History Of Shoulder Injury Research Articles

Residual Impact of Previous Injury on Musculoskeletal Characteristics in Special Forces Operators.

BackgroundMusculoskeletal injuries are a significant burden to United States Army Special Operations Forces. The advanced tactical skill level and physical training required of Army Special Operators highlights the need to optimize musculoskeletal characteristics to reduce the likelihood of suffering a recurrent injury.PurposeTo identify the residual impact of previous injury on musculoskeletal characteristics.Study DesignCross-sectional study; Level of evidence, 3.MethodsIsokinetic strength of the knee, shoulder, and back and flexibility of the shoulder and hamstrings were assessed as part of a comprehensive human performance protocol, and self-reported musculoskeletal injury history was obtained. Subjects were stratified based on previous history of low back, knee, or shoulder injury, and within-group and between-group comparisons were made for musculoskeletal variables.ResultsKnee injury analysis showed no significant strength or flexibility differences. Shoulder injury analysis found internal rotation strength of the healthy subjects (H) was significantly higher compared with injured (I) and uninjured (U) limbs of the injured group (H, 60.8 ± 11.5 percent body weight [%BW]; I, 54.5 ± 10.5 %BW; U, 55.5 ± 11.3 %BW) (P = .014 [H vs I] and P = .05 [H vs U]). The external rotation/internal rotation strength ratio was significantly lower in the healthy subjects compared with injured and uninjured limbs of the injured group (H, 0.653 ± 0.122; I, 0.724 ± 0.121; U, 0.724 ± 0.124) (P = .026 [H vs I] and P = .018 [H vs U]). Posterior shoulder tightness was significantly different between the injured and uninjured limb of the injured group (I, 111.6° ± 9.4°; U, 114.4° ± 9.3°; P = .008). The back injury analysis found no significant strength differences between the healthy and injured groups.ConclusionFew physical differences existed between operators with prior knee or back injury. However, operators with a previous history of shoulder injury demonstrated significantly less shoulder strength than uninjured operators as well as decreased shoulder flexibility on the injured side. All operators, regardless of prior injury, must perform the same tasks; therefore, a targeted injury rehabilitation/human performance training specifically focused on internal rotation strength and tightness of the posterior capsule may help reduce the risk for recurrence of injury. Operators presenting with musculoskeletal asymmetries and/or insufficient strength ratios may be predisposed to musculoskeletal injury.Clinical RelevanceSpecific fitness programs to compensate for deficiencies in strength and flexibility need to be designed that may reduce the risk of injuries in Special Forces Operators.

Shoulder Injury - Bicycling

HISTORY: A 44-year-old left-hand dominant male triathlete sustained a right shoulder injury in a biking accident. He was riding his bike down the road when a car door opened, and he hit the door causing his bike to flip over. He immediately had right shoulder pain and could not move his arm. He had no previous history of shoulder injury or pain. He was within blocks of his orthopedist so he went to the office where radiographs were taken. He was told they were normal and to do ROM exercises. After 2 weeks he was still symptomatic so an MRI was obtained. He presented to our clinic 3 weeks after the injury. He was very active and wanted to return to triathlons. PHYSICAL EXAMINATION: He was in no distress. He had no swelling and vascular examination was normal. He had extremely limited range of shoulder motion with no external rotation without pain. He was neurologically intact including motor and sensation to his right extremity. He had full range of motion of his fingers, wrist and elbow. DIFFERENTIAL DIAGNOSIS: Fracture of scapula Fracture of proximal humerus Dislocated shoulder TEST AND RESULTS: Plain anterior-posterior and axillary radiographs of the shoulder: chronic locked posterior dislocation of right shoulder MRI and CT of shoulder confirms diagnosis with no fractures FINAL WORKING DIAGNOSIS: Fixed sub-acute posterior dislocation of right shoulder. TREATMENT AND OUTCOMES: Four weeks after injury, obtained a closed reduction under anesthesia but stable only in abducted position. Consequently applied body spica cast with arm in abduction and slight external rotation. Arm in body spica cast for 5 weeks. Allowed passive and active range of motion of wrist, hand, and fingers, but not elbow or shoulder. Vicodin for pain. Arm portion of the cast bivalved at 2 weeks to allow for elbow range of motion. Cast removed at 5 weeks post-op. Radiographs before and after cast removal showed the humeral head to be in good position. Transitioned to external rotation brace and started gentle ROM of shoulder. Radiographs at 2 months showed the humeral head was concentric in the glenoid. External rotation brace discontinued. At 3 months post-op, started physical therapy and returned to indoor biking, running, and swimming with the exception of overhead strokes. Returned to triathlon events at 13 months post-op.

