Shoulder problems in overhead sports. Part I

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May 15, 2014 - ciated with sports involving various kinds of throws are very common. ... Lower extremities and the trunk, while providing stable base ... ed on baseball pitchers [2,4,6,7–15,20,26,30]. ... cessive phases: windup, cocking (early and late), accelera- ... sponds to deceleration phase and post-ball release to a fol-.
© Polish Orthopedics and Traumatology, 2014; 79: 50-58

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Review Article

Received: 2013.11.26 Accepted: 2014.01.15 Published: 2014.05.15

Shoulder problems in overhead sports. Part I – biomechanics of throwing

"VUIPST$POUSJCVUJPO A Study Design B Data Collection C Statistical Analysis D Data Interpretation E Manuscript Preparation F Literature Search G Funds Collection

Piotr Krzysztof Kaczmarek1 AE, Przemysław Lubiatowski1,2 AEG, Paweł Cisowski1 BF, Monika Grygorowicz3 EFG, Marcin Łepski1 F, Jan Długosz1,2 F, Piotr Ogrodowicz1,2 F, Witold Dudziński1 DFG, Maciej Nowak4 DF, Leszek Romanowski2 AG Department of Physiotherapy, Rehasport Clinic, Poznań, Poland Department of Traumatology, Orthopaedics and Hand Surgery, Poznań University of Medical Science, Poznań, Poland 3 Department of Research and Development, Rehasport Clinic, Poznań, Poland 4 Medical Center, Dynasplint, Poznań, Poland 1 2

Source of support: The project was funded by the National Science Center based on decision number DEC-2011/01/B/NZ7/03596

Summary The article discusses the biomechanical processes that occur during an overhead throw. This activity is highly specialized and requires full and proper function from the shoulder joint. It consists of active and passive stabilization and synchronous work of the accelerating and decelerating muscles. The process of the overhead throw can be divided into several phases that differ from each other in biomechanical parameters and involvement of specific muscles.

Keywords: Full-text PDF: Word count: Tables: Figures: References:

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Przemysław Lubiatowski, Department of Traumatology, Orthopaedics and Hand Surgery, Poznań University of Medical Science, Poznań, Poland, e-mail: [email protected]

Kaczmarek P.K. et al. – Shoulder problems in overhead sports…

BACKGROUND The shoulder is a part of kinetic chain and is exposed to a great stress in terms of mobility and stability of force, endurance and motor control of muscles. Therefore, injuries associated with sports involving various kinds of throws are very common. As much as 75% of such injuries involve upper extremity and most are localized in the shoulder region [1]. Basic mechanics and phases of throwing have been examined and described by many authors [2–10]. Others conducted electrmyographic activity studies (EMG) [1,9–15] or analysed dynamic and passive structures stabilizing shoulder joint during a throw [16–18] and their association with various types of injuries commonly seen in overhead motion. Integrity of those structures protects against shoulder joint instability and impingement syndromes. The balance between mobility and stability of the shoulder is very delicate. There is a very thin line between optimal movement and possible damage. Any changes in the throw technique, poor elasticity or muscle fatigue may be adequate to disturb that balance and result in injury during fast, repetitive throws [1,9]. Several types of throw can be distinguished: a two-handed throw, a one-handed throw, an overhead throw, a side throw and a throw from the bottom. Amongst them, one-handed overhead throw is the most common motion in sports, used by pitchers or handball players. Due to this kind of motion executed throw is the fastest and most precise. An overhead throw can be described as displacement of an object in space using one hand with simultaneous extension of the elbow and internal rotation of the shoulder [19–21]. The main goal of the paper is to collect and systematize current knowledge of physiology and pathology of overhead throw. Due to the volume of material, this paper has been divided into two parts. The first article will address physiology and mechanism of the throw. Focus will be placed on precise description of individual phases of the throw, based on analysis of a baseball pitcher and the approximation of kinetic chain concept. Basic differences and similarities between a handball throw and ways of executing this motion in other overhead sports will also be discussed. The second paper will consider the whole cascade of changes leading to the development of multiple shoulder joint pathologies related to throwing.

