Scapular kinematics in professional wheelchair tennis players

BackgroundParticipating in wheelchair tennis increases the demands placed on the shoulder and could increase the risk of developing shoulder pain and injury that might be associated with differences in scapular kinematics. The aim of the study was to examine the presence of shoulder pain and scapular kinematics in professional wheelchair tennis players.MethodScapular kinematics were obtained in 11 professional wheelchair tennis players, 16 people with shoulder impingement and 16 people without shoulder impingement during humeral elevation and lowering. Clinical examination of the wheelchair tennis players was undertaken using the Wheelchair Users Shoulder Disability Index (WUSPI) and clinical signs of shoulder impingement.FindingsThe WUSPI questionnaire (mean = 28 SD 13.8) demonstrated wheelchair tennis participants experienced little shoulder pain and clinical examination revealed negative impingement tests. Wheelchair tennis players had greater scapular posterior tilt during humeral elevation (3.9° SE 1.71; P = 0.048) and lowering (4.3° SE 1.8; P = 0.04) on the dominant compared to non-dominant side. The dominant scapulae of wheelchair tennis players were significantly (P = 0.014) more upwardly rotated (21° SD 6.7) than the scapulae of people with shoulder impingement (14.1° SD 7.0) during scapular plane humeral elevation.InterpretationThis first study of scapular kinematics in professional wheelchair tennis athletes demonstrated bilateral asymmetries and differences to able-bodied participants with shoulder impingement. Understanding the role of sport participation on shoulder function in wheelchair users would assist in the development of preventative and treatment exercise programmes for wheelchair users at risk of shoulder injury and pain.     

Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement

BACKGROUND AND PURPOSE: Treatment of patients with impingement symptoms commonly includes exercises intended to restore "normal" movement patterns. Evidence that indicates the existence of abnormal patterns in people with shoulder pain is limited. The purpose of this investigation was to analyze glenohumeral and scapulothoracic kinematics and associated scapulothoracic muscle activity in a group of subjects with symptoms of shoulder impingement relative to a group of subjects without symptoms of shoulder impingement matched for occupational exposure to overhead work. SUBJECTS: Fifty-two subjects were recruited from a population of construction workers with routine exposure to overhead work. METHODS: Surface electromyographic data were collected from the upper and lower parts of the trapezius muscle and from the serratus anterior muscle. Electromagnetic sensors simultaneously tracked 3-dimensional motion of the trunk, scapula, and humerus during humeral elevation in the scapular plane in 3 handheld load conditions: (1) no load, (2) 2. 3-kg load, and (3) 4.6-kg load. An analysis of variance model was used to test for group and load effects for 3 phases of motion (31(-60(, 61(-90(, and 91(-120(). RESULTS: Relative to the group without impingement, the group with impingement showed decreased scapular upward rotation at the end of the first of the 3 phases of interest, increased anterior tipping at the end of the third phase of interest, and increased scapular medial rotation under the load conditions. At the same time, upper and lower trapezius muscle electromyographic activity increased in the group with impingement as compared with the group without impingement in the final 2 phases, although the upper trapezius muscle changes were apparent only during the 4.6-kg load condition. The serratus anterior muscle demonstrated decreased activity in the group with impingement across all loads and phases. CONCLUSION AND DISCUSSION: Scapular tipping (rotation about a medial to lateral axis) and serratus anterior muscle function are important to consider in the rehabilitation of patients with symptoms of shoulder impingement related to occupational exposure to overhead work. [Ludewig PM, Cook TM. Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement.     

Comparison of scapular kinematics between elevation and lowering of the arm in the scapular plane

Objective. To compare scapular orientation during both the concentric (elevation) and eccentric (lowering) phases of scapular plane abduction in subjects with and without shoulder impingement.

Design. Mixed model analysis of variance with one between-subjects factor (group) and within-subjects factors of phase, humeral angle, and trial.

Background. Abnormal scapular kinematics have been identified in shoulder impingement patients during the concentric phase of arm elevation, and under static conditions. Because abnormal scapular motion is observed clinically during the eccentric phase of arm elevation, analysis of this phase of motion is warranted.

