Shoulder Damage Research Articles

Locked Posterior Shoulder Dislocation with Accompanying Fracture: A Debilitating Rare Injury for Athletes?

Shoulder dislocation is undoubtedly one of the most common injuries in traumatology. Posterior dislocation of the shoulder is regarded as comparatively rare compared to anterior dislocation, whilst it is strikingly extraordinary for this type of injury to be accompanied by a concomitant fracture. Accurate diagnosis and appropriate treatment can be considerably demanding, while being vitally important in this exceedingly rare condition. These injuries are broadly considered to be under-reported in the existing literature, especially among high-demand athletes. We present a rare case of a high-demand athlete sustaining a traumatic locked posterior shoulder dislocation with an accompanying fracture treated in our Institution. A detailed clinical examination and plain radiography revealed the peculiar condition, and a CT scan was subsequently performed for more thorough evaluation of the injury. The patient underwent surgery on the day following admission for repair of the extensive shoulder damage, and a deltopectoral approach was utilized. Reduction of the metaphyseal fracture and the dislocation was accomplished with gentle manipulations, and stabilization was obtained with an anatomic plate. A modified McLaughlin procedure was carried out to address the reverse Hill-Sachs lesion. The postoperative period was uneventful, followed by a painstaking physical rehabilitation program, and the patient returned successfully to his sporting activities 6 months postoperatively. By presenting this thought-provoking case, we stress the challenging nature of these immensely infrequent injuries while also highlighting the requirement for more sensitive factor-specific studies regarding their optimal treatment.

Clinical and ultrasonographic evaluation of uninjured dominant shoulder in amateur rugby players vs a control group: a pilot study

BackgroundRugby is a sport involving a great number of shoulder collisions. Traumatic stress of the shoulder can weaken the static stabilizers and promote major injuries as dislocation or full-thickness tears of the rotator cuff. The goal of this study is to evaluate the clinical and ultrasonographic dominant shoulder factures in a group of amateur rugby players, with no history of shoulder injuries, and to compare them with those of a control group.Methods52 male subjects join in the study: 26 amateur rugby players and 26 subjects, which did not practice rugby or competitive sport. Clinical history was obtained from all subjects, followed by dominant shoulder physical and ultrasonographic exams.ResultsRugby players showed a higher prevalence of positive clinical test, suggesting subacromial impingement than control group (p = 0.01).Among rugby group, five players (19,2%) showed positive test for radiculopathy (p = 0,02), and ten players (73,1%) reported shoulder pain needing pain-reliever drugs at list one time in the last six months (p = 0.001). In rugby group, ultrasound exams showed 23,1% degenerative changes and 30,8% tendon calcifications in supraspinatus tendons (p < 0.05).ConclusionsUninjured dominant shoulder of rugby players shows higher prevalence of clinical and ultrasound changes compare to control. Some rugby players without history of cervical symptoms show positive clinical test of cervical radiculopathy. Clinical and ultrasonographic monitoring of the shoulder can play a role in prevention and knowledge of silent shoulder damage in these athletes.

A Study on Processing Defects and Parameter Optimization in Abrasive Suspension Jet Cutting of Carbon-Fiber-Reinforced Plastics.

Abrasive suspension jet (ASJ), an accurate cold-cutting technology, can address traditional processing issues relating to carbon-fiber-reinforced plastics (CFRPs) like tool wear, interlayer delamination, large heat-affected zone, and low surface roughness. This study employed the use of an ASJ to cut CFRPs and an ultra-depth optical microscope to scan the cut surface to analyze interlayer delamination, surface roughness, kerf taper, and shoulder damage. Regression analysis was conducted to establish a prediction model for cutting quality based on surface roughness, kerf taper, and shoulder damage. Various types of CFRP cutting quality were analyzed using jet parameters. It was found that the use of ASJ to process CFRP results in the following defects: The range of surface roughness variation is from 0.112 μm to 0.144 μm. Surface roughness is most influenced by stand-off distance, followed by traverse speed and jet pressure. The range of kerf taper variation is from 4.737° to 10.1°. Kerf taper is most influenced by stand-off distance, followed by jet pressure and traverse speed. The range of shoulder damage variation is from 3.384 μm2 to 10 μm2. Shoulder damage is most influenced by jet pressure, followed by traverse speed and stand-off distance. A prediction model for cutting quality was developed based on surface roughness, kerf taper, and shoulder damage, providing data support for ASJ cutting of CFRPs. The optimal parameter combination is a stand-off distance of 1 mm, a jet pressure of 30 MPa, and a traverse speed of 30 mm/min.

