When I joined the 1974 Los Angeles Dodgers, right-handed pitcher, Andy Messersmith, and I became friends.   While in the dugout or traveling, we talked baseball.   While eating, I noticed that Andy had difficulty bending his pitching elbow sufficiently to feed himself.  

     Andy said that not only could he not bend his pitching elbow sufficiently to easily feed himself, he could not brush his teeth, comb his hair, wash his face and so on.   I compared his pitching elbow’s flexion angle with his non-pitching elbow.   His flexion angles differed dramatically.   I suggested that we scientifically investigate this difference.   Andy agreed to visit me at Michigan State University after the season.  

     On January 15, 1975, Andy and I presented ourselves to Professor Bert M. Bez MD, the Chairman of the Division of Anesthesia in MSU's College of Osteopathic Medicine.   To prevent muscle action interference, Professor Bez bi-laterally anesthetized our brachial plexuses.   (At the brachial plexus, cervical nerves' five (C5), six (C6), seven (C7), eight (C8) and thoracic nerve one (T1) intertwine to form the arm’s radial, median, ulnar, musculocutaneous and axillary nerves.   The brachial plexus lies beneath the clavicle’s middle and the scapula’s coracoid process.)

     Using the Subclavian Perivascular Technique, Professor Bez bi-laterally administered 20cc of a 1% solution of Lidocaine (Xylocaine).   Lidocaine anesthetized the motor nerves that stimulate the elbow flexors and extensors.   Without muscle action, only skeletal structures could limit elbow flexion and extension.  

     An Olin Heath Center Radiographic technician placed our arms into the proper X-ray positions and forcefully fully extended and flexed our elbows.   Another technician captured Anterior/Posterior (A/P) and Medial/Lateral (M/L) views of our forcefully extended elbows and a Medial/Lateral (M/L) view of our forcefully flexed elbows.  

     I used the original X-rays to make the following observation and measurements.   However, because the technician could not completely extend or flex our pitching elbows, some elbow structures did not contact the X-ray plates.   Therefore, parallax error may cause some incorrect measurements.

     From the Anterior/Posterior view of the forcefully extended elbows, I:  
01.   measured the humeral mid-shaft width and cortex depth,
02.   evaluated the medial epicondyle,
03.   evaluated the trochlea/olecranon process articular surfaces,
04.   evaluated the olecranon fossa,
05.   evaluated the capitulum/radial head articular surfaces,
06.   evaluated the lateral epicondyle,
07.   measured and evaluated the radial head,
08.   measured the radial tuberosity,
09.   measured the radial mid-shaft width and cortex depth and
10.   measured the ulnar mid-shaft width and cortex depth.  

     Whereas the humeral mid-shaft of my non-pitching arm measured one-inch wide with the cortex one-quarter inch thick, the humeral mid-shaft of my pitching arm measured one and one-eighth inches wide with the cortex three-eighth inch thick.   Therefore, the humeral mid-shaft of my pitching arm is one-eighth inch wider and one-eighth inch thicker.

     Whereas the medial epicondyle of my non-pitching arm showed normal trabeculae and mineralization and a smooth, uninterrupted surface, the medial epicondyle of my pitching arm showed slightly abnormal trabeculae and considerably increased mineralization, especially proximally, but a smooth, uninterrupted surface.   Therefore, the medial epicondyle of my pitching arm has a slightly abnormal traveculae and considerably increased mineralization, especially proximally.

     The articular surfaces of my trochlea/olecranon process joint in my non-pitching and pitching arms appeared evenly-spaced, smooth and uninterrupted.

     The olecranon fossa of my non-pitching and pitching arms showed normal trabeculae and mineralization and no abnormalities.

     The articular surfaces of the capitulum/radial head joint in my non-pitching and pitching arms appeared even-spaced, smooth and uninterrupted.

     The lateral epicondyle of my non-pitching and pitching arms showed normal trabeculae and mineralization and a smooth, uninterrupted surface.

     The radial head of my non-pitching and pitching arms measured one inch wide with normal trabeculae and mineralization.