Methods. Twenty-six symptomatic and 26 healthy subjects performed five repetitions of humeral scapular plane abduction. An electromagnetic tracking device described three-dimensional scapular kinematics during arm elevation and lowering. Angular values for scapular anterior/posterior tipping in the sagittal plane, upward/downward rotation in the scapular plane, and internal/external rotation in the transverse plane were calculated. Scapular orientation relative to the thorax at humeral angles of 40°, 60°, 80°, 100°, and 120° was statistically tested for effects of phase and trial, or for interactions of phase with group or humeral angle.

Results. Internal rotation was significantly increased in the eccentric phase for both groups at the 100° angle (P<0.05) and for the symptomatic group only at the 120° angle (P<0.05). Scapular anterior tipping was significantly decreased during the eccentric phase in both groups at the 80° (P<0.001), 100° (P<0.0001), and 120° (P<0.0001) angles.

Conclusions. Small but statistically significant differences in scapular tipping and internal rotation during the eccentric phase of arm elevation were identified at higher humeral angles in both subject groups, while no significant phase differences for scapular upward rotation or for scapular variables at lower humeral angles were found. Averaged across phases, the symptomatic group demonstrated significant reductions in upward rotation at lower humeral elevation angles, and significant increases in anterior tipping at higher elevation angles as compared to the healthy group.

Relevance Normal and abnormal scapular kinematics during varying types of motion need to be understood in order to optimally design rehabilitation programs for individuals with impingement syndrome.     

Three-dimensional shoulder kinematics during a pressure relief technique and wheelchair transfer

OBJECTIVE: To assess 3-dimensional scapulothoracic and glenohumeral kinematics in able-bodied subjects during a weight-relief raise and while transferring to and from a wheelchair. DESIGN: Repeated-measures analysis of variance. SETTING: Research laboratory. PARTICIPANTS: Twenty-five able-bodied subjects without spinal cord injury or shoulder symptoms (20 men, 5 women; age range, 20-37y). INTERVENTIONS: Completion of weight-relief raise and transfer tasks. Main Outcome Measures: An electromagnetic motion capture system tracked 3-dimensional position and orientation of the thorax, scapula, and humerus. Absolute angular values assessed included scapular downward and upward rotation, internal and external rotation, and posterior and anterior tipping all relative to the thorax, as well as humeral internal and external rotation relative to the scapula. Data were compared across 3 phases of the weight-relief raise and for transfer direction (leading arm, trailing arm). RESULTS: Key findings included significantly increased anterior tipping and internal rotation of the scapula and decreased scapular upward rotation and external rotation of the humerus during the weight-relief raise. The leading arm showed significantly greater scapular anterior tipping and internal rotation and less scapular upward rotation and humeral external rotation than the trailing arm during the final phase of the transfer. CONCLUSIONS: Both the weight-relief raise and transfer result in scapular and humeral positions and directions of motion that may negatively impact the available subacromial space. This may present increased risk for injury or progression of shoulder pain in persons who must routinely perform these tasks.     

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

BackgroundMost 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.MethodsShoulder 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.FindingsPeriods 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 plane elevation (by acromion), whereas the supraspinatus was most susceptible during propulsion (by acromion and coracoacromial ligament).InterpretationThe occurrence of mechanical impingement during certain manual wheelchair tasks, even without increased load/resistance, demonstrates the importance of kinematics inherent to a task as a determinant of impingement. Frequency of and technique used to complete daily tasks should be carefully considered to reduce impingement risk, which may help preserve shoulder health long-term.     

