Measurement of three dimensional shoulder movement patterns with an electromagnetic tracking device in patients with a frozen shoulder

Kinematic stabilization after the Latarjet procedure: beyond the triple blocking effect

BACKGROUND

The rationale for the Latarjet procedure was described as the "triple blocking" effect. Satisfactory surgical outcomes have been reported after surgery. However, it has been reported that the "triple blocking" effect increases joint stability, but it does not fully restore it. Moreover, the procedure is nonanatomic and concerns remain regarding the effects. The study of scapulohumeral rhythm, which is a clinical parameter used for the functional evaluation of shoulder kinematics, can offer new perspectives on the rationale for the procedure. This study aimed to compare the shoulder kinematics of patients after the Latarjet procedure to the shoulders of a healthy population using magnetic and inertial measurement units with a motion analysis system.

METHODS

A retrospective study with prospective data collection was conducted on 28 patients who underwent the open Latarjet procedure for recurrent shoulder instability. At a minimum 12-month follow-up, each patient was evaluated by assessing the range of motion, the Rowe score, and the Constant-Murley score. Patients were examined using the ShowMotion 3D kinematic tracking system (NCS Lab, Modena, Italy), which uses wireless wearable noninvasive magnetic and inertial measurement units sensors to assess the three-dimensional kinematics of the shoulder. For each plane of elevation (ie, flexion and abduction), the scapulohumeral rhythm was described by three scapulothoracic rotations (ie, protraction-retraction, mediolateral rotation and posterior-anterior tilting) as a function of humeral anteflexion or humeral abduction.

RESULTS

The mean time from first shoulder dislocation to surgery was 6.6 ± 3 years (range, 1-12 years). No intraoperative complications occurred, and computed tomography (CT) performed 3 months after surgery showed graft union in all patients. After a mean follow-up time of 32.4 ± 20 months (range, 12-96), the mean Constant-Murley score and Rowe scores were 94.5 ± 4.8 (range, 84-100) and 96.7 ± 3.5 (range, 90-100), respectively. All patients showed no signs of glenohumeral arthritis on X-ray examination. Scapular posterior tilt and scapular internal rotation were significantly greater in the patient group than in the healthy population for the flexion-extension and abduction-adduction movements along the whole shoulder range of motion (all P < .05); no differences were found in upward/downward scapular rotation.

CONCLUSION

A greater scapular posterior tilt and scapular internal rotation were observed after the Latarjet procedure. The modified position of the scapula was maintained during the entire range of motion, suggesting a shoulder-stabilizing kinematic effect in addition to the bony, sling and bumper effects.

Differences in biomechanical and metabolic factors between patients with frozen shoulder and asymptomatic individuals. A cross-sectional study

BACKGROUND

the pathogenesis of frozen shoulder (FS) is thought to be one of inflammation and fibrosis possibly influenced by hyperglycemia. Biomechanical changes of the shoulder joint in terms of muscle strength, scapular kinematics and proprioception might occur in FS.

OBJECTIVES

to compare muscle strength, scapular kinematics, proprioception, and blood glucose levels within patients with FS and to asymptomatic individuals.

DESIGN

cross-sectional study.

METHOD

Thirty-five patients with FS and 35 asymptomatic age and gender-matched individuals underwent physical assessment to determine muscle strength (abduction, external and internal rotation), scapular kinematics (both visually and with a plurimeter), proprioception (joint position sense), and blood glucose level.

RESULTS

Patients with FS showed a decrease in muscle strength in their affected shoulder compared to both the unaffected shoulder and asymptomatic individuals. Significant differences were found between the affected and unaffected shoulder in the FS group and between groups (FS versus controls) in scapular upward rotation (plurimeter) at 30° and 60° abduction. No difference in scapular kinematics (visual observation), proprioception, and blood glucose levels was found neither between shoulders in the FS group nor between groups.

CONCLUSION

A clinically relevant difference in muscle strength and increase in scapular upward rotation were found in the affected shoulder of patients with FS compared to their unaffected side and controls. However, no evidence of different levels of scapular kinematics (visual observation), proprioception, and blood glucose levels in the affected shoulder compared to the unaffected shoulder or controls is lacking.

The effect of muscle-biased manual therapy on shoulder kinematics, muscle performance, functional impairment, and pain in patients with frozen shoulder

BACKGROUND

Frozen shoulder (FS) is characterized by restricted active and passive shoulder mobility and pain.

PURPOSE

Compare the effect of muscle-biased manual therapy (MM) and regular physical therapy (RPT) in patients with FS.

STUDY DESIGN

Pretest-post-test control group study design.

METHODS

We recruited 34 patients with FS and compared the effect of 12-session MM and RPT. The outcome measures were scapular kinematics and muscle activation, scapular alignment, shoulder range of motion, and pain intensity. Two-way analysis of variance was used to examine the intervention effect with α = 0.05.

RESULTS

Both programs resulted in similar improvements in pain and shoulder function. Compared to the RPT, MM resulted in increased posterior tilt (MM: 7.04°-16.09°, RPT: -2.50° to -4.37°; p = 0.002; ES = 0.261) and lower trapezius activation (MM: 260.61%-470.90%, RPT: 322.64%-313.33%; p = 0.033; ES = 0.134) during scaption, and increased posterior tilt (MM: 0.70°-15.16°, RPT: -9.66° to -6.44°; p = 0.007; ES = 0.205) during the hand-to-neck task. The MM group also showed increased GH backward elevation (MM: 37.18°-42.79°, RPT: 43.64°-40.83°; p = 0.004, ES = 0.237) and scapular downward rotation (MM: -2.48° to 6.80°, RPT: 1.93°-1.44°; p < 0.001; ES = 0.404) during the thumb-to-waist task, enhanced shoulder abduction (MM: 84.6°-102.3°, RPT: 85.1°-92.9°; p = 0.02; ES = 0.153), and improved scapular alignment (MM: 10.4-9.65 cm, RPT: 9.41-9.56 cm; p = 0.02; ES = 0.114).

CONCLUSIONS

MM was superior to the RPT regarding scapular neuromuscular performance. Clinicians should consider adding muscle-biased treatment when treating FS.

Using skeletal position to estimate human error rates in telemanipulator operators

In current telerobotics and telemanipulator applications, operators must perform a wide variety of tasks, often with a high risk associated with failure. A system designed to generate data-based behavioural estimations using observed operator features could be used to reduce risks in industrial teleoperation. This paper describes a non-invasive bio-mechanical feature capture method for teleoperators used to trial novel human-error rate estimators which, in future work, are intended to improve operational safety by providing behavioural and postural feedback to the operator. Operator monitoring studies were conducted in situ using the MASCOT teleoperation system at UKAEA RACE; the operators were given controlled tasks to complete during observation. Building upon existing works for vehicle-driver intention estimation and robotic surgery operator analysis, we used 3D point-cloud data capture using a commercially available depth camera to estimate an operator's skeletal pose. A total of 14 operators were observed and recorded for a total of approximately 8 h, each completing a baseline task and a task designed to induce detectable but safe collisions. Skeletal pose was estimated, collision statistics were recorded, and questionnaire-based psychological assessments were made, providing a database of qualitative and quantitative data. We then trialled data-driven analysis by using statistical and machine learning regression techniques (SVR) to estimate collision rates. We further perform and present an input variable sensitivity analysis for our selected features.