     The radial tuberosity of my non-pitching and pitching arms measured thirteen-sixteenths inch wide with normal trabeculae and mineralization and a smooth, uninterrupted surface.

     Whereas the radial mid-shaft of my non-pitching arm measured three-quarters inch wide with the cortex one-eighth inch thick, the radial mid-shaft of my pitching arm measured thirteen-sixteenth inch wide with the cortex one-eighth inch thick.   Therefore, the radial mid-shaft of my pitching arm was one-sixteenth of an inch wider.

     Whereas the ulnar mid-shaft of my non-pitching arm measured five-eighths inch wide with the cortex one-eighth inch thick, the ulnar mid-shaft of my pitching arm measured five-eighth inch wide with the cortex three-sixteenth inch thick.   Therefore, the ulnar mid-shaft of my pitching arm measure one-sixteenth inch thicker.

     Whereas the humeral mid-shaft of Andy’s non-pitching arm measured one inch wide with the cortex one-quarter inch thick, the humeral mid-shaft of Andy’s pitching arm measured one and one-quarter inch wide with the cortex seven-sixteenth inch thick.   Therefore, the humeral mid-shaft of Andy’s pitching arm measured one-quarter inch wider with its cortex three-sixteenth inch thicker.

     Whereas the medial epicondyle of Andy’s non-pitching arm showed normal trabeculae and mineralization and a smooth, uninterrupted surface, the medial epicondyle of Andy’s pitching arm showed abnormal trabeculae and a considerably increased mineralization in its proximal one-half, a smooth, uninterrupted surface and a wide fissure appeared in the medial epicondyle/trochlear union.   Therefore, the medial epicondyle of Andy’s pitching arm showed abnormal trabeculae, considerably increased mineralization in its proximal one-half and an abnormal fissure between the medial epicondyle and trochlea.

     The articular surfaces of the trochlea/olecranon process joint of Andy’s non-pitching and pitching arms appeared even-spaced, smooth and uninterrupted.   However, two loose pieces of cartilage lay near to the medial aspect of the articular surfaces of the trochlea/olecranon process joint in Andy’s pitching arm.

     Whereas the olecranon fossa of Andy’s non-pitching arm showed normal trabeculae and mineralization and no abnormalities, the olecranon fossa of Andy’s pitching arm showed abnormal trabeculae, increased mineralization and a large calcified cartilage fragment in the fossa’s center.   Therefore, the olecranon fossa of Andy’s pitching arm showed abnormal trabeculae, increased mineralization and a large calcified piece of cartilage or bone fragment in the center of the fossa.

     Whereas the articular surfaces of the capitulum/radial head joint of Andy’s non-pitching arm appeared even-spaced, smooth and uninterrupted, the articular surfaces of the capitulum/radial head joint of Andy’s pitching arm had uneven spacing and a deepened hollow in the radial head.   Therefore, the articular surfaces of the capitulum/radial head joint of Andy’s pitching arm had abnormal trabeculae and demineralization.

     Whereas the lateral epicondyle of Andy’s non-pitching arm showed normal trabeculae and mineralization with a smooth, uninterrupted surface, the lateral epicondyle of Andy’s pitching arm showed abnormal trabeculae and decreased mineralization around its edge with a smooth, uninterrupted surface.   Therefore, the lateral epicondyle of Andy’s pitching arm ahs abnormal trabeculae and decreased mineralization around its edge.

     Whereas the radial head of Andy’s non-pitching arm measured one and one-sixteenth inch wide with normal trabeculae and mineralization, the radial head of Andy’s pitching arm measured one and one-eighth inches wide with an enlarged, deformed shape, normal trabeculae and slightly increased mineralization.   Therefore, the radial head of Andy’s pitching arm has enlarged, deformed and increased its mineralization.

     The radial tuberosity of Andy’s non-pitching and pitching arms measured three-quarter inch wide with normal trabeculae and mineralization and a smooth, uninterrupted surface.