Strength Asymmetry of the Shoulders in Elite Volleyball Players

Volleyball players are reported to have shoulder strength imbalances. Previous authors have primarily investigated small samples of male players at a single skill level, without considering playing position, and with inconsistent findings. To evaluate shoulder strength asymmetry and a history of shoulder injury in a large sample of professional volleyball players of both sexes across different playing positions and skill levels. Descriptive laboratory study. A sample of 183 volleyball players (99 men, 84 women). We assessed shoulder internal-rotator and external-rotator concentric strength at 60°/s using an isokinetic dynamometer and dominant-nondominant differences in shoulder strength and strength ratios using repeated-measures analyses of variance. Peak torque was normalized for body mass and external-rotation/internal-rotation concentric strength. Internal-rotation strength was asymmetric in favor of the dominant side in both sexes, regardless of previous shoulder injury status. Male volleyball players had a lower shoulder strength ratio on the dominant side, regardless of previous shoulder injury status. However, this finding was valid only when hand dominance was taken into account. Female volleyball players playing at a higher level (ie, first versus second division) were 3.43 times more likely to have an abnormal strength ratio. Playing position was not associated with an abnormal shoulder strength ratio or strength asymmetry. In male volleyball players, the external-rotation/internal-rotation strength ratio of the dominant shoulder was lower, regardless of playing position, skill level, or a previous shoulder injury. In female players, the ratio was less only in those at a higher skill level. Although speculative, these findings generally suggest that female volleyball players could have a lower risk of developing shoulder-related problems than male volleyball players. Isokinetic shoulder testing may reveal important information about the possible risk factors for shoulder injuries, so we recommend including it in the functional screening of volleyball players.

Adaptive changes in the dominant shoulders of female professional overhead athletes

The aim of our study was to evaluate adaptive changes in the dominant shoulders of female professional overhead athletes, their mutual association, and relation between adaptive changes and shoulder injury. Thirty-six female professional volleyball and handball players were divided into two groups: 14 athletes were included in the symptomatic group (positive shoulder injury history and specific shoulder tests) and 22 athletes were included in the asymptomatic group (negative shoulder injury history and specific shoulder tests). Clinical examinations with specific shoulder tests, evaluation of rotational mobility, and symptoms of malposition and dyskinesis of the dominant scapula (SICK scapula syndrome) were performed. Glenohumeral rotators were isokinetically tested at 60 and 150°/s, with evaluation of stability ratios and rotator fatigability. On average, the participants had decreased internal rotation (P<0.001) and increased external rotation (P<0.001), lower spiking (P<0.01 at 60 and 150°/s) and conventional ratios (P≤0.01 at 60 and 150°/s), lower eccentric external rotator peak torques (eER) (P≤0.05 at 60 and 150°/s), and marginally lower eccentric internal rotator peak torques at 60°/s (P=0.061) on the dominant side compared with the nondominant side. The symptomatic group showed decreased ER (P=0.021), higher deficit of dominant eER at 60°/s (P=0.049), and higher fatigability of internal (P=0.013) and external rotators (P=0.028). The athletes with increased ER had more scapular lateralization (ρ=0.340, P=0.042), higher spiking ratios at 60°/s (ρ=0.349, P=0.037) and 150°/s (ρ=0.330, P=0.049), and lower cocking ratios at 60°/s (ρ=-0.477, P=0.003). Decreased dominant ER, higher deficit of dominant eccentric ER peak torques, and higher dominant rotator fatigability correlate with previous shoulder pain/injury. Different adaptive changes (rotational mobility, SICK scapula signs, and glenohumeral muscular imbalance) are inter-related. As a form of both prevention and rehabilitation for the athletes at risk, we recommend individually adjusted shoulder training on the basis of clinical and isokinetic testing.