Design and Implementation of Hybrid Exoskeleton for Oil Palm Harvester to Reduce Muscle Strain

When it comes to safety at the workplace, palm oil harvesters are highly exposed to body pain and muscular fatigue, which in the long term may lead to permanent spinal or shoulder damage that will undoubtedly result in different extreme societal difficulties. Meager investment in safety and long hours of manual work in awkward posture is the main challenge in ensuring safety in the palm oil field. This study aimed to develop a novel light hybrid exoskeleton exclusively built for palm oil harvesting to reduce muscular strain, maintain minimum cost, and ensure material availability in the local market. The iso-elasticity approach and DC linear motor were used for gravitational and muscular torque compensation and position control. Muscular EMG signal was taken and filtered to investigate the muscle strain reduction after implementing the developed hybrid exoskeleton. The result shows that the overall muscle strain was reduced by 16% using the passive exoskeleton and 23% using the hybrid exoskeleton compared to freehand. According to the results, it is evident that the developed exoskeleton can be implemented in palm oil harvesting, which will reduce the pain level of the workers at a significant rate.

Applicability and Cost Implication of Labor-Based Methods for Sustainable Road Maintenance (SRM) in Developing Countries

Regular maintenance keeps roads in a good working condition for users. Road maintenance can be conducted using labor and machine based methods. In this study, applicability and costs of labor-based, namely employment intensive (EI), labor intensive (LI), and labor-based equipment-supported (LBES) road maintenance methods were investigated with a case study in Tigray region, northern Ethiopia. The objectives of this study were therefore to (a) identify road defects and outline the corresponding labor-based maintenance methods, (b) compare relative costs of the three labor-based road maintenance methods, and (c) explore indicators of sustainable road maintenance (SRM) practices for developing countries. The results of this study showed that the labor-based methods are suitable for maintaining a wide range of road defects such as pavement cracks, bleeding, potholes, and rutting. Results of the cost analysis revealed that the LI and EI were 6% and 36% cheaper than the LBES method for repairing shoulder damage in asphalt roads. Roadside bush clearing using LBES resulted in 40% and 147% cost saving compared to EI and LI methods, respectively. Average share of labor cost compared to combined cost of labor and equipment in EI, LI, and LBES was 97%, 79%, and 37%, respectively. Unit rates of maintenance activities for different labor-based methods were also developed for Tigray region. The developed road maintenance unit rates will be useful for estimating cost of labor-based methods in Tigray and other similar regions in Ethiopia. In this study, 45 suitability indicators under 10 categories and three themes (social, economic, and environmental) were developed to improve future road maintenance practices in developing countries. Finally, it is recommended to use SRM practices to increase sustainability of road infrastructure in developing countries.

Some aspects of physical therapy for shoulder injuries

The article is devoted to the problem of finding effective and sufficient measures of physical therapy in restoring the functioning of patients with shoulder lesions. Chronic conditions associated with shoulder damage leads to a impairment in the quality of life of a patient, which can negatively affect its social realization and the work it performs.&#x0D; Pain in the shoulder region can occur due to pathologies of the musculoskeletal system, including impingement syndrome, tendonitis, partial and complete rupture of the rotator cuff of the shoulder, as well as adhesive capsulitis, shoulder bursitis, shoulder instability and shoulder arthritis. These lesions are manifested not only by severe pain, but also by decreased functioning, limited movement in the joint, decreased strength. The purpose of the study is to investigate the effectiveness of integrated use of modern measures of physical therapy for shoulder injuries. Theoretical and empirical research methods were used: analysis, generalization, comparison and ranking of the obtained information, observation, experiment, statistical methods.&#x0D; The study was conducted among a group of people with a chronic condition of the shoulder. It took place on the basis of a yoga studio in Dnipro. Eleven participants (5 women and 6 men) were selected and underwent physical therapy classes twice a week for 8 weeks. Among the means of physical therapy were used joint mobilizations according to the concept of Mulligan, means of the PNF method, classical and modified yoga exercises.&#x0D; The proposed program of physical therapy of shoulder lesions in patients with low and medium pain and limited range of motion in the joint showed high efficiency, almost all indicators were reliable.