KINETIC CHAIN High-energy activities of the upper extremity like throwing, punching or serving result from integrated, multisegmented and sequential movement of individual joints as well as the action of muscles [23,32]. This mutual coordination of different body parts is called a kinetic chain. Proper function of kinetic chain allows for generation of maximal force and kinetic energy and its transfer from lower extremities to the trunk and to the upper extremity during aforementioned activities. Individual parts of a kinetic chain must be characterized by optimal elasticity, muscle strength and endurance, proper level of proprioception and ability to perform specific exercises in a repeatable manner. Any kind of kinetic chain failure may increase the stress exerted on i.e. structures of the shoulder, leading to pain, microtrauma

and result in damage [32]. In a properly functioning kinetic chain surface, lower extremities and trunk act as force generators, while shoulder plays a role of a link delivering and regulating the generated force. The arm, however, is a part of the mechanism delivering this force directly to the ball [22]. Lower extremities and the trunk Muscles of the lower extremity take part in generating kinetic energy and providing stable base for support of movement of distal segments. A stable base produces foundation for local and global stabilizers of the trunk (transversus abdominis and spinal muscles) jointly responsible for central stabilization, providing dynamic stability of the trunk. Larger muscles, such as erector spinae or abdominal muscles (external and internal oblique, rectus abdominis, quadratus lumborum) as well as hip abductors, play a significant role in generating and transferring force and providing stability for upper extremity function [32]. Lower extremities and the trunk, while providing stable base for arm movement and torque resulting from rotation of the pelvis and trunk, generate 50–55% of total force and kinetic energy. Any disruption in the functioning of trunk rotation, weakness of hip abductors and trunk flexors results in breaking the kinetic chain, which may lead to excessive abduction and external rotation of a shoulder joint, thus increasing load exerted on anterior and posterior structures of the shoulder, including the labrum [24–28]. Scapula and upper extremity Scapula provides support for the head of humerus and is an insertion site for muscles that control movement of an arm and press the head of humerus into a socket (rotator cuff muscles, deltoid muscle, biceps brachii, coracoradialis muscle). The scapula itself is controlled by muscles that stabilize it against the chest (trapezius, rhomboidei, levator scapulae, pectoralis minor and serratus anterior muscles). Function of those muscles allows for proper alignment and stabilization of the scapula in space, so that the joint cavity holds the head of humerus steadily and securely, rotating at high speeds. Scapula has to move fluently into protraction and retraction on a posterolateral chest wall, while the arm changes its position starting from the windup to the followthrough phase. Therefore, we may observe its movement along with the humerus, maintaining a safe movement zone of the shoulder joint, thus avoiding excessive range of movement in relation to the acetabulum [9,32,34]. The correct position of scapula, allowing for optimal activation of muscles surrounding the shoulder joint is in retraction and external rotation, which is provided mainly by serratus anterior muscle. It can be obtained by synergistic action of hip and trunk muscles along with the scapula and the arm. This sequential action ensures maximal activation of muscles attached to the scapula [33], providing stable foundation for attached rotator cuff muscles [34]. Scapular retraction is an integral part of proper scapulohumeral rhythm during shoulder movements [32]. Disturbances in normal alignment or motion of the scapula are termed scapular dyskinesis. Dyskinesis results from lack of elasticity of the shoulder joint, weakness of muscles

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or muscle imbalance [25,27]. The final components of a kinetic chain, which generate 36% of kinetic energy transmitted to the ball, include elbow and wrist. Dynamic extension occurring in the elbow provides 21% of transferred energy of the throw. At the same time, is the most vulnerable segment of kinetic chain next to the shoulder joint. The remaining 15% of the force and kinetic energy comes from palmar flexion of the wrist.

