Ultrasonographic measurement of the acromiohumeral distance in spinal cord injury: Reliability and effects of shoulder positioning

Abstract

Objective: To investigate the reliability of ultrasonographic measurement of acromiohumeral distance (AHD) and the effects of shoulder positioning on AHD among manual wheelchair users (MWUs) with spinal cord injury (SCI) and an able-bodied control group. Methods: Ten MWUs with SCI and 10 able-bodied subjects participated in this study. The ultrasonographic measurements of AHD from each subject were obtained by two raters during passive and active scapular plane arm elevation in neutral, 45°, 90°with and without resistance and in a weight relief raise position. The measurements were recorded again by each rater using the same procedures after a 30-minute time interval. All raters were blinded to each other's measurements. Setting: University Laboratories and Veteran Affairs Healthcare System. Results: Intra-rater (intraclass correlation coefficient, ICC > 0.83) and inter-rater (ICC > 0.78) reliability was excellent for both the MWUs with SCI and able-bodied groups across all arm positions except for the 45°p osition in the control group for one of the raters (intra-rater: ICC < 0.40 and inter-rater: ICC < 0.60). AHD significantly reduced when the shoulder was in the 90°arm elevated positions with or without resistance. Conclusion: Findings from our study demonstrated that ultrasonography is a reliable means to evaluate AHD in both able bodied and individuals with SCI, who are known to have significant shoulder pathology. This technique could be used to develop reference measures and to identify changes in AHD caused by interventions.

Effects of Repetitive Shoulder Activity on the Subacromial Space in Manual Wheelchair Users

“…For a power of 0.95, an α level of 0.05, and an effect size of 1.09 using a paired t -test, a sample size of 23 was required for this study. The effect size was calculated based on ultrasound data collected from wheelchair users in previous reliability study [ 12 ]. Inclusion criteria included using a manual wheelchair as primary means of mobility, able to perform at least 10 WR in a row without assistance, and between 18 and 65 years of age.…”

“…The subacromial space was quantified by measuring the AHD using ultrasound techniques as described in a previous reliability study [ 12 ]. The intrarater reliability of the AHD measurement with the shoulder in a neutral and WR position resulted in a standard error of measurement of 0.21 and 0.52 mm and intraclass correlation coefficient of 0.93 and 0.98, respectively [ 12 ]. A single examiner conducted all scans for each subject using a Philips HD11 1.0.6 ultrasound machine with a 5–12 MHz linear transducer.…”

“…A baseline US video was recorded with the shoulder in a neutral and resting position. Before and within one minute after each protocol, imaging was completed while the subject isometrically held the WR position [ 12 ]. We chose to examine AHD while subjects held the WR position because it provides a measure of what the AHD looks like under realistic, functional loading conditions.…”

“…We recently described a reliable method to quantify the subacromial space by using ultrasound while holding a WR position [ 12 ]. Ultrasound has the advantage of enabling the shoulder to be scanned in a functional posture.…”

Changes to Biceps and Supraspinatus Tendons in Response to a Progressive Maximal Treadmill-Based Propulsion Aerobic Fitness Test in Manual Wheelchair Users: A Quantitative Musculoskeletal Ultrasound Study

“…Measures of variance (dispersion of pixel values around the mean), skewness (asymmetry of the median pixel value), entropy (randomness of pixel values), and contrast (quantity of local variation in grayscale between reference pixels and their neighbours) provided first- and second-order insights into the heterogeneity of the ROI. Finally, the acromiohumeral distance (AHD), considered a good indicator of the size of the subacromial space outlet, was computed as the shortest line (i.e., distance) possible between the acromion and the humeral head [ 41 ]. Additional information pertaining to these measures is available [ 27 , 42 ].…”