Shoulder Kinematics Is Not Influenced by External Load During Elevation in the Scapular Plane

The current study aimed to compare the shoulder kinematics (3D scapular orientation, scapular angular displacement and scapulohumeral rhythm) of asymptomatic participants under unloaded and loaded conditions during unilateral shoulder elevation in the scapular plane. We used a repeated-measures design with a convenience sample. Eleven male participants with an age range of 21-28 years with no recent history of shoulder injury participated in the study. The participants performed isometric shoulder elevation from a neutral position to approximately 150 degrees of elevation in the scapular plane in intervals of approximately 30 degrees during unloaded and loaded conditions. Shoulder kinematic data were obtained with videogrammetry. During shoulder elevation, the scapula rotated upwardly and externally, and tilted posteriorly. The addition of an external load did not affect 3D scapular orientation, scapular angular displacement, or scapulohumeral rhythm throughout shoulder elevation (P > .05). In clinical practice, clinicians should expect to observe upward and external rotation and posterior tilt of the scapula during their assessments of shoulder elevation. Such behavior was not influenced by an external load normalized to 5% of body weight when performed in an asymptomatic population.

Reproducibility of shoulder short range of motion in isokinetic and isometric strength testing

Strength testing of the shoulder external and internal rotators is an important part of the evaluation and follow-up of a patient with a shoulder injury. Several studies have tested the reproducibility of such testing basing their conclusions mainly on intraclass correlation coefficient (ICC) values. The main goal of our research was to assess fully the reproducibility of isokinetic and isometric strength testing using both absolute (ICC) and relative reproducibility indices. A sample of 21 healthy recreational athletes without any history of shoulder injury was tested twice within a 1-week period using the TechnoGym REV900 isokinetic dynamometer. Testing was performed in a short range of motion (30°) at the angular velocities 30°/second and 60°/second in the concentric and isometric (at an angle of 30°) modes of contraction for both muscle groups. External rotators were tested in the eccentric mode of contraction at both testing velocities. Reproducibility analysis included ICC, repeated measures analysis of variance (ANOVA), standard error of measurement (SEM), smallest real difference (SRD), and Bland and Altman analysis. Mean ICC ranged from 0.80 to 0.94; repeated measures ANOVA did not show any difference between the two test sessions (p > 0.05). In general, SEM% ranged from 6.0% to 9.9% and SRD% from 17% to 28%. Based on our findings, we conclude that the strength testing protocol used in our study showed an excellent reproducibility and can be safely used in clinical settings to monitor the strength changes in a group of individuals or in a single individual.

Isometric Shoulder Strength Reference Values for Physically Active Collegiate Males and Females

Background:It is common clinical practice to assess muscle strength during examination of patients following shoulder injury or surgery. Strength comparisons are often made between the patient’s injured and uninjured shoulders, with the uninjured side used as a reference without regard to upper extremity dominance. Despite the importance of strength measurements, little is known about expected normal baselines of the uninjured shoulder. The purpose of this study was to report normative values for isometric shoulder strength for physically active college-age men and women without history of shoulder injury.Methods:University students—546 males (18.8 ± 1.0 years, 75.3 ± 12.2 kg) and 73 females (18.7 ± 0.9 years, 62.6 ± 7.0 kg)—underwent thorough shoulder evaluations by an orthopaedic surgeon and completed bilateral isometric strength measurements with a handheld dynamometer. Variables measured included internal rotation, external rotation, abduction, supine internal rotation and external rotation at 45°, and lower trapezius in prone flexion.Results:Significant differences were found between the dominant and nondominant shoulder for internal rotation, internal rotation at 45°, abduction, and prone flexion in males and in internal rotation at 45° and prone flexion for females (P ≤ 0.01).

Comparison of Upper Arm Kinematics During a Volleyball Spike Between Players With and Without a History of Shoulder Injury

Volleyball players are at high risk of overuse shoulder injuries, with spike biomechanics a perceived risk factor. This study compared spike kinematics between elite male volleyball players with and without a history of shoulder injuries. Height, mass, maximum jump height, passive shoulder rotation range of motion (ROM), and active trunk ROM were collected on elite players with (13) and without (11) shoulder injury history and were compared using independent samples t tests (P < .05). The average of spike kinematics at impact and range 0.1 s before and after impact during down-the-line and cross-court spike types were compared using linear mixed models in SPSS (P < .01). No differences were detected between the injured and uninjured groups. Thoracic rotation and shoulder abduction at impact and range of shoulder rotation velocity differed between spike types. The ability to tolerate the differing demands of the spike types could be used as return-to-play criteria for injured athletes.