BIOMECHANICS OF THE THROW Throwing is a complex activity combining translational and rotational movements [29], that develop angular velocities reaching up to 7000 deg/sec [1,2,11,36]. It puts a lot of stress onto both the anterior and posterior structures of the shoulder, resulting in microtrauma of soft tissue surrounding the joint, which may result in overuse injury. For this reason, pain and dysfunction of the shoulder are very common among throwing athletes [1,19–21,29]. From a mechanical point of view, the aim of movement is to gradually develop potential energy, which is then transformed into kinetic energy. In this state it is transferred to the ball through fluent movement [29]. Most studies concerning the biomechanics of the throw have been conducted on baseball pitchers [2,4,6,7–15,20,26,30]. Analysis of this issue can help in understanding the mechanics of throw in other types of sports. Mechanics of overhead throw have been described by many authors as an array of 5 or 6 successive phases: windup, cocking (early and late), acceleration, deceleration and follow-through [6–8]. It is obvious that various techniques of overhead throw differ from each other depending on rules of the game or type of sport activity and related various movement strategies. For this reason, different phases of overhead movement may look and be called differently in various sports. However, from a biomechanical point of view, kinetic chain function and goals of individual phases are similar. With regard to handball players windup phase corresponds to pelvis and trunk rotation (Figure 1A, 1B) or run-up and approach (Figures 1C, 1D and 2C, 2D) or turning (Figure 2A, 2B) or run up and take off phase (Figure 3A, 3B) depending on the type of throw. Moment of ball release corresponds to deceleration phase and post-ball release to a follow-through phase. Other phases are called the same in both baseball and handball. Windup The goal of this phase is to put the body in an optimal position to start the throw. It allows the pitcher to achieve maximal effectiveness, strength and speed. The windup is a stage between initiation of movement and the moment itself, when the ball is pulled out of the glove. The crucial element of this phase is a so-called “push off”, during which the stride leg (opposite to the throwing arm) takes off from the ground. It results in transferring body weight from the rear to the opposite leg, which rotates approximately 90 degrees together with the trunk. Due to the take off movement, the centre of body mass is shifted anteriorly and maintains this direction for all subsequent phases of the throw. At the end of this phase the pitcher is positioned perpendicularly to the target. Hip and knee joints of the

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limb opposite to the rotating one is in flexion, therefore the pitcher achieves appropriate balanced position and is able to move to the next phase. Windup lasts from 0.5 to 1.3 seconds and finishes with separation of hands and the ball leaving the glove [2]. At this stage the lower part of the body and the trunk play a significant role in achieving the final speed of the throw. Toyoshima et al. demonstrated that circa 50% of throw speed is the effect of a stride and trunk rotation, and the remaining part comes from shoulder, elbow, wrist and finger activity. During this phase low muscle activity was observed [1,9]. Cocking phase This phase of throw can be divided into two separate parts: early cocking and late cocking. It’s a very dynamic phase where the arm is placed in a 90-degree abduction, maximal external rotation (ABER position) and horizontal abduction. This position results in full stretching of muscles that accelerate the arm. From now on, the energy generated by different body segments, mainly the lower extremities and the trunk, is quickly and systematically transferred to the ball though upper extremity [1,9]. Early cocking After the windup phase knee joint of rotating lower limb (pivot leg) is bent, lowering the centre of body mass, and the opposite lower limb (stride leg) extends and moves forward in the direction of the target. The trunk is kept as far back as possible to maximize its ability to rotate, which influences velocity of the throw. While a stride leg continues to extend in the direction of the tilt, the knee and hip joint of the rotating leg extend as well, pushing the whole body forward. During this the time, hip joints rotate in the direction of the target followed by trunk rotation in the same direction. With appropriate coordination, the throwing arm will be put halfway through a cocking position, between the early and late cocking phase, achieving approximately 90 degrees abduction, 30 degrees horizontal abduction and 50 degrees external rotation. During this time the foot of the stride leg contacts the ground, ending the first stage of cocking phase [1,9]. Late cocking Late cocking phase starts when the foot of the stride leg opposite to the throwing arm touches the ground. When touching the ground hips, pelvis and shoulders continue their rotational movement toward the target. However, in this phase most dynamic changes occur in the shoulder and elbow joints. The shoulder of the throwing arm is now in a position of 90 degrees abduction, 30 degrees horizontal abduction and 90–120 degrees external rotation. The hip and shoulder girdle are still moving in a direction of the target, which produces the highest angular velocity. The arm, however, undergoes further external rotation. On ground contact, the arm increases the range of external rotation by as much as 125 degrees from a 50 degrees position during the first foot contact up to the value of 175 degrees. At this point the maximal amount of energy necessary to provide the arm with appropriate speed is generated. In this position internal rotators are maximally stretched – eccentrically loaded and static stabilizers are twisted into a thick,

