Differences in scapular and humeral head position between swimmers and non‐swimmers

The aims of this study were to determine differences between swimmers/non‐swimmers, males/females and dominant/non‐dominant sides for scapular and humeral head position, while accounting for size, and to determine the relationship between scapular and humeral head position. 46 teenage swimmers (30 females) and 43 non‐swimmers (28 females) were measured. The distances between (a) medial spine of the scapula and T3/4 (Superior Kibler), (b) inferior scapula and T7/8 (Inferior Kibler) and (c) anterior acromion and anterior humeral head were recorded while teenagers stood with their hands‐on hips. There was no main effect difference between swimmers and non‐swimmers for scapular or humeral head position. There were interactions for swim status/dominance (Superior Kibler; P=0.005, Inferior Kibler; P<0.001) and swim status/gender (Superior Kibler; P=0.027). The humeral head was significantly further from the acromion on the dominant side (adjusted mean difference=1.4 mm, P=0.004). Little relationship between scapular and humeral head position was evident. Clinicians should be aware that swim status, in combination with gender or dominance may affect scapular position but does not affect humeral head position. Where swimming had an effect, it minimized differences between genders and sides. The small dominance effect on the humeral head position is unlikely to be clinically detectable.     

盂肱关节前方不稳MR表现与关节镜手术所见比较

 目的 探讨盂肱关节前方不稳的关节镜检查和3.0T MRI表现。方法 收集45例盂肱关节前方不稳患者的MRI检查及关节镜检查资料,回顾性对照分析MRI与多角度镜头关节镜手术结果,总结损伤类型、程度,采用Kappa检验分析MRI与关节镜诊断结果的一致性,观察MRI对各种损伤诊断结果及敏感度。结果 盂唇损伤在盂肱关节前方不稳病变中占84.4%(38/45),其中前下盂唇损伤占 51.1%(23/45),盂唇损伤合并Hill-sachs损伤、关节囊损伤占44.2%(20/45),盂唇损伤合并骨性Bankart损伤占17.7%(8/45)。MRI诊断前下盂唇损伤、HAGL病变、Hill-sachs病变的敏感度分别为78.2%、71.0%、90.0%。MRI与关节镜诊断结果具有一致性,其中诊断肩胛下肌及肌腱损伤及骨性Bankart损伤的结果完全一致,诊断前下盂唇损伤、HAGL病变及Hill-sachs病变的一致性较好,诊断SLAP损伤一致性一般。结论 3.0T MRI能够较准确地显示盂肱关节前方不稳常见病变及MRI征象,为临床早期诊断和治疗提供依据。     

Dynamic MR imaging and stress testing in glenohumeral instability: comparison with normal shoulders and clinical/surgical findings

Our objectives were to test the hypotheses that: 1) during shoulder motion, glenohumeral alignment differs between asymptomatic shoulders and those with symptomatic instability; 2) during magnetic resonance (MR)-monitored physical exam or stress testing, glenohumeral alignment differs between asymptomatic shoulders and those with instability; and 3) glenohumeral translation during MR stress testing correlates with findings of shoulder instability by clinical exam and exam under anesthesia (EUA). Using an open-configuration 0.5 T MR imaging (MRI) system, we studied symptomatic shoulders in 11 subjects and compared them to their contralateral asymptomatic shoulders. Each shoulder was studied during abduction/adduction and internal/external rotation to determine the humeral head position on the glenoid. An examiner also performed the MR stress test on each shoulder by applying manual force on the humeral head during imaging. All shoulders were assigned an instability grade from the MR stress test, and this grade was correlated with: 1) clinical exam grade assigned during preoperative assessment by an orthopedic surgeon and 2) intraoperative instability grade by EUA immediately preceding arthroscopy. With dynamic abduction and internal/external rotation, the humeral head remained centered on the glenoid in 9 of 11 shoulders, but in two subjects there were dramatic demonstrations of subluxation. With stress testing, a trend toward more joint laxity was demonstrated in symptomatic than in asymptomatic joints (P = 0.11). MR grading of instability correlated directly with clinical grading in six cases and underestimated the degree of instability relative to clinical exam in the other cases. MR instability grading systematically underestimated instability compared with EUA in 7 of the 10 cases that underwent surgical repair. We concluded that dynamic MR evaluation of glenohumeral alignment did not demonstrate abnormalities in symptomatic shoulders in 8 of 10 patients, whereas 2 patients showed dramatic findings of subluxation. Manual stress testing during dynamic MR examination showed a strong correlation with clinical instability grading. Dynamic shoulder MR examination during stress testing could, with further validation, become a useful adjunct to shoulder instability evaluations. J. Magn. Reson. Imaging 2001;13:748-756.     

