National Collegiate Athletic Association Swimmers With Glenohumeral Multidirectional Laxity Have an Increased Glenohumeral Joint Range of Motion Profile.

CONTEXT: Adaptations in glenohumeral joint laxity and range of motion (ROM) are prevalent in competitive swimmers. Increased glenohumeral laxity in swimmers has been found to exist in multiple directions. However, it is unclear if swimmers with multidirectional laxity (MDL) possess altered glenohumeral ROM compared with swimmers without MDL. The purpose of this study was to compare the glenohumeral ROM characteristics of external rotation (ER), internal rotation (IR), total arc of motion (ER + IR), and total arc of motion ratio (ER/IR) between swimmers with MDL and without MDL. Our secondary objective was to investigate the effect of MDL on self-reported pain and function. DESIGN: Observational study. METHODS: Twenty-nine NCAA Division I swimmers (females: 15 and males: 14; age 19.5 [1.2] y; body mass index 23.9 [2.0] km/m2) participated in a preseason physical assessment including measures of glenohumeral ROM and joint laxity. These measures were used to determine the presence or absence of MDL for both shoulders of each participant. Glenohumeral ROM characteristics were compared between shoulders with MDL and shoulders without MDL with independent t tests. Self-reported pain and function scores were recorded biweekly across the season with a modified Kerlan-Jobe Orthopedic Clinic questionnaire. The seasonal average Kerlan-Jobe Orthopedic Clinic questionnaire scores were compared between swimmers with MDL and swimmers without MDL with analysis of variance, with factors of sex and MDL status. RESULTS: Shoulders with MDL possessed increased glenohumeral IR (P < .001; effect size: 0.65) and total arc of motion (P < .004; effect size: 0.45) compared with shoulders without MDL. There were no differences in ER. There was no difference in self-reported pain and function between groups. CONCLUSIONS: Shoulders with MDL possess increased glenohumeral IR and total arc of motion compared with shoulders without MDL. The presence of MDL may not affect self-reported pain and function in competitive swimmers.

Reliability and Validity of a Clinical Assessment Tool for Measuring Scapular Motion in All 3 Anatomical Planes.

CONTEXT: A single clinical assessment device that can be used to objectively measure scapular motion in each anatomical plane is not currently available. The development of a novel electric goniometer would allow scapular motion in all 3 anatomical planes to be quantified. OBJECTIVE: To investigate the reliability and validity of an electric goniometer for measuring scapular motion in each anatomical plane during upper extremity elevation. DESIGN: Cross-sectional study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Sixty participants (29 women, 31 men; age = 30 ± 14 years, height = 1.73 ± 0.10 m, mass = 75.32 ± 16.90 kg) recruited from the general population. INTERVENTION(S): An electric goniometer was used to record clinical measurements of scapular position at rest and total arc of motion (excursion) during active upper extremity elevation in 2 testing sessions separated by several days. Measurements were recorded independently by 2 examiners. In 1 session, scapular motion was recorded simultaneously using a 14-camera, 3-dimensional optical motion-capture system. MAIN OUTCOME MEASURE(S): Reliability analysis included examination of clinical measurements for scapular position at rest and excursion during each condition. Both the intrarater reliability between testing sessions and the interrater reliability recorded in the same session were assessed using intraclass correlation coefficients (ICCs [2,3]). The criterion validity was examined by comparing the mean excursion values of each condition recorded using the electric goniometer and the 3-dimensional optical motion-capture system. Validity was assessed by evaluating the average difference and root mean square error. RESULTS: The between-sessions intrarater reliability was moderate to good (ICC [2,3] range = 0.628-0.874). The within-session interrater reliability was moderate to excellent (ICC [2,3] range = 0.545-0.912). The average difference between total excursion values recorded using the electric goniometer and the 3-dimensional optical motion-capture system ranged from -7° to 4°, and the root mean square error ranged from 7° to 10°. CONCLUSIONS: The reliability of scapular measurements was best when a standard operating procedure was used. The electric goniometer provided an accurate measurement of scapular excursions in all 3 anatomical planes during upper extremity elevation.