Shoulder Damage Model and Its Application for Single Point Diamond Machining of ZnSe Crystal.

The damaging of ZnSe crystal has a significant impact on its service performance and life. Based on the specific cutting energies for brittle and ductile mode machining, a model is proposed to evaluate the damage depth in the shoulder region of ZnSe crystal during single point diamond machining. The model considers the brittle-ductile transition and spring back of ZnSe crystal. To verify the model, the elastic modulus, hardness, spring back, and friction coefficient of ZnSe crystal are measured by nanoindentation and nanoscratch tests, and its critical undeformed chip thickness is obtained by spiral scratching. Meanwhile, orthogonal cutting experiments are conducted to obtain the different shoulder regions and cutting surfaces. The shoulder damage depth is analyzed, indicating that the effect of the feed on the damage depth at a high cutting depth is stronger than that at a low one. The model is verified to be effective with an average relative error of less than 7%. Then, the model is used to calculate the critical processing parameters and achieve a smooth ZnSe surface with a roughness Sa = 1.0 nm. The model is also extended to efficiently predict the bound of the subsurface damage depth of a cutting surface. The research would be useful for the evaluation of surface and subsurface damages during the ultra-precision machining of ZnSe crystal.

Neuroplasticity Caused by Peripheral Proprioceptive Deficits.

Proprioceptive feedback is crucial for motor control and stabilization of the shoulder joint in everyday life and sports. Shoulder dislocation causes anatomical and proprioceptive feedback damage that contributes to subsequent dislocations. Previous recurrent anterior shoulder instability (RSI) studies did not investigate functional neuroplasticity related to proprioception of the injured shoulder. Thus, we aimed to study the differences in neuroplasticity related to motor control between patients with RSI and healthy individuals, using functional magnetic resonance imaging, and assess the effects of peripheral proprioceptive deficits due to RSI on CNS activity. Using passive shoulder motion and voluntary shoulder muscles contraction tasks, we compared the CNS correlates of proprioceptive activity between patients having RSI (n = 13) and healthy controls (n = 12) to clarify RSI pathophysiology and the effects of RSI-related peripheral proprioceptive deficits on CNS activity. Decreased proprioception-related brain activity indicated a deficient passive proprioception in patients with RSI (P < 0.05 family-wise error, cluster level). Proprioceptive afferent-related right cerebellar activity significantly negatively correlated with the extent of shoulder damage (P = 0.001, r = -0.79). Functional magnetic resonance imaging demonstrated abnormal motor control in the CNS during voluntary shoulder muscles contraction. Our integrated analysis of peripheral anatomical information and brain activity during motion tasks can be used to investigate other orthopedic diseases.

Kinect-based integrated physiotherapy mentor application for shoulder damage

With the increasing rate of disabled people in the world, the number of people in need of physiotherapy is increasing. Most of the disabled persons with shoulder damaged should do physiotherapy exercises. The telerehabilitation systems using developed technologies have advantages over conventional physiotherapy methods. Such systems have the potential to improve communication between patients and physiotherapists. They also allow for easier information and medical data sharing. In this study, a telerehabilitation system based on Kinect Sensor (Kinect 2) was developed to observe and evaluate shoulder damaged patient exercises by using the Kinect skeletal monitoring feature. The proposed system consists of two basic components: the web application that enables the communication between patients and physiotherapists, allows the physiotherapist to observe/update patient exercise data, patients information, and the console application which enables the patients to perform their exercises correctly. This console app was developed for patients with shoulder damage. Abduction, flexion, internal rotation, external rotation, extension exercises can be performed correctly thanks to the developed application. The proposed system was evaluated in Bilecik State Hospital for 29 shoulder damaged volunteers. 14 of the volunteers were treated with the conventional methods and 15 of them were treated with the proposed system. The recovery of the volunteers was analyzed for each intragroup and intergroup comparison was made. Statistically, significant decreases were observed in the limitations of the patients treated with the proposed system. For abduction, flexion, internal rotation, and external rotation exercises, the Kinect-based physiotherapy mentor application was more successful than conventional method, while all volunteers treated by the proposed method had no limitations in extension exercise. As a result, the Kinect-based physiotherapy mentor application can be used as an alternative telerehabilitation method for patients with shoulder damaged.

