Shoulder magnetic resonance imaging findings in manual wheelchair users with spinal cord injury

Spectrum and patterns of shoulder pathology on MRI in symptomatic elite wheelchair basketball athletes

BACKGROUND

Wheelchair basketball (WCB) is a popular para-sport adapted for athletes with physical disabilities. Shoulder injuries are commonly reported among WCB athletes. However, the understanding of the specific patterns and characteristics of shoulder injuries in WCB players is currently limited, and there is a lack of comprehensive literature available on this subject.

OBJECTIVES

To investigate the spectrum of pathologies observed in elite wheelchair basketball (WCB) athletes referred for MRI evaluation of symptomatic injuries of the shoulder.

METHODS

Retrospective review of consecutive elite WCB athletes referred for MRI evaluation of symptomatic shoulder injury. Demographic, clinical, and functional data including international wheelchair basketball federation (IWBF) classification of each athlete were collected. A total of 28 MRI studies were reviewed. Excluding MRI examinations of the same shoulder, 18 study cases were assessed for pathology of the rotator cuff (RC), labrum, long-head of biceps tendon, glenohumeral and acromioclavicular joints, and osseous lesions of the humerus or glenoid. Correlations between clinical-demographic features and MRI findings were statistically evaluated.

RESULTS

Supraspinatus tears were observed in 72.2%, infraspinatus tears in 50%, and subscapularis tears in 38.9% shoulders. Articular-sided partial tears frequently involved posterior supraspinatus (88.9%) and anterior infraspinatus (100%). Labral tears were seen in 38.9%, with involvement of the posterosuperior labrum in all tears. Hill-Sachs and osseous Bankart lesions (5.6%), and anterior-inferior labral tears (11.1%), were uncommon findings. Statistically significant correlations were observed of low IWBF point class and non-ambulatory athletes with subscapularis tendinosis (p = 0.015, p = 0.001) and tearing (p = 0.050, p = 0.013), and athletes with limited trunk control with subscapularis tendinosis (p = 0.013).

CONCLUSIONS

RC tears are common in elite WCB athletes with pattern of RC and labral tearing suggesting internal (superior-posterior) impingement as a contributory pathoetiologic mechanism. Non-ambulatory, low IWBF point class athletes, as well as those with limited trunk control have a statistically significant increase in subscapularis tendon pathology on MRI.

Finite Element Model of the Shoulder with Active Rotator Cuff Muscles: Application to Wheelchair Propulsion

The rotator cuff is prone to injury, remarkably so for manual wheelchair users. To understand its pathomechanisms, finite element models incorporating three-dimensional activated muscles are needed to predict soft tissue strains during given tasks. This study aimed to develop such a model to understand pathomechanisms associated with wheelchair propulsion. We developed an active muscle model associating a passive fiber-reinforced isotropic matrix with an activation law linking calcium ion concentration to tissue tension. This model was first evaluated against known physiological muscle behavior; then used to activate the rotator cuff during a wheelchair propulsion cycle. Here, experimental kinematics and electromyography data was used to drive a shoulder finite element model. Finally, we evaluated the importance of muscle activation by comparing the results of activated and non-activated rotator cuff muscles during both propulsion and isometric contractions. Qualitatively, the muscle constitutive law reasonably reproduced the classical Hill model force-length curve and the behavior of a transversally loaded muscle. During wheelchair propulsion, the deformation and fiber stretch of the supraspinatus muscle-tendon unit pointed towards the possibility for this tendon to develop tendinosis due to the multiaxial loading imposed by the kinematics of propulsion. Finally, differences in local stretch and positions of the lines of action between activated and non-activated models were only observed at activation levels higher than 30%. Our novel finite element model with active muscles is a promising tool for understanding the pathomechanisms of the rotator cuff for various dynamic tasks, especially those with high muscle activation levels.