Effect of shoulder pain on shoulder kinematics during weight-bearing tasks in persons with spinal cord injury

Nawoczenski DA, Riek LM, Greco L, Staiti K, Ludewig PM. Effect of shoulder pain on shoulder kinematics during weight-bearing tasks in persons with spinal cord injury.ObjectiveTo assess 3-dimensional scapulothoracic and glenohumeral kinematics between subjects with spinal cord injury and disease (SCI/D) with and without shoulder pain during a weight-relief raise and transfer task.DesignCase-control, repeated-measures analysis of variance.SettingMovement analysis laboratory.ParticipantsSubjects (N=43; 23 with clinical signs of impingement and 20 without) between 21 and 65 years of age, at least 1 year after SCI/D (range, 1–43y) resulting in American Spinal Injury Association Impairment Scale T2 motor neurologic level or below, and requiring the full-time use of a manual wheelchair.InterventionsWeight-relief raises and transfer tasks.Main Outcome MeasuresAn electromagnetic tracking system acquired 3-dimensional position and orientation of the thorax, scapula, and humerus. Dependent variables included angular values for scapular upward and downward rotation, posterior and anterior tilt, and internal and external rotation relative to the thorax, and glenohumeral internal and external rotation relative to the scapula. The mean of 3 trials was collected, and angular values were compared at 3 distinct phases of the weight-relief raise and transfer activity. Comparisons were also made between transfer direction (lead vs trail arm) and across groups.ResultsKey findings include significantly increased scapular upward rotation for the pain group during transfer (P=.03). Significant group differences were found for the trailing arm at the lift pivot (phase 2) of the transfer, with the pain group having greater anterior tilt (mean difference ± SE, 5.7°±2.8°). The direction of transfer also influenced kinematics at the different phases of the activity.ConclusionsPotentially detrimental magnitude and direction of scapular and glenohumeral kinematics during weight-bearing tasks may pose increased risk for shoulder pain or injury in persons with SCI/D. Consideration should be given to rehabilitation strategies that promote favorable scapular kinematics and glenohumeral external rotation.     

The specificity of fatiguing protocols affects scapular orientation: Implications for subacromial impingement

Background

Shoulder impairments are often associated with altered scapular kinematics. As muscles control scapular movement, functionally altering muscle performance through fatigue may produce scapular kinematics that mimic those of injured patients. The aim of this study was to examine if changes in scapular tilt, rotation and pro/retraction following two different upper extremity fatiguing protocols have any implications with respect to subacromial impingement.

Methods

Scapular orientation was monitored during posturally constrained static holds (at 0°, 45° and 90° of humeral elevation) before and after two fatiguing protocols, one global and one local. Both protocols are associated with producing changes in shoulder skeletal arrangement.

Findings

Following the global fatiguing protocol, there was significantly more scapular posterior tilt (P < 0.01) and upward rotation (P < 0.02), particularly at 90° humeral elevation. No changes in scapular orientation occurred following the local fatiguing protocol.

Interpretation

Scapular orientation changes following muscle fatigue acted to increase the subacromial space. Thus, the rotator cuff muscles, not the scapular stabilizers, have more influence on actively preventing mechanical subacromial impingement. The lack of evidence of reduction of the subacromial space thus implicates superior humeral head translation as a more likely primary mechanism of the initiation of subacromial impingement.     

Use of a geared wheelchair wheel to reduce propulsive muscular demand during ramp ascent: Analysis of muscle activation and kinematics

Background

Shoulder muscle overuse has been linked to the high prevalence of shoulder injuries in manual wheelchair users. Ramp ascent is a barrier that is often faced by manual wheelchair users that requires higher muscle activations than level wheelchair propulsion. Additionally, reported subjective measures of shoulder pain are reduced amongst manual wheelchair users when using a wheelchair wheel outfitted with a gear mechanism. The purpose of the current investigation was to investigate shoulder muscle activation levels and upper limb kinematics during ramp ascent with and without the use of a geared wheel.

Methods

Thirteen healthy participants (6 male and 7 female) performed ramp ascent on four ramp grades (1:12, 1:10, 1:8, 1:6) using three wheel conditions (gear, no gear, standard). Electromyographic (EMG) activity of select shoulder muscles as well as kinematics of the right upper limb were collected during ramp ascent. Peak and integrated EMG as well as peak wrist, elbow, and shoulder kinematics were obtained from all ramp ascent trials.

