Proposal For Balance In Shoulder Of Throwers And Non-Throwers

Bones and Muscles in Human Shoulder

Discuss about the Proposal for Balance in Shoulder of Throwers and Non-Throwers.

Bones are important for the human body not only to provide the body a structure, but it also anchor muscles and store calcium. Lawrence et al. (2014) states that among all the bines, shoulder bones are very crucial and its ball-and-socket joint allow human to lift things with ease. There are three major bones in human shoulder such as the clavicle, scapula and humerus. Apart from these bones, the shoulder also comprises of its associated muscles like tendons and ligaments. The shoulder joints is formulated with the articulations between the shoulder bones. The joint of the shoulder is known as glenohumeral joint however  can included as acromioclavicular joint and is considere to be the major joint of the shoulder. Moreover, Lawrence et al. (2014) also portrays that humerus of the shoulder is attached with the head sitting and the scapula in the glenoid cavity. As mentioned earlier, the shoulder joint is a socket and ball joint that help a human to rotate their arms and allow them to hinge their shoulder out and up away from the body.

On the other hand, the capsule can be considered as soft tissue, which envelope the entricles of the glenohumeral joint and it is attached with the humerus, major part of the biceps and scapula. Even it lined of a smooth and thin synovial membrane. Timmons et al. (2013) moreover mentioned that the stability of the shoulder is provided from the four major group of the must that together forms the Rotator cuff. These combination of four muscles that are subscapularis, supraspinatus, teres minor and infraspinatus surround the shoulder joint. The rotator cuff usually adheres to glenohumeral capsule and the humeral head is closely attached with the capsule. The human shoulder should be flexible enough in order to perform vast range of activities in proper manner. The flexibility of the human shoulder helps an individual to pull, push and lift. It is important to prevent the injury of the shoulder; otherwise it can lead to immense critical situation. If the muscle is balanced, then it helps an individual to provide a perfect performance in the daily activities. From various incidents, it has been shown that muscle imbalance is majorly responsible for shoulder injury.

Rokito et al. (1998) furthermore depicts the origin of various shoulder injuries is the plyometric exercise; there should be proper awareness and guidelines for the athletes during shoulder exercise. The athletes should have adopted appropriate techniques in order to prevent any kind of shoulder injury. Throwing ability is the significant skill for the success in handball and it includes the lower and upper muscle for enhancing the efficiency of the arm (Wang, Macfarlane and Cochrane. 2000). The athletes endure several repetitive stresses of micro traumatic on shoulder because of high-level psychological demand on the surrounded tissues. It can be seen that most of the shoulder injury cases happen only because of muscle fatigue, muscle weakness, inappropriate throwing exercising equipments, excessive and imbalance capsule laxity (Jobe, 1998). However, there are also instances of the shoulder injuries because of glenoid labrum, rotator cuff muscle and gleno-humeral capsule. During the acceleration phase, the internal rotator muscles perform concentrically.

Shoulder Injury and Prevention

On the other hand, Wang and Cochrane (2001) mention that during the entire deceleration phase, the external rotator muscles perform eccentrically. The responsibility of this particular muscle is to maintain the dynamic stabilisation of glenohumeral joint. The assessment of the functional strength of these muscles can be compared with the internal rotator muscles, which play an important role for the injury rehabilitation and prevention. Lawrence et al. (2014) also mention that the glenohumeral joint is unstable in an inherent manner and it is solely based on the bony configurations, however, at the same situation, this joint comes with most freedom as it helps to perform various functions. The musculo-tendinous unit and the ligaments maintain the fundamental stability of the glenohumeral joint in proper manner (Codine, Bernard, Pocholle, Benaim, & Brun, 1997). The repetitive over arm activities and motions in the sports like handball activities needs to be synchronised and coordinated action of the shoulder muscle. In the sports, there are requirement of proper strength balance of antagonist muscle, which is fundamental. Drouin et al. (2004) highlight that the role and responsibilities of the rotator cuff muscles are functional and critical as it helps the human shoulder to stabilise. A close observation in the internal and external rotation process of the shoulder suggests enough strength, which is significant for the rehabilitation for the ultimate prevention of the shoulder injury. The shoulder injury of an active person or an athlete should be treated with well designed and non-operation program of rehabilitation (Wang et al. 2000). It is noteworthy to mention here that the rehabilitation programs consist of the flexibility exercise, strengthening exercise and then returning to the usual throwing exercise.

On the other hand, only the physical therapist or the clinicians can do the testing of the actual strength of the isokinetic myscle in order to monitor the possible external and internal contralateral rotator balance and deficiencies ratio in between the strength of internal rotator and external rotator shoulder muscle (Wilk, et al. 2002). The anatomy, structure and function of the shoulder must have to be understood by the throwing athletes and their conditioning coaches so that they can enhance their performance and the injuries relating with the shoulder can be avoided properly.  Thus, the prime objective of this study is to compare the rotator muscle balance in shoulder of throwers athletes and the people who never perform such activities like throwing.

