***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background No quantitative data on glenohumeral translation exist allowing one to distinguish insufficiency of the active or passive stabilizers in different forms of shoulder instability . Hypothesis To determine whether 1 ) in traumatic or atraumatic shoulder instability an increase of glenohumeral translation can be observed in specific relevant arm positions , 2 ) muscle activity leads to recentering of the humeral head , and 3 ) there exist differences between traumatic and atraumatic instability . Study Design Prospect i ve clinical trial . Methods In 12 patients with traumatic and 10 patients with atraumatic instability , both shoulders  were examined in different arm positions — with and without muscle activity — by using open magnetic resonance imaging and a three-dimensional postprocessing technique . Results At 90 ° of abduction and external rotation , translation ( anterior-inferior ) was significantly higher in patients with traumatic unstable shoulders compared with their contralateral side ( 3.6 ± 1.5 versus 0.7 ± 1.6 mm ) . In patients with atraumatic instability , significantly increased translation ( 4.7 ± 2.0 mm ) was observed , with the direction being nonuniform . Muscle activity led to significant recentering in traumatic but not in atraumatic instability . Conclusions In traumatic instability , increased translation was observed only in functionally important arm positions , whereas intact active stabilizers demonstrate sufficient recentering . In atraumatic instability , a de central ized head position was recorded also during muscle activity , suggesting alterations of the active stabilizers . Clinical Relevance Clinical Relevance : These data are relevant for optimizing diagnostics and therapeutic strategies Most systematic review s rely substantially on the assessment of the method ological quality of the individual trials . The aim of this study was to obtain consensus among experts about a set of generic core items for quality assessment of r and omized clinical trials ( RCTs ) . The invited participants were experts in the field of quality assessment of RCTs . The initial item pool contained all items from existing criteria lists . Subsequently , we reduced the number of items by using the Delphi consensus technique . Each Delphi round comprised a question naire , an analysis , and a feedback report . The feedback report included staff team decisions made on the basis of the analysis and their justification . A total of 33 international experts agreed to participate , of whom 21 completed all question naires . The initial item pool of 206 items was reduced to 9 items in three Delphi rounds . The final criteria list ( the Delphi list ) was satisfactory to all participants . It is a starting point on the way to a minimum reference st and ard for RCTs on many different research topics . This list is not intended to replace , but rather to be used alongside , existing criteria lists BACKGROUND AND PURPOSE Assessment of the quality of r and omized controlled trials ( RCTs ) is common practice in systematic review s. However , the reliability of data obtained with most quality assessment scales has not been established . This report describes 2 studies design ed to investigate the reliability of data obtained with the Physiotherapy Evidence Data base ( PEDro ) scale developed to rate the quality of RCTs evaluating physical therapist interventions . METHOD In the first study , 11 raters independently rated 25 RCTs r and omly selected from the PEDro data base . In the second study , 2 raters rated 120 RCTs r and omly selected from the PEDro data base , and disagreements were resolved by a third rater ; this generated a set of individual rater and consensus ratings . The process was repeated by independent raters to create a second set of individual and consensus ratings . Reliability of ratings of PEDro scale items was calculated using multirater kappas , and reliability of the total ( summed ) score was calculated using intraclass correlation coefficients ( ICC [ 1,1 ] ) . RESULTS The kappa value for each of the 11 items ranged from.36 to.80 for individual assessors and from.50 to.79 for consensus ratings generated by groups of 2 or 3 raters . The ICC for the total score was.56 ( 95 % confidence interval=.47-.65 ) for ratings by individuals , and the ICC for consensus ratings was.68 ( 95 % confidence interval=.57-.76 ) . DISCUSSION AND CONCLUSION The reliability of ratings of PEDro scale items varied from " fair " to " substantial , " and the reliability of the total PEDro score was " fair " to " good . Descriptive studies have shown that shoulder complaints  can be persistent and recurrent , requiring long term evaluation of treatment.1 Unfortunately , in most r and omised studies comparing treatments for shoulder complaints the study period varies from a few weeks ( trials of non-steroidal anti-inflammatory drugs ) to 3 - 6 months ( injection therapy and physiotherapy trials).2–4 ) In a trial in 1994 - 5 of treatment of shoulder complaints in general practice we showed that in a study period of 11 weeks , injection therapy with a corticosteroid was superior to  physiotherapy  and manipulative therapy in the patients whose complaints originated from the structures of the glenohumeral joint , the subacromial space , or the acromioclavicular joint ( synovial group).5 In the patients whose complaints related to functional disorders of the cervical spine , the upper thoracic spine , or the adjoining ribs ( shoulder girdle group ) , manipulation was superior to physiotherapy . To assess the various treatments in A method for directly measuring the position of the humeral head on the face of the glenoid in different positions of abduction of the arm was developed . We studied three subject groups : 12 patients with normal shoulders ( group 1 ) , 15 patients with stage II impingement syndrome ( group 2 ) , and 20 patients with rotator cuff tears or stage III impingement ( group 3 ) . The study consisted of a series of anteroposterior roentgenograms in the plane of the scapula with the arm in neutral rotation . Roentgenograms were obtained at 20 degrees intervals as the arm was elevated in the plane of the scapula from 0 degree to 120 degrees . Patients held a weight equal to 2 1/2 % of body weight in the h and . The parameters measured were excursion of the humeral head on the glenoid face , expressed as the distance that the center of the head lies above or below the center of the glenoid , arm angle , scapulothoracic angle , and glenohumeral angle . For patients with normal shoulders ( group 1 ) , there was no significant change in position of the humeral head with arm elevation . In contrast , those with stage II impingement ( group 2 ) had significant ( p < 0.05 ) superior displacement of the center of the humeral head with arm elevation . Patients with rotator cuff tears ( group 3 ) demonstrated a significant rise ( p < 0.05 ) during the first 40 degrees of abduction . The average position of the humeral head in the two pathologic patient groups was superior ( p < 0.05 ) to the average head position in the normal patient group . There was no significant difference in head position between patients with stage II impingement and patients with rotator cuff tear . The ratio of the glenohumeral angle to the scapulothoracic angle during abduction was calculated for our patient groups . In both patient groups , arm abduction had a larger scapulothoracic component than for normal shoulders . The superior migration of the humeral head is a probable result of cuff failure , either partial or complete 
    Output:
    
Evidence , however , indicated that not only the passive , but also the active and control subsystems of the shoulder may need to be considered when determining the direction of the translational gliding of the HOH .