A clinical method for identifying scapular dyskinesis, part 1: reliability.

CONTEXT: Shoulder injuries are common in athletes involved in overhead sports, and scapular dyskinesis is believed to be one causative factor in these injuries. Many authors assert that abnormal scapular motion, so-called dyskinesis, is related to shoulder injury, but evidence from 3-dimensional measurement studies regarding this relationship is mixed. Reliable and valid clinical methods for detecting scapular dyskinesis are lacking. OBJECTIVE: To determine the interrater reliability of a new test designed to detect abnormal scapular motion. DESIGN: Correlation design using ratings from multiple pairs of testers. SETTING: University athletic training facilities. PATIENTS OR OTHER PARTICIPANTS: A sample of 142 athletes (from National Collegiate Athletic Association Divisions I and III) participating in sports requiring intense overhead arm use. INTERVENTION(S): Participants were videotaped from the posterior aspect while performing 5 repetitions of bilateral, weighted (1.4-kg [3-lb] or 2.3-kg [5-lb]) shoulder flexion and frontal-plane abduction. Videotapes from randomly chosen participants were subsequently viewed and independently rated for the presence of scapular dyskinesis by 6 raters (3 pairs), with each pair rating 30 different participants. Raters were trained to detect scapular dyskinesis using a self-instructional format with standardized operational definitions and videotaped examples of normal and abnormal motion. MAIN OUTCOME MEASURE(S): Scapular dyskinesis was defined as the presence of either winging or dysrhythmia. Right and left sides were rated independently as normal, subtle, or obvious dyskinesis. We calculated percentage of agreement and weighted kappa (kappa(w)) coefficients to determine reliability. RESULTS: Percentage of agreement was between 75% and 82%, and kappa(w) ranged from 0.48 to 0.61. CONCLUSIONS: The test for scapular dyskinesis showed satisfactory reliability for clinical use in a sample of overhead athletes known to be at increased risk for shoulder symptoms.

A clinical method for identifying scapular dyskinesis, part 2: validity.

CONTEXT: Although clinical methods for detecting scapular dyskinesis have been described, evidence supporting the validity of these methods is lacking. OBJECTIVE: To determine the validity of the scapular dyskinesis test, a visually based method of identifying abnormal scapular motion. A secondary purpose was to explore the relationship between scapular dyskinesis and shoulder symptoms. DESIGN: Validation study comparing 3-dimensional measures of scapular motion among participants clinically judged as having either normal motion or scapular dyskinesis. SETTING: University athletic training facilities. PATIENTS OR OTHER PARTICIPANTS: A sample of 142 collegiate athletes (National Collegiate Athletic Association Division I and Division III) participating in sports requiring overhead use of the arm was rated, and 66 of these underwent 3-dimensional testing. INTERVENTION(S): Volunteers were viewed by 2 raters while performing weighted shoulder flexion and abduction. The right and left sides were rated independently as normal, subtle dyskinesis, or obvious dyskinesis using the scapular dyskinesis test. Symptoms were assessed using the Penn Shoulder Score. MAIN OUTCOME MEASURE(S): Athletes judged as having either normal motion or obvious dyskinesis underwent 3-dimensional electromagnetic kinematic testing while performing the same movements. The kinematic data from both groups were compared via multifactor analysis of variance with post hoc testing using the least significant difference procedure. The relationship between symptoms and scapular dyskinesis was evaluated by odds ratios. RESULTS: Differences were found between the normal and obvious dyskinesis groups. Participants with obvious dyskinesis showed less scapular upward rotation (P < .001), less clavicular elevation (P < .001), and greater clavicular protraction (P = .044). The presence of shoulder symptoms was not different between the normal and obvious dyskinesis volunteers (odds ratio = 0.79, 95% confidence interval = 0.33, 1.89). CONCLUSIONS: Shoulders visually judged as having dyskinesis showed distinct alterations in 3-dimensional scapular motion. However, the presence of scapular dyskinesis was not related to shoulder symptoms in athletes engaged in overhead sports.

Effect of the Scapula Reposition Test on shoulder impingement symptoms and elevation strength in overhead athletes.

STUDY DESIGN: Two group, repeated measures design. OBJECTIVES: To determine whether manually repositioning the scapula using the Scapula Reposition Test (SRT) reduces pain and increases shoulder elevation strength in athletes with and without positive signs of shoulder impingement. BACKGROUND: Symptom alteration tests may be useful in determining a subset of those with shoulder pathology who may benefit from interventions aimed at improving scapular motion abnormalities. METHODS AND MEASURES: One hundred forty-two college athletes underwent testing for clinical signs of shoulder impingement. Tests provoking symptoms were repeated with the scapula manually repositioned into greater retraction and posterior tilt. A numeric rating scale was used to measure symptom intensity under both conditions. Isometric shoulder elevation strength was measured using a mounted dynamometer with the scapula in its natural position and with manual repositioning. A paired t test was used to compare the strength between positions. The frequency of a significant increase in strength with scapular repositioning, defined as the minimal detectable change (90% confidence interval), was also assessed. RESULTS: Of the 98 athletes with a positive impingement test, 46 had reduced pain with scapular repositioning. Although repositioning produced an increase in strength in both the impingement (P=.001) and non-impingement groups (P=.012), a significant increase in strength was found with repositioning in only 26% of athletes with, and 29% of athletes without positive signs for shoulder impingement. CONCLUSION: The SRT is a simple clinical test that may potentially be useful in an impairment based classification approach to shoulder problems.