Long-term results after resection of the coracoacromial ligament for shoulder impingement in athletes

The impingement syndrome with shoulder pain is a well known problem in many sports, such as swimming. Anterior acromioplasty or only resection of the coracoacromial ligament have been used for the patients who do not respond to noninvasive therapy. In this retrospective study, the long-term results after resection of the coracoacromial ligament were evaluated. Of 30 operated patients, 25 were examined on average 4 years after surgery. Almost all were active athletes at the elite professional level (national team) or the league competitive level. Their mean age was 23 years at the time of the operation and the dominant symptom was shoulder pain on effort. At follow-up 21 (84%) were judged as excellent or good and 4 (16%) as fair or poor. Resection of the coracoacromial ligament without acromioplasty is a simple surgical procedure and a useful solution to an otherwise therapy-resistant impingement shoulder pain in athletes.     

The neuromuscular fatigue induced by repeated scrums generates instability that can be limited by appropriate recovery

The aim of this study was to evaluate the influence of the fatigue on the machine scrum pushing sagittal forces during repeated scrums and to determine the origin of the knee extensor fatigue. Twelve elite U23 rugby union front row players performed six 6-s scrums every 30 s against a dynamic scrum machine with passive or active recovery. The peak, average, and the standard deviation of the force were measured. A neuromuscular testing procedure of the knee extensors was carried out before and immediately after the repeated scrum protocol including maximal voluntary force, evoked force, and voluntary activation. The average and peak forces did not decrease after six scrums with passive recovery. The standard deviation of the force increased by 70.2 ± 42.7% (P < 0.001). Maximal voluntary/evoked force and voluntary activation decreased (respectively 25.1 ± 7.0%, 14.6 ± 5.5%, and 24 ± 9.9%; P < 0.001). The standard deviation of the force did not increase with active recovery and was associated with lower decrease of maximal voluntary/evoked force and voluntary activation (respectively 12.8 ± 7.9%, 4.9 ± 6.5%, and 7.6 ± 4.1%; all P < 0.01). As a conclusion repeated scrummaging induced an increased machine scrum pushing instability associated with central and peripheral fatigue of the knee extensors. Active recovery seems to limit all these manifestations of fatigue.     

Traumatic anterior shoulder instability in the athlete

Anterior glenohumeral dislocation is common among athletes and may progress to recurrent instability. The pathoanatomy of instability and specific needs of each individual should be considered to prevent unnecessary absence from sport. Traditionally, primary dislocations have been managed with immobilization followed by rehabilitation exercises and a return to sporting activity. However, arthroscopic stabilization and external rotation bracing are increasingly used to prevent recurrent instability. In addition to the typical capsulolabral disruptions seen following a primary dislocation, patients with recurrent instability often have coexistent osseous injury to the humeral head and glenoid. In patients without significant bone loss, open soft‐tissue stabilizations have long been considered the ‘gold standard treatment’ for recurrent instability, but with advances in technology, arthroscopic procedures have gained popularity. However, enthusiasm for arthroscopic repair has not been supported with evidence, and there is currently no consensus for treatment. In patients with greater bone loss, soft‐tissue stabilization alone is insufficient to treat recurrent instability and open repair or bone augmentation should be considered. We explore the recent advances in epidemiology, classification, pathoanatomy and clinical assessment of young athletes with anterior shoulder instability, and compare the relative merits and outcomes of the different forms of treatment.     

Deformation of coracoacromial ligament during overhead movement as an early indicator of subacromial impingement in elite adolescent badminton players

ABSTRACT

Objectives: Deformation of the coracoacromial ligament during overhead movement has been linked to shoulder pathologies such as impingement and rotator cuff tear. We, therefore, explored this relationship in a group of elite adolescent badminton players.

