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a. Wrist Joint
Bones
1. Metacarpals
Metacarpals
are wrist joints' bones of interest. Wrists contain eight carpal
and five metacarpals bones.
2. Carpals
Eight
carpals somewhat line up into two rows. Proximal rows somewhat
join with radial and ulnar distal ends. From thumb to little
finger, scaphoid and lunate bones articulate with radius' distal
ends, while triquetrum and pisiform bones only line up with ulnas'
distal ends. Pisiform bones lay against triquetrum bones that
lay against hamate bones. Distal carpal rows articulate with
proximal ends of five metacarpals. Trapezium bones articulate
with thumb's metacarpal I and with portions of index fingers'
metacarpal II. Small trapezoid bones articulate with index fingers'
metacarpal II. Large capitate bones articulate with middle fingers'
metacarpal III. Hamate bones articulate with ring fingers' metacarpal
IV and little fingers' metacarpal V.
b. Wrist Joint
Kinesiological Actions
Wrist
joint actions include metacarpal movements. Metacarpals move
anteriorly, posteriorly, medially and laterally.
1. Extensions occur when wrist joint muscles contract to
move metacarpals' posterior surfaces closer to forearms' posterior
surfaces.
2. Flexions occur when wrist joint muscles contract to move
metacarpals' anterior surfaces closer to forearms' anterior surfaces.
3. Radial Flexions occur when wrist joint muscles contract
to move thumbs closer to radius' lateral surfaces.
4. Ulnar Flexions occur when wrist joint muscles contract
to move little fingers closer to ulnas' medial surfaces.
c. Wrist Joint
Muscles
Wrist
joint muscles attach to metacarpals from humeruses. These muscles
position metacarpals and phalanges differently for different
pitches. For magnus fastballs, metacarpals and phalanges parallelly
move toward home plates. For curves, metacarpals ulnarly flex
to have metacarpal V lead. For airfoil pitches, metacarpals radially
flex to have metacarpal I lead.
1. Flexor
Carpi Radialis
Flexor
carpi radialis muscles attach to bases of metacarpal II and IIIs'
plantar surfaces and to humeral medial epicondyles. When flexor
carpi radialis muscles contract, anterior surfaces of metacarpals
II and III and humerus' medial epicondyles move closer together.
Flexor carpi radialis muscles indirectly flex, medially flex
and medially extend ulnas. Flexor carpi radialis muscles indirectly
pronate radiuses. Flexor carpi radialis muscles flex and radially
flex metacarpals. During forearm accelerations, flexor carpi
radialis muscles medially extend elbow joints, pronate forearm
joints and flex wrists.
While
flexor carpi radialis muscles flex wrist joints, they also radially
flex wrist joints. When pitchers throw airfoil pitches, metacarpal
I lead wrist joints. Flexor carpi radialis muscles are second
superior-most of five flexor epicondyle muscles.
2. Flexor
Carpi Ulnaris
Flexor
carpi ulnaris muscles attach to bases of metacarpal Vs' plantar
surfaces and to humeral medial epicondyles. When flexor carpi
ulnaris muscles contract, anterior surfaces of metacarpal Vs
and humerus' medial epicondyles move closer together. Flexor
carpi ulnaris muscles indirectly flex, medially flex and medially
extend ulnas. Flexor carpi ulnaris muscles indirectly supinate
fully pronated radiuses. Flexor carpi ulnaris muscles flex and
ulnarly flex metacarpals. During forearm accelerations, flexor
carpi ulnaris muscles medially extend elbow joints and flex wrist
joints.
While
flexor carpi ulnaris muscles flex wrist joints, they also ulnarly
flex wrist joints. When pitchers throw curves, metacarpal IVs
lead wrist joints. Flexor carpi ulnaris muscles are fourth superior-most
of five flexor epicondyle muscles.
3. Palmaris
Longus
Palmaris
longus muscles attach to palms' transverse ligaments and to humeral
medial epicondyles. When palmaris longus muscles contract, palms
and humerus' medial epicondyles move closer together. Palmaris
longus muscles indirectly flex, medially flex and medially extend
ulnas. Palmaris longus muscles flex metacarpals. During forearm
accelerations, palmaris longus muscles medially extend elbow
joints and flex wrist joints.
Eight
percent of the population do not have palmaris longus muscles.
To check for palmaris longus muscles, press thumb and little
finger tips together. Palmaris longus tendons pop up on wrists'
anterior surfaces. Palmaris longus muscles are only wrist tendons
that wrist retinaculums do not encase.
After
Dodger team physicians diagnosed Tommy John's flexor epicondyle
muscle injury, they discovered that Tommy also lost his ulnar
collateral ligament. Surgeons had to reattach the five flexor
epicondyle muscles and replace the medial collateral ligament.
Surgeons used Tommy's right arm palmaris longus tendon to replace
his left medial collateral ligament.
Unfortunately,
surgeons made a mistake. They crimped the ulna nerve as it passed
through a groove behind his medial epicondyle. They should have
moved his ulnar nerve to his forearm's anterior surface. After
Tommy demonstrated intrinsic hand muscle function loss and little
finger and lateral ring finger half sensitivity loss, surgeons
re-operated and moved his ulnar nerve.
The
second operation gave Tommy more rehabilitation time. Ulnar nerve
regeneration requires one year. Therefore, Tommy could not return
for the 1975 season. Consequently, his flexor epicondyle muscles
and new ulnar collateral ligament gained additional time to strengthen.