Kaczmarek P.K. et al. – Shoulder problems in overhead sports…

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Figure 1. Phases of a pivot throw ((A) Lateral view; (B) – Anterior view) and a hip throw ((C) – Lateral view; (D) – Anterior view) in handball. fibrous band. The musculoskeletal system and capsuloligamentous complex have to generate antagonistic forces onto the joint in order to maintain its stability and prevent injury. Many authors have defined the value of maximal external rotation in the shoulder joint as 160 degrees to 185 degrees among professional players. Both early and late cocking phases take from 0.5 to 1 second, while together they last approximately 1.5 seconds [1,2,9,30].

Acceleration In this most explosive phase of the throw – the ball is rapidly accelerated from a nearly stationary position to the speed of up to 43 m/s (155 km/h) in 50 ms. It constitutes less than 2% of the time needed to execute a throw. Duration of acceleration was within a narrow range of 42 to 58 ms [2]. Dillman et al. described internal rotation movement in the acceleration

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Polish Orthopedics and Traumatology, 2014; 79: 50-58

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Early cocking

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Figure 2. Phases of standing throw/penalty shot ((A) – Lateral view; (B) – Anterior view) and standing throw with run-up ((C) – Lateral view; (D) – Anterior view) in handball. phase as “one of the fastest human motions” [7]. From the position of maximal external rotation (175 deg), the arm in glenohumeral joint is violently internally rotated to 90 degrees external rotation, in which ball release occurs. During maximal external rotation in the late cocking phase, arm achieves a torque of around 1695 N-m, while in the acceleration phase during internal rotation, previous torque is rapidly reversed

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in accordance with the direction of rotation, and achieves value of 1582 N-m [1,9]. Maximal value of angular velocity of the shoulder during internal rotation is 9198 deg/s, and mean value is between 6100 to 7000 deg/s [1,2,11]. As this phase is initiated, load distribution on passive stabilizers of the shoulder changes. The load on anterior part

Kaczmarek P.K. et al. – Shoulder problems in overhead sports…

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Figure 3. Phases of jump throw ((A) – Lateral view; (B) – Anterior view) and specific phases of jump throw ((C) – Lateral view; (D) – Anterior view) in handball. of IGHL decreases with derotation of the shoulder, as well as rapid abduction and internal rotation of the humerus. It is subsequently transferred onto other ligamentous structures, mostly on the posterior part of the capsule. Laxity of anterior part of IGHL exposes the anterosuperior labrum to higher risk of injury, as high incidence of throwing injuries take place in this location [1,4–7].

Right before ball release the arm moves back slightly in the direction of horizontal abduction in response to rapid internal rotation of the humerus. When the ball is released the arm is positioned in 0 degrees horizontal abduction. The release of the ball finishes the acceleration phase [1].

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Deceleration The main goal of this phase and the subsequent followthrough phase is to decrease the speed of the arm after ball release and safely dissipate excess kinetic energy, which had not been transferred to the ball, thus minimizing the risk of tissue injury. The deceleration phase occurs during initial 50 ms after ball release. It is characterized by high value of angular deceleration generated by the posterior group of shoulder girdle muscles (500 000 deg/s2), hence extreme load exerted on those structures, which may lead to injury. The arm still moves in the direction of internal rotation, while extension occurs in the elbow joint. In the deceleration phase, angular velocity of internal rotation decreases from the highest values to 0. From the position of neutral horizontal abduction, when the ball is released, the glenohumeral joint is horizontally adducted. After ball release, the arm is rapidly abducted in the glenohumeral joint to 110 degrees. Deviations from this position exceeding 10 degrees (below 80 degrees or above 120 degrees abduction) may cause improper arm positioning. Deceleration phase ends when neutral position of 0 degrees rotation is achieved [1,10]. Follow-through It is described as a passive phase, in which the body meets the throwing arm. This phase consists of extension of the leading leg, adduction and horizontal adduction of the glenohumeral joint and flexion of the elbow joint. The rotating leg moves forwards, right to the place of ground contact of the opposite leg. It allows the player to assume a well-balanced position, and ends the throwing motion at the same time. With adduction, anterior and superior parts of the capsule restrict posterior and inferior humeral head movement. As shown from EMG analysis, all of the shoulder girdle and upper extremity muscles display low or moderate activity during this phase of throw [1,10].

