Browsing by Subject "Shoulder"

Now showing 1 - 5 of 5
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    Postoperative Radiotherapy Breast Cancer Treatment: Musculoskeletal and Functional Implications
    (2023-09) Braudy, Renata
    ABSTRACT Purpose/Hypotheses: The overall purpose of this study was to better understand the effect of post-lumpectomy radiation therapy (RT) on skeletal muscle morphology, shoulder kinematics, and shoulder function following treatment for unilateral breast cancer. We hypothesized that within the same breast cancer survivor, the affected (treated) side would demonstrate significantly different shoulder kinematics and skeletal muscle morphology than the unaffected (untreated) side. We also hypothesized that RT dose delivered to specific muscles within the radiation field would adversely affect self-reported shoulder function. A small study was first performed on healthy volunteers to determine intra-rater reliability of a novel method of skeletal muscle B-mode ultrasonography (US) to evaluate echo intensity (EI) and cross-sectional area (CSA) of three muscles within the radiation field that have the potential to affect shoulder function. Number of Participants: 31 (5 healthy volunteers for US reliability, 26 breast cancer survivors for main study) Materials and Methods: This was a single center, non-therapeutic, observational cross-sectional study with two parts. First, 5 healthy volunteers participated in the US reliability study which involved three repeated measures of the pectoralis major (PMaj), pectoralis minor (PMin), and serratus anterior (SA) bilaterally. Second, 26 breast cancer survivors who were at least 1-year post-completion of RT following lumpectomy plus sentinel lymph node biopsy for the treatment of unilateral breast cancer then participated in the main study. Three-dimensional kinematic data were collected using electromagnetic sensors during forward shoulder flexion and abduction. Musculoskeletal US was used to determine skeletal muscle CSA and EI of the PMaj, PMin, and SA muscles of the treated and untreated sides. Radiation dose analyses were performed for those same 3 muscles using pre-existing computed tomography radiation simulation scans. The Penn Shoulder Score (PSS) and a custom questionnaire were also given to participants. Data were analyzed using Wilcoxon rank sum tests to determine difference across sides and groups, Spearman correlation to examine associations between variables, and multiple linear regression to examine covariate effects. Ultrasound intrarater reliability was performed on the healthy participants using intraclass correlation coefficient (ICC) analysis. Statistical significance cutoff value was set at 0.05 for all tests. Results: PMaj and PMin CSA and EI were reliable (ICC > 0.70) and used in the breast cancer survivor study. SA CSA and EI were not reliable (ICC < 0.7) and were used in the main study as exploratory analyses only. Breast cancer survivors demonstrated more sternoclavicular elevation during arm elevation on their affected side vs. their unaffected side. No significant differences existed between the affected and unaffected sides for other shoulder kinematic variables nor for ultrasound EI and CSA. In general, Penn Shoulder Score values were high, but a few specific functional movements were more commonly noted as being difficult which has clinical implications. Some PMin, PMaj, and SA radiation values were significantly correlated with multiple aspects of the PSS (total score and subscales). Trends were found for the PMin radiation dose and total radiation dose to affect the PSS, although correction for multiple testing made these statistically insignificant. Conclusions: Our data suggests that there may be a significant effect of postoperative RT on shoulder function in breast cancer survivors after unilateral lumpectomy and sentinel lymph node biopsy. Kinematic analysis demonstrated increased clavicle elevation on the affected side vs the unaffected side during arm elevation, but clinical relevance is uncertain. B-mode US was a reliable method of quantifying PMaj and PMin CSA and EI, but it was not reliable for the SA. B-mode US may not be sensitive enough to detect significant differences in EI and CSA in these muscles following RT. The PMaj, PMin, and SA receive a significant amount of radiation during treatment which may affect patient-reported shoulder pain. Although PSS scores were generally high, participants consistently reported ‘some difficulty’ with certain functional tasks that highlight the specific impairments many breast cancer survivors have following treatment. Additionally, breast cancer survivors complained not just of ‘shoulder pain’ but also stiffness, tightness, achiness, and other impairments in their shoulder, chest wall, and arm that need to be recognized and addressed by medical providers. This research demonstrates potential relationships between adjuvant RT and shoulder function which need to be further investigated to provide breast cancer survivors with the highest quality of life possible.