Discriminating the precision of inertial sensors between healthy and damaged shoulders during scaption movement: A cross-sectional study

BackgroundShoulder assessment in rehabilitation is focused on kinematic properties due to the variability of symptomatology and clinical expression of shoulder injuries. AimTo perform a receiver operating characteristic analysis of the kinematic variables involved in the functional mobility of the shoulder that allow the identification of discriminating variables between healthy and diseased shoulders during scaption motion. MethodAnalytical cross-sectional study of diagnostic effectiveness was performed in 27 subjects suffering from shoulder damage and 14 asymptomatic controls. Scaption kinematics were evaluated using four inertial sensors placed on the humerus, scapula, forearm and sternum. Three variables (mobility, velocity and acceleration) were obtained from each sensor and the norm of the resultant vector was calculated from each axis. A discriminatory receiver operating characteristic analysis was performed, obtaining the area under the curve, sensitivity and specificity. FindingsSignificant differences from both the resultant vectors and the axis depended on the body segment analysed were observed. Greater movement velocity and acceleration were observed in the asymptomatic group. Receiver operating characteristic analysis, scapular protraction-retraction mobility distinguished with a diagnostic sensitivity of 83.3% and specificity of 90.9% between asymptomatic and shoulder-damaged patients. These diagnosis values were 83.3% and 72.7% for scapular anterior-posterior velocity. Scapular kinematics, in terms of mobility and velocity, are the key variables in shoulder assessment. InterpretationThis study discriminated between patients suffering from shoulder damage and asymptomatic subjects based on shoulder kinematics during scaption motion. Scapular mobility and velocity were found to be key variables in shoulder assessment, along with the humerus.

My new normal: A patient's perspective on polymyalgia rheumatica

My new normal: A patient's perspective on polymyalgia rheumatica

Between Two Rocks and in a Hard Place: Reflecting on the Biomechanical Basis of Shoulder Occupational Musculoskeletal Disorders.

The aim was to review the biomechanical origins of occupational shoulder damage, while considering the complexity of shoulder mechanics and musculoskeletal consequences of diverse task demands. Accessible measures of physical exposures are the primary focus of occupational shoulder assessments and analyses. This approach has led to guidelines and intervention strategies that are often inadequate for mitigating shoulder disorders amongst the complexity of modern workplace demands. Integration of complex shoulder mechanics into occupational assessments, analyses, and interventions is critical for reducing occupational shoulder injury risk. This narrative review describes shoulder biomechanics in the context of common injury mechanisms and consequent injuries, with a particular focus on subacromial impingement syndrome. Several modulators of shoulder injury risk are reviewed, including fatigue, overhead work, office ergonomics considerations, and pushing and pulling task configurations. Relationships between work requirements, muscular demands, fatigue, and biomechanical tissue loads exist. This review highlights that consideration of specific workplace factors should be integrated with our knowledge of the intricate arrangement and interpersonal variability of the shoulder complex to proactively evaluate occupational shoulder demands and exposures. A standard method for evaluating shoulder muscle exposures during workplace tasks does not exist. An integrated approach is critical for improved work design and prevention of shoulder tissue damage and accompanying disability. This review is particularly relevant for researchers and practitioners, providing guidance for work design and evaluation for shoulder injury prevention by understanding the importance of the unique and complex mechanics of the shoulder.

Schulterverletzungen im Lateinamerikanischen Formationstanz

BackgroundCharacteristic for Latin American formation dance are turning-,catapulting- and pulling movements affecting the shoulder-arm-region. The aim of thisstudy is to analyse shoulder injuries in Latin American formation dancers. Material and methodsA total of n=81 dancers (m: n= 43; w: n= 38) volunteered for thisretrospective cross-sectional cohort study using questionnaires. Results22.8% (m: 21.9%, f: 23.7%, p= 0.310) of dancers suffered from shoulderinjuries at least once during a 12-month period. Gender-specific non-significant differences regarding the affected side (f: right 80%, left 13.3%; m: right: 38.5%, left 46.2%, p=0.429) were observed. Most of the shoulder injuries occurred during the technically maximum difficulties (m: 76.9%; f: 73.3%, p= 0.675) characteristic for Latin American formation dance. 31.6% of the female dancers (m: 29.3% vs. f: 34.2%, p=0.884) reported to suffer from chronic shoulder damage (right>left: m: 41.7% vs. f:38.5%, p= 0.137). ConclusionThe results reveal the need to consider an additive coordination-, strength- and stabilization training for the shoulder girdle. However, further studies with a higher number of cases are necessary in order to identify risk factors for shoulder problems and to finally clarify the existing gender-specific aspects.