THROW ANALYSIS IN HANDBALL Various techniques of overhead movement or throw differ from each other due to different game rules, ball size and weight or movement strategies of opponent players during defense or attack. However, these movements are somehow similar to each other, particularly regarding upper body kinematics, which is why it is possible to define basic movement patterns of overhead motion, which are common for a variety of sports [37]. It is well known that professional handball players use different techniques of throw depending on their position on the field. It is also dictated by the behaviour of defensive players of the opposing team [36]. Previous studies on handball players [38–43] were based on the analysis of three types of throw: standing throw (Figure 1A, 1B), standing throw with run-up (Figure 1C, 1D) and jump throw (Figure 3A, 3B). Among these three different techniques, the jump throw is the most common during the game [36]. Wagner et al. (2008) estimated that a jump throw constitutes 73–75% of all throws during the game. About 14–18% of throws are made with run-up, while 6–9% are penalty throws, 2–4% constitute diving throws and only 1% of all throws are direct, free throws (passes) [31,35]. For the list to be complete,

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the pivot throw (Figure 2A, 2B) and hip throw (Figure 2C, 2D) should also be mentioned. Jump throw technique is the most typical among other throw techniques used in handball. Take-off usually occurs from the leg opposite to the throwing arm. Because of this, the player is able to achieve correct natural coordination, which allows for successful, strong and accurate throw toward the target. Jump throw can be divided into 5 phases: approach, take-off, flight, throw and landing (Figure 3C, 3D) [41]. Approach Considering the final step of approach, this is the period between lifting the swinging leg from ground and the take-off leg contacting the ground. The main goal of this phase is to achieve optimal conditions (or starting position) to complete the remaining phases of throwing [41]. Take-off This phase is a period between contact of the take-off leg with the ground to the moment when this limb leaves the ground. Concomitant decrease in horizontal speed and increase in vertical speed occurs here [41]. Flight Since flight of the body is a parabolic movement, parameters describing horizontal and vertical velocities at the take-off define basic characteristics of the flight regardless of the takeoff manner. The throwing arm is in a position of abduction and maximal external rotation (ABER) during this phase – similarly to the cocking phase of baseball pitchers [41,45]. Throw The moment of the throw differs depending on the take-off manner. For example, when the take-off is made from the leg ipsilateral to the throwing arm, the throw is executed just before the landing. Ball acceleration and release take place at that time [41,45]. Landing After releasing the ball, throwing arm continues to move forward and downward, while the whole body prepares for landing – as in the follow-through phase executed by pitchers. For the most part, the take-off leg is the first to come in contact with the ground. At the same time knee joint flexes to absorb landing energy. The other leg absorbs the rest of the force and helps maintain balance [41]. Analyses of various throw techniques demonstrated, that higher throw speeds are achieved in case of a standing throw with a run-up, than with a jump throw or a standing throw [45,46]. They showed that angular velocity of internal rotation of the shoulder at the time of ball release, maximal extension of the elbow and the time necessary to achieve maximal pelvic angle greatly influence ball speed. Van den Tillaar and Ettema (2004) suggest that 67% of ball speed is a result of angular velocity produced by summation of elbow extension and shoulder internal rotation. World-class handball players reach maximal angular velocity of shoulder internal

Kaczmarek P.K. et al. – Shoulder problems in overhead sports…

rotation of 8130±1200°/s and ball speed at the moment of ball release of 25.1±0.8 m/s during a standing throw [36].

(incomplete proximal-to-distal sequence) depending on the situation during the game [43].