Acute effect of scapular mobilization with associated myofascial release on butterfly performance: Randomized clinical trial

INTRODUCTION

To evaluate the acute effect of scapular mobilization with associated myofascial release compared to scapular mobilization without myofascial release on butterfly stroke sports performance.

DESIGN

Randomized clinical trial.

METHOD

Pilot study that non-probabilistically convenience sampling that selected butterfly swimmers who were simply randomized into three groups to receive the standard protocol (scapular mobilization with release of the subscapularis muscle by the lateral edge of the scapula and rib cage detachment) in intervention group (IG), sham group (SG) (scapular mobilization without subscapularis muscle release and without rib cage detachment) or no intervention in control group (CG). We evaluated the stroke frequency, length, and average speed of 30 swimmers using the 8.15 Kinovea® motion analysis system.

RESULTS

The findings showed that, compared to the CG and IG, the SG showed a significant reduction in mean velocity (p = 0.002; p = 0.02, respectively), stroke frequency (p = 0.002; p = 0.003, respectively), and stroke length (p = 0.01; p = 0.05, respectively).

DISCUSSION

The results showed that manual therapy through scapular mobilization without associated myofascial release with detachment of the scapula from the rib cage worsened the swimming efficiency indicators even after 30 min of application of the technique. The limitations of the studies are related to the sample size, the risk of non-probabilistic contraction bias and the lack of blinding of the evaluators. Thus, the results of this study should be evaluated with caution.

Defining the glenohumeral range of motion required for overhead shoulder mobility: an observational study

Background

Recovery of overhead mobility after shoulder surgery is time-consuming and important for patient satisfaction. Overhead stretching and mobilization of the scapulothoracic and glenohumeral (GH) joints are common treatment interventions. The isolated GH range of motion (ROM) of flexion, abduction, and external rotation required to move above 120° of global shoulder flexion in the clinical setting remains unclear. This study clarified the GH ROM needed for overhead mobility.

Methods

The timely development of shoulder ROM in patients after shoulder surgery was analyzed. Passive global shoulder flexion, GH flexion, abduction, and external rotation ROM were measured using goniometry and visually at 2-week intervals starting 6-week postsurgery until the end of treatment. Receiver operating characteristic curves were used to identify the GH ROM cutoff values allowing overhead mobility.

Results

A total of 21 patients (mean age 49 years; 76% men) after rotator cuff repair (71%), Latarjet shoulder stabilization (19%), and arthroscopic biceps tenotomy (10%) were included. The ROM cutoff value that accurately allowed overhead mobility was 83° for GH flexion and abduction with the area under the curve (AUC) ranging from 0.90 to 0.93 (p < 0.001). The cutoff value for GH external rotation was 53% of the amount of movement on the opposite side (AUC 0.87, p < 0.001).

Conclusions

Global shoulder flexion above 120° needs almost full GH flexion and abduction to be executable. External rotation ROM seems less important as long as it reaches over 53% of the opposite side.

Relationship between pain and range of motion in frozen shoulder

Background

A frozen shoulder (FS) is characterized by pain and limited range of motion (ROM). Although physical assessment of ROM is important for diagnosing and staging FS, ROM cannot be accurately assessed in clinical practice because of pain and muscle contraction. This study aimed to measure changes in shoulder joint ROM before and after anesthesia (ΔROM) in patients with FS and investigate the factors affecting these changes.

Methods

This study included 54 patients (age, 55.6 ± 9.4 years; 17 males; disease duration, 6.6 ± 3.4 months) with FS before manipulation under transmission anesthesia. FS was defined as having a ROM in external rotation (ER) that was less than 50% of that in the unaffected shoulder. Pain at night and during motion was assessed using a numerical rating scale. Before anesthesia, the passive ROM of forward flexion (FF), abduction (AD), and ER were measured in the supine position. After confirming that the anesthesia was effective, passive ROM was measured again.

Results

The ROM in the FF, AD, and ER after anesthesia was significantly higher than that before anesthesia (P < .001). ΔROM in the FF, AD, and ER was significantly correlated with pain at night (r = 0.51, P < .001; r = 0.45, P < .001; and r = 0.39, P = .004, respectively). Furthermore, ΔROM in the ER was significantly correlated with pain during motion (r = 0.31, P = .023) and disease duration (r = -0.31, P = .021).

Conclusion

The ROM of the FS is susceptible to pain and muscle contraction. Interventions, such as physical therapy, may be recommended after pain relief.

Effects of elevation on shoulder joint motion: comparison of dynamic and static conditions

BACKGROUND

Although visual examination and palpation are used to assess shoulder motion in clinical practice, there is no consensus on shoulder motion under dynamic and static conditions. This study aimed to compare shoulder joint motion under dynamic and static conditions.

METHODS

The dominant arm of 14 healthy adult males was investigated. Electromagnetic sensors attached to the scapular, thorax, and humerus were used to measure three-dimensional shoulder joint motion under dynamic and static elevation conditions and compare scapular upward rotation and glenohumeral joint elevation in different elevation planes and angles.

RESULTS

At 120° of elevation in the scapular and coronal planes, the scapular upward rotation angle was higher in the static condition and the glenohumeral joint elevation angle was higher in the dynamic condition (P&lt;0.05). In scapular plane and coronal plane elevation 90°- 120°, the angular change in scapular upward rotation was higher in the static condition and the angular change in scapulohumeral joint elevation was higher in the dynamic condition (P&lt;0.05). No differences were found in shoulder joint motion in the sagittal plane elevation between the dynamic and static conditions. No interaction effects were found between elevation condition and elevation angle in all elevation planes.

CONCLUSIONS

Differences in shoulder joint motion should be noted when assessing shoulder joint motion in different dynamic and static conditions. Level of evidence: Level III, diagnostic cross-sectional study.

Shoulder Kinematics of Axillary Web Syndrome in Women Treated for Breast Cancer

OBJECTIVE

To better understand how the shoulder moves in breast cancer survivors with axillary web syndrome (AWS), we compared 3-dimensional (3D) shoulder kinematics during shoulder elevation among breast cancer survivors with and without AWS 5 years postoperatively. Although research consistently shows decreased shoulder range of motion with AWS, we do not understand the underlying biomechanics.

DESIGN

Nested case control study.

SETTING

University Academic Breast Center.

PARTICIPANTS

Twenty-five women who had surgery 5 years previously for unilateral breast cancer with the removal of at least 1 lymph node participated in this study (N=25). Twelve participants had AWS; 13 women did not have AWS.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Three-dimensional shoulder kinematic data during shoulder forward flexion, scapular plane abduction, and coronal plane abduction were collected using 3D electromagnetic motion tracking. Kinematic data were extracted at 30°, 60°, 90°, and 120° of arm elevation for scapular upward rotation, internal rotation, and posterior tilt as well as for glenohumeral external rotation.