Findings

Peak EMG of the shoulder flexors decreased by an average of 17% (P ? 0.0229) during ramp ascent with the geared wheel. Integrated EMG increased by 67% (P ? 0.0034) as a consequence of an 86% increase (P = 0.0009) in ramp ascent duration during the geared wheel condition. There were no significant differences between the non-geared and standard wheel conditions.

Interpretation

Caution must be used if using the gear ratio for prolonged periods due to potential for muscle fatigue since the overall muscle effort to move a fixed distance is higher with the gear ratio. Reducing peak demands may benefit wheelchair users with performing more strenuous tasks of daily living.     

Scapulohumeral rhythm and associated spinal motion

BACKGROUND: To investigate the coordination of humeral, scapular and thoracolumbar spine motions during a number of unilateral and bilateral upper limb movements in a range of movement conditions. METHODS: Thirty-two healthy women performed unilateral and bilateral arm elevations in three planes-sagittal, coronal and scapular. Scapular, humeral and spinal orientations were measured at 100 Hz using a multi-sensor, 6-degree-of-freedom electromagnetic tracking system. Segmental displacements were computed following International Society of Biomechanics recommendations. FINDINGS: Humeral, scapular and thoracic segments demonstrate consistent, synchronous interactions. Scapular upward rotation is significantly greater on the non-dominant side than the dominant in all planes of movement and in both unilateral and bilateral arm movement. Unilateral and bilateral arm movements produce significantly different ranges and patterns of spinal motion and ranges of scapular external rotation. There does not appear to be any effect of age, height or weight on the ranges or patterns of motion of the shoulder girdle and spine during arm elevation. INTERPRETATION: Movement of the arm into elevation, irrespective of the plane of motion, has significant implications for the shoulder girdle and the thoracic spine. Clinical assessment of the shoulder should include the thoracic spine.     

Shoulder dysfunction assessment: self-report and impaired scapular movements

BACKGROUND AND PURPOSE: Shoulder dysfunction is common in various patient populations. This investigation was performed to assess shoulder dysfunction with self-report and performance-based functional measures. SUBJECTS: Fifty men (25 with shoulder dysfunction and 25 without shoulder dysfunction) participated in this study. METHODS: Self-report functional disabilities were assessed with the Flexilevel Scale of Shoulder Function (FLEX-SF), and electromagnetic tracking sensors were used to monitor 3-dimensional scapular movements during 4 functional tasks. RESULTS: Relative to the control group, the group with shoulder dysfunction showed significant alterations in scapular movements (averages of 6.9 degrees less posterior tipping, 5.7 degrees less upward rotation, and 2.3 cm more elevation). Scapular kinematics correlated significantly (r) with the Self-report FLEX-SF measure during functional tasks (posterior tipping = .454 to .712, upward rotation = .296 and .317, and elevation = -.310). DISCUSSION AND CONCLUSION: Functional disabilities were identified with self-report and performance-based functional measures. The inadequate scapular posterior tipping and scapular upward rotation as well as the excessive elevation may have implications in planning intervention strategies for people with shoulder dysfunction.     

Shoulder function and 3-dimensional scapular kinematics in people with and without shoulder impingement syndrome

BACKGROUND AND PURPOSE: Several factors such as posture, muscle force, range of motion, and scapular dysfunction are commonly believed to contribute to shoulder impingement. The purpose of this study was to compare 3-dimensional scapular kinematics, shoulder range of motion, shoulder muscle force, and posture in subjects with and without primary shoulder impingement syndrome. SUBJECTS: Forty-five subjects with impingement syndrome were recruited and compared with 45 subjects without known pathology or impairments matched by age, sex, and hand dominance. METHODS: Shoulder motion and thoracic spine posture were measured goniometrically, and force was measured with a dynamometer. An electromagnetic motion analysis system was used to capture shoulder kinematics during active elevation in both the sagittal and scapular planes as well as during external rotation with the arm at 90 degrees of elevation in the frontal plane. RESULTS: The impingement group demonstrated slightly greater scapular upward rotation and clavicular elevation during flexion and slightly greater scapular posterior tilt and clavicular retraction during scapular-plane elevation compared with the control group. The impingement group demonstrated less range of motion and force in all directions compared with the control group. There were no differences in resting posture between the groups. DISCUSSION AND CONCLUSION: The kinematic differences found in subjects with impingement may represent scapulothoracic compensatory strategies for glenohumeral weakness or motion loss. The decreased range of motion and force found in subjects with impingement support rehabilitation approaches that focus on strengthening and restoring flexibility.     