Jump throw, standing throw, standing throw with a run-up and pivot throw, are basic skills that a handball player should demonstrate. Variations in throwing technique are possible and mainly concern movements of the lower extremity and pelvis – such as maximal angle of backward rotation of pelvis during cocking or maximal angular velocity during acceleration [43,45]. A standing throw technique assumes that the leading leg is kept on the ground during the entire duration of the throw and it is a typical position for a penalty throw (Figure 1A, 1B). In a standing throw with run-up one foot contacts the ground after the run-up, which can be compared to a lunge made by pitchers during the windup and cocking phase (Figure 1C, 1D). At the moment of jump throw the player has to perform vertical take-off from one leg at the end of the approach and rotate the pelvis and trunk through movement of the opposite leg during flight phase (Figure 3A, 3B). Whereas during a pivot throw the player generally jumps vertically from one or two legs just after performing the pivot movement (Figure 2A, 2B) [44].

Despite significant differences in throw techniques seen in throwing sports, there are many common elements. For example, stride leg anchors the body providing a stable base of support for the pelvis, trunk and throwing arm, which allows for achieving greater acceleration and better energy transfer, giving a momentum. The described situation is common for javelin throw, baseball throw as well as standing throw with a run up, as seen in handball. Moreover, maximal angular velocity is achieved in a similar way. Its increase takes place in the proximal-to-distal direction, starting from pelvis rotation, through trunk rotation and elbow extension, ending with internal rotation of an arm. Similarities also concern movements of the throwing arm manifesting as similar angular values in joints, which can be mostly seen in the acceleration phase [43].

Proximal-to-distal movement sequence A proximal-to-distal movement sequence analysis showed that achievement of maximal angular velocities and hence transfer of kinetic energy from the proximal to distal segments occurs in a specific manner: from pelvis rotation, through trunk rotation, trunk flexion, elbow extension, internal rotation of the arm to arm flexion [43]. This specific arrangement of successive movements of individual body segments is typical for overhead movements and was observed by many researchers [43,47,48]. Specific nature of this movement sequence manifests itself in achieving maximal angular velocity of elbow extension before reaching maximal angular velocity of internal rotation of the arm. It was established that elbow extension in the throwing arm occurs earlier to reduce shoulder internal rotation torque [37,42,43]. Angular velocity of elbow extension is reduced to prevent excessive extension or hyperextension of elbow joint and thus, to minimize the risk of muscle or joint injury [43]. The greatest angle of elbow extension and therefore, smallest internal rotation torque in the shoulder was measured at the time of ball release, when angular velocity of internal rotation in the shoulder reached its maximum [43]. Most handball players use both movement sequences: classic (complete proximal-to-distal sequence) and specific

In conclusion, the differences between aforementioned throwing techniques in handball mainly arise from different angular velocities of internal rotation of the pelvis, trunk and the throwing arm. These, in turn, result from differences in movements of lower extremities and decreased angle of maximal external rotation of pelvis and trunk.

CONCLUSIONS A throw is an extremely dynamic activity, exerting high loads on all joint structures. Its efficiency depends on various factors among, which proper functioning of the kinetic chain is most important. It provides fluent kinetic energy transfer from lower extremities through pelvis and trunk, up to the throwing limb, finally influencing the value of ball momentum. Moreover, correct functioning of a kinetic chain prevents overloading of individual segments, thus, decreasing the chance of sustaining an injury. Accurate understanding of each phase of a throw and variations between different techniques of its execution, together with the knowledge of basic physical, endurance and anthropometric parameters should be an essential element in creating a training programme for individual players. Acknowledgments We thank Jakub Łucak (handball player; SPR Chrobry Głogów) and Konrad Szczukocki (beach handball player, BHT Piotrkowianin JUKO Piotrków Trybunalski) for their help in making the video and the possibility to use their image.