Development and evaluation of the ARM algorithm: A novel approach to quantify musculoskeletal disorder risk factors in manual wheelchair users in the real world

This study aimed to develop and evaluate the ARM (arm repetitive movement) algorithm using inertial measurement unit (IMU) data to assess repetitive arm motion in manual wheelchair (MWC) users in real-world settings. The algorithm was tested on community data from four MWC users with spinal cord injury and compared with video-based analysis. Additionally, the algorithm was applied to in-home and free-living environment data from two and sixteen MWC users, respectively, to assess its utility in quantifying differences across activities of daily living and between dominant and non-dominant arms. The ARM algorithm accurately estimated active and resting times (>98%) in the community and confirmed asymmetries between dominant and non-dominant arm usage in in-home and free-living environment data. Analysis of free-living environment data revealed that the total resting bout time was significantly longer (P = 0.049) and total active bout time was significantly shorter (P = 0.011) for the non-dominant arm. Analysis of active bouts longer than 10 seconds showed higher total time (P = 0.015), average duration (P = 0.026), and number of movement cycles per bout (P = 0.020) for the dominant side. These findings support the feasibility of using the IMU-based ARM algorithm to assess repetitive arm motion and monitor shoulder disorder risk factors in MWC users during daily activities.

Sex-Related Differences in Shoulder Complex Joint Dynamics Variability During Pediatric Manual Wheelchair Propulsion

More than 80% of adult manual wheelchair users with spinal cord injuries will experience shoulder pain. Females and those with decreased shoulder dynamics variability are more likely to experience pain in adulthood. Sex-related differences in shoulder dynamics variability during pediatric manual wheelchair propulsion may influence the lifetime risk of pain. We evaluated the influence of sex on 3-dimensional shoulder complex joint dynamics variability in 25 (12 females and 13 males) pediatric manual wheelchair users with spinal cord injury. Within-subject variability was quantified using the coefficient of variation. Permutation tests evaluated sex-related differences in variability using an adjusted critical alpha of P = .001. No sex-related differences in sternoclavicular or acromioclavicular joint kinematics or glenohumeral joint dynamics variability were observed (all P ≥ .042). Variability in motion, forces, and moments are considered important components of healthy joint function, as reduced variability may increase the likelihood of repetitive strain injury and pain. While further work is needed to generalize our results to other manual wheelchair user populations across the life span, our findings suggest that sex does not influence joint dynamics variability in pediatric manual wheelchair users with spinal cord injury.

Changes in neuromuscular activation, heart rate and rate of perceived exertion over the course of a wheelchair propulsion fatigue protocol

Shoulder pain is common in persons with spinal cord injury and has been associated with wheelchair use. Fatigue related compensation strategies have been identified as possibly impacting the development of shoulder injury and pain. The purpose of this study was to investigate the progression of performance fatigability (i.e., decline in objective measure of performance including neuromuscular activation and increase in heart rate) and perceived fatigability (i.e., increased perceived exertion) during a 15-min fatigue protocol including maximum voluntary overground wheelchair propulsion. Fifty participants with paraplegic spinal cord injury completed three 4-min rounds of wheelchair propulsion, separated by 90 s of rest, on a figure-8 course consisting of two turns and full stops per lap in their manual wheelchairs (ClinicalTrials.gov: NCT03153033). Electromyography (EMG) signal of five muscles acting on the shoulder joint, heart rate (HR), and rate of perceived exertion (RPE) were measured at the beginning and end of every 4 min of propulsion. Root Mean Square (RMS) and Mean Power Frequency were calculated from EMG data. There was a significant increase in %RMS of the pectoralis major pars sternalis and trapezius pars descendens, HR, and RPE with greatest changes during the first 4 min of the protocol. The observed changes in neuromuscular activation in only two of the shoulder muscles may impact muscular imbalances and the development of shoulder injuries and should be further studied. The current study gives clearer insight into the mechanisms of performance fatigability and perceived fatigability throughout a wheelchair propulsion fatigue protocol.

The Influence of Age at Pediatric-Onset Spinal Cord Injury and Years of Wheelchair Use on Shoulder Complex Joint Dynamics During Manual Wheelchair Propulsion

Objective

To assess the association of age at pediatric-onset spinal cord injury (SCI) and years of manual wheelchair use with shoulder dynamics.