Scapula kinematics and associated impingement risk in manual wheelchair users during propulsion and a weight relief lift

Background

Shoulder impingement syndrome is a common upper extremity pathology in manual wheelchair users. Central to impingement is the orientation of the scapula and humerus as they determine the available subacromial space. The purpose of this study was to examine the scapulothoracic and glenohumeral internal/external rotation kinematics during the time of peak shoulder loading of propulsion and weight relief lift conditions to assess possible risk of impingement.

Methods

Scapula, humerus and trunk kinematics were measured for twelve manual wheelchair users over three conditions: level propulsion, ramp propulsion, and a weight relief lift. Scapulothoracic and glenohumeral kinematic variables were characterized for the full cycle of each condition as well as at the period of peak loading.

Findings

Common to all activities was an externally rotated glenohumeral joint and an anteriorly tilted and internally rotated scapula. At peak loading, glenohumeral internal/external rotation showed a significant difference between conditions, and post hoc analysis revealed that the weight relief lift displayed significantly less external rotation at peak loading when compared to level and ramp propulsion.

Interpretation

All activities placed the scapula in a potentially dangerous orientation for development of shoulder impingement. The weight relief lift, with a decrease in glenohumeral external rotation and large superior forces at the shoulder, potentially places the shoulder of the manual wheelchair user at the greatest risk for impingement soft tissue injury. Preventative strength training and activity modification may provide measures to slow progression of impingement development and associated pain in the manual wheelchair user.     

Effects of muscle fatigue on 3-dimensional scapular kinematics

OBJECTIVE: To determine the effects of fatigue during an external rotation task on 3-dimensional scapular kinematics. DESIGN: A single-group, pretest-posttest measurement design. SETTING: Research laboratory. PARTICIPANTS: Thirty healthy subjects. INTERVENTIONS: Not applicable.Main Outcome Measures: Three-dimensional scapular kinematics were recorded with a Polhemus magnetic tracking device during arm elevation in the scapular plane. RESULTS: There was a significant fatigue effect for all scapular rotations in the early to middle phases of humeral elevation. Significantly less posterior tilting (up to 90 degrees of elevation), external rotation (up to 120 degrees of elevation), and upward rotation (up to 60 degrees of elevation) were observed. Additionally, there were fair to good correlations (r range,.39-.60) between the changes in scapular posterior tilting and the amount of muscle fatigue. CONCLUSIONS: Fatigue in shoulder external rotation altered the scapular resting position and the movement of posterior tilting in the early range during arm elevation in the scapular plane. Observed changes in scapular kinematics may affect the amount of area in the subacromial space and facilitate impingement. Data regarding changes produced by fatigue of the external rotators may also help with the development of a model of diminished rotator cuff function.     

Comparison of scapular kinematics and muscle strength between those with a positive and a negative Scapular Assistance Test