A Comparison of Glenoid Morphology and Glenohumeral Range of Motion Between Professional Baseball Pitchers With and Without a History of SLAP Repair

We sought to examine the relation among glenoid morphology, glenohumeral range of motion (ROM), and history of shoulder injury in professional baseball pitchers. We studied 58 professional baseball pitchers. Internal rotation (IR) and external rotation (ER) ROM was measured at 90° of abduction. Horizontal adduction (HAdd) ROM was also measured. Glenoid superior inclination and glenoid retroversion (GRV) were then measured radiographically. Separate mixed-model analyses of variance were used to compare dependent measures between the dominant and nondominant shoulders of pitchers with or without a history of SLAP repair. Significant interaction effects were interpreted by use of a test for simple main effects (α = .05). GRV was significantly greater on the dominant side (8.7° ± 5.6°) versus nondominant side (5.5° ± 5.2°) (P = .001), whereas glenoid superior inclination was equivalent (99.5° ± 4.3° for dominant side v 99.2° ± 4.4° for nondominant side, P = .853). Post hoc analysis indicated that pitchers with a history of SLAP repair did not display an adaptive increase in dominant GRV compared with nondominant GRV (P = .016). There were no statistical differences between groups for ER (P = .29), IR (P = .39), or HAdd (P = .39). The dominant shoulder displayed greater ER (mean increase, 6.2° ± 12.2°) with a complementary decrease in IR (mean decrease, 5.8° ± 13.2°) and HAdd (mean decrease, 8.9° ± 13.7°) compared with the nondominant side. Our findings suggest that the development of increased GRV in the dominant shoulder of professional baseball pitchers may be a protective adaptive change not reflected in glenohumeral ROM measures. Level IV, therapeutic case series.

Anterior Shoulder Instability Associated with Coracoid Nonunion in Patients with a Seizure Disorder

An association between coracoid fracture and glenohumeral instability with both a seizure disorder and the subsequent development of coracoid nonunion has not previously been recognized. This is clinically important as patients with a seizure disorder and glenohumeral instability frequently require a primary osseous reconstructive procedure, such as coracoid osteotomy and transfer to the anterior glenoid rim (the Bristow-Latarjet procedure), to address glenoid osseous deficiency. We report on coracoid fracture nonunion in five patients with a seizure disorder and anterior glenohumeral instability and discuss the implications for surgical treatment. Coracoid fracture was specifically sought on three-dimensional reconstructions of computed tomography scans in a consecutive series of 234 patients presenting to our unit with recurrent anterior instability. In addition to demographic data, we specifically sought information on any history of shoulder injury, the mechanism of injury, or previous seizure activity in these patients. In patients with a coracoid fracture or nonunion viewed to be at high risk of failure with a soft-tissue procedure, an open osseous reconstructive procedure was performed. The type of operative procedure was determined by the location of the nonunion. We identified six coracoid fracture nonunions in association with anterior glenohumeral instability in five patients (mean age, 26.8 years; range, twenty-four to thirty years). All patients had instability occurring in association with seizures. In the four shoulders with the anatomic location of the coracoid nonunion at its so-called elbow, a standard Bristow-Latarjet procedure was performed. In the two shoulders in which the nonunion was more distal, an Eden-Hybbinette procedure was performed. We recommend having a high index of suspicion of coracoid fracture when treating patients with a seizure disorder who have anterior glenohumeral instability. In these patients, preoperative computed tomographic images allow the diagnosis of a coracoid nonunion to be made prior to surgery and help to determine whether there is sufficient intact coracoid bone to allow a Bristow-Latarjet procedure to be performed.