     Whereas the radial mid-shaft of Andy’s non-pitching arm measured eleven-sixteenth inch wide with the cortex three-sixteenth inch thick, the radial mid-shaft of Andy’s pitching arm measured three-quarter inch wide with the cortex one-quarter inch thick.   Therefore, the radial mid-shaft of Andy’s pitching arm is one-sixteenth inch thicker with the cortex one-sixteenth inch thicker.

     Whereas the ulnar mid-shaft of Andy’s non-pitching arm measured five-eighth inch wide with the cortex one-quarter inch thick, the ulnar mid-shaft of Andy’s pitching arm measured five-eighth inch wide with the cortex three-sixteenth inch thick.   Therefore, the cortex of the ulnar mid-shaft of Andy’s pitching arm is one-sixteenth inch thicker.

     I used the original X-rays to make the following observations and measurements.   However, because the technician could not completely extend or flex our pitching elbows, some elbow structures did not contact the X-ray plates.   Therefore, parallax error may cause incorrect measurements.

     From the Medial/Lateral views of our forcefully extended elbows views, I:  
01.   measured humeral olecranon fossa depth,
02.   evaluated the articular surface of the anterior humeral capitulum,
03.   measured the ulnar coranoid process and
04.   measured the maximum extension angles of our elbow.  

     During maximum elbow extension, the olecranon process contacts the olecranon fossa to limit the extension angle of the elbow.   To measure the maximum extension angle of the elbow, we placed dots on the anterior surface of the humeral mid-shaft, where the olecranon process touched the olecranon fossa and on the anterior surface of the ulnar mid-shaft on the medial/lateral X-rays of the extended elbows.   Then, we drew lines from the humeral mid-shaft dot to the olecranon process/fossa dot and on to the ulnar mid-shaft dot.   Lastly, we centered a compass on olecranon process/fossa dot such that it superimposed the humeral line and measured the ulnar angle.

     Whereas the olecranon process of my non-pitching arm penetrated one inch into its olecranon fossa, the olecranon process of my pitching arm penetrated eleven-sixteenth inch into its olecranon fossa.   Therefore, the olecranon process of my pitching arm penetrated into the olecranon fossa five-sixteenth inch less.

     My capitulum’s anterior articular surface showed normal trabeculae and mineralization and a smooth, uninterrupted surface.   My capitulum’s anterior articular surface showed normal trabeculae and mineralization and a smooth surface interrupted only by a small, round enlargement on its anterior/superior aspect.   My pitching capitulum’s articular surface showed a small, round enlargement on its anterior/superior aspect.

     My coranoid process measured one and nine-sixteenth inches long and showed normal trabeculae and mineralization with a smooth, uninterrupted surface.   My coranoid process measured one and five-eighth inches long and showed normal trabeculae and mineralization with a smooth, uninterrupted surface.   My pitching coranoid process measured one-eighth inch longer.  Pitching decreased my elbow’s maximum extension angle by twelve degrees.

     The compass determined that my elbow’s maximum extension angle is one hundred and eighty-four degrees.  The compass determined that my elbow’s maximum extension angle is one hundred and seventy-two degrees.

     Whereas the olecranon process of Andy’s non-pitching arm penetrated fifteen-sixteenth inch into its olecranon fossa, the olecranon process of Andy’s pitching arm penetrated one and three-sixteenth inches into its olecranon process.   Therefore, the olecranon process of Andy’s pitching arm penetrated three-quarter inch less into its olecranon fossa.

     The capitulum’s anterior articular surface of Andy’s non-pitching and pitching arms had normal trabeculae and mineralization and a smooth, uninterrupted surfaces.

     Whereas the coronoid process of Andy’s non-pitching arm measured one and one-half inches long and showed normal trabeculae and mineralization with no abnormalities, the coronoid process of Andy’s pitching arm measured one and seven-eighth inches long and showed abnormal trabeculae and increased mineralization with a rough, irregular surface and signs of arthritis.   Therefore, the coronoid process of Andy’s pitching arm measured three-eighth inch longer with a rough, irregular surface and signs of arthritis.