BackgroundThe Scapular Assistance Test was suggested to directly assess the influence of scapular motion on pain and indirectly measure the function of the scapular rotators. However, it is still not clear if individuals with a positive Scapular Assistance Test actually present changes in scapular motion and muscle strength. This study compared scapular kinematics and muscle strength between those with a positive Scapular Assistance Test and those with a negative Scapular Assistance Test.MethodsFifty individuals with shoulder pain were randomly allocated to: positive (n = 25) or negative Scapular Assistance Test (n = 25) group. Scapular kinematics was measured during elevation and lowering of the arm. Strength of the serratus anterior and lower trapezius was also measured. Two-way analysis of variance was used to compare kinematics between groups. Unpaired Student's t-test and Mann-Whitney test were used to compare strength of serratus anterior and lower trapezius, respectively.FindingsThere were no differences (P > 0.05) in scapular internal rotation and upward rotation between both groups. For scapular tilt, there was group main effect (P < 0.05) during elevation and lowering of the arm, whereas the positive Scapular Assistance Test group presented greater scapular anterior tilt. There was no difference (P > 0.05) in strength between groups.InterpretationIndividuals with a positive Scapular Assistance Test are more likely to present decreased scapular posterior tilt in those with shoulder pain. Strength of the scapular muscles seems to be same in those with a positive and a negative Scapular Assistance Test.     

Influence of age on scapulo-thoracic orientation

Background. Scapular activity during shoulder motion is critical for normal shoulder function. With aging, muscle function deteriorates in almost all people, which may lead to shoulder impingement syndrome.

Methods. Forty-four normal subjects, 23 men and 21 women aged from 16 to 73 years with a mean age 48, were enrolled in the study. Static antero-posterior radiography at both 0° and 90° of abduction were undertaken and correlation between age and scapular orientations were evaluated by Pearson’s correlation coefficient test. The purpose of this study is to investigate the relationship between aging and scapulo-thoracic orientation.

Findings. Significant correlation coefficients were observed between aging and scapular orientations. With the shoulder at 0° abduction, posterior tilt showed significant negative correlation with aging. At 90° abduction, both posterior tilt and upward rotation angle correlated negatively with aging. The correlation was apparent at 90° abduction.

Interpretation. The results indicate that shoulder aging closely relates to changes of scapular orientation, which consist of decreases of the posterior tilt at 0° and 90° abduction and the upward rotation angle at 90°. The current study indicated that one of the effects of aging on the shoulder is a decrease of posterior tilt and upward rotation angle as seen in an abducted position; and that these alterations are similar to the scapular kinematics of shoulder impingement syndrome. By taking this concept into consideration, the effects of aging on shoulder kinematics can be appropriately evaluated.     

Impingement pain affects kinematics of breast cancer survivors in work-related functional tasks

BackgroundBreast cancer survivors may encounter upper limb morbidities post-surgery. It is currently unclear how these impairments affect arm kinematics, particularly during functional task performance. This investigation examined upper body kinematics during functional tasks for breast cancer survivors and an age-matched control group.MethodsFifty women (aged 35–65) participated: 25 breast cancer survivors who had undergone mastectomy and 25 age-range matched controls. Following basic clinical evaluation, including shoulder impingement tests, motion of the torso and upper limbs were tracked during six upper limb-focused functional tasks from which torso, scapular, and thoracohumeral angles were calculated. Between-group differences were evaluated with independent t-tests (p < .05). The breast cancer group was then divided based upon impingement tests and differences between the three new groups were tested with one-way ANOVAs (p < .05).FindingsBreast cancer survivors had higher disability scores, lower range of motion, and lower performance scores. The largest kinematic differences existed between the breast cancer survivors with impingement pain and the two non-pain groups. During overhead tasks, right peak scapular upward rotation was significantly reduced (d = 0.80–1.11) in the breast cancer survivors with impingement pain. This group also demonstrated trends of decreased peak humeral abduction and internal rotation at extreme postures (d = 0.54–0.78). These alterations are consistent with kinematics considered high risk for rotator cuff injury development.InterpretationImpingement pain in breast cancer survivors influences functional task performance and may be more important to consider than self-reported disability when evaluating pain and potential injury development.     