RESULTS

Women with AWS demonstrated 15.2° less scapular upward rotation at 120° humerothoracic elevation (95% confidence interval [-25.2, -5.2], P=.005), regardless of plane. No significant between-group differences were found for any other angle of scapular upward rotation, nor for scapular internal rotation, scapular posterior tilt, or glenohumeral axial rotation at any angle.

CONCLUSIONS

Five years after surgery for breast cancer, women diagnosed with AWS have altered scapulohumeral kinematics that may place them at an increased risk of shoulder pain based on existing kinematic literature in healthy cohorts. This information can help guide rehabilitation programs for breast cancer survivors to facilitate pain-free upper extremity function after treatment.

Effect of Functional Scapular Stabilization Training on Function and Pain in Frozen Shoulder Syndrome: A Randomized Controlled Trial

OBJECTIVE

The purpose of this study was to determine the effect of functional scapular stabilization training compared with the standard physical therapy on function and pain in people with frozen shoulder syndrome (FSS).

METHODS

In a single-blind randomized controlled trial, 86 people with FSS were randomly allocated into the intervention group (functional stabilization training [n = 43]) and control group (standard physical therapy [n = 43]) using block randomization for 12 weeks. The primary outcome measures were the Shoulder Pain and Disability Index and the numeric pain rating scale. The secondary outcome measures were range of motion (ROM), range of passive abduction, and coracoid pain test. All the outcome measures were carried out by an independent blind outcome assessor at baseline and at the end of 12 weeks.

RESULTS

A significant group × time interaction effect was observed for the Shoulder Pain and Disability Index (95% CI, 2.95-16.74; P < .01) and the numeric pain rating scale (95% CI, 0.67-2.07; P < .01) at the end of 12 weeks. The external rotation ROM showed a statistical significance with a mean change of 7.8° and P value of <.01.

CONCLUSION

The present findings show that scapular functional stabilization training resulted in improvement of function, reduction in pain, and greater improvement in external rotation ROM in patients with FSS. Also, our study findings suggest the involvement of rotator interval and inferior soft-tissue structures as indicated by the coracoid pain test and range of passive abduction.

Comparison of shoulder muscle strength, shoulder range of motion and scapular motion in men with ankylosing spondylitis and healthy men: a case-controlled study

Background/Aims

Ankylosing spondylitis mainly affects the vertebral column, meaning that the assessment of the physical function of the upper extremity and scapulothoracic region in ankylosing spondylitis is often overlooked. Therefore, the aim of this study was to investigate shoulder muscle strength, shoulder active range of motion and three-dimensional scapular motion in patients with ankylosing spondylitis.

Methods

The study included 18 men with ankylosing spondylitis, and 16 age-matched typically healthy men as the control group. Muscle strength, active range of motion, and three-dimensional scapular motion were assessed with a digital hand-held dynamometer, an inclinometer, and an electromagnetic tracking device respectively.

Results

A decrease in shoulder flexion and abduction muscle strength on both the dominant side (P<0.001, P=0.001) and non-dominant side (P<0.001, P<0.001) was found in the ankylosing spondylitis group compared to the control group. A decrease in shoulder flexion, abduction, and external and internal rotation active range of motion on both the dominant side (P=0.001, P<0.001, P=0.015, P<0.001, respectively) and non-dominant side (P=0.001, P<0.001, P=0.017, P<0.001 respectively) was observed in the ankylosing spondylitis group. There was an increase in the upward rotation of the scapula on the non-dominant side at 30, 60, and 90° humeral elevations in the ankylosing spondylitis group compared to the control group (P=0.018, P=0.003, P=0.001 respectively). The other parameters of the scapular motion did not differ between groups (P>0.05).

Conclusions

This study showed that shoulder muscle strength and active range of motion were lower, and the upward rotation of the scapula was greater in men with ankylosing spondylitis compared to typically healthy men. The kinetics and kinematics parameters of the shoulder and scapula should be considered when assessing the physical function of patients with ankylosing spondylitis.

Reliability of the assessment of scapular posterior tilt angle using the smartphone and scapular movement during arm elevation in healthy individuals and patients with frozen shoulder: a cross-sectional study

Background

Frozen shoulders are associated with abnormal scapular movements. However, scapular posterior tilt movement in frozen shoulders has not been investigated using simple clinical methods. This study aimed to clarify the reliability of scapular posterior tilting movement using a smartphone and scapular posterior tilting movement in healthy individuals and patients with frozen shoulder.

Methods

The participants were 22 healthy young (age 25.9 ± 4.1 years), 22 healthy middle-aged (age 52.6 ± 4.4 years), and 37 individuals with frozen shoulder (age 56.0 ± 7.0 years). Scapular posterior tilting movement was measured at shoulder flexion 0° (0° posterior tilt), shoulder flexion 90° (90° posterior tilt), and scapular tilt excursion using a smartphone. The intrarater reliability was calculated using the intraclass correlation coefficient (1, 3).

Results

Intrarater reliability at 0° posterior tilt and 90° posterior tilt was 0.76 and 0.84, respectively. The 0° posterior tilt was not significantly different among the three groups (P = .90). The 90° posterior tilt was not significantly different among the three groups (P = .06). The scapular tilt excursions were significantly greater in the frozen shoulder group than in the middle-aged group (P = .03).

Conclusion

Measurement of scapular posterior tilting movement using a smartphone was highly reliable. The frozen shoulder might compensate for the limited arm elevation of the glenohumeral joint by scapular posterior tilting movement.

Reachable Workspace and Proximal Function Measures for Quantifying Upper Limb Motion

There are a lack of quantitative measures for clinically assessing upper limb function. Conventional biomechanical performance measures are restricted to specialist labs due to hardware cost and complexity, while the resulting measurements require specialists for analysis. Depth cameras are low cost and portable systems that can track surrogate joint positions. However, these motions may not be biologically consistent, which can result in noisy, inaccurate movements. This paper introduces a rigid body modelling method to enforce biological feasibility of the recovered motions. This method is evaluated on an existing depth camera assessment: the reachable workspace (RW) measure for assessing gross shoulder function. As a rigid body model is used, position estimates of new proximal targets can be added, resulting in a proximal function (PF) measure for assessing a subject's ability to touch specific body landmarks. The accuracy, and repeatability of these measures is assessed on ten asymptomatic subjects, with and without rigid body constraints. This analysis is performed both on a low-cost depth camera system and a gold-standard active motion capture system. The addition of rigid body constraints was found to improve accuracy and concordance of the depth camera system, particularly in lateral reaching movements. Both RW and PF measures were found to be feasible candidates for clinical assessment, with future analysis needed to determine their ability to detect changes within specific patient populations.

Dynamic scapular recognition exercise improves scapular upward rotation and shoulder pain and disability in patients with adhesive capsulitis: a randomized controlled trial

BACKGROUND

Examine the ability of a dynamic scapular recognition exercise to improve scapular upward rotation and decrease shoulder pain and disability in patients with adhesive capsulitis of the shoulder.