     Whereas the compass determined that the maximum extension angle of Andy’s non-pitching elbow was one hundred and seventy-four degrees, the compass determined that the maximum extension angle of Andy’s pitching elbow was one hundred and thirty-nine degrees.   Therefore, pitching decreased the maximum extension angle of Andy’s pitching elbow by thirty-five degrees.

     I used the original X-rays to make direct observations and measurements.   However, because the technician could not completely extend or flex our pitching elbows, some elbow structures did not contact the X-ray plates.   Therefore, parallax error may cause incorrect measurements.

     From the Medial/Lateral views of our forcefully flexed elbows, I:
01.   measured how far the ulnar coranoid process penetrated into the humeral coronoid fossa,
02.   measured and evaluated the olecranon process,
03.   evaluated the posterior articular surface of the humeral trochlea and
04.   measured the maximum flexion angle of our elbows.  

     During maximum elbow flexion, the coronoid process contacts the coronoid fossa to limit the flexion angle.   Therefore, to measure the flexion angle of the elbow, we placed dots on the anterior surface of the humeral mid-shaft, where the ulnar coronoid process contacts the humeral coronoid fossa and on the anterior surface of the ulnar mid-shaft on the medial/lateral X-rays of the forceably flexed elbows.   Then, we drew a line from humeral mid-shaft dot to the coronoid process/fossa dot and onto the ulnar mid-shaft dot.  Lastly, we centered a compass on the coronoid process/fossa dot such that it superimposed the humeral line and measured the ulnar angle.

     The coronoid process of my non-pitching and pitching arms penetrated one-eighth inch into its coronoid fossa.

     Whereas the olecranon process of my non-pitching arm measured one and one-sixteenth inches and showed normal trabeculae and mineralization with a smooth, uninterrupted surface, the olecranon process measured one inch long and showed normal trabeculae and mineralization with, except for a small ridge on its superior/posterior aspect, a smooth, uninterrupted surface.   Therefore, the olecranon process of my pitching arm measured one-sixteenth inch longer and showed a small ridge on its superior-posterior aspect.

     The trochlea’s posterior articular surfaces of my non-pitching and pitching arms were smooth and uninterrupted.

     Whereas the compass determined that my elbow’s maximum flexion angle of my non-pitching arm was thirty-four degrees, the compass determined that my elbow’s maximum flexion angle of my pitching arm was forty-six degrees.   Therefore, pitching decreased the maximum flexion angle of my pitching elbow by twelve degrees.

     The coronoid processes of Andy’s non-pitching and pitching arms penetrated one-quarter inch into their coranoid fossas.

     While the olecranon process of Andy’s non-pitching arm measured one and one-eighth inches and showed normal trabeculae and mineralization with a smooth, uninterrupted surface, the olecranon process of Andy’s pitching arm measured one and three-eighth inches long and showed abnormal trabeculae and increased mineralization with a rough, irregular surface.   Therefore, while the olecranon process of Andy’s pitching arm measured only one-sixteenth inch longer, it showed abnormal trabeculae, increased mineralization and arthritis.

     Whereas the trochlea’s posterior articular surface of Andy’s non-pitching arm was smooth and uninterrupted, the trochlea’s posterior articular surface of Andy’s pitching arm showed normal trabeculae and mineralization with a rough, irregular surface with arthritis.   Therefore, the trochlea’s posterior articular surface of Andy’s pitching arm showed a rough, irregular surface with arthritis.

     Whereas the compass determined that the maximum flexion angle of Andy’s pitching elbow was thirty-three degrees, the compass determined that the maximum flexion angle of Andy’s pitching elbow was sixty-six degrees.   Therefore, pitching decreased the maximum flexion angle of Andy’s pitching arm by thirty-three degrees.

