries. Whereas clavicles and humeruses cannot vary force application lengths, changing humerus/ulna joint angles permit pitchers to apply straight-line forces to pitches.

d. Pitching Elbow Joint Actions

1. Transition

During transitions, elbow joint muscles isoanglosly laterally flex ulnas to approximately one hundred and fifty degree elbow angles. Lateral flexions require humerus outward rotations and ulna flexions. Humerus lateral epicondyle muscles laterally flex ulnas.

2. Upper Arm Acceleration

During upper arm accelerations, elbow joint muscles isoanglosly medially flex ulnas to fix elbow joint angles. Humeruses powerfully drive toward home plate. Medial flexions require humerus inward rotations and ulna flexions. Humerus medial epicondyle muscles medially flex ulnas.

3. Forearm Acceleration

During forearm accelerations, elbow joint muscles powerfully mioanglosly medially flex elbow joints. After humeruses start decelerating, ulnas start driving toward home plates.

4. Deceleration

During decelerations, elbow joint muscles plioanglosly laterally flex elbow joints to stop ulnas' forward movements. Strong ligaments prevent ulnas from moving away from humeruses during forearm accelerations and slamming back into humeruses during decelerations. However, radial heads do not have similar strong ligaments. Consequently, radiuses do move away from humeruses and slam back into humerus during forearm accelerations and decelerations.

Coaching Adult Pitchers