Design

Upper extremity kinematics and hand-rim kinetics were obtained during manual wheelchair propulsion. An inverse dynamics model computed three-dimensional acromioclavicular, sternoclavicular, and glenohumeral joint dynamics. Linear mixed effects models evaluated the association of age at injury onset and years of wheelchair use with shoulder dynamics.

Setting

Motion laboratory within a children's hospital.

Participants

Seventeen manual wheelchair users (N=17; 6 female, 11 male; mean age: 17.2 years, mean age at SCI onset: 11.5 years) with pediatric-onset SCI (levels: C4-T11) and International Standards for Neurological Classification of SCI grades: A (11), B (3), C (2), and N/A (2).

Interventions

Not applicable.

Main Outcome Measures

Acromioclavicular, sternoclavicular, and glenohumeral angles and ranges of motion, and glenohumeral forces and moments.

Results

We observed a decrease in maximum acromioclavicular upward rotation (ß [95% confidence interval {CI}]=3.02 [0.15,5.89], P=.039) and an increase in acromioclavicular downward/upward rotation range of motion (ß [95% CI]=0.44 [0.08,0.80], P=.016) with increasing age at SCI onset. We found interactions between age at onset and years of use for maximum glenohumeral abduction (ß [95% CI]=0.16 [0.03,0.29], P=.017), acromioclavicular downward/upward rotation range of motion (ß [95% CI]=-0.05 [-0.09,-0.01], P=.008), minimum acromioclavicular upward rotation (ß [95% CI]=-0.34 [-0.64,-0.04], P=.026). A decrease in glenohumeral internal rotation moment (ß [95% CI]=-0.09 [-0.17,-0.009], P=.029) with increasing years of use was found.

Conclusions

Age at injury and the years of wheelchair use are associated with shoulder complex biomechanics during wheelchair propulsion. These results are noteworthy, as both age at SCI onset and years of wheelchair use are considered important factors in the incidence of shoulder pain. These results suggest that investigations of biomechanical changes over the lifespan are critical.

Classification of Wheelchair Related Shoulder Loading Activities from Wearable Sensor Data: A Machine Learning Approach

Shoulder problems (pain and pathology) are highly prevalent in manual wheelchair users with spinal cord injury. These problems lead to limitations in activities of daily life (ADL), labor- and leisure participation, and increase the health care costs. Shoulder problems are often associated with the long-term reliance on the upper limbs, and the accompanying "shoulder load". To make an estimation of daily shoulder load, it is crucial to know which ADL are performed and how these are executed in the free-living environment (in terms of magnitude, frequency, and duration). The aim of this study was to develop and validate methodology for the classification of wheelchair related shoulder loading ADL (SL-ADL) from wearable sensor data. Ten able bodied participants equipped with five Shimmer sensors on a wheelchair and upper extremity performed eight relevant SL-ADL. Deep learning networks using bidirectional long short-term memory networks were trained on sensor data (acceleration, gyroscope signals and EMG), using video annotated activities as the target. Overall, the trained algorithm performed well, with an accuracy of 98% and specificity of 99%. When reducing the input for training the network to data from only one sensor, the overall performance decreased to around 80% for all performance measures. The use of only forearm sensor data led to a better performance than the use of the upper arm sensor data. It can be concluded that a generalizable algorithm could be trained by a deep learning network to classify wheelchair related SL-ADL from the wearable sensor data.

