Objective: To investigate the prevalence of rotator cuff and long head of the biceps pathologies in manual wheelchair (MWC) users with spinal cord injury (SCI). Design: Cross-sectional study. Setting: Outpatient clinic at a tertiary medical center. Participants: Forty-four adult MWC users with SCI (36 men and 8 women) with an average age (SD) of 42 (13) years. SCI levels ranged from C6 to L1; complete and incomplete SCI. Outcome Measures: Participants’ demographic and anthropometric information, presence of shoulder pain, Wheelchair User’s Pain Index (WUSPI) scores, and magnetic resonance imaging findings of shoulder pathologies including tendinopathy, tendon tears, and muscle atrophy. Results: Fifty-nine percent of the participants reported some shoulder pain. The prevalence of any tendinopathy across the rotator cuff and the long head of biceps tendon was 98%. The prevalence of tendinopathy in the supraspinatus was 86%, infraspinatus was 91%, subscapularis was 75%, and biceps was 57%. The majority of tendinopathies had mild or moderate severity. The prevalence of any tears was 68%. The prevalence of tendon tears in the supraspinatus was 48%, infraspinatus was 36%, subscapularis was 43%, and biceps was 12%. The majority of the tears were partial-thickness tears. Participants without tendon tears were significantly younger (P < 0.001) and had been wheelchair user for a significantly shorter time (P = 0.005) than those with tendon tears. Conclusion: Mild and moderate shoulder tendinopathy and partial-thickness tendon tears were highly prevalent in MWC users with SCI. Additionally, the findings of this study suggest that strategies for monitoring shoulder pathologies in this population should not be overly reliant on patient-reported pain, but perhaps more concerned with years of wheelchair use and age.

Shoulder pain and pathology are extremely common for individuals with spinal cord injuries (SCI) who use manual wheelchairs (MWC). Although risky humeral kinematics have been measured during wheelchair-based activities performed in the lab, little is known about arm kinematics in the free-living environment. The purpose of this study was to measure the humeral elevation workspace throughout a typical day for individuals with SCI who use a MWC and matched able-bodied controls. Thirty-four individuals with SCI who use a MWC (42.7±12.7 years of age, 28 males/6 females, C6-L1) and 34 age-and sex-matched controls were enrolled. Participants wore three inertial measurement units (IMU) on their upper arms and torso for one to two days. Humeral elevation angles were estimated and the percentage of time individuals spent in five elevation bins (0–30°, 30–60°, 60–90°, 90–120°, and 120–180°) were calculated. For both arms, the SCI cohort spent a significantly lower percentage of the day in 0–30° of humeral elevation (Dominant: SCI = 15.7±12.6%, Control = 32.1±15.6%, p<0.0001; Non-Dominant: SCI = 21.9±17.8%, Control = 34.3±15.5%, p = 0.001) and a significantly higher percentage of time in elevations associated with tendon compression (30–60° of humeral elevation, Dominant: SCI = 62.8±14.4%, Control = 49.9.1±13.0%, p<0.0001; Non-Dominant: SCI = 58.8±14.9%, Control = 48.3±13.6%, p = 0.003) than controls. The increased percentage of time individuals with SCI spent in elevations associated with tendon compression may contribute to increased shoulder pathology. Characterizing the humeral elevation workspace utilized throughout a typical day may help in understanding the increased prevalence of shoulder pain and pathology in individuals with SCI who use MWCs.

Arm use in manual wheelchair (MWC) users is characterized by a combination of overuse and a sedentary lifestyle. This study aimed to describe the percentage of daily time MWC users and able-bodied individuals spend in each arm use intensity level utilizing accelerometers. Arm use intensity levels of the upper arms were defined as stationary, low, mid, and high from the signal magnitude area (SMA) of the segment accelerations based on in-lab MWC activities performed by eight MWC users. Accelerometry data were collected in the free-living environments from forty MWC users and 40 sex- and age-matched able-bodied individuals. The SMA intensity levels were applied to the free-living data and the percentage of time spent in each level was calculated. The SMA intensity levels were defined as, stationary: ≤0.67 g, low: 0.671–3.27 g, mid: 3.27–5.87 g, and high: >5.871 g. The dominant arm of both MWC users and able-bodied individuals was stationary for most of the day and less than one percent of the day was spent in high intensity arm activities. Increased MWC user age correlated with increased stationary arm time (R = 0.368, p = 0.019). Five and eight days of data are needed from MWC users and able-bodied individuals, respectively, to achieve reliable representation of their daily arm use intensities.

The high prevalence of upper extremity joint injuries among manual wheelchair users is largely attributed to the high repetitive loading during propulsion. The purpose of this study was to evaluate the effects of using geared wheels for manual wheelchair mobility on shoulder joint biomechanics. Fourteen able-bodied participants performed overground propulsion and ramp ascension using standard and geared manual wheelchair wheels. Spatial temporal parameters, glenohumeral joint kinematics, and shoulder muscle activity were quantified. Findings indicated that regardless of the level of slope, the propulsion speed and stroke distance decreased significantly (p ≪ 0.001), and the stroke frequency increased significantly (p ≤ 0.025) during geared manual wheelchair propulsion. The glenohumeral joint ranges of motion in the coronal plane (p ≤ 0.005) and peak joint angles in the coronal (p ≤ 0.023) and transverse (p ≤ 0.012) planes were significantly different between standard and geared wheels usage. Shoulder muscle activity was substantially less using the geared wheels with significant findings in the pectoralis major (level floor, p ≤ 0.008) and infraspinatus (p ≤ 0.014) peak muscle activity, and the anterior deltoid (p ≤ 0.014) and pectoralis major (p ≤ 0.015) integrated muscle activity. However, the shoulder flexor normalized integrated muscle activity (muscle activity per stroke distance) was not different between the wheels.

Background: Falls in people with multiple sclerosis (pwMS) lead to morbidity and expense. Objective: Identify clinical metrics associated with falls. Methods: Eighty-six pwMS completed fall surveys, timed 25-foot walk (T25FW), and motion analysis with Clario Opal devices. Logistic regression models were created. Results: Median age was 54.5 years (range 21–73), 62% (53) were female. The cohort included 58% with relapsing (50) and 42% with progressive MS (36). Those who reported falling in the last year were older (median age 58 vs 52.5, p = .03) and had a higher Patient Determined Disease Step (PDDS) score (median 3 vs 1, p < .0001). Falls were associated with worse balance metrics including sway area (median 2.3 degrees ² vs 1.2, p = .01), jerk (median 3.3 m ² /s ⁵ vs 1.6, p = .005), and slower T25FW (median 11.5 s vs 8; p < .0001). A multivariable regression model based on gait aid use and T25FW time >10.8 s (c = 0.80) was derived. Having both features portended a probability of falling of 0.97, while having neither, a probability of 0.26. Conclusions: Falls in pwMS are more frequent in patients who are older, have higher PDDS, slower walking, and worse balance. Gait aid use and T25FW >10.8 s were strongly associated with falls in the past year.