METHODS

A test-retest randomized controlled study design was used. A total of sixty-six patients with unilateral adhesive capsulitis were equally divided into two groups. The study group received a dynamic scapular recognition exercise using a wireless biofeedback system, while the control group received placebo treatment in the form of active range-of-motion (ROM) exercises of the sound upper limb. A digital inclinometer was used to measure the scapular upward rotation and ROM of the shoulder joint, and the Shoulder Pain and Disability Index (SPADI) was used to measure the shoulder pain and disability.

RESULTS

Study results showed that after two weeks, there were statistically significant differences between the study and control groups in scapular upward rotation and shoulder flexion and abduction (P < .05) and nonsignificant differences in shoulder external rotation and SPADI (P > .05). After two and six months, there were statistically significant differences between study and control groups in scapular upward rotation; shoulder flexion, abduction and external rotation; and SPADI scores (P < .05).

CONCLUSION

This study showed that a dynamic scapular recognition exercise significantly improves scapular upward rotation and the ROM of shoulder flexion and abduction after two weeks. At two and six months, this exercise improves scapular upward rotation; ROM of shoulder flexion, abduction, and external rotation; and SPADI scores. These improvements persisted for six months after the performance of this exercise.

The latissimus dorsi tendon functions as an external rotator after arthroscopic-assisted transfer for massive irreparable posterosuperior rotator cuff tears

PURPOSE

Latissimus dorsi tendon transfer is a surgical option for the treatment of massive irreparable posterosuperior rotator cuff tear. Whether a favourable clinical outcome is due to the latissimus dorsi muscle contraction rather than the passive tenodesis effect remains to be confirmed. The purpose of the current case-control study was to evaluate the shoulder kinematics and latissimus dorsi activation after latissimus dorsi tendon transfer.

METHODS

Eighteen patients suffering from irreparable rotator cuff tear that underwent latissimus dorsi tendon transfer and 18 healthy individuals were examined using a 3D kinematic tracking system and electromyography. Active maximal flexion-extension and abduction-adduction of the humerus were measured for the operated and the contralateral shoulder of the patients and the shoulder of healthy individuals to evaluate the range of motion (ROM) and scapulohumeral rhythm. Electromyographic comparison of isometric contraction between the latissimus dorsi of the operated and contralateral shoulder was carried out.

RESULTS

After arthroscopic-assisted latissimus dorsi tendon transfer, patients showed comparable flexion and abduction ROM to their asymptomatic contralateral shoulders and to the shoulders of healthy individuals. Significantly higher scapular ROM values were found between the latissimus dorsi tendon transfer side and the shoulders of healthy individuals. While performing external rotation with 0° shoulder abduction, a greater percentage of the electromyographic peak value (p = 0.047) and a higher latissimus dorsi internal/external rotation ratio (p = 0.004) were noted for the transferred muscle in comparison to the contralateral shoulder.

CONCLUSION

Although the arthroscopic-assisted latissimus dorsi tendon transfer failed to normalize scapulothoracic joint movements of patients, a functional latissimus flap and a shoulder ROM similar to the contralateral side or the shoulder of healthy individuals can be expected after this procedure in patients with massive irreparable posterosuperior rotator cuff tear.

LEVEL OF EVIDENCE

III.

Measurement of Pectoralis Minor Muscle Length in Women Diagnosed With Breast Cancer: Reliability, Validity, and Clinical Application

BACKGROUND

Decreased pectoralis minor muscle length is common after primary breast cancer treatment and can result in an abnormal position of the scapula. This position can contribute to shoulder pain and pathomechanics and can lead to problems such as impingement syndrome, rotator cuff tears, and frozen shoulder. Currently, there are limited reliable methods for measuring pectoralis minor length.

OBJECTIVE

The objective of this study was to examine the reliability and validity of measuring pectoralis minor length in women diagnosed with breast cancer.

DESIGN

This was a cross-sectional reliability and validity study.

METHODS

Bilateral pectoralis minor length (in centimeters) was assessed using a palpation meter in women (N = 29) diagnosed with breast cancer by 2 licensed physical therapists who were masked to the measures. Bilateral pectoralis minor length was also measured using a motion capture system to assess validity.

RESULTS

Intratester reliability (intraclass correlation coefficient, ICC [3,k] = 0.971; 95% confidence interval [CI] = 0.939-0.986; standard error of measurement [SEM] = 0.16 cm) and intertester reliability (ICC[3,k] = 0.915; 95% CI = 0.81-0.962; SEM = 0.31 cm) were excellent for the palpation meter on the affected side and the unaffected side (intratester reliability: ICC[3,k] = 0.951; 95% CI = 0.897-0.977; SEM = 0.19 cm; intertester reliability: ICC[3,k] = 0.945; 95% CI = 0.877-0.975; SEM = 0.22 cm). Significant correlations were found between the motion capture system and the palpation meter on the affected side (r = 0.87) and the unaffected side (r = 0.81). Bland-Altman plots between the palpation meter and the motion capture system demonstrated that all the measures fell within the limits of agreement.

LIMITATIONS

This study encountered possible errors with the accuracy of the motion capture system tracking because of the proximity of the markers and inherent volumetric restrictions.

CONCLUSIONS

The palpation meter is a reliable, valid, easily administered, and cost-effective tool for assessing pectoralis minor length in women with breast cancer.

The Coupled Kinematics of Scapulothoracic Upward Rotation

BACKGROUND

Scapulothoracic upward rotation (UR) is an important shoulder complex motion allowing for a larger functional work space and improved glenohumeral muscle function. However, the kinematic mechanisms producing scapulothoracic UR remain unclear, limiting the understanding of normal and abnormal shoulder movements.

OBJECTIVE

The objective of this study was to identify the coupling relationships through which sternoclavicular and acromioclavicular joint motions contribute to scapulothoracic UR.

DESIGN

This was a cross-sectional observational study.

METHODS

Sixty participants were enrolled in this study; 30 had current shoulder pain, and 30 had no history of shoulder symptoms. Shoulder complex kinematics were quantified using single-plane fluoroscopy and 2D/3D shape matching and were described as finite helical displacements for 30-degree phases of humerothoracic elevation (30 degrees-60 degrees, 60 degrees-90 degrees, and 90 degrees-120 degrees). A coupling function was derived to estimate scapulothoracic UR from its component motions of acromioclavicular UR, sternoclavicular posterior rotation, and sternoclavicular elevation as a function of acromioclavicular internal rotation. The proportional contributions of each of the component motions were also calculated and compared between phases of humerothoracic elevation and groups.

RESULTS

Scapulothoracic UR displacement could be effectively predicted using the derived coupling function. During the 30- to 60-degree humerothoracic elevation phase, acromioclavicular UR accounted for 84.2% of scapulothoracic UR, whereas sternoclavicular posterior rotation and elevation each accounted for < 10%. During later phases, acromioclavicular UR and sternoclavicular posterior rotation each accounted for 32% to 42%, whereas sternoclavicular elevation accounted for < 11%.

LIMITATIONS

Error due to the tracking of sternoclavicular posterior rotation may have resulted in an underprediction of its proportional contribution and an overprediction of the proportional contribution of acromioclavicular UR.

CONCLUSIONS

Acromioclavicular UR and sternoclavicular posterior rotation are the predominant component motions of scapulothoracic UR. More research is needed to investigate how these coupling relationships are affected by muscle function and influenced by scapular dyskinesis.