Hand-rim biomechanics during geared manual wheelchair propulsion over different ground conditions in individuals with spinal cord injury

Geared manual wheelchair wheels, a recently developed alternative propulsion mechanism, have the potential to alleviate the high upper extremity demands required for wheelchair propulsion and help decrease the risk of secondary injuries in manual wheelchair users. The objective of this study was to investigate the effects of using geared manual wheelchairs on hand-rim biomechanics of wheelchair propulsion in individuals with spinal cord injury (SCI). Seven manual wheelchair users with SCI propelled their wheelchairs equipped with geared wheels over tile, carpet, and up a ramp in low gear (gear ratio 1.5:1) and standard gear (gear ratio 1:1) conditions. Hand-rim kinetics and stroke cycle characteristics were measured using a custom instrumented geared wheel. Using the geared wheels in the low gear condition, propulsion speed (P = 0.013), peak resultant force (P = 0.005), peak propulsive moment (P < 0.006), and peak rate of rise of the resultant force (P = 0.035) decreased significantly in comparison with the standard gear condition. The significant increase in the number of stroke cycles when normalized to distance (P = 0.004) and decrease in the normalized integrated moment (P = 0.030) indicated that although a higher number of stroke cycles are required for travelling a given distance in the low gear than the standard gear condition, the low gear condition might be less demanding for the upper extremity. These results suggest that geared wheels could be a useful technology for manual wheelchair users to independently accomplish strenuous propulsion tasks including mobility on carpeted floors and ramp ascension, while reducing the risk factors contributing to the incidence of secondary upper extremity injuries.

Progression of rotator cuff tendon pathology in manual wheelchair users with spinal cord injury: A 1-year longitudinal study

OBJECTIVE

To investigate the progression of rotator cuff tendon pathology across one year in manual wheelchair (MWC) users with spinal cord injury (SCI) and matched able-bodied individuals, and to explore the association between pain, age, and duration of wheelchair use with the progression of rotator cuff pathology.

DESIGN

Longitudinal cohort study, 1-year follow-up.

SETTING

Outpatient clinic at a tertiary medical center.

PARTICIPANTS

Twenty-four adult MWC users with SCI (20 men) with an average age (SD) of 37(12) years and 24 age and sex-matched able-bodied individuals.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

Presence of shoulder pain was collected. Magnetic resonance imaging (MRI) abnormalities of rotator cuff tendons including tendinopathy and tendon tears at baseline and 1-year follow-up visits were graded by a board-certified musculoskeletal radiologist, and three categories of tendon pathology scores including individual tendon scores, unilateral cuff scores, and bilateral cuff scores were calculated for each participant.

RESULTS

Fifty-four percent of the MWC users reported shoulder pain at both time points which was significantly higher than able-bodied cohort at baseline (17%, P = 0.012) and year 1 (21%, P = 0.021). Rotator cuff tendon pathology was detected as mainly mild tendinopathies and low-grade partial-thickness tears in both cohorts at both time points but was more common in MWC users. The results for the bilateral cuff scores indicated a significant (P < 0.008) progression of rotator cuff tendon pathology in the MWC users over one year. MRI findings did not change significantly for the able-bodied cohort across time. There was no association of pain, age, or duration of MWC use with progression of rotator cuff pathology in MWC user cohort.

CONCLUSION

MWC users had a higher prevalence of pain than matched able-bodied cohort, but pain was minimal and not function-limiting. Bilateral cuff TOTAL scores showed pathology progression in MWC users, but MRI findings remained stable in the able-bodied cohort. MWC users were 3.4 times more likely to experience pathology progression than the able-bodied cohort.

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

Objective

This study aimed to identify acute changes in biceps and supraspinatus tendon characteristics before and after a graded exercise test to exhaustion (GXT) in highly trained wheelchair rugby (WR) athletes. A secondary aspect was to define chronic tendon adaptations related to the impairment of the athlete and the occupation of the tendon within the subacromial space (occupation ratio).

Methods

Twelve WR athletes with different impairments (age = 32 ± 6 years; body mass = 67.2 ± 11.2 kg; 9.0 ± 3.6 years competing) volunteered for this study. Performance Corrected Wheelchair Users Shoulder Pain Index was used to quantify shoulder pain. Quantitative Ultrasound Protocols (QUS) were used to define supraspinatus and biceps tendon thickness, echogenicity, and echogenicity ratio of both dominant and non-dominant shoulder before and after the GXT including 22 ± 3.1 min submaximal propulsion and 10.2 ± 1.7 min maximal propulsion on a treadmill. Furthermore, the acromio-humeral distance (AHD) defined from ultrasound (US) images was used to calculate the occupation ratios.