REFERENCES: 1. Kelley MJ, Clark WA: Orthopedic Therapy of the Shoulder. 2nd ed. Lippincott Williams & Wilkins, 1994 2. Pappas AE, Zawacki RM, Sullivan TJ: Biomechanics of baseball pitching: A preliminary report. Am J Sports Med, 1985; 13(4): 216–22 3. Zarins B, Andrews JR, Carson WG: Injuries to the throwing arm. Philadelphia: Saunders (W.B.) Co Ltd., 1985 4. Braatz JH, Gogia PP: The mechanics of pitching. J Orthop Sports Phys Ther, 1987; 9(3): 56–59 5. Kegerreis S, Jenkins WL, Malone TR: Sports injury management: Throwing injuries. Baltimore: Williams & Wilkins, 1990 6. Fleisig GS, Dillman CJ, Andrews JR: A biomechanical description of the shoulder joint during pitching. Sports Med Update, 1991; 6: 10

7. Dillman CJ, Fleisig GS, Andrews JR: Biomechanics of pitching with emphasis upon shoulder kinematics. J Orthop Sports Phys Ther, 1993; 18(2): 402–8 8. Werner SL, Fleisig GS, Dillman CJ: Biomechanics of the elbow during baseball pitching. J Orthop Sports Phys Ther, 1993; 17(6): 274–78 9. Park SS, Loebenberg ML, Rokito AS et al: The Shoulder in Baseball Pitching: Biomechanics and related injuries – Part 1. Bull Hosp Jt Dis, 2002; 61(1): 68–79 10. Park SS, Loebenberg ML, Rokito AS et al: The Shoulder in Baseball Pitching: Biomechanics and related injuries – Part 2. Bull Hosp Jt Dis, 2003; 61(2): 68–79

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Polish Orthopedics and Traumatology, 2014; 79: 50-58 11. DiGiovine NM, Jobe FW, Pink M et al: An electromyographic analysis of the upper extremity in pitching. J Shoulder Elbow Surg, 1992; 1(1): 15–25

31. Wagner H, Pfusterschmied J, von Duvillard SP, Muller E. Performance and kinematics of various throwing techniques in team-handball. J Sports Sci, 2011; 10: 73–80

12. Glousman R, Jobe FW, Tibone J et al: Dynamic EMG analysis of the throwing shoulder with glenohumeral instability. J Bone Joint Surg Am, 1988; 70(2): 220–26

32. Sciascia A, Cromwell R: Kinetic chain rehabilitation: A theoretical framework. Rehabil Res Pract, 2012; 2012: 1–8

13. Gowan ID, Jobe FW, Tibone J et al: A comparative electromyographic analysis of the shoulder during pitching: professional versus amateur pitchers. Am J Sports Med, 1987; 15(6): 586–90 14. Jobe FW, Tibone JE, Perry J et al: An EMG analysis of the shoulder in throwing and pitching. Am J Sports Med, 1983; 11(1): 3–5 15. Jobe FW, Moynes DR, Tibone JE et al: An EMG analysis of the shoulder in pitching: a second report. Am J Sports Med, 1984; 12(3): 218–20 16. Ferrari DA: Capsular ligaments of the shoulder: anatomical and functional study of the anterior superior capsule. Am J Sports Med, 1990; 18(1): 20–24 17. Howell SM, Kraft TA: The role of the supraspinatus and infraspinatus muscles in glenohumeral kinematics of anterior shoulder instability. Clin Orthop Relat Res, 1991; (263): 128–34 18. Bradley JP, Tibone JE: Electromyographic analysis of muscle action about the shoulder. Clin Sports Med, 1991; 10(4): 789–805 19. Sakurai S: Motion analysis of overhand throwing: past, present, future. 18 International Symposium on Biomechanics in Sports, 2000 20. Sakurai S et al: A three-dimensional cinematographic analysis of upper limb movement during fastball and curveball baseball pitches. J Appl Biomech, 1993; 9(1): 47–65 21. Sakurai S, Chentanez T, Elliott BC: International comparison of the development trend of overhand throwing ability. Med Sci Sports Exercises, 1998; 30(5): 151 22. Burkhart SS, Morgan CD, Kibler WB: The disabled throwing shoulder: spectrum of pathology part III: the SICK scapula, scapular dyskinesis, the kinetic chain and rehabilitation. Arthroscopy, 2003; 19(6): 641–61 23. Kibler WB: Biomechanical analysis of the shoulder during tennis activities. Clin Sports Med, 1995; 14(1): 79–85 24. Happee R, Van Der Helm FC: Control of shoulder muscles during goaldirected movements, an inverse dynamic analysis. J Biomech, 1995; 28(10): 1179–91 25. Jobe FW, Kvitne RS: Operative techniques in upper extremity sports injuries. St. Louis: Mosby, 1996 26. Watkins RG, Dennis S, Dillin WH et al: Dynamic EMG analysis of torque transfer in professional baseball pitchers. Spine, 1989; 14(4): 404–8