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    Risk of reduced subacromial space during activities of daily living for users of manual wheelchairs
    (2013-02) Zhao, Kristin Daigle
    Background and significance: Users of manual wheelchairs have to perform many movements within the confines of the wheelchair as well as utilize the wheelchair as a means of locomotion, for transferring to adjacent seating, and performing weight relief lifts, among other activities. The shoulder does not normally function as a weight bearing joint; however, users of manual wheelchairs rely heavily on their shoulder joints for these activities and shoulder pain is prevalent. There is general consensus that reduced subacromial space caused by altered glenohumeral kinematic patterns during wheelchair activities exposes the soft tissues at the shoulder, primarily the rotator cuff tendons, to mechanical compression during movement. The purpose of this study was to model the potential impact of angular kinematics during activities of daily living (wheelchair propulsion, weight relief raises, and scapular plane abduction) on the underlying subacromial space and resulting proximity of anatomical structures in a population of manual wheelchair users with reported shoulder pain. Research Methods: Fifteen spinal cord injured individuals participated in the study. The individuals used manual wheelchairs as their primary means of mobility and reported anterolateral shoulder joint pain presumed to be caused by mechanical impingement. The three-dimensional position and orientation of the subjects’ thorax, scapula, and humerus were collected using an electromagnetic tracking system during weight relief, propulsion, and scapular plane abduction. Scapulothoracic (3 rotations), glenohumeral (3 rotations) and thorax flexion/extension angles were determined throughout the tasks. Each subject’s glenohumeral rotation values were combined with CT-generated bone models of the scapula and humerus to simulate all three tasks. At each of the time steps, the proximity (distance) mapping and minimum distance from each of three tendon footprints (infraspinatus, supraspinatus, and subscapularis) to the acromion and coracoacromial ligament were determined. Analysis: Between-task and within-task comparisons of the angular kinematics were performed using repeated-measures ANOVA. Between-task comparisons of the minimum distance were performed using repeated-measures ANOVA, while the proximity maps were qualitatively assessed. Sensitivity of the linear distance values to errors in kinematic values were computed as well as an exploratory regression to predict linear distances from glenohumeral kinematics. Results: Significant between-task and within task differences were observed in many of the kinematic variables. The weight relief task possessed peak values for scapulothoracic internal rotation and anterior tilt, and glenohumeral internal rotation, and when comparing mean event data, it possessed greater anterior tilt (equal to propulsion) and glenohumeral internal rotation. Scapular plane abduction possessed the least at-risk kinematics, with the smallest event data across tasks for anterior tilt and glenohumeral internal rotation as well as for peak scapular internal rotation, anterior tilt, and glenohumeral internal rotation. Further, significant between-task differences were seen in linear distance values and risk (area between linear distance curves and 5.0mm threshold). In general, linear distances were smaller and risks were higher between the tendon footprints and the acromion (versus the coracoacromial ligament). Further, linear distances were smaller and risks higher during propulsion and scapular plane abduction, than during weight relief. Sensitivity analysis of the linear distance values resulted in sub millimeter changes for ± 3 degree changes in glenohumeral rotations and less than 2.0 mm for ± 6 degree changes. Proximity maps (within 2.0 mm and 5.0 mm thresholds) depicted changes in location of the maps on the tendon footprints and acromion, as well as coverage area, between tasks and muscles. The supraspinatus proximity area within a 2.0 mm threshold was greater than the infraspinatus area for both propulsion and scapular plane abduction, and within the 5.0 mm threshold for scapular plane abduction. Significant differences were only seen between the two tasks for the infraspinatus areas within 2.0 mm and 5.0 mm with larger areas during propulsion. Discussion and conclusions: When the current study findings were evaluated according to currently-held beliefs about at-risk scapulothoracic kinematics, the weight relief task placed the shoulder at greater risk for reduction in the subacromial space. Findings from the linear distance and risk analysis, however, did not support this result. Scapular plane abduction and propulsion were found to cause substantial risk of impingement using these measures. As subacromial impingement risk is defined based on glenohumeral motion changes, future research should focus on the glenohumeral articulation rather than on the scapula and humeral motions independently to attempt to define risk.
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    Shoulder Complex Kinematics in Individuals Clinically Classified with Multidirectional Instability: A Pre- Versus Post-Exercise Analysis
    (2023) Silverson, Oliver
    Background: The clinical classification of glenohumeral joint instability is characterized by presumed increased humeral translations in conjunction with symptomology. Prior research reports inconsistent trends in glenohumeral joint kinematic differences between individuals clinically classified with glenohumeral joint instability and asymptomatic controls classified with stable shoulders. Limitations surrounding clinical classification criteria and motion tracking methods likely contribute to the lack of consistent kinematic trends. Additionally, the effect of participation in repetitive, resisted, shoulder activities in individuals clinically classified with glenohumeral joint instability has not yet been examined. Purpose and approach: The purpose of this dissertation was to implement previously validated methods to clinically classify individuals with presumed glenohumeral joint instability and utilize state-of-the art kinematic assessment methods to: (1) determine the glenohumeral joint kinematic characteristics of individuals clinically classified with instability, (2) investigate the glenohumeral and scapulothoracic joint kinematic effects of exposure to repetitive, resisted, shoulder activity in this group, and (3) explore the effect of scapulothoracic rotations on humeral translations during arm raising. Results: Results from aim 1 indicated individuals clinically classified with glenohumeral joint instability possessed significantly more average anterior humeral position (0.8 mm) compared to asymptomatic matched controls during unweighted scapular plane abduction (SAB). No other kinematic differences between groups were detected. Results from aim 2 identified there was a significant decrease in average normalized contact path length (10%) between the humeral head and glenoid face during SAB and significantly less average scapular internal rotation during SAB (2.5°) and humerothoracic internal rotation (IR) (3.2°) after exposure to moderate levels of repetitive, resisted, shoulder activity. Results from aim 3 indicated there was not a significant relationship between scapulothoracic rotation and humeral translations during SAB. Summary: Findings from aim 1 of this research demonstrated that only one out of four kinematic variables used measure glenohumeral joint stability were statistically different between individuals clinically classified with glenohumeral joint instability and matched controls during unweighted SAB. These findings suggest that the magnitude of joint stability classified with passive laxity tests may not necessarily relate to dynamic joint stability. Further, perhaps more consistent kinematic differences could be identified under more vigorous task conditions. Evidence from aim 2 of this research demonstrated that participation in moderate levels of shoulder activity provoked statistically different changes in only one out of four kinematic variables used to measure glenohumeral joint stability and resulted in minimal changes (≤3.2°) in scapulothoracic kinematics during active arm raising and a simulated swimming task. These findings suggest that perhaps participation in more strenuous repetitive, resisted, shoulder activities may induce greater kinematic effects. Lastly, findings from aim 3 do not suggest the magnitude of scapular rotations affect the amount of humeral translations in individuals clinically classified with glenohumeral joint instability and imply that other factors may potentially influence glenohumeral joint stability during activity.