Results

A mixed-effect multilevel analysis that included shoulder as grouping variable, demonstrated a significant reduction in the echogenicity of the biceps following GXT whilst controlling for impairment [spinal cord injury (SCI) and non-SCI] and the occupation ratio (β = −9.01, SEβ = 2.72, p = 0.001, 95% CI = [−14.34; −3.68]). This points toward fluid inflow into the tendon that may be related to overload and acute inflammation. In addition, persons with a SCI (n = 8) had a thicker supraspinatus tendon in comparison to persons with non-SCI (n = 3) which may be related to chronic tendon adaptations (β = −0.53 mm, SEβ = 0.26, p = 0.038, 95% CI = [−1.04; −0.03]). Finally, a greater occupation ratio was associated with signs of tendinopathy (i.e., greater biceps and supraspinatus tendon thickness, and lower supraspinatus echogenicity and echogenicity ratio).

Conclusion

Acute biceps tendon adaptations in response to the GXT in highly trained WR athletes were evident with chronic adaptations in the supraspinatus tendon being related to the impairment of the athlete. Ultrasound can be used to monitor tendon adaptations in WR athletes for medical diagnosis to assist the scheduling and type of training.

Relationship Between Shoulder Pain and Joint Reaction Forces and Muscle Moments During 2 Speeds of Wheelchair Propulsion

The purpose of this study was to determine shoulder joint reaction forces and muscle moments during 2 speeds (1.3 and 2.2 m/s) of wheelchair propulsion and to investigate the relationship between joints reaction forces, muscle moments, and shoulder pain. The measurements were obtained from 20 manual wheelchair users. A JR3 6-channel load sensor (±1% error) and a Qualisys system were used to record 3-dimensional pushrim kinetics and kinematics. A 3-dimensional inverse dynamic model was generated to compute joint kinetics. The results demonstrated significant differences in shoulder joint forces and moments (P < .01) between the 2 speeds of wheelchair propulsion. The greatest peak shoulder joint forces during the drive phase were anterior directed (Fy, 184.69 N), and the greatest joint moment was the shoulder flexion direction (flexion moment, 35.79 N·m) at 2.2 m/s. All the shoulder joint reaction forces and flexion moment were significantly (P < .05) related to shoulder pain index. The forces combined in superior and anterior direction found at the shoulder joint may contribute to the compression of subacromial structure and predispose manual wheelchair users to potential rotator cuff impingement syndrome.

Temporo-spatial parameters, shoulder kinematics and acute tendon changes in four different stroke patterns in men wheelchair users with spinal cord injury

BACKGROUND

Manual wheelchair propulsion causes the shoulder tendon pathologies in wheelchair users with spinal cord injury due to its repetitive nature. Four different wheelchair stroke patterns can cause varying amounts of acute changes in the shoulder tendons.

OBJECTIVE

To evaluate and compare acute changes in the supraspinatus and biceps tendons and acromio-humeral distance (AHD) after propulsion between different stroke patterns in individuals with spinal cord injury. Additionally, to associate tendon changes with demographic and biomechanical characteristics.

DESIGN

Prospective and comparative study between four groups.

SETTING

Tertiary rehabilitation hospital.

PATIENTS

Men wheelchair users with spinal cord injury.

INTERVENTIONS

Participants were divided into 4 groups according to stroke pattern (arcing, semicirculer (SC), single-loop (SL) and double-loop (DL)), in which they used their wheelchair on a motorized treadmill at a speed of 1 m/s. A sample of 40 people was created, 10 in each group. All participants performed a propulsion test.

MAIN OUTCOME MEASURES

Temporo-spatial variables and shoulder kinematics were analyzed. Supraspinatus tendon thickness (SSTT), long head of biceps tendon thickness (LHBTT) and AHD were measured before and after the propulsion test.