Shoulder instability surgery in Norway

Background and purpose In January 2008, we established the Norwegian Register for Shoulder Instability Surgery. We report on the establishment, the baseline data, and the results at 1-year follow-up.Methods Primary and revision shoulder stabilization is reported by the surgeon on a 1-page paper form containing the patient's history of shoulder injury, clinical findings, and perioperative findings. The WOSI questionnaire for self-assessment of shoulder function is completed at baseline and at follow-up after 1, 2, and 5 years. To evaluate the completeness of registration, we compared our data with those in the Norwegian Patient Registry (NPR).Results The NPR reported 39 hospitals performing shoulder stabilizations. 20 of these started to report to our register during 2009, and 464 procedures (404 primary, 59 revisions) were included up to December 31, 2009, which represented 54% of the procedures reported to NPR. Of the 404 primary procedures, 83% were operations due to anterior instability, 10% were operations due to posterior instability, and 7% were operations due to multidirectional instability. Arthroscopic soft tissue techniques were used in 88% of the patients treated for primary anterior instability and open coracoid transfer was used in 10% of such patients. At 1-year follow-up of 213 patients, we found a statistically significantly improved WOSI score in all types of instability. 10% of the patients treated with arthroscopic anterior labral repair and 16% treated with arthroscopic posterior labral repair reported recurrent instability. No statistically significant difference in functional improvement or rate of recurrence was found between these groups.Interpretation The functional results are in accordance with those in previous studies. However, the incidence of recurrent instability 1 year after arthroscopic labral repair is higher than expected.

Three‐dimensional repositioning tasks show differences in joint position sense between active and passive shoulder motion

Proprioception is important in maintaining shoulder joint stability. Previous studies investigated the effects of unconstrained multiplanar motion, with subjects able to move freely in space, on repositioning tasks for active shoulder motion but not passive motion. We sought to further explore joint position sense with 3D passive, robot-guided motions. We hypothesized that target repositioning error would be greater in the case of passively placed targets than for actively placed targets. To investigate, 15 healthy individuals participated (8 female, 7 male), who were at most 6 ft (183 cm) tall to accommodate the equipment, and who had no history of shoulder injury, surgery, or significant participation in throwing sports. Target orientations were centered at 44° of elevation and 32° of horizontal rotation from the frontal plane. Two sets of 10 trials were performed. The first set involved active placement followed by active replacement, and the second set involved passive, robot-guided, placement followed by active replacement. Repositioning error was greater following passive placement than active placement (p < 0.001). These results further our understanding of the differences between active and passive joint position sense at the shoulder.

Electromyography activities for shoulder muscles over various movements on different torque changes

The aim of the present study was to investigate the patterns of shoulder muscle activation and joint torques during maximal effort eccentric contractions with shoulder extension, abduction, and diagonal movements on the isokinetic device. Participants in this investigation were nine men and four women with no history of shoulder injury or disorders. They all participated in overhead sports at least three days a week, and volunteered to participate in this study for shoulder isokinetic muscle strength testing. They performed eccentric muscle action with shoulder flexion, abduction, and diagonal movements at velocities of 60 rad·s−1 and 180 rad· s−1, which was followed alternately by passive shoulder flexion, abduction and diagonal movement at a velocity of 30 rad· s−1, and total range of motion was standardised to 90°. Electromyography (EMG) and torque values were calculated to every 10°, except for the start and end 5° during each task. During each test, the isokinetic force output and muscle activation were synchronised. EMG data were normalised by percentage of maximum voluntary isometric contraction (%MVIC). EMG signals were recorded by surface EMG from the anterior deltoid (AD), middle deltoid (MD), posterior deltoid (PD), upper trapezius (UT), middle trapezius (MT), and biceps brachii (BB) muscles during this test. All of the muscle patterns were significantly decreased at the last compared with the initial part during eccentric shoulder flexion movement, except for the BB muscle (P < 0.05). AD and BB muscles played a similar role when peak torque was generated under load during eccentric muscle action with varying shoulder movements. PD and UT muscle activities were significantly lower than the other muscle activities during eccentric contraction with shoulder flexion and abduction movements, and the PD and UT muscles played a significant role in conjunction with MD and MT muscles in varying degrees during eccentric contraction with shoulder diagonal movements at 180 rad·s−1 (P < 0.05). Our study demonstrated that MT muscle activity was greatly influenced when torque values showed a peak moment under load during maximum effort, eccentric contraction with shoulder abduction and diagonal movements. However, the MD, PD, UT, and MT muscle activities had no great influence when peak torque was generated under load during eccentric muscle action with shoulder diagonal movement at high velocity. The present study suggested that varying eccentric muscle activity patterns may be needed to investigate proper training and functional contributions of upper extremity muscles to stabilisation of the shoulder joint when peak torque was generated under load.