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    Shoulder joint and muscle exposure in violin musicians: a three dimensional kinematic and electromyographic exposure variation analysis.
    (2009-05) Reynolds, Jonathan F.
    Subacromial impingement syndrome is a common disorder in the right shoulders of orchestral violinists. Studies performed to date on this population have been limited in terms of kinematic methods used, resulting in inability to relate recorded motions to clinically relevant motions. They have also used temporal EMG analysis, which can be misleading in terms of exposure. Previous kinematic research on non-musician populations, and using non-occupational tasks, have indicated that subacromial impingement is associated with reduced posterior tilting and upward rotation of the scapula, as well as increased upper trapezius and decreased serratus anterior activation.This study compared 20 violinists (3 males and 17 females) with right sided SIS to 30 normal controls (11 males and 19 females) in the performance of 30-second, randomized performances of slow and fast standardized musical repertoire (each score being played 4 times). Surface EMG of upper trapezius and serratus anterior were sampled at 1,000 Hz using pre-amplified electrodes and signals were further amplified and RMS processed at 100 ms to improve signal to noise ratio. Signals were normalized to resting EMG and relative voluntary electrical activity (RVE). Three-dimensional kinematic data were captured in a standardized fashion by mathematically embedding local coordinate systems within the trunk, scapula and humerus, and rotations of these segments about the embedded axes were sampled at 100 Hz. EMG and 3-D kinematic data were then analyzed using Exposure Variation Analysis (EVA) methods, which expresses 3 amplitudes of the EMG or kinematic signal in terms of time spent at each amplitude level. EVA arrays were expressed in 3X3 graphs and were analyzed in terms of speed effects (fast and slow), and injury effects (injured and uninjured) using Mixed-Effects Multinomial Logistic Regression statistical methods. The reliability of the EVA method was evaluated by calculating intraclass correlation coefficients (ICC) and standard error of the measurement (SEM) statistics for all EVA cells and for all dependent variables. The EVA methods used in this study were found to have moderate to high levels of reliability (moderate to high ICC and low SEM). The EVA method was able to discern differences in terms of speed and injury in both injured and uninjured participants. Musicians in both groups were observed to play in positions of increased glenohumeral internal rotation compared to non-musician subjects participating in other research studies at similar humeral elevation angles. Injured musicians were noted to play in positions characterized by increased posterior scapular tilting for longer durations of time, increased scapular upward rotation for longer durations of time, and increased scapular internal rotation at slow speeds. Injured musicians were also noted to adopt positions of increased scapular posterior tilting, increased scapular upward rotation for longer durations of time, and increased scapular internal rotation at fast speeds. When compared to their uninjured counterparts, injured musicians were also noted to perform with reduced amplitude but more static (longer duration) glenohumeral flexion, as well as with slightly increased glenohumeral external rotation compared to uninjured musicians. Injured musicians were noted to perform with increased short duration, low amplitude upper trapezius activity at slow speeds, while they played with reduced long duration, high amplitude recruitment at fast speeds. Lastly, injured musicians were noted to demonstrate increased amplitude of recruitment of serratus anterior at both slow and fast speeds. The EVA method of data reduction employed in this study was instrumental in identifying these differences where more traditional methods (also attempted in this study) failed to identify group differences with respect to injury. This study has therefore identified a reliable kinematic and EMG data reduction technique that can be used to assess the kinematics of shoulder motion, as well as the upper trapezius and serratus anterior muscle activation in violin musicians. The findings of this study suggest that violinists develop SIS because of the positions they adopt in playing the violin, and that the injured musicians may have developed compensatory strategies to avoid discomfort.
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    Using Ultrasound to View Your Rotator Cuff.
    (2012-07-23) Scheff, Kent