The effect of intracortical bone pin on shoulder kinematics during dynamic activities

Intracortical bone pins are introduced as gold standard for analysing skeletal motion because of eliminating soft tissue artefact. However, excluding this methodological error might be in cost of intervening movement pattern by local anaesthesia and pain of external tool within body. The purpose of this study was to examine whether intracortical bone pins alter shoulder joint kinematics or coordination. Three subjects were analysed during arm elevation/depression in frontal and sagittal planes. Retroreflective skin markers captured the motion in two sessions, before and after inserting bone pins (SKIN and PIN sessions), respectively. Thoracohumeral and scapulothoracic kinematics and scapulohumeral rhythm (SHR) were compared between two sessions. Thoracohumeral exhibited lower elevation and internal rotation in PIN session especially close to maximum arm elevation. The highest differences were observed for scapulothoracic kinematics, with higher retraction during abduction as well as higher posterior tilt, lateral rotation and retraction during flexion in PIN session. In addition, no systematic changes in SHR between subjects was found. Statistically significant lower SHR in PIN session was observed over 87-100% of thoracohumeral elevation/depression cycle in frontal plane and over 25-61% in sagittal plane. Further studies should treat carefully toward the clinical validity of shoulder joint kinematics after inserting bone pins.

A pilot study of ultrasound-guided acupotomy for the treatment of frozen shoulder

This study retrospectively analyzed the feasible effectiveness of ultrasound-guided acupotomy (USGAP) for the treatment of frozen shoulder (FS). A total of 36 patients with FS were analyzed in this retrospective study. All 36 patients received extracorporeal shock-wave therapy (ESWT). In addition, 18 of them also underwent USGAP intervention and were assigned to a treatment group, while the other 18 patients did not receive such intervention and were assigned to a control group. The primary efficacy endpoint was pain intensity, as measured by the Numeric Rating Scale (NRS). The secondary efficacy endpoint was assessed by the score of shoulder pain and disability index (SPADI). Furthermore, the adverse events were also documented during the treatment period. All efficacy endpoints were measured after the treatment. After treatment, patients who received USGAP exerted better efficacy endpoints in pain relief, as measured by NRS scale (P < .01), and shoulder disorders, as evaluated by SPADI (P < .01), than subjects who did not receive USGAP. Additionally, no adverse events occurred in either group. The results of this study indicated that USGAP may be used for the treatment of FS effectively. More studies are still needed to warrant the present results.

Which method for frozen shoulder mobilization: manual posterior capsule stretching or scapular mobilization?

OBJECTIVES

This study aimed to compare the superiority of scapular mobilization, manual capsule stretching, and the combination of these two techniques in the treatment of frozen shoulder patients to evaluate the acute effects of these techniques on shoulder movements.

METHODS

This study designed to a single-blinded, randomized, and pre-post assessment study. This study was included 54 patients diagnosed with stage 3 frozen shoulder. Group 1 (n=27) received scapular mobilization, and Group 2 (n=27) received manual posterior capsule stretching. After the patients were assessed, the interventions were re-applied with a crossover design to obtain results for the combined application (n=54). The range of motion, active total elevation, active internal rotation, and posterior capsule tensions of the shoulder joint were recorded before and immediately after mobilization.

RESULTS

Statistical analysis showed an increase in all range of motion values (p<0.05), except for shoulder internal rotation (p>0.05), without significant difference among the groups (p>0.05). The posterior capsule flexibility did not change in any group (p>0.05).

CONCLUSIONS

Scapular mobilization and manual posterior capsule interventions were effective in improving the acute joint range of motion in frozen shoulder patients.

SCAPULAR SUBSTITUTION AFTER ROTATOR CUFF REPAIR CORRELATES WITH POSTOPERATIVE PATIENT OUTCOME

BACKGROUND

Scapular substitution is an alteration of scapulohumeral kinematics that may occur when patients have shoulder pain or dysfunction. These abnormal scapular kinematic patterns have been recognized in patients with rotator cuff tears. It remains unknown if 1) normal scapular kinematics can be restored with rehabilitation after rotator cuff repair surgery and 2) abnormal scapular kinematics are associated with inferior patient-determined outcome scores, range of motion, or strength.

PURPOSE

The purpose of this study was to determine 1) if scapular substitution can be decreased or improved with rehabilitation after rotator cuff repair surgery and 2) if the presence or amount of scapular substitution was correlated with patient-determined outcome scores, range of motion, or strength after rotator cuff repair surgery.

STUDY DESIGN

Retrospective review of prospectively collected data (LOE IV).

METHODS

Forty-eight patients who underwent post-operative rehabilitation after an arthroscopic rotator cuff repair were reviewed for this study. The outcomes measures of interest included: patient-determined outcome scores (WORC, Simple Shoulder Test, the ASES Score, the Shoulder Activity Score, and the SANE rating), identification and quantification of scapular substitution, active range of motion, and strength. Outcomes were prospectively collected up to 12 months after surgery and assessed retrospectively.

RESULTS

As patients progress through their first year of rehabilitation from a rotator cuff repair, the amount of scapular substitution decreases but remains statistically significantly greater than the contralateral, asymptomatic side. At all post-operative time points, patients with scapular substitution, (determined subjectively by a physical therapist), had 1) inferior WORC, ASES, SANE, and SST scores, 2) inferior flexion, abduction, and external rotation range of motion, and 3) inferior scaption strength compared to those patients without subjective scapular substitution.

CONCLUSIONS

Rehabilitation decreases but does not normalize the amount of scapular substitution up to one year after rotator cuff repair. Subjective identification of scapular substitution is associated with inferior patient-determined outcome scores, range of motion, and strength.

LEVEL OF EVIDENCE

4 - Prognosis study.

Restriction of Passive Glenohumeral Abduction Combined With Normal Passive External Rotation Is a Diagnostic Feature of Calcific Tendinitis

Background:

Passive glenohumeral range of motion may be characteristically limited to specific shoulder pathologies. While pain associated with loss of range of passive external glenohumeral rotation is recognized as a salient feature in adhesive capsulitis, restriction of glenohumeral range of motion in calcific tendinitis of the supraspinatus tendon has never been studied.

Hypothesis:

On the basis of clinical observation, we hypothesized that calcific tendinitis of the supraspinatus tendon is associated with loss of passive glenohumeral abduction without loss of external rotation.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Ranges of passive glenohumeral rotation and abduction, which are measured with a standardized protocol in our institution, were retrospectively reviewed and compared for patients diagnosed with either adhesive capsulitis or calcific tendinitis of the supraspinatus tendon. A total of 57 patients met the inclusion criteria for the calcific tendinitis, and 77 met the inclusion criteria for the adhesive capsulitis group.

Results:

When compared with the contralateral, unaffected shoulder, glenohumeral abduction in the calcific tendinitis group was restricted by a median of 10° (interquartile range [IQR], –20° to –5°) as opposed to glenohumeral external rotation, which was not restricted at all (median, 0°; IQR, 0° to 0°). The adhesive capsulitis group showed a median restriction of glenohumeral abduction of 40° (IQR, –50° to –30°) and a median restriction of passive glenohumeral external rotation of 40° (IQR, –60° to –30°).