Glenohumeral Muscle Activation During Provocative Tests Designed to Diagnose Superior Labrum Anterior-Posterior Lesions

Background: Despite considerable medical advances, arthroscopy remains the only definitive means of superior labrum anterior-posterior (SLAP) lesion diagnosis. Natural shoulder anatomic variants limit the reliability of radiographic findings and clinical evaluations are not consistent. Accurate clinical diagnostic techniques would be advantageous because of the invasiveness, patient risk, and financial cost associated with arthroscopy. Purpose: The purpose of this study was to examine the behavior of the joint-stabilizing muscles in provocative tests for SLAP lesions. Electromyography was used to characterize the muscle behavior, with particular interest in the long head of the biceps brachii (LHBB), as activation of the long head and subsequent tension in the biceps tendon should, based on related research, elicit labral symptoms in SLAP lesion patients. Study Design: Controlled laboratory study. Methods: Volunteers (N = 21) without a history of shoulder injury were recruited. The tests analyzed were active compression, Speed’s, pronated load, biceps load I, biceps load II, resisted supination external rotation, and Yergason’s. Tests were performed with a dynamometer to improve reproducibility. Muscle activity was recorded for the long and short heads of the biceps brachii, anterior deltoid, pectoralis major, latissimus dorsi, infraspinatus, and supraspinatus. Muscle behavior for each test was characterized by peak activation and proportion of muscle activity. Results: Speed’s, active compression palm-up, bicep I, and bicep II produced higher long head activations. Resisted supination external rotation, bicep I, bicep II, and Yergason’s produced a higher LHBB proportion. Conclusion: Biceps load I and biceps load II elicited promising long head behavior (high activation and selectivity). Speed’s and active compression palm up elicited higher activation of the LHBB, and resisted supination and Yergason’s elicited selective LHBB activity. These top performing tests utilize a unique range of test variables that may prove valuable for optimal SLAP test design and performance. Clinical Relevance: This study examines several provocative tests that are frequently used in the clinical setting as a means of evaluating a potential SLAP lesion.

Humeral Retrotorsion in Collegiate Baseball Pitchers With Throwing-Related Upper Extremity Injury History

Background:Collegiate baseball pitchers, as well as position players, exhibit increased humeral retrotorsion compared with individuals with no history of overhead sport participation. Whether the humeral retrotorsion plays a role in the development of throwing-related injuries that are prevalent in collegiate baseball pitchers is unknown.Hypotheses:Humeral retrotorsion will be significantly different in collegiate pitchers with throwing-related shoulder or elbow injury history compared with pitchers with no injury history. Humeral retrotorsion can also discriminate participants with and without shoulder or elbow injury.Study Design:Cross-sectional study.Methods:Comparisons of ultrasonographically-obtained humeral retrotorsion were made between 40 collegiate pitchers with and without history of throwing-related shoulder or elbow injury. The ability of humeral retrotorsion to discriminate injury history was determined from the receiver operating characteristic area under the curve.Results:Participants with an elbow injury history demonstrated a greater humeral retrotorsion limb difference (mean difference = 7.2°, P = 0.027) than participants with no history of upper extremity injury. Participants with shoulder injury history showed no differences in humeral torsion compared with participants with no history of injury. Humeral retrotorsion limb difference exhibited a fair ability (receiver operating characteristic area under the curve = 0.74) to discriminate elbow injury history.Conclusions:Collegiate pitchers with a history of elbow injury exhibited a greater limb difference in humeral retrotorsion compared with pitchers with no history of injury. No differences in humeral retrotorsion variables were present in participants with and without shoulder injury history.Clinical Relevance:Baseball players with a history of elbow injury demonstrated increased humeral retrotorsion, suggesting that the amount of retrotorsion and the development of elbow injury may be associated.