Humeral lengthening using a retrograde motorized intramedullary lengthening nail

An elite-level 13-year-old female overhead athlete, with a previous history of bone cyst and fracture at age 8, presented with a humeral length discrepancy of 75 mm which had increased to 81 mm within 1 year. Antegrade correction with a motorized lengthening nail was considered but declined due to risk of shoulder damage and pain. In an off-label manner, a femoral motorized lengthening nail was modified and utilized with retrograde placement. Lengthening instructions were modified weekly to account for rapid humeral growth, to minimize soft-tissue tension, and to maximize regenerate quality. By 11 weeks, humeral length was clinically corrected. Three weeks after ceasing lengthening, full range of motion of the shoulder and elbow returned. Once the site had formed new cortex on all four sides, the nail was removed, and return to full activity occurred 4 months later.

Acute Versus Delayed MRI Imaging and Associated Pathology in Traumatic Shoulder Dislocations

Objectives:Delayed management of patients with shoulder instability may increase the prevalence and severity of concomitant intra-articular shoulder injuries resulting from persistent instability. We hypothesize that patients with a longer delay from an initial dislocation event to MRI demonstrate a greater degree of intra-articular shoulder damage.Methods:We performed a retrospective review of 89 patients from a single institution with clinically and radiographically confirmed traumatic, anterior, primary shoulder dislocations. Patients were divided into two groups: those undergoing MRI less than (N=44; LT6) or greater than (N=45; GT6) 6 months from the initial dislocation event. MRI assessment included evaluation of the severity of cartilage damage and bone loss, in addition to the presence of soft-tissue injuries to the labrum, capsule and rotator cuff. Subsequent treatment including type and method of surgical intervention, as well as recurrent postoperative instability, were evaluated.Results:The delayed MRI group demonstrated a greater degree of pathology compared to the early imaging group. A higher percentage of SLAP tears (58% vs. 34%), posterior labral tears (22% vs. 7%) and cartilage damage (73% vs. 27%) were present in the GT6 versus LT6 group. There was no difference in anterior glenoid bone loss. For those patients who underwent surgical stabilization for symptomatic instability, there was a statistically significant difference in recurrence of instability between the early MRI group (0/21) than that of the delayed MRI group (6/33 or 18%).Conclusion:Patients who undergo MRI greater than 6 months from the time of primary shoulder dislocation demonstrate a greater incidence and severity of intra-articular pathology including SLAP tears, posterior labral tears and anterior glenoid cartilage damage. Recurrent instability is significantly higher after shoulder stabilization surgery when performed more than 6 months from the primary dislocation event.

Age-related changes analyzing shoulder kinematics by means of inertial sensors

BackgroundShoulder kinematics alteration has been previously proven in subjects suffering from shoulder damage, which is also related to shoulder degenerative changes as consequence of aging. Because of that, it would be interesting to investigate age-related kinematics. The main objective was to analyze age-related differences in shoulder kinematics by means of inertial sensors in asymptomatic subjects during shoulder abduction and flexion. MethodsTwenty-five right arms were measured (11 from the young adult group and 14 from the older adult group). In the young group, age ranged between 20 and 34years old, while in the older group age ranged between 45 and 72years old. Angular mobility and linear acceleration from the scapula, humerus and sternum as well as mobility in the glenohumeral and scapulothoracic joints were calculated by three inertial sensors. Subjects performed shoulder abduction and flexion. FindingsSignificant differences in mobility were found in humerus and scapula in mobility and acceleration during both tasks. Those differences varied depending on the plane analyzed. A moderate negative correlation between age and humerus and scapula ranged from −0.624** to −0.409*. A positive correlation was found in some planes. InterpretationThe results from the present study suggest that humerus elevation and scapular protraction-retraction as well as medio-lateral rotation are more likely to present kinematics age-related differences, i.e. older: age is associated with less mobility and acceleration in some planes and axes. Results provide inertial tridimensional measures from shoulder complex comparing groups of different age. Findings also concur with previous research supporting age-related shoulder changes.