Conclusion:

Calcific tendinitis of the supraspinatus does not typically cause loss of external rotation but is frequently associated with mild isolated restriction of abduction. This finding can be used to clinically differentiate adhesive capsulitis from calcific tendinitis.

Kinematic patterns in normal and degenerative shoulders. Part II: Review of 3-D scapular kinematic patterns in patients with shoulder pain, and clinical implications

BACKGROUND

The global range of motion of the arm is the result of a coordinated motion of the shoulder complex including glenohumeral (GH), scapulothoracic, sternoclavicular and acromioclavicular joints.

METHODS

This study is a non-systematic review of kinematic patterns in degenerated shoulders. It is a based on our own research on the kinematics of the shoulder complex and clinical experience.

RESULTS

For patients with subacromial impingement syndrome without rotator-cuff tears, most kinematic studies showed a small superior humeral translation relative to the glenoid and decreased scapular lateral rotation and posterior tilt. These scapular kinematic modifications could decrease the subacromial space and favor rotator-cuff tendon injury. For patients with shoulder pain and restricted mobility, the studies showed a significant increase in scapular lateral rotation generally seen as a compensation mechanism of GH decreased range of motion. For patients with multidirectional GH instability, the studies found an antero-inferior decentering of the humeral head, decreased scapular lateral rotation and increased scapular internal rotation.

CONCLUSION

The clinical or instrumented assessment of the shoulder complex with a degenerative pathology must include the analysis of scapula-clavicle and trunk movements complementing the GH assessment. Depending on the individual clinical case, scapular dyskinesis could be the cause or the consequence of the shoulder degenerative pathology. For most degenerative shoulder pathologies, the rehabilitation program should take into account the whole shoulder complex and include first a scapular and trunk postural-correcting strategy, then scapulothoracic muscle rehabilitation (especially serratus anterior and trapezius inferior and medium parts) and finally neuromotor techniques to recover appropriate upper-limb kinematic schemas for daily and/or sports activities.

The immediate effect of muscle release intervention on muscle activity and shoulder kinematics in patients with frozen shoulder: a cross-sectional, exploratory study

Background

Contractile tissue plays an important role in mobility deficits in frozen shoulder (FS). However, no study has assessed the effect of the muscle release technique on the muscle activation and kinematics in individuals with FS. The purposes of this study were to assess the differences in shoulder muscle activity and kinematics between the FS and asymptomatic groups; and to determine the immediate effects of muscle release intervention in the FS group.

Methods

Twenty patients with FS and 20 asymptomatic controls were recruited. The outcome measures included muscle activity of the upper and lower trapezius (UT and LT), infraspinatus (ISp), pectoralis major (PM), and teres major (TM), shoulder kinematics (humeral elevation, scapular posterior tilt (PT) and upward rotation (UR), shoulder mobility, and pain. Participants in the FS group received one-session of heat and manual muscle release. Measurements were obtained at baseline, and immediately after intervention. Multivariate analysis of variance was used for data analysis. The level of significance was set at α=0.05.

Results

Compared to the controls, the FS group revealed significantly decreased LT (difference =55.89%, P=0.001) and ISp muscle activity (difference =26.32%, P =0.043) during the scaption task, and increased PM activity (difference =6.31%, P =0.014) during the thumb to waist task. The FS group showed decreased humeral elevation, scapular PT, and UR (difference = 35.36°, 10.18°, 6.73° respectively, P <0.05). Muscle release intervention immediately decreased pain (VAS drop 1.7, P <0.001); improved muscle activity during scaption (UT: 12.68% increase, LT: 35.46% increase, P <0.05) and hand to neck (UT: 12.14% increase, LT: 34.04% increase, P <0.05) task; and increased peak humeral elevation and scapular PT during scaption (95.18°±15.83° to 98.24°±15.57°, P=0.034; 11.06°±3.94° to 14.36°±4.65°, P=0.002), and increased scapular PT during the hand to neck (9.47°±3.86° to 12.80°±8.33°, P=0.025) task. No statistical significance was found for other group comparisons or intervention effect.

Conclusion

Patients with FS presented with altered shoulder muscle activity and kinematics, and one-session of heat and manual muscle release showed beneficial effects on shoulder muscle performance, kinematics, mobility, and pain.

Trial registration

Retrospectively registered on Jan 18, 2016 (ACTRN 12616000031460).

Electronic supplementary material

The online version of this article (10.1186/s12891-017-1867-8) contains supplementary material, which is available to authorized users.

Three-dimensional shoulder motion after teres major or latissimus dorsi tendon transfer for posterosuperior rotator cuff tears

BACKGROUND

Teres major (TM) transfer and latissimus dorsi (LD) transfer are essential treatment options in patients with posterosuperior rotator cuff (RC) tears. The purpose of this study was to quantify shoulder kinematics before and after TM transfer and LD transfer in posterosuperior RC tear patients.

METHODS

In this prospective cohort study, we quantitatively measured shoulder movements using an electromagnetic tracking device (Flock of Birds) preoperatively and 1 year after either TM (n = 13) or LD (n = 9) tendon transfer. Additional outcome measures included the Constant score (CS), patient-reported pain, and quantitative range of motion. Scapular kinematics were evaluated during arm abduction.

RESULTS

By use of a quantitative assessment, forward flexion (from 87° to 106°, P = .007), abduction (from 86° to 106°, P = .010), and external rotation in abduction (from 52° to 70°, P = .019) improved. Both transfers reduced pain (from 50 to 10 mm, P < .001), and the CS improved (from 37 to 62 points, P < .001). No significant differences in postoperative improvement in pain and function were found between TM and LD tendon transfers. The TM transfer group showed increased scapular lateral rotation compared with the LD transfer group (13°; 95% confidence interval [CI], 4.8° to 21.7°; P = .003). We were unable to detect differences between TM transfer and LD transfer in the change in protraction (3.2°; 95% CI, -6.3° to 12.8°; P = .489) and posterior tilt (3.5°; 95% CI, -3.5° to 10.5°; P = .313).

CONCLUSION

Tendon transfer surgery resulted in an overall improvement in CS, pain relief, and quantitative range of motion in the treatment of an irreparable posterosuperior RC tear. Scapular lateral rotation gradually increased after TM transfer, reminiscent of RC function, whereas such an increase was not observed after LD transfer.

Kinematic analysis of the shoulder complex after anatomic and reverse total shoulder arthroplasty: A cross-sectional study

BACKGROUND

The movement of the arm relative to the trunk results from coordinated 3D glenohumeral and scapulothoracic movements. Changes in scapula kinematics may occur after total shoulder arthroplasty and could affect clinical and functional outcomes.

OBJECTIVES

To assess the 3D movement of the scapula during arm elevation after anatomic and reverse total shoulder arthroplasty.

