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Lin, Yen-Sheng (2013) ULTRASONOGRAPHIC MEASUREMENT OF ACROMIOHUMERAL DISTANCE IN MANUAL WHEELCHAIR USERS. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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Subacromial impingement syndrome is one of the most common problems among manual wheelchair users (MWUs). While the mechanism of impingement is associated with the encroachment of subacromial space, few studies have investigated the relationship between space narrowing and intense repetitive wheelchair activities. Ultrasound offers a non-invasive, radiation free, portable, and relatively cost-effective modality to identify acromiohumeral distance (AHD) between acromion and humeral head. We established moderate to excellent intra- and inter-rater reliability and intra- and inter-video reproducibility of the ultrasonographic AHD measurement in 10 MWUs with spinal cord injury and 10 able-bodied individuals in Chapter 2. AHD was significantly impacted while the shoulder was in overhead positions with or without muscle contraction. The effects of repetitive shoulder external rotations between two groups revealed that MWUs group had greater AHD decreases between 45° arm elevation and neutral. In Chapter 3, twenty-three MWUs performed two shoulder muscle-fatiguing protocols. AHD narrowing was detected in holding a weight relief raise compared to a neutral position. AHD was significantly reduced with the electromyography signs of sternal pectoralis major muscle fatigue after multiple weight relief push-ups. In addition, participants who experienced higher shoulder pain scores and perceived exertion after shoulder external rotation fatiguing exercises showed greater AHD narrowing. Chapter 4 investigated if shoulder biomechanics during the start-up phases of propulsion were related to the AHD measurement. Twenty-one MWUs took part in an intense wheelchair propulsion course. Pushing with a technique that resulted in higher shoulder internal rotation moments and lower posterior forces during startup was linked to more acute AHD narrowing. AHD measurements related to shoulder circumference and years since injury. The findings of this research support the clinical practice guideline of reducing overhead shoulder activities and limiting weight relief raises for pressure relief technique to protect the integrity of subacromial space following spinal cord injury. Ultrasonographic measurement of the AHD provides a reliable and direct examination, easy to implement means to identify risk factors for better understanding the mechanisms of subacromial impingement syndrome. This imaging technique may help clinicians to evaluate intervention strategies and exercise prescriptions to minimize the risks for developing subacromial impingement syndrome.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Lin, Yen-Shengyel14@pitt.eduYEL14
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairKoontz, Alicia Makoontz@pitt.eduAKOONTZ
Committee MemberBoninger, Michael Lboninger@upmc.eduBONINGER
Committee MemberCooper, Rory Arcooper@pitt.eduRCOOPER
Committee MemberStetten, George
Committee MemberFarrokhi, Shawn Sfarrokhi@pitt.eduFARROKHI
Date: 24 May 2013
Date Type: Publication
Defense Date: 18 March 2013
Approval Date: 24 May 2013
Submission Date: 17 April 2013
Access Restriction: 1 year -- Restrict access to University of Pittsburgh for a period of 1 year.
Number of Pages: 131
Institution: University of Pittsburgh
Schools and Programs: School of Health and Rehabilitation Sciences > Health and Rehabilitation Sciences
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: Ultrasound; Subacromial Space; Shoulder; Rotator Cuff; Subacromial Impingement Syndrome; Muscle Fatigue; Biomechanics; Wheelchair; Weight Relief; Overground Propulsion; Electromyography; Kinetics; Kinematics; Reliability;
Date Deposited: 24 May 2013 14:27
Last Modified: 19 Dec 2016 14:40


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