Examining assessment methods of scapular motion: Comparing results from planar elevations and functional task performance

BackgroundScapular kinematics of breast cancer survivors are most often evaluated during arm elevation. However, known compensations exist during functional task performance. The purpose of this study was to determine if scapular kinematics of breast cancer survivors during arm elevation are related to scapular kinematics during functional task performance.MethodsScapular kinematics of 25 non-cancer controls and 25 breast cancer survivors (split by presence of impingement pain) during arm elevation in 3 planes and 3 reaching and lifting functional tasks were measured. Scapular upward rotation and scapulohumeral rhythm (SHR) at 30° increments of arm elevation were calculated. Between-group differences of upward rotation during arm elevation were evaluated with one-way ANOVAs (p < 0.05). The association of upward rotation angle and SHR during arm elevation and functional tasks was tested with Pearson correlations (p < 0.05).FindingsScapular upward rotation was reduced for the breast cancer survivor with pain at lower levels of arm elevation in each plane by up to 7.1° (p = .014 to 0.049). This is inconsistent with functional task results, in which upward rotation decrements occurred at higher levels of arm elevation. Upward rotation angles and SHR during arm elevation had an overall weak-to-moderate relationship (r = 0.003 to 0.970, p = .001 to 0.048) to values from functional tasks. Arm elevation during sagittal plane elevation demonstrated scapular upward rotation that was most closely associated to upward rotation during functional task performance.InterpretationInconsistent relationships suggests that clinical evaluations should adopt basic functional movements for scapular motion assessment to complement simple arm elevations.     

Effects of Kinesio Taping on scapular kinematics and electromyographic activity in subjects with shoulder impingement syndrome

ObjectiveTo investigate the effects of Kinesio Taping® (KT) on scapular kinematics and electromyographic (EMG) activity in subjects with shoulder impingement syndrome (SIS).MethodsTwenty subjects with a diagnosis of SIS performed abduction, scaption, and flexion movements in two load conditions: (1) without load and (2) holding a dumbbell. The same movements were evaluated again with the use of KT over the deltoid muscle with a 20% tension. Scapular kinematics data of the shoulder complex were captured with BTS SMART-DX at a frequency rate of 100 Hz. EMG activity was evaluated for the upper trapezius, lower trapezius, middle deltoid, and serratus anterior muscles with BTS FREE EMG 1000 at a frequency rate of 1000 Hz. The root mean square values normalized by the maximal voluntary contraction and the peak values of upward rotation, internal rotation, and posterior tilt were compared with the KT conditions through repeated-measures ANOVA (α = 0.05) using SPSS software.ResultsNo significant differences between KT conditions were found for scapular kinematics (p > 0.05). For EMG activity, a reduction in the lower trapezius was found (p < 0.05) during abduction with load (p < 0.05) and elevation without load (p < 0.05).ConclusionsAccording to the results of this study, it was not possible to verify changes in scapular kinematics in subjects with SIS. However, a reduction in EMG activity was observed for the lower trapezius muscle. Therefore, caution should be taken in prescribing KT for SIS subjects, who already have a reduction in EMG activity in this muscle, as KT may have an adverse effect.     

Effect of sitting posture on 3-dimensional scapular kinematics measured by skin-mounted electromagnetic tracking sensors

OBJECTIVE: To determine the effect of trunk sitting posture on scapular kinematics during humeral elevation by using skin-mounted electromagnetic tracking sensors. DESIGN: Repeated-measures design contrasting scapular kinematics in 2 different sitting postures. SETTING: A biomechanics laboratory in Hong Kong with a real-time, 3-dimensional electromagnetic tracking device for measuring movements of the scapula. PARTICIPANTS: A sample of 16 healthy adults (12 women, 4 men; age, 21.6+/-3.92y) with full, pain-free shoulder range of motion and no history of shoulder pathology. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Movements of the scapula were measured while each subject performed humeral elevation in an upright seated position and a slouched seated position. RESULTS: In both postures, posterior tip, lateral and upward rotation of the scapula, and lateral rotation of the humerus were observed during humeral elevation. When the slouched posture was adopted, there were significant decreases in the posterior tip and lateral rotation of the scapula, but there was no significant change in the magnitude of the upward rotation of the scapula. CONCLUSION: Increased thoracic kyphosis significantly alters the kinematics of the scapula during humeral elevation.