When Tommy returned, he was ready and won the 1976 Comeback Player
of the Year Award. Tommy pitched major league baseball twelve
more years.
4. Extensor
Carpi Radialis Brevis
Extensor
carpi radialis brevis muscles attach to bases of metacarpal IIIs'
dorsal surfaces and to humeral lateral epicondyles. When extensor
carpi radialis brevis muscles contract, metacarpal IIIs' posterior
surfaces and humerus' lateral epicondyles move closer together.
Extensor carpi radialis brevis muscles indirectly extend and
laterally extend ulnas. Depending on whether radiusrd have pronated
or supinated, extensor carpi radialis brevis muscles either supinate
or pronate radiuses. Extensor carpi radialis brevis muscles extend
metacarpals. During decelerations, extensor carpi radialis brevis
muscles extend and laterally extend elbow joints, supinate forearm
joints and extend metacarpal joints.
5. Extensor
Carpi Radialis Longus
Extensor
carpi radialis longus muscles attach to bases of metacarpal IIs'
dorsal surfaces and to humerus' lateral supracondylar ridges.
When extensor carpi radialis longus muscles contract, metacarpal
IIs' posterior surfaces and humerus' lateral epicondyles move
closer together. Extensor carpi radialis longus muscles indirectly
extend and laterally extend ulnas. Extensor carpi radialis longus
muscles supinate radiuses. When radiuses fully supinate, extensor
carpi radialis longus muscles pronate radiuses. Extensor carpi
radialis longus muscles extend and radially flex metacarpals.
During decelerations, extensor carpi radialis longus muscles
extend and laterally extend elbow joints, supinate pronated radiuses
and extend metacarpals.
Sport
Medicine personnel refer to humerus' lateral epicondyles as extensor
epicondyles and extensor epicondyle injuries as '
Tennis
Elbow.' Tennis serve decelerations and backhand ground stroke
accelerations stress humeral lateral epicondyle muscles.
During
1975, Stan Smith (Wimbledom and Davis Cup Doubles Champion) sought
rehabilitation advice. I diagnosed that he had torn his extensor
carpi radialis longus muscle from its bone. When muscles arise
from bones, muscle connective tissues intertwines with bone outer
surface tissues. Stan tore connective tissue from bone tissue.
Connective
tissue/bone tissue tears pains sharply when athletes start to
exercise too fast too soon. However, when athletes start slowly
and wait for blood to flow into injured tissues, they perform
relatively normally. Connective tissue/bone tissue tears require
months of specific, diligent rehabilitations.
Athletes
concurrently must correct injury-producing mechanical flaws.
Stan incorrectly decelerated his tennis serves with his humeral
lateral epicondyle muscles. Stan also incorrectly accelerated
his backhand ground strokes with extension-locked elbow joints.
Extension-locked elbow joints severely stress humeral lateral
epicondyle muscles. Consequently, during tennis serve decelerations,
I advised Stan Smith to use his large back of his shoulder muscles
and, during his backhand ground stroke, I advised Stan to slightly
bend his elbow joint.
6. Extensor
Carpi Ulnaris
Extensor
carpi ulnaris muscles attach to bases of metacarpal Vs' dorsal
surfaces and to humeral lateral epicondyles. When extensor carpi
ulnaris muscles contract, metacarpal Vs' posterior surfaces and
humerus' lateral epicondyles move closer together. Extensor carpi
ulnaris muscles indirectly extend, laterally extend and laterally
flex ulnas. Extensor carpi ulnaris muscles pronate radiuses.
Extensor carpi ulnaris muscles extend and ulnarly flex metacarpals.
During decelerations, extensor carpi ulnaris muscles extend and
ulnarly flex wrist joints.
In
conclusion, wrist joint muscles position metacarpals and phalanges
differently for different pitches. When pitchers throw magnus
fastballs, wrist joint muscles parallelly move metacarpals and
phalanges through releases. When pitchers throw curves, wrist
joint muscles ulnarly flex metacarpals to have fifth digits lead
through releases. When pitchers throw airfoil pitches, wrist
joint muscles radially flex metacarpals to have first digits
lead through releases.
d. Pitching
Wrist Joint Actions
1. Transition
During
transitions, wrist joint muscles maximally mioanglosly extend
and radially flex metacarpals. From maximal wrist joint extensions,
pitchers prepare to maximally flex wrist joints through releases.
From maximal wrist joint radially flexions, pitchers prepare
to maximally ulnarly flex wrist joints through releases when
specific pitches require.
2. Upper Arm
Acceleration
During
upper arm accelerations, wrist joint muscles isoanglosly flex
and ulnarly flex extended and radially flexed metacarpals. Uniform
accelerations require uniform forces. Therefore, wrist joint
muscles uniformly isoanglosly flex and ulnarly flex metacarpals.
3. Forearm
Acceleration
During
forearm accelerations, wrist joint muscles maximally mioanglosly
flex and ulnarly flex metacarpals. Wrist joint actions occur
immediately prior to pitch releases.
4. Deceleration
During
decelerations, wrist joint musles plioanglosly extend and ulnarly
flex metacarpals. After releasing pitches, baseballs' resistances
disappear and metacarpals accelerate. Therefore, wrist joint
deceleration muscles encounter increased stresses. |