33. Kibler WB, McMullen J, Uhl T: Shoulder rehabilitation strategies, guidelines, and practice. Operative Techniques in Sports Medicine, 2000; 8(4): 258–67 34. Lippitt S, Vanderhooft JE, Harris S et al: Glenohumeral stability from concavity-compression: a quantitative analysis. J Shoulder Elbow Surg, 1993; 2(1): 27–35 35. Wagner H, Kainrath S, Müller E: Coordinative and tactical parameters of team-handball jump throw. The correlation of level of performance, throwing quality and selected techniquetactical parameters. Leistungssport, 2008; 38: 35–41 36. Wagner H, Buchecker M, von Duvillard SP et al: Kinematic description of elite vs. low level players in team-handball jump throw. J Sports Sci Med, 2010; 9: 15–23 37. Wagner H, Pfusterschmied J, Tilp M et al: Upper-body kinematics in team-handball throw, tennis serve, and volleyball spike. Scand J Med Sci Sports, 2012; [Epub ahead of print] 38. Fradet L, Botcazou M, Durocher C et al: Do handball throws always exhibit a proximal-to-distal segment sequence? Eur J Sport Sci, 2004; 22: 439–47 39. Gorostiaga EM, Granados C, Ibanez J et al: Differences in physical fitness and throwing velocity among elite and amateur male handball players. Int J Sports Med, 2005; 37: 225–32 40. Pori P, Bon M, Sibila M: Jump shot performance in team handball. A kinematic model evaluated on the basis of expert modeling. Kinesiol, 2005; 37: 40–49 41. Sibila M, Pori P, Bon M: Basic kinematic differences between two types of jump shot techniques in handball. Acta Universita Palacki Olomuc, 2003; 33: 19–26 42. Van den Tillaar R, Ettema G: A Force-velocity relationship and coordination patterns in overarm throwing. J Sports Sci Med, 2004; 3: 211–19 43. Wagner H, Pfusterschmied J, von Duvillard S et al: Skill-dependent proximal-to-distal sequence in team-handball throwing. J Sports Sci, 2012; 30: 21–29 44. Wagner H, Buchecker M, Müller E: Kinematic analysis in team-handball jump throw. 27 International Conference on Biomechanics is Sports, 2009

27. Kibler WB, Livingston BP: Closed chain rehabilitation for the upper and lower extremity. J Am Acad Orthop Surg, 2001; 9(6): 412–21

45. Wagner H, Pfusterschmied J, von Duvillard SP et al: Performance and kinematics of various throwing techniques in team-handball. J Sports Sci, 2011; 10: 73–80

28. Young JL, Herring SA, Press JM et al: The influence of the spine on the shoulder in the throwing athlete. J Back Musculoskelet Rehabil, 1996; 7: 5–17

46. Van den Tillaar R, Ettema G: A Three-dimensional analysis of overarm throwing in experienced handball players. J Appl Biomech, 2007; 23: 12–19

29. Napolitano R, Brady DM: The diagnosis and treatment of shoulder injuries in the throwing athlete. J Chiropr Med, 2002; 1(1): 23–30

47. Fleisig SG, Barrentine SW, Zheng N et al: Kinematic and kinetic comparison of baseball pitching among various levels of development. J Biomech, 1999; 32: 1371–75

30. Copeland S: Throwing injuries of the shoulder. Br J Sp Med, 1993; 27(4): 221–27

58

48. Van den Tillaar R, Ettema G: Is there a proximal-to-distal sequence in overarm throwing in team-handball? J Sports Sci, 2009; 27: 949–55