Role of Rotator Cuff Muscles

In order to collect information, there will be 14 participants, who will participate in the research. Among them, there are 7 students, who does not participate in the sport including overhead throwing and 7 members from the non-professional handball team. There was a relative information paper, which was provided to the participants. I have provided 24 hours time to the participants in order to understand what should be done on the provided paper. I have also signed a consent form from them for taking their permission whether they desire to participate in the research. Moreover, a protocol is also provided to them so that they can understand the entire research requirement and the aim for which I am conducting the research. I also asked them if they have any query regarding their participation in the study and complete the provided paper. The handball team, who participated in the research, have 1 goalkeeper, 2 backs, 1 pivot, 2 wingers and 1 centre. The major approach that I have taken in selecting the respondent was to select participants, who are asymptomatic and free from pain.

All the participants were asked to warm up for 5 minutes at a comfortable workload by using arm-cyucle-ergometer and after that, the participants will be placed in Primus BTE for evaluating the eccentric and concentric strength measurement for the dominant upper limb. The subjects will be assumed the position of supine and there will be placement of standard stabilisation strapping across the hips and chest of the subjects. The shoulder of the participants abducted to 90° and even the elbow flexed to 90°, which is the position of the upper extremity according to the manufacturer specification. The actual strength of the external and internal rotators can be tested with 120° range of the motion. The subjects of this study will perform 3 submaximal trials for familiarising themselves with ranges of motion and accommodating the resistance of dynamometer. The subjects will be tested after that with maximum of the 5 repetitions of carrying out angular speeds of 300°/s and 60°/s for performing the concentric action and 300°/s for completing the eccentric action. The high reliability for isokinetic testing depends on these numbers of repetitions. All the sets of all the subjects are provided a 60-s rest period to prevent fatigue build-up. During the conduction of the research, consistent verbal commands will also be provided. The help of an expert, who is trained for isokinetic testing devices and experienced is considered for testing and evaluating the tests.

Testing Procedures

The shoulder is generally used in various sports; therefore, there are possibilities of more injury in the shoulder muscles and particularly overuse injuries. The competitive sports like baseball, volleyball, javelin throwing, swimming and tennis need repeated and forceful arm activities that produce a very high incidents of the shoulder injuries (Stratford and Balsor 1994). The ballistic actions in all of these mentioned sports involve large amounts of the eccentric pressures on the rotator cuff muscles and there are chances of shoulder injury. The rotator cuff tendinitis, impingement and instability are the significant overuse injuries of the shoulder (Wang and Cochrane 2001). The repetitive and constant practices of same movement can be determined as a major mechanism of the overuse injuries of the shoulder. Even the consequences can lead to the imbalance in between the antagonist and agonist muscles. During the excessive eccentric pressure, muscle imbalance contributes to the shoulder injury (Zanca, Oliveira, Saccol, Mattiello-Rosa. 2011). In order to analyse the muscle performance and strengths for the injured and healthy athletes, the isokinetic dynamometer can be used. Drouin, Valovich-mcLeod, Shultz, Gansneder and Perrin. (2004) have mentioned that the isokinetic dynamometer provides relevant measurement of the torque, velocity and the position on the repeated trials, which has been proved to be valid enough for the research and clinical purposes. In certain case, the isokinetic dynamometer is interlinked with the shoulder injuries.

Reference List

Drouin, J.M., Valovich-mcLeod, T.C., Shultz, S.J., Gansneder, B.M. and Perrin, D.H., 2004. Reliability and validity of the Biodex system 3 pro isokinetic dynamometer velocity, torque and position measurements. European journal of applied physiology, 91(1), pp.22-29.

Lawrence, R.L., Braman, J.P., Laprade, R.F. and Ludewig, P.M., 2014. Comparison of 3-dimensional shoulder complex kinematics in individuals with and without shoulder pain, part 1: sternoclavicular, acromioclavicular, and scapulothoracic joints. journal of orthopaedic & sports physical therapy, 44(9), pp.636-A8.

Rokito, A.S., Jobe, F.W., Pink, M.M., Perry, J. and Brault, J., 1998. Electromyographic analysis of shoulder function during the volleyball serve and spike. Journal of Shoulder and Elbow Surgery, 7(3), pp.256-263.

Stratford, P.W. and Balsor, B.E., 1994. A comparison of make and break tests using a hand-held dynamometer and the Kin-Com. Journal of Orthopaedic & Sports Physical Therapy, 19(1), pp.28-32.

Timmons, M.K., Lopes-Albers, A.D., Borgsmiller, L., Zirker, C., Ericksen, J. and Michener, L.A., 2013. Differences in scapular orientation, subacromial space and shoulder pain between the full can and empty can tests. Clinical Biomechanics, 28(4), pp.395-401.

Wang, H.K. and Cochrane, T., 2001. Mobility impairment, muscle imbalance, muscle weakness, scapular asymmetry and shoulder injury in elite volleyball athletes. Journal of Sports Medicine and Physical Fitness, 41(3), p.403.

Wang, H.K., Macfarlane, A. and Cochrane, T., 2000. Isokinetic performance and shoulder mobility in elite volleyball athletes from the United Kingdom. British Journal of Sports Medicine, 34(1), pp.39-43.

Zanca, G.G., Oliveira, A.B., Saccol, M.F., Ejnisman, B. and Mattiello-Rosa, S.M., 2011. Functional torque ratios and torque curve analysis of shoulder rotations in overhead athletes with and without impingement symptoms. Journal of sports sciences, 29(15), pp.1603-1611.