DESIGN/METHODS

This was a single-centre, non-randomized, controlled cross-sectional study. Patients with anatomic (n = 14) and reverse total shoulder arthroplasty (n = 9) were prospectively enrolled and were compared to age-matched asymptomatic controls (n = 23). 3D scapular kinematics were assessed by a non-invasive, electromagnetic method during arm abduction and flexion. 3D scapular rotations and 3D linear displacements of the barycentre (geometrical centre) at rest and at 30°, 60° and 90° arm elevation; as well as scapulohumeral rhythm were analysed. Participant groups were compared using one-way ANOVA and Bonferroni post-hoc testing for normally distributed data, and Mann-Whitney U test for non-normally distributed data.

RESULTS/FINDINGS

Total range of scapular lateral rotation and barycentre displacement were increased, and scapulohumeral rhythm was reduced, in patients with anatomic and reverse total shoulder arthroplasty compared with age-matched controls; however, the global scapular kinematic pattern was preserved.

CONCLUSION/INTERPRETATION

For patients after total shoulder arthroplasty, the increased contribution of the scapula to arm elevation is consistent with a compensatory mechanism for the reduced glenohumeral mobility. The stability of the global scapula kinematic pattern reflects its mechanical and neuromotor strength.

Effects of two different mobilization techniques on pain, range of motion and functional disability in patients with adhesive capsulitis: a comparative study

[Purpose] This study aimed to compare the effects of two different mobilization techniques in the management of patients with adhesive capsulitis. [Subjects and Methods] Thirty non-diabetic men and women with adhesive capsulitis were randomly allocated to the reverse distraction group (n=15) or Kaltenborn group (n=15). The reverse distraction technique and Kaltenborn’s caudal and posterior glides (grades III and IV) were applied 10–15 times along with conventional physical therapy for 18 treatment sessions in 6 weeks. Pain was measured with a visual analog scale, abduction and external rotation range of motion with goniometry, hand behind back reach with inch tape, and functional disability with the Flexilevel scale of shoulder function before and after the treatment. [Results] Although all the variables improved significantly in both groups after 18 intervention sessions, reverse distraction was significantly better than Kaltenborn’s caudal and posterior glides in decreasing pain and improving abduction range of motion and functional scores. [Conclusion] This study supports the clinical use of reverse distraction as an alternative to conventional mobilization techniques to decrease pain and improve range of motion and functional scores in patients with adhesive capsulitis.

Three-dimensional shoulder kinematics normalize after rotator cuff repair

BACKGROUND

Patients with a rotator cuff (RC) tear often exhibit scapular dyskinesia with increased scapular lateral rotation and decreased glenohumeral elevation with arm abduction. We hypothesized that in patients with an RC tear, scapular lateral rotation, and thus glenohumeral elevation, will be restored to normal after RC repair.

METHODS

Shoulder kinematics were quantitatively analyzed in 26 patients with an electromagnetic tracking device (Flock of Birds) before and 1 year after RC repair in this observational case series. We focused on humeral range of motion and scapular kinematics during abduction. The asymptomatic contralateral shoulder was used as the control. Changes in scapular kinematics were associated with the gain in range of motion. Shoulder kinematics were analyzed using a linear mixed model.

RESULTS

Mean arm abduction and forward flexion improved after surgery by 20° (95% confidence interval [CI], 2.7°-36.5°; P = .025) and 13° (95% CI, 1.2°-36.5°; P = .044), respectively. Kinematic analyses showed decreases in mean scapular protraction (ie, internal rotation) and lateral rotation (ie, upward rotation) during abduction by 3° (95% CI, 0.0°-5.2°; P = .046) and 4° (95% CI, 1.6°-8.4°; P = .042), respectively. Glenohumeral elevation increased by 5° (95% CI, 0.6°-9.7°; P = .028) at 80°. Humeral range of motion increased when scapular lateral rotation decreased and posterior tilt increased.

CONCLUSIONS

Scapular kinematics normalize after RC repair toward a symmetrical scapular motion pattern as observed in the asymptomatic contralateral shoulder. The observed changes in scapular kinematics are associated with an increased overall range of motion and suggest restored function of shoulder muscles.

Does Scapular Motion Regress with Aging and is It Restricted in Patients with Idiopathic Frozen Shoulder?

Purposes:

It has been reported that the amount of posterior tilt and upward rotation in scapular motions decreases with aging. The purposes of the current study were to investigate age related scapular motion regression and scapular restriction in patients with idiopathic frozen shoulder (IFS).

Methods:

The groups were recruited as follows: two groups of 50 asymptomatic subjects aged in their twenties and fifties, and 56 patients with IFS. We passively moved the scapula toward 8 directions: elevation/depression; upward/downward rotation; external/internal rotation; and anterior/posterior tilt. The grading of scapular motion was ranged from 0 to 3 (3, normal; and 0, severe restriction) and the score for each direction and the total aggregated score for all directions were calculated.

Results:

Scapular restriction was present in 3 subjects (6%) in the normal 20s group, 10 (14%) in the 50s group, and 51 (91%) in the IFS group. The total score between the normal 20s and 50s groups did not show statistical difference; however, greater significance was present between the normal 50s group and the IFS group (p < 0.01). There was statistical significance in depression (p < 0.01), downward rotation (p < 0.01), and posterior tilt (p < 0.01) among the 3 groups.

Conclusion:

Depression, downward rotation, and posterior tilt substantially regress with aging. Scapular motions towards depression, downward rotation, external rotation, and posterior tilt are severely restricted in the IFS group.

Collecting shoulder kinematics with electromagnetic tracking systems and digital inclinometers: A review

The shoulder complex presents unique challenges for measuring motion as the scapula, unlike any other bony segment in the body, glides and rotates underneath layers of soft tissue and skin. The ability for clinicians and researchers to collect meaningful kinematic data is dependent on the reliability and validity of the instrumentation utilized. The aim of this study was to review the relevant literature pertaining to the reliability and validity of electromagnetic tracking systems (ETS) and digital inclinometers for assessing shoulder complex motion. Advances in technology have led to the development of biomechanical instrumentation, like ETS, that allow for the collection of three-dimensional kinematic data. The existing evidence has demonstrated that ETS are reliable and valid instruments for collecting static and dynamic kinematic data of the shoulder complex. Similarly, digital inclinometers have become increasingly popular among clinicians due to their cost effectiveness and practical use in the clinical setting. The existing evidence supports the use of digital inclinometers for the collection of shoulder complex kinematics as these instruments have been demonstrated to yield acceptable reliability and validity. While digital inclinometers pose a disadvantage to ETS regarding accuracy, precision, and are limited to two-dimensional and static measurements, this instrument provides clinically meaningful data that allow clinicians and researchers the ability to measure, monitor, and compare shoulder complex kinematics.

Kinematic comparison and description of the 3-dimensional shoulder kinematics of 2 shoulder rotation tests

OBJECTIVES

The purpose of this study was to compare shoulder external rotation range of motion (ROM) during the hand-behind-neck (HBN) test and a standard shoulder external rotation test and to describe the 3-dimensional scapular motion during the HBN test.

METHODS

An electromagnetic tracking device was used to assess the dominant shoulder of 14 healthy participants while performing active full ROM in a standard shoulder external rotation test in an elevated position (EREP) and in the HBN test. The humeral and scapular 3-dimensional positions at the end of EREP and HBN were compared using a paired-sample t test. A correlation analysis was performed between humeral and scapular angles to assess the contribution of scapular motion to the full shoulder ROM during the HBN test.