     My three sets of bi-lateral X-rays showed the following pitching arm irregularities:  
01.   My humeral mid-shaft measured one-eighth inch wider with its cortex also one-eighth inch thicker.
02.   My medial epicondyle showed slightly abnormal trabeculae with the mineralization of the proximal one-half considerably increased.
03.   My ulnar mid-shaft cortex measured one-sixteen inch thicker.
04.   My ulnar olecranon process penetrated into its olecranon fossa five-sixteenth inch less.
05.   My ulnar olecranon process measured one-sixteenth inch longer and showed a small ridge on its superior-posterior aspect.
06.   My elbow lost twelve degrees of maximum extension angle.   07.   My articular surface of capitulum showed a small, round enlargement on its anterior/superior aspect.
08.   My ulnar coranoid process measured one-eighth inch wider.
09.   My elbow lost twelve degrees of maximum flexion angle.

     Andy’s three sets of bi-lateral X-rays showed the following pitching arm irregularities:
01.   Andy's humeral mid-shaft measured one-quarter inch wider and its cortex three-sixteenth inch thicker.
02.   Andy's humeral medial epicondyle showed abnormal trabeculae and considerably increased mineralization in its proximal one-half.
03.   Andy's humeral trochlea/olecranon process’ articular surfaces showed two loose cartilage fragments on its medial aspect.
04.   An abnormal fissure showed between Andy's pitching medial epicondyle and trochlea.
05.   The articular surface of Andy's humeral trochlea showed a rough, irregular posterior surface with arthritis.
06.   Andy's ulnar olecranon fossa showed abnormal trabeculae, increased mineralization and a large calcified cartilage fragment in the fossa’s center.
07.   Andy's ulnar olecranon process penetrated into its olecranon process three-quarter inch less.
08.   Whereas Andy's ulnar olecranon process measured only one-sixteenth inch longer, it showed abnormal trabeculae, increased mineralization and arthritis.
09.   Andy's elbow lost thirty-five degrees of maximum extension angle.
10.   The articular surfaces of Andy's capitulum/radial head showed abnormal trabeculae and demineralization.
11.   Andy's radial head enlarged, deformed and increased its mineralization.
12.   Andy's ulnar coranoid process measured three-eighth inch longer with a rough, irregular surface and signs of arthritis.
13.   Andy's elbow lost thirty-three degrees of maximum flexion angle.  

               |----------------------------------------------------|
               |     Maximum Flexion     |     Maximum Extension    |
               |     Flexion Angle       |     Extension Angle      |
               |----------------------------------------------------|
               |Non-Pitching|  Pitching  |Non-Pitching|  Pitching   |
               |     Arm    |     Arm    |     Arm    |     Arm     |
 |------------------------------------------------------------------|
 |  Marshall   |     34o    |     46o    |     184o   |    172 o     |
 |------------------------------------------------------------------|
 | Messersmith |     33o    |     66o    |     174o   |    139 o     |
 |------------------------------------------------------------------|

     Whereas the maximum flexion angle of my non-pitching elbow measured thirty-four degrees, the maximum flexion angle of Andy’s non-pitching elbow measured thirty-three degrees.   Therefore, I had one less degree in the maximum flexion angle in my non-pitching elbow.

     Whereas the maximum extension angle of my non-pitching elbow measured one hundred and eighty-four degrees, the maximum extension angle of Andy’s non-pitching elbow measured one hundred and seventy-four degrees.   Therefore, I had ten more degrees in the maximum extension angle in my non-pitching elbow.

     To determine the maximum range of motion of the elbow, we subtract the maximum flexion angle from the maximum extension angle.   For my non-pitching elbow, I subtracted thirty-four degrees from one hundred and eighty-four degrees.   Therefore, the range of motion of my non-pitching elbow was one hundred and fifty degrees.   For Andy’s non-pitching elbow, I subtracted thirty-three degrees from one hundred and seventy-four degrees.   Therefore, the range of motion of Andy non-pitching elbow was one hundred and forty-one degrees.

     Whereas the flexion angle of my pitching elbow measured forty-six degrees, the flexion angle of Andy’s pitching elbow measured sixty-six degrees.   Therefore, Andy had twenty less degrees of flexion angle in his pitching elbow.   Recall that Andy had difficulty feeding himself with his pitching elbow.

