Neck Strength Evaluated With Fixed and Portable Dynamometers in Asymptomatic Individuals: Correlation, Concurrent Validity, and Agreement.

OBJECTIVE: The purpose of this study was to assess the correlation, concurrent validity, and agreement between the isometric cervical force measurements obtained with fixed and portable dynamometers in asymptomatic individuals. METHODS: Fifty asymptomatic individuals performed 3 maximal isometric contractions for flexion, extension, and lateral flexion of the cervical spine using fixed and portable dynamometers. The correlation and concurrent validity for the measurements of the portable and fixed dynamometers were analyzed using Spearman's correlation coefficient and the intraclass correlation coefficient (ICC), respectively. The agreement between the force values of the portable and fixed dynamometers was measured using the Bland-Altman method. RESULTS: Isometric cervical force measurements obtained with the fixed dynamometer and portable dynamometer showed a moderately to highly significant correlation for flexion (rs = 0.74), extension (rs = 0.82), right lateral flexion (rs = 0.74), and left lateral flexion (rs = 0.68). The concurrent validity was moderate to good for all measurements (ICC2,3 = 0.67-0.80). The fixed and portable dynamometers did not agree, with a significant mean difference between the methods of 2.8 kgf (95% confidence interval [CI], 2.1-3.4 kgf) for cervical flexion, 5.3 kgf (95% CI, 4.2-6.4 kgf) for extension, and 9.1 kgf (95% CI, 0.4-2.1 kgf) for left lateral flexion. The limits of agreement were broad for all movements, with errors that varied between 61% and 77% of the mean force obtained with the fixed dynamometer. CONCLUSION: The neck strength measurements obtained with the fixed and portable dynamometers demonstrated high to moderate correlation and had moderate to good comparability for asymptomatic participants. However, they did not agree in that the 2 methods did not provide equivalent measurements, and, therefore, based on these findings, the same equipment should always be used when reassessing an individual.

Interaction of scapular dyskinesis with hand dominance on three-dimensional scapular kinematics.

INTRODUCTION: This study aimed to evaluate the effect of scapular dyskinesis and its interaction with hand dominance and humerothoracic angles on three-dimensional scapular kinematics in asymptomatic individuals in all planes of arm motion. METHODS: Forty-five asymptomatic participants, seventeen men and twenty-eight women, were separated into two groups: with (n = 22) and without scapular dyskinesis (n = 23) according to the Yes/No classification. Scapular kinematic data of dominant and non-dominant sides in both groups were measured with an electromagnetic tracking device during arm elevation and lowering phases in scapular, frontal and sagittal planes. A linear mixed model of covariance adjusted for age and BMI was used, which included hand dominance (dominant and non-dominant), group (with and without scapular dyskinesis), angles (30°, 60°, 90°, and 120°), and the interaction effect (group × hand dominance × humerothoracic angle). RESULTS: There was a significant interaction effect on scapular anterior tilt and upward rotation in the sagittal plane, and for internal rotation and anterior tilt in the frontal and scapular planes. The effects of hand dominance on three-dimensional scapular kinematics, as increased anterior tilt, internal rotation and upward rotation, were greater in individuals without scapular dyskinesis. CONCLUSION: The effects of dominant side as increased upward rotation, internal rotation, and anterior tilt at higher humerothoracic angles for all planes of arm motion, were greater in individuals without scapular dyskinesis. Our findings may assist the scapular assessment which in individuals without scapular dyskinesis, bilaterally, possible between side differences in the scapular motions may be related to a dominance effect.

Inclinometer Reliability for Shoulder Ranges of Motion in Individuals With Subacromial Impingement Syndrome.

OBJECTIVE: This study aimed to determine the intra- and interrater reliability of active and passive range of motion in the shoulders of individuals with subacromial impingement syndrome using a digital inclinometer. METHODS: The raters evaluated active and passive range of motion in the shoulder of 50 individuals with unilateral subacromial impingement syndrome in movements including flexion, abduction, extension, external rotation in a neutral position, external rotation with the arm at 90° of abduction, and internal rotation with the arm at 90° of abduction. The tests were performed by 2 examiners on the same day, with a 10-minute interval, and were repeated by 1 examiner after a 2- to 4-day interval. Reliability was analyzed using the intraclass correlation coefficient (ICC2,3). RESULTS: There was moderate to excellent interrater (ICC2,3 = 0.50-0.95) and intrarater (ICC2,3 = 0.74-0.94) reliability. In the interrater analysis, the standard error of measurement (SEM) ranged from 4.1° to 10°, the percentage SEM (%SEM) ranged from 2% to 17%, and the minimum detectable change ranged from 9.5° to 23.4°. In the intrarater analysis, the SEM ranged from 4° to 9.2°, %SEM ranged from 3% to 14%, and the minimum detectable change ranged from 9.3° to 21.4°. CONCLUSION: The digital inclinometer showed moderate to excellent reliability for measuring active and passive range of motion in shoulders with unilateral subacromial impingement syndrome.