Download - Throwing Phases
-
7/29/2019 Throwing Phases
1/23
2013
-
7/29/2019 Throwing Phases
2/23
Flexion - Extension
Abduction - Adduction
Medial and lateral rotation
(Internal and external rotation)
Transverse abduction - adduction
-
7/29/2019 Throwing Phases
3/23
6 main phases
I. Wind upII. Early cocking
III. Late cocking
IV. Acceleration
V. DecelerationVI. Follow-through
-
7/29/2019 Throwing Phases
4/23
Begins at the start of movement and ends whenthe lead leg is maximally lifted
-
7/29/2019 Throwing Phases
5/23
The coiling phase
Potential energy is developed
The center of gravity is raised
No appreciable stress on the shoulder and elbow
-
7/29/2019 Throwing Phases
6/23
front leg strides forward
trunk rotation
Center of gravity lowered
shoulder abducted to 90,shoulder ext rotation,
scapular retraction, andelbow flexion
-
7/29/2019 Throwing Phases
7/23
The four rotator cuff musclesfire to hold the head of thehumerus within the glenoidfossa.
Deltoid and supraspinatusproduce abduction
Infraspinatus and teres minorinitiate external rotation andassist abduction
trapezius and rhomboids retractthe scapula
EMG : Early Deltoid, Late Cuff
-
7/29/2019 Throwing Phases
8/23
This phase begins when the lead foot makes contact with the
ground during the stride phase (early cocking ) and ends when thethrowing arm achieves its maximum external rotation
Rotation of the hips and pelvis helps set up the rotation that willbe transferred to the torso and shoulders.
Muscles acting at the shoulder and scapula position the glenoidfossa against the head of the humerus and stabilize the scapula.
Specifically these include the levator scapula, serratus anterior,
rhomboids, trapezius, and pectoralis minor.
-
7/29/2019 Throwing Phases
9/23
-
7/29/2019 Throwing Phases
10/23
The rotator cuff muscles maintain tension at this point
to keep the head of the humerus stable
inside the glenoid fossa.
The internal rotators of the shoulder
will develop tension to slow down
and prevent excessive external rotation.
-
7/29/2019 Throwing Phases
11/23
external rotation -EXTREME
external rotationterminated by forces
from anterior joint capsule
& ligaments
subscapularis
pectoralis major
triceps brachii teres major
latissimus dorsi
-
7/29/2019 Throwing Phases
12/23
common injuriesresulting fromEXTREME externalrotation
tendinitis ofsupraspinatustendon
muscle strain ofpectoralis major,teres major, orlatissimus dorsi
-
7/29/2019 Throwing Phases
13/23
This is the quickest phase of the throw.
Starts just after the shoulder reaches maximumexternal rotation and ends when the ball is released.
The internal rotators of the shoulder have beenstretched like a coiled spring during the previousphase. They shorten rapidly, assisted by this spring-like effect, and produce very rapid internal rotationof the shoulder.
-
7/29/2019 Throwing Phases
14/23
characterized by
initiation of elbowextension
shoulder internal rotation
maintenance of shoulder
abduction at 90
shoulder transverseabduction
scapular protraction
Humerus IR 100 deg / 0.5sec
Eccentric to concentricconversion
transverse abduction and
internal rotation subscapularis,
latissimus dorsi
teres major
pectoralis major
scapular protraction serratus anterior
elbow extension triceps brachii
-
7/29/2019 Throwing Phases
15/23
Muscle contraction with movement
muscle shortens or lengthen
2 subtypes :
Concentric : The muscle shortens during the contraction
Tension Applied load
Eccentric : The muscle lengthen during contraction
-
7/29/2019 Throwing Phases
16/23
Starts when the ball is released and ends when
maximum internal rotation of the shoulder isreached.
The throwing arm is horizontally adducted andinternally rotated to the neutral or anatomical
position and the scapula is protracted. Posterior muscles of the G-H Joint, especially
the Teres Minor, slow down the movement atthe shoulder while the retractors of the scapula
slow down the scapular protraction.
-
7/29/2019 Throwing Phases
17/23
Begins when when the internal rotation of the
shoulder ends and finishes when the throwerreturns to a balanced position.
The arm deceleration process helps reduce theforce and therefore the stress on the joints andmuscles involved
-
7/29/2019 Throwing Phases
18/23
This part of the movement is designed to extendthe time that it takes to come to a stop as well asdistribute the forces to the body and leg.
The posterior muscles of the G-H Joint are very
important to continue the deceleration processat the shoulder.
The serratus anterior is very active in stabilizingscapular rotation while the rhomboids and the
middle part of the trapezius continue to slowdown and reduce the force of scapularprotraction.
-
7/29/2019 Throwing Phases
19/23
-
7/29/2019 Throwing Phases
20/23
-
7/29/2019 Throwing Phases
21/23
-
7/29/2019 Throwing Phases
22/23
-
7/29/2019 Throwing Phases
23/23