Testing procedures for SLAP lesions of the shoulder involving contraction and torsion of biceps long head and glenohumeral glides

Testing procedures for SLAP lesions of the shoulder can combine resisted elbow flexion, forearm pronation and supination, and glenohumeral glides. These procedures reproduce symptoms by increasing biceps long head active tension or passive torsion, and by placing the shoulder in an unstable position. We compared activation of biceps long head and pain intensity, between supinated and pronated forearm positions, between different glides, and between individuals with and without shoulder impairment. A case control study. Twelve participants with suspected SLAP lesions and twelve with no history of shoulder injury volunteered. Electromyography measured muscle activity in biceps long head, normalised against maximum voluntary isometric contraction (MVIC). Subjective pain intensity scores were recorded. Biceps long head activity was greater in forearm supination (mean 39% MVIC) than pronation (mean 24% MVIC), but pain was higher in pronation (mean 4.5/10) than supination (3.2/10). Biceps long head activity was greater when testing without a glide, but there was no difference in pain comparing the glide conditions. The impaired group experienced more pain (mean 3.9/10) than controls (mean 0.3/10) but there was no difference in shoulder muscle activity. No one combination of testing procedures appeared to be diagnostic of SLAP lesions in our sample. This study supports the theory that biceps long head acts as a stabiliser of the shoulder, and suggests that clinical testing procedures for SLAP lesions may need to inhibit biceps long head activity. The addition of glides to SLAP testing procedures did not affect the reproduction of pain.

Operative versus nonoperative treatment after primary traumatic anterior glenohumeral dislocation: expected-value decision analysis

The optimal management strategy for primary traumatic anterior glenohumeral dislocation remains controversial. Patients have traditionally been managed nonoperatively, but high recurrence rates in certain populations have led to increased interest in early operative stabilization. The purpose of this study was to use expected-value decision analysis to determine the optimal management strategy--nonoperative treatment or arthroscopic stabilization--for a first-time traumatic anterior shoulder dislocation. Probabilities for the occurrences of the potential outcomes after nonoperative and arthroscopic treatment of a first-time traumatic anterior glenohumeral dislocation were determined from a systematic review of the literature. Utilities for these outcomes were obtained from a questionnaire on patient preferences completed by 42 subjects without a history of shoulder injury. A decision tree was constructed, fold-back analysis was performed to determine optimal management, and sensitivity analyses were used to determine the effect on decision making of varying outcome probabilities and utilities. Nonoperative treatment was associated with a utility value of 5.9 and early arthroscopic surgery with a value of 7.6. On sensitivity analysis, it was found that when the rate of recurrence after nonoperative treatment falls below 32% or when the utility value for successful arthroscopic stabilization falls below 6.6, nonoperative treatment is the preferred management strategy. Arthroscopic stabilization was the preferred strategy after a primary anterior glenohumeral dislocation. In clinical settings where the likelihood of recurrent instability is low after nonoperative care or when an informed patient has an aversion to surgery, nonoperative treatment may be the preferred treatment strategy.

The epidemiology of shoulder injuries in rugby union football

BackgroundShoulder injuries are a significant risk in rugby union football. However, the aetiology and the risk factors associated with shoulder injuries are not well understood.ObjectiveTo analyse the incidence and risk...

Shoulder laxity and traumatic shoulder instability in professional rugby players

ObjectiveThis study aimed to see whether the risk of shoulder dislocation is associated with innate shoulder laxity, in professional rugby players.MethodologyWe performed a pilot study where we validated techniques we...

The impact of compliance on sports injury prevention effect estimates in randomized controlled trials

occurred in players with no history of shoulder injury in the last 3 years (injury incidence rate of 3.5/1000 pph). Extrinsic risk factors were shoulder pads and player position. 36% players used shoulder pads during games. An injury incidence rate of 3.5/1000 pph was recorded for players not wearing shoulder pads during a match compared to 0.8/1000 pph for wearers. Back Five positions had the highest injury incidence rate of 7.9/1000 pph. Being tackled and tackling were the two mechanisms of injury that contributed to 67% of the total time loss. During the season, 41% of participants reported experiencing shoulder pain but that did not stop them from participating in matches and did not appear to be correlated with injury risk. Discussion: A recursive injury model was applied to the study design and analysis. Shoulder pain or impairment did not appear to be associated with injury. Tackling, either as a tackler or being tackled is the main inciting event for shoulder injuries, which is consistent with other studies on injury in rugby union. Recursiveness may not be relevant to shoulder injury risk.