     Whereas the extension angle of my pitching elbow measured one hundred and seventy-two degrees, the extension angle of Andy’s pitching elbow measured one hundred and thirty-nine degrees.   Therefore, Andy had thirty-three less degrees of extension angle in his pitching elbow.

     To determine the range of motion of the elbow, we subtract the flexion angle from the extension angle.   For my pitching elbow, I subtracted forty-six degrees from one hundred and seventy-two degrees.   Therefore, the range of motion of my pitching elbow was one hundred and twenty-six degrees.   For Andy’s pitching elbow, I subtracted sixty-six degrees from one hundred and thirty-nine degrees.   Therefore, the range of motion of Andy’s pitching elbow was seventy-three degrees.

     To determine how much pitching had decreased the range of motion in the pitching elbow, we subtract the range of motion of the pitching elbow from the range of motion of the non-pitching elbow.

     For me, we subtracted the one hundred and twenty-six degrees in my pitching elbow from the one hundred and fifty degrees in my non-pitching elbow.   I had twenty-four less degrees in my pitching elbow.   Therefore, at this point in my professional baseball career, pitching cost me twenty-four degrees of the range of motion in my pitching elbow.

     For Andy, we subtracted the seventy-three degrees in his pitching elbow from the one hundred and forty-one degrees in his non-pitching elbow.   Andy had sixty-eight less degrees in his pitching elbow.   Therefore, at this point in his professional baseball career, pitching cost Andy sixty-eight degrees of the range of motion in his pitching elbow.

     With the ‘Traditional’ pitching technique, coaches teach pitchers to reverse rotate their hips and shoulders to take the baseball laterally behind their body.   The consequence of this instruction is that pitchers have to laterally return the pitching arm to the pitching arm side of their body.   This action initiates a horizontal centripetal force that circles the forearm outward.   To prevent their ulnar olecranon process from slamming into their humeral olecranon fossa, pitchers have to powerfully contract their bracialis muscle.

     The brachialis muscle attaches to the coronoid process of the ulna.   Therefore, the coronoid process epiphysis is a traction epiphysis for elbow flexion during the ‘Traditional’ pitching motion.   When pitchers unnecessarily and excessively stress their coronoid processes, their coronoid processes enlarges.   Consequently, these enlarged coranoid processes decrease the flexion angle of their elbows.

     To prevent the loss of the flexion angle of the pitching elbow, pitchers have to stop unnecessarily and excessively stressing the ulnar coronoid process.   This means that they have to stop initiating the lateral centripetal force that causes the forearm to circle laterally outward.   This means that coaches have to stop teaching pitchers to reverse rotate their hips and shoulders and taking the baseball laterally behind their body.   Instead, I recommend that pitchers pendulum swing their pitching arm straight back toward second base up to the height of the driveline for their pitches.   Then, pitchers can apply force to the baseball in straight-lines toward home plate without any unnecessary or excessive stress on the coronoid processes of their ulna.   Future pitchers should be able to feed themselves, comb their hair, tie a tie and so on with their pitching arms.

     With the ‘Traditional’ pitching technique, coaches teach pitchers to pull their pitching arms downward and across the front of their body.   The consequence of this instruction is that pitchers slam the ulnar olecranon processes into their humeral olecranon fossas.

     The olecranon process epiphysis becomes a collision epiphysis.   These repetitive collisions increase the thickness of the hyaline cartilage in the olecranon fossa, which decreases their depth.   Consequently, the decreased depth of the olecranon fossa decreases the extension angle of the elbow.

     To prevent the loss of the extension angle of the pitching elbow, pitchers have to stop slamming their olecranon processes into their olecranon fossas.   This means that the have to stop pulling their pitching arm downward and across the front of their body.   Instead, I recommend that pitchers drive the forearm in straight-lines toward home plate with powerful forearm pronations that prevent the collision between the olecranon process and fossa.   In this way, the forearm rotates through elbow extension and never permits the elbow to ‘lock’.