RESULTS

SC pattern had lower cadance and larger contact angle. A reduction in SSTT and LHBTT in arcing pattern, LHBTT and AHD in SC pattern and, LHBTT in DL pattern was observed (all P < 0.05). However, SL pattern did not differ significantly in all ultrasonographic measurements (all P > 0.05). Body mass index was associated with a decrease in SSTT. Age and number of daily push-up were associated with a decrease in AHD.

CONCLUSIONS

Less tendon changes after the propulsion in the SL pattern suggested that the supraspinatus and biceps tendons were preserved in this pattern. The SL pattern may be a better choice for men wheelchair users with supraspinatus and biceps tendon pathologies. This article is protected by copyright. All rights reserved.

Biological Sex-Related Differences in Glenohumeral Dynamics Variability during Pediatric Manual Wheelchair Propulsion

Shoulder pain and pathology are extremely common in adult manual wheelchair users with spinal cord injury (SCI). Within this population, biological sex and variability in shoulder joint dynamics have been shown to be important contributors to both shoulder pain and pathology. Sex-related differences in shoulder dynamics variability during pediatric manual wheelchair propulsion may influence a user's lifetime risk of shoulder pain and pathology. The purpose of this study was to assess the influence of biological sex on variability in three-dimensional (3-D) glenohumeral joint dynamics in pediatric manual wheelchair users with SCI. An inverse dynamics model computed 3-D glenohumeral joint angles, forces, and moments of 20 pediatric manual wheelchair users. Levene's tests assessed biological sex-related differences in variability. Females exhibited less variability in glenohumeral joint kinematics and forces, but greater variability in joint moments than males. Evaluation of glenohumeral joint dynamics with consideration for biological sex and variability strengthens our interpretation of the relationships among shoulder function, pain, and pathology in pediatric manual wheelchair users.Clinical Relevance- Female pediatric manual wheelchair users may be at an increased risk of shoulder repetitive strain injuries due to decreased glenohumeral joint motion and force variability during propulsion. This work establishes quantitative methods for determining the effects of biological sex on the variability of shoulder joint dynamics.

Inertial Measurement Unit-Derived Ergonomic Metrics for Assessing Arm Use in Manual Wheelchair Users With Spinal Cord Injury: A Preliminary Report

Background:

Individuals with spinal cord injury (SCI) who use manual wheelchairs (MWCs) have a higher rate of rotator cuff pathology progression than able-bodied individuals.

Objectives:

This study aimed to test the ability of risk and recovery metrics of arm use to differentiate between (1) MWC users with SCI and matched able-bodied participants (cross-sectional matched-sample study) and (2) MWC users with rotator cuff pathology progression over 1 year from those without pathology progression (longitudinal study).

Methods:

Thirty-four MWC users and 34 age- and sex-matched able-bodied individuals were recruited. Upper arm risk (humeral elevation >60°) and recovery (static ≥5 seconds and humeral elevation <40°) metrics were calculated from wireless inertial measurement units (IMUs) worn on the upper arms and torso in the free-living environment. Two separate magnetic resonance imaging studies were completed and assessed for a subset of 16 MWC users approximately 1 year apart.

Results:

The frequency of risk events (p = .019), summated duration of recovery events (p = .025), and duration of each recovery event (p = .003) were higher for MWC users than able-bodied participants. The summated duration of risk events (p = .047), frequency of risk events (p = .027), and risk to recovery ratio (p = .02) were higher and the summated duration of recovery events (p = .036) and frequency of recovery events (p = .047) were lower for MWC users with rotator cuff pathology progression (n = 5) compared to those without progression (n = 11).

Conclusion:

IMU-derived metrics quantifying arm use at postures >60° and risk to recovery ratios may provide insights of potential risk factors for rotator cuff pathology progression.

Application and Reliability of Accelerometer-Based Arm Use Intensities in the Free-Living Environment for Manual Wheelchair Users and Able-Bodied Individuals

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.