RTUS was found to have fair to good inter-rater reliability as a tool to measure acromiohumeral distance with the shoulder in a neutral position and with 60° of both active and passive arm abduction.

Context: Compromise to the acromiohumeral distance has been reported in participants with subacromial impingement syndrome compared with healthy participants. In clinical practice, patients with subacromial shoulder impingement are given strengthening programs targeting the lower trapezius (LT) and serratus anterior (SA) muscles to increase scapular posterior tilt and upward rotation. We are the first to use neuromuscular electrical stimulation to stimulate these muscle groups and evaluate how the muscle contraction affects the acromiohumeral distance.Objective: To investigate if electrical muscle stimulation of the LT and SA muscles, both separately and simultaneously, increases the acromiohumeral distance and to identify which muscle-group contraction or combination most influences the acromiohumeral distance.Design: Controlled laboratory study. Setting: Human performance laboratory. Patients or Other Participants: Twenty participants (10 men and 10 women, age ¼ 26.9 6 8.0 years, body mass index ¼ 23.8) were screened. Intervention(s): Neuromuscular electrical stimulation of the LT and SA.Main Outcome Measure(s): Ultrasound measurement of the acromiohumeral distance.Results: Acromiohumeral distance increased during contraction via neuromuscular electrical stimulation of the LT muscle (t 19 ¼ À3.89, P ¼ .004), SA muscle (t 19 ¼ À7.67, P ¼ .001), and combined LT and SA muscles (t 19 ¼ À5.09, P ¼ .001). We observed no differences in the increased acromiohumeral distance among the 3 procedures (F 2,57 ¼ 3.109, P ¼ .08).Conclusions: Our results supported the hypothesis that the muscle force couple around the scapula is important in rehabilitation and scapular control and influences acromiohumeral distance.

Taping techniques applied to the scapula had an immediate effect of increasing the AHD in healthy shoulders in 60° of passive arm abduction. Results suggest that taping for increasing posterior scapular tilt and increasing scapular upward rotation can influence the AHD and is a useful adjunct to rehabilitation in patients with subacromial impingement syndrome.

The aim of the current study is to assess the intra-rater and inter-rater reliability of real time ultrasound scanning in measuring static humeral head position. Real time ultrasound scanning, an experimental clinical measurement, was used to record measurements of the humeral head position in a sample of (20) healthy volunteers [9 male, 11 female]. While the participant was seated in a standardized chair, Hips and knees were positioned at 90 degrees of flexion. The humeral head position of each subject was imaged at three ultrasound view [anterior, posterior and superior] in a different arm positions; images were repeated three times for each position by the same examiner on the same day to assess Intra-rater reliability. The Images were then analysed by the researcher and a second investigator to assess inter-tester reliability. Intra-rater and inter-rater reliability were quantified by using the intraclass correlation coefficient and standard error of measurement, the smallest detectable difference values were calculated and were used to estimate the magnitude of change that is predictable to exceed measurement error. The intra-rater reliability for all positions was found to be excellent for all tests ranged from 0.83 to 0.99 respectively. Inter -rater reliability between examiners was found to be good to excellent for all test positions ranged from 0.66 to 0.98, and the standard error of measurement for all positions was less than the calculated mean. This study demonstrates that real time ultrasound scanning is a reliable method of assessing the location of the humeral head in a number of arm positions in healthy subjects when measured by the same examiner and this may suggest that RTUS could be used to assess the impact of rehabilitation programme or surgical interventions for shoulder pathology.