Method: We performed bilateral shoulder physical and ultrasonographic examination in 35 adolescent asymptomatic badminton players, 13 players with unilateral shoulder pain, and 15 non-athletes of similar age. Coracoacromial ligament deformation, defined as the maximal vertical distance between the ligament apex to a line connecting the acromion and coracoid process, was measured during shoulder abduction and internal rotation and compared within and between groups. Other ultrasonographic measurements and the incidence of shoulder pathologies were also evaluated.

Result: Among badminton athletes who reported dominant shoulder pain, coracoacromial ligament deformation was significantly larger in their dominant shoulder than in their non-dominant shoulder (3.5 and 2.0 mm, respectively; p = 0.013); this difference was not present in other groups. Regardless of the presence or absence of pain, athletes displayed more coracoacromial ligament deformation and increased supraspinatus tendon thickness in their dominant shoulder than did the control group. Abnormal ultrasound findings were noted in all groups; however, the incidence was not significantly different.

Conclusion: Increased coracoacromial ligament deformation during overhead movement is associated with shoulder pain in elite adolescent badminton players. Our findings may help clinicians identify athletes at risk of subacromial impingement syndrome.     

Shoulder instability in thefemale athlete

Glenohumeral instability is relatively commonly observed in the female athlete. Studies have shown an increased incidence of both asymptomatic and pathological laxity among women. Female athletes participating in sports involving repetitive use of the upper extremity may be at particular risk for developing symptoms. Shoulder instability is classified according to etiology, onset, degree, and direction. Accurate diagnosis is important to determine proper management. Female athletes presenting with symptoms of shoulder instability should be initially treated with a comprehensive rehabilitation program emphasizing strengthening of the rotator cuff and dynamic scapular stabilizing muscles. After failure of nonoperative management, satisfactory results can be obtained using either open or arthroscopic surgical techniques.     

Recurrent anterior shoulder instability: a review of the Latarjet procedure and its postoperative rehabilitation

The shoulder is the most common joint to dislocate in the human body, with the dislocation often occurring in the anterior direction. This injury frequently results in soft tissue injury (eg, labral tear, capsular stretching) or bone injury (eg, glenoid or humeral head bone loss), which commonly leads to persistent deficits of shoulder function and a high risk of subsequent instability episodes in young, active patients. Patients with a significant degree of glenoid bone loss (> 25%) may require surgical intervention using the Latarjet procedure, which is an open bony augmentation of the glenoid. This procedure involves transferring the tip of the coracoid to the anteroinferior glenoid, creating a bony block and musculotendinous sling to prevent instability. Rehabilitation after the procedure is a slow progression over 4 to 6 months to regain range of motion and strength, while protecting the bony augmentation. Recent reports have shown success with the Latarjet procedure, as indicated by patient satisfaction scores and a low rate of recurrent instability.     

Avoiding complications in arthroscopic subacromial space and instability surgery

Arthroscopic shoulder surgery has become a safe tool for evaluation and treatment of a wide range of shoulder problems with few complications. With ever-improving technology (and commitment to motor skill development among arthroscopists), we can expect to maintain this low rate despite increasing procedure complexity. Avoiding complications in arthroscopic shoulder surgery requires careful preoperative planning, judicious patient selection, a thorough understanding of arthroscopic anatomy, and facility with arthroscopic techniques.     

Risk factors for shoulder pain and injury in swimmers: A critical systematic review

Swimming is one of the most popular recreational and competitive sporting activities. In the 2013/2014 swimming season, 9630 men and 12,333 women were registered with the National Collegiate Athletics Association in the USA. The repetitive nature of the swimming stroke and demanding training programs of its athletes raises a number of concerns regarding incidence and severity of injuries that a swimmer might experience during a competitive season. A number of risk factors have previously been identified but the level of evidence from individual studies, as well as the level of certainty that these factors predispose a swimmer to pain and injury, to our knowledge has yet to be critically evaluated in a systematic review. Therefore, the primary objective of this review is to conduct a systematic review to critically assess the published evidence for risk factors that may predispose a swimmer to shoulder pain and injury. Three electronic databases, ScienceDirect, PubMed and SpringerLink, were searched using keywords “(Injury OR pain) AND (Swim*)” and “(Shoulder) AND (Swim*)”. Based on the inclusion and exclusion criteria, 2731 unique titles were identified and were analyzed to a final 29 articles. Only articles with a level of evidence of I, II and III were included according to robust study design and data analysis. The level of certainty for each risk factor was determined. No studies were determined to have a high level of certainty, clinical joint laxity and instability, internal/external rotation, previous history of pain and injury and competitive level were determined to have a moderate level of certainty. All other risk factors were evaluated as having a low level of certainty. Although several risk factors were identified from the reviewed studies, prospective cohort studies, larger sample sizes, consistent and robust measures of risk should be employed in future research.     

