Shoulder mechanical impingement risk associated with manual wheelchair tasks in individuals with spinal cord injury

Abstract

Background-Most individuals with spinal cord injury who use manual wheelchairs experience shoulder pain related to wheelchair use, potentially in part from mechanical impingement of soft tissue structures within the subacromial space. There is evidence suggesting that scapula and humerus motion during certain wheelchair tasks occurs in directions that may reduce the subacromial space, but it hasn't been thoroughly characterized in this context. Methods-Shoulder motion was imaged and quantified during scapular plane elevation with/ without handheld load, propulsion with/without added resistance, sideways lean, and weight-relief raise in ten manual wheelchair users with spinal cord injury using biplane fluoroscopy and computed tomography. For each position, minimum distance between rotator cuff tendon insertions (infraspinatus, subscapularis, supraspinatus) and the coracoacromial arch was determined. Tendon thickness was measured with ultrasound, and impingement risk scores were defined for each task based on frequency and amount of tendon compression.Findings-Periods of impingement were identified during scapular plane elevation and propulsion but not during pressure reliefs in most participants. There was a significant effect of activity on impingement risk scores (P< 0.0001), with greatest impingement risk during scapular plane elevation followed by propulsion. Impingement risk scores were not significantly different between scapular plane elevation loading conditions (P= 0.202) or propulsion resistances (P= 0.223). The infraspinatus and supraspinatus tendons were both susceptible to impingement during *

Scapular kinematic variability during wheelchair propulsion is associated with shoulder pain in wheelchair users

“…However, this study suggests important kinematic information related to shoulder pain may be occurring in the orientation of proximal joints during the push phase. Specifically, all wheelchair users exhibited mean scapular and humeral kinematics (an internally rotated, downwardly rotated scapula and abducted humerus) that may impose stress on the subacromial tissue within the shoulder complex (Morrow et al, 2011, Mozingo et al, 2020. Therefore, it is postulated that more uniform (less variable) scapular kinematics displayed by wheelchair users with moderate shoulder pain may impose this repeated stress on a small tissue area (Hamill et al, 2012).…”

“…In addition, since the elbow and shoulder joints are less constrained during the push phase it is worth evaluating these joints during both the push and recovery phases of the propulsion cycle. During wheelchair propulsion, wheelchair users exhibit scapular and humeral kinematics that impose mechanical stress on tissues within the shoulder (Morrow et al, 2011;Mozingo et al, 2020). However, it is currently unclear whether these orientations would be more common in wheelchair users with greater levels of shoulder pain.…”

Shoulder Tendon Adaptations Following a Graded Exercise Test to Exhaustion in Highly Trained Wheelchair Rugby Athletes With Different Impairments

“…Research using US and MRI has indicated that wheelchair users with a spinal cord injury (SCI) experience a number of shoulder pathologies, with tendinopathies or chronic tendon degeneration of the bicipital and supraspinatus tendons amongst the most common (15)(16)(17). Supraspinatus and biceps tendinopathy has also been associated with impingement due to a reduction in the sub-acromial space and therefore a greater occupation ratio [i.e., thickness of the tendon relative to the acromio-humeral distance (AHD)] (18), which naturally occurs during overhead and propulsion activities (18)(19)(20). Previous research identified differences in the occupation ratio between persons with subacromial impingement syndrome and healthy controls which further underscored the value of not only investigating tendon thickness and AHD separately (21,22).…”

“…Previous research identified differences in the occupation ratio between persons with subacromial impingement syndrome and healthy controls which further underscored the value of not only investigating tendon thickness and AHD separately (21,22). Subsequently, ample research has utilized US to establish the thickness and structure of the supraspinatus and biceps tendon, as well as the AHD to quantify the subacromial space, in manual wheelchair users with SCI (20,(23)(24)(25). However, previous research has primarily focused on SCI wheelchair users and to date, only one study investigated shoulder tendon characteristics in a sample of WR athletes including persons with a tetraplegia (n = 11), paraplegia (n = 21), and non-SCI (n = 2) (26).…”

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

“…The biceps tendon was selected since it is a biarticular muscle that contributes greatly (i.e., elevated relative muscular utilization ratio) to both net shoulder flexion and elbow flexion and extension moments during closed kinetic chain movements, such as the propulsive moment generated during the push phase of manual wheelchair propulsion [ 34 ], and frequently presents signs of tendinopathy among MWU SCI [ 29 ]. As for the supraspinatus tendon, it was selected since it presents an elevated risk of mechanical impingement during propulsion [ 35 ] resulting in most part from the scapular kinematics [ 36 ], contributes greatly (i.e., elevated relative muscular utilization ratio) to the net shoulder moments during the push and recovery phases of manual wheelchair propulsion [ 34 ], and frequently present signs of tendinopathy among MWU SCI [ 29 ]. Due to tendon adaptations from mechanical loading, it is anticipated that significant and clinically meaningful differences in tendon integrity will be found immediately after completion of the test, compared to immediately before.…”