The effects of a rotator cuff tear on activities of daily living in older adults: A kinematic analysis

Rotator cuff tears (RCT) in older individuals may compound age-associated physiological changes and impact their ability to perform daily functional tasks. Our objective was to quantify thoracohumeral kinematics for functional tasks in 18 older adults (mean age=63.3±2.2), and compare findings from nine with a RCT to nine matched controls. Motion capture was used to record kinematics for 7 tasks (axilla wash, forward reach, functional pull, hair comb, perineal care, upward reach to 90°, upward reach to 105°) spanning the upper limb workspace. Maximum and minimum joint angles and motion excursion for the three thoracohumeral degrees of freedom (elevation plane, elevation, axial rotation) were identified for each task and compared between groups. The RCT group used greater minimum elevation angles for axilla wash and functional pull (p≤0.0124) and a smaller motion excursion for functional pull (p=0.0032) compared to the control group. The RCT group also used a more internally rotated maximum axial rotation angle than controls for functional reach, functional pull, hair comb, and upward reach to 105° (p≤0.0494). The most differences between groups were observed for axial rotation, with the RCT group using greater internal rotation to complete functional tasks, and significant differences between groups were identified for all three thoracohumeral degrees of freedom for functional pull. We conclude that older adults with RCT used more internal rotation to perform functional tasks than controls. The kinematic differences identified in this study may have consequences for progression of shoulder damage and further functional impairment in older adults with RCT.

어깨 손상에 따른 골프 드라이버 스윙의 근활성도 분석

Objective : The purpose of this study was to describe the correlation between the activity of the muscles of upper and lower limbs of a golf driver swing according to shoulder injury. Method : The subjects were 18 professional golfers (7 male in KPGA and 11 female in KLPGA). Using surface electromyography, we evaluated muscle activities during the golf drive swing. Surface electrodes were used to record the level of muscle activity in the left Deltoid(MD), Triceps Brachii(TB), Pectoralis(PM), Trapezius(UT), Rectus Femoris(RF), Vastus Medialis Obilique(VMO), Biceps Femoris(BF), Gastrocnemius(GCM) muscles during the golfer's swing. The golf swing was divided into five phases: take away, forward swing, acceleration, early follow through, late follow through. Results : The results can be summarized as follows: MD, VMO had statistically significant difference in take away phases, GCM had statistically significant difference in acceleration phases, MD, PM, VMO had statistically significant difference in early follow through phases, PM had statistically significant difference in late follow through phases, Conclusion : Muscle activity of the 8 muscles(Deltoid, Triceps Brachii, Pectoralis, Trapezius, Rectus Femoris, Vastus Medialis Obilique, Biceps Femoris, Gastrocnemius) along the shoulder damage or absence of has shown that they are organically connected to each of the phases.

The effect of mechanical dehuskers on the quality of macadamia kernels when dehusking macadamia fruit at differing harvest moisture contents

Dehusking to remove the fibrous husk of the macadamia fruit following abscission is an essential first step in postharvest handling of macadamia nuts. Commercial dehusking uses machines, causing trauma for nuts. Mechanical dehusking of macadamia fruit at “field” (mean harvest) moisture content causes shoulder damage but the effect on kernel quality of dehusking fruit that has dried while on the ground between harvest rounds to “low harvest” moisture content is not known. We dehusked macadamia fruit by hand and with two mechanical dehuskers at field moisture content (23%) and at low harvest moisture content (10–12%) after ambient drying for three weeks. After-roast-darkening (dark, reject kernels), shoulder damage and weight of pieces increased while whole kernel was reduced when dehusking at low harvest moisture content compared with dehusking at field moisture content. There were only minor differences between mechanical dehuskers for kernel damage and no difference between dehuskers for dark roasted kernel. Kernel quality of macadamia is more affected by slow, ambient drying than the type of dehusker used. Improving harvest management by reducing time between harvest rounds is more important to macadamia kernel quality than the type of dehusker used.

SHOULDER INJURY PREVENTION IN VOLLEYBALL: PERFORMANCE AND KINEMATICS ANALYSIS OF ALTERNATIVE SPIKE TECHNIQUES

BackgroundRepetitive stresses during spike movements in volleyball, make the shoulder one of the most commonly exposed body parts, bringing athletes to prematurely interrupt their career.ObjectiveDifferent spike techniques are supposed to...