Epidemiology of all-complaint injuries in youth basketball

This study evaluated the incidence and characteristics of all-complaint injuries, including acute and overuse injuries, in female and male youth basketball players. A total of 518 players (16 ± 1.4 years; 38.6% females), from 63 teams, participated in this prospective cohort study. Players were observed through one competitive high school or club basketball season to record exposure and all-complaint injuries, defined as any complaint resulting from participating in basketball-related activities, including but irrespective of the need for medical attention or time loss. Injury incidence rates and rate ratios were derived from Poisson's regression with 99.4% CI (Bonferroni's correction for multiple comparisons). The overall injury incidence rate was 14.4 (99.4% CI: 12.2-17.0) injuries/1000 h; 13.8 (99.4% CI: 11.2-16.8) in females and 14.8 (99.4% CI: 11.7-18.8) in males. While the incidence of injury was similar across injury classifications for female and male players, a potential lower overuse knee injury rate was noted for females vs males [IRR = 0.61 (99.4% CI: 0.34-1.07)]. The most commonly injured body location was the ankle (45%) in females and the knee (51%) in males. Overuse (vs acute) injuries were about 2x more common in the knee while acute (vs overuse) injuries were about 3x more common in the ankle, overall, and for female and male players. Based on an all-complaint injury definition, injury rates in competitive female and male youth basketball players are much higher than previously reported. This study provides an evidence base to inform more tailored interventions to reduce injuries in youth basketball.     

Non-contrast MR imaging of the glenohumeral joint. Part II. Glenohumeral instability and labrum tears

MR imaging of the shoulder without contrast is frequently used for evaluation of glenohumeral instability in spite of the popularity of MR arthrography. With proper imaging technique, familiarity with normal anatomy and variants as well as knowledge of the expected pathologic findings high diagnostic accuracy may be achieved.Part I of this Review Article Non-contrast MR imaging of the glenohumeral joint: Normal anatomy appeared in the previous issue (Number 10/Oct. 2004). See also:     

Exercise program for prevention of groin pain in football players: a cluster‐randomized trial

Groin injuries cause major problems in sports and particularly in football. Exercise is effective in treating adductor‐related groin pain, but no trials have been published regarding the specific prevention of groin pain or prevention specifically targeting overuse injuries in sport using exercise programs. We performed a cluster‐randomized trial including 55 football clubs representing 1211 players. The clubs were randomized to an exercise program aimed at preventing groin injuries (n=27) or to a control group training as usual (n=28). The intervention program consisted of six exercises including strengthening (concentric and eccentric), coordination, and core stability exercises for the muscles related to the pelvis. Physiotherapists assigned to each club registered all groin injuries. Twenty‐two clubs in each group completed the study, represented by 977 players. There was no significant effect of the intervention (HR=0.69, 95% CI 0.40–1.19). The risk of a groin injury was reduced by 31%, but this reduction was not significant. A univariate analysis showed that having had a previous groin injury almost doubles the risk of developing a new groin injury and playing at a higher level almost triples the risk of developing a groin injury.     

Dynamic knee control and movement strategies in athletes and non‐athletes in side hops: Implications for knee injury

Athletes exposed to rapid maneuvers need a high level of dynamic knee stability and robustness, while also controlling whole body movement, to decrease the risk of non‐contact knee injury. The effects of high‐level athletic training on such measures of movement control have not, however, been thoroughly evaluated. This study investigated whether elite athletes (who regularly perform knee‐specific neuromuscular training) show greater dynamic knee robustness and/or different movement strategies than non‐athletic controls, in relation to overall knee function. Thirty‐nine women (19 athletes, 20 controls) performed standardized rebound side hops (SRSH) while a motion capture system synchronized with two force plates registered three‐dimensional trunk, hip, and knee joint angles and moments. Dynamic knee robustness was evaluated using finite helical axis (FHA) inclination angles extracted from knee rotation intervals of 10°, analyzed with independent t tests. Angle and moment curves were analyzed with inferential methods for functional data. Athletes had superior knee function (less laxity, greater hop performances, and strength) but presented similar FHA inclination angles to controls. Movement strategies during the landing phase differed; athletes presented larger (a) hip flexion angles (during 9%‐29% of the phase), (b) hip adduction moments (59%‐99%), (c) hip internal rotation moments (83%‐89%), and (d) knee flexion moments (79%‐93%). Thus, elite athletes may have a greater ability than non‐athletes to keep the knee robust while performing SRSH more efficiently through increased engagement of the hip. However, dynamic knee robustness associated with lower FHA inclination angles still show room for improvement, thus possibly decreasing knee injury risk.     

Evaluation of general joint laxity, shoulder laxity and mobility in competitive swimmers during growth and in normal controls

The aim of the study was to evaluate differences between competitive swimmers and a reference group of school children concerning general joint laxity, laxity of the glenohumeral joint and range of motion in the shoulder. Materials and methods. Competitive swimmers (n = 120) were compared with references consisting of age and gender matched school children (n = 1277). General joint laxity was evaluated with the Beighton score. Anterior glenohumeral laxity was assessed according to the drawer test, and inferior glenohumeral laxity according to the sulcus test. Shoulder rotation was measured with a goniometer. RESULTS: Male swimmers of both age groups showed a higher degree of general joint laxity compared with the reference group while 9-year-old female swimmers alone had a lower degree of general joint laxity compared with references. No significant difference concerning shoulder laxity was noticed between groups. There was a decreased internal rotation in male and female swimmers as compared with the reference group. External rotation was reduced in female swimmers as compared with the female references. The same result was observed in male swimmers, but only at the age of 12 years. CLINICAL CONSEQUENCE: Competitive swimming in children seems to lead to a decreased range of motion with regard to shoulder rotation. However, the reason for this is still unclear and further investigations are needed.     

Isokinetic rotator muscles fatigue in glenohumeral joint instability before and after Latarjet surgery A pilot prospective study

We aimed to analyze the changes in isokinetic internal (IR) and external (ER) rotator muscles fatigue (a) in patients with non‐operated recurrent anterior instability, and (b) before and after shoulder surgical stabilization with the Bristow–Latarjet procedure. Thirty‐seven patients with non‐operated unilateral recurrent anterior post‐traumatic instability (NG) were compared with 12 healthy subjects [control group (CG)]. Twenty patients with operated recurrent anterior instability group (OG) underwent isokinetic evaluation before and 3, 6, and 21 months after Bristow–Latarjet surgery. IR and ER muscles strength was evaluated with Con‐Trex® dynamometer, with subjects seated and at a 45° shoulder abduction angle in scapular plane. IR and ER muscle fatigue was determined after 10 concentric repetitions at 180°·s^?1 through the fatigue index, the percent decrease in performance (DP), and the slope of peak torque decrease. There were no differences in rotator muscles fatigue between NG and CG. In OG, 3 months post‐surgery, IR DP of operated shoulder was significantly (P < 0.001) higher than presurgery and 6 and 21 months post‐surgery. Rotator muscles fatigability was not associated with recurrent anterior instability. After surgical stabilization, there was a significantly higher IR fatigability in the operated shoulder 3 months post‐surgery, followed by recovery evidenced 6 months post‐surgery and long‐term maintenance over 21 months.     

Subtalar instability of the foot: A review and results after surgical treatment

Most subtalar ligamentous injuries occur in combination with ankle ligament injuries, but the exact aetiology and the true incidence remain unknown. The aim of this study was to review the problem, propose a definition and to analyze the results of an anatomic reconstructive surgical technique in the treatment of subtalar instability. Twenty-two patients suffering from chronic subtalar instability of the foot were operated with anatomical reconstruction. The cervical, the lateral talo-calcaneal and the calcaneo-fibular ligaments were imbricated and reinforced with the lateral root of the inferior extensor retinaculum. After a minimum of 2 years follow-up the functional results were excellent or good in 18 of 22 (82%) patients and fair or poor in 4 of 22 (18%). All of the patients with unsatisfactory results suffered from residual ankle pain, two of whom also had residual instability. No reoperations have been performed. Surgical complications were seen in three patients, all minor nerve injuries of the lateral branch of the superficial peroneal nerve. These complications had no bearing on the functional results, however. This procedure was found to be feasible in patients with chronic subtalar instability.