RESULTS

No significant differences were found between the HBN test and the EREP at the end-range of the glenohumeral external rotation (HBN: 15.6° ± 6.3° vs EREP: 23.4° ± 4.7°; P = .08) and on scapular internal-external rotation (HBN test: 21.2° ± 6.3° vs EREP: 15.6° ± 1.8°; P = .23). Significant differences were found in scapular upward rotation (HBN: 21.2° ± 6.3° vs EREP: 15.6° ± 1.8°; P < .01) and scapular spinal tilt (HBN: -0.4° ± 2.3° vs EREP: 8.1° ± 2.1°; P < .01). There was a positive correlation between the humeral angles and scapular internal and posterior spinal tilt angles with the HBN test.

CONCLUSIONS

The results of the present study showed that, in young asymptomatic participants with no known shoulder pathology, the end-range of shoulder rotation was similar in the HBN test and in a standard shoulder rotation test. During the HBN test, the scapula assumed a more internal and anterior spinal tilted position at the end-range of active shoulder external rotation. These results suggest that the HBN test may be used to assess the end-range of glenohumeral external rotation.

The comparison of scapular upward rotation and scapulohumeral rhythm between dominant and non-dominant shoulder in male overhead athletes and non-athletes

Previous studies have stated that the scapulohumeral rhythm dysfunction can make person prone to glenohumeral joint pathologies. The purpose of this study was to compare scapular upward rotation and scapulohumeral rhythm between dominant and non-dominant shoulder in male overhead athletes and non-athletes. Seventeen overhead athletes and seventeen non-athletes volunteered for this study. Two inclinometers were used to measure humeral abduction and scapular upward rotation in rest position, 45°, 90° and 135° humeral abduction in frontal plane. Findings indicated there was no significant asymmetry in scapular upward rotation and scapulohumeral rhythm in different abduction angles between dominant and non-dominant shoulder in non-athletes. In contrast, overhead athletes' dominant shoulders have more downward rotation in scapular rest position and more upward rotation in 90° and 135° shoulder abduction than non-dominant shoulders. Also, overhead athletes presented scapulohumeral rhythm asymmetry between dominant and non-dominant shoulder in 90° and 135° humeral abduction as dominant shoulders have less scapulohumeral rhythm ratio than non-dominant shoulders. Furthermore, overhead athletes dominant shoulders have more scapular downward rotation in scapular rest position, more scapular upward rotation in 90° and 135° humeral abduction and less scapulohumeral rhythm ratio in 45°, 90° and 135° humeral abduction than non-athletes in dominant shoulders. We suggest that clinicians should be aware that some scapular asymmetry may be common in some athletes. It should not be considered as a pathological sign but rather an adaptation to extensive use of upper limb.

Shoulder limited joint mobility in people with diabetes mellitus

BACKGROUND

Limited joint mobility at the shoulder is an understudied problem in people with diabetes mellitus. The purpose of this study was to determine the differences in shoulder kinematics between a group with diabetes and those without diabetes.

METHODS

Fifty-two participants were recruited, 26 with diabetes and 26 non-diabetes controls (matched for age, BMI and sex). Three-dimensional position of the trunk, scapula and humerus were collected using electromagnetic tracking sensors during scapular plane elevation and rotation movements.

FINDINGS

Glenohumeral external rotation was reduced by 11.1°-16.3° (P<0.05) throughout the humerothoracic elevation range of motion, from neutral to peak elevation, in individuals with diabetes as compared to controls. Peak humerothoracic elevation was decreased by 10-14°, and peak external rotation with the arm abducted was decreased 22° in the diabetes group compared to controls (P<0.05). Scapulothoracic and glenohumeral internal rotation motions were not different between the two groups.

INTERPRETATION

Shoulder limited joint mobility, in particular decreased external rotation, was seen in individuals with diabetes as compared to control participants. Future research should investigate causes of diabetic limited joint mobility and strategies to improve shoulder mobility and prevent additional detrimental changes in movement and function.

Validation of a new method for assessing scapular anterior-posterior tilt

BACKGROUND

Electromagnetic tracking systems have enabled some investigators and clinicians to measure tri-planar scapular motion; yet, they are not practical and affordable options for all clinicians. Currently, the ability to affordably quantify scapular motion is limited to monitoring only the motion of scapular upward rotation, with use of a digital inclinometer.

HYPOTHESIS/PURPOSE

The objective of this study was to determine the criterion-related validity of a modified digital inclinometer when used to measure the motion of scapular anterior-posterior (AP) tilt.

MATERIALS & METHODS

Thirteen volunteers, free from any history of shoulder injury, reported for a single testing session. Each subject underwent a brief shoulder and posture examination in order to confirm the absence of pathology. Subjects actively performed clinically relevant amounts of humeral elevation in the scapular plane while in a seated position. An electromagnetic tracking system (Ascension Technology, Burlington, VT) and a modified inclinometer (Pro 360, Baseline®, Fabrication Enterprises, White Plains, NY) were used to acquire scapular AP tilt over the same shoulder motions. Criterion-related validity was determined using Pearson Product Moment correlations.

RESULTS

Correlation analyses revealed significant moderate to good associations (r = 0.63 to 0.86, p < 0.01) between scapular AP tilt measures obtained with a digital inclinometer and an electromagnetic tracking system.

CONCLUSIONS

A modified digital inclinometer is a moderately valid device to use for the quantification of scapular AP tilt. Further study is warranted to establish reliability and to validate use of the device in patients with shoulder injury or pathology. The modified inclinometer expands the clinician's ability to quantify scapular kinematic motion during the clinical evaluation and rehabilitation process.

LEVEL OF EVIDENCE

Level 3.

Dynamic comparison of segmentary scapulohumeral rhythm between athletes with and without impingement syndrome

Background:

Patients who have shoulder pain usually have compensatory or contributory deviation of shoulder motion during arm elevation. In the traditional scapulohumeral rhythm, the share of the acromioclavicular (AC) and the sternoclavicular (SC) joint movements and also the role of AC internal rotation angle are unknown.

Objectives:

The main purpose of this study was to measure and compare the segmentary scapulohumeral rhythm (SSHR) during scapular arm elevation at a steady rotational speed in athletes with and without impingement syndrome.

Patients and Methods:

Using a speedometer, the maximum speed of arm elevation was measured in 21 men in each of the involved and uninvolved groups. Using fluoroscopy on the dominant side, SSHR during scapular arm elevation at a rotational speed equal to 1/30 of maximum speed was compared between the two groups. The ratio of glenohumeral (GH) elevation angle to AC rotation angle in the scapular plane was considered as SSHR.

Results:

The maximum speed of arm elevation between the two groups was significantly different (P < 0.001). The rhythm of the involved group significantly exceeded the rhythm of the uninvolved group in a part of the first quarter range of the arm elevation. SSHR during arm elevation in the uninvolved group did not change significantly (P = 0.845); however, it decreased significantly in the involved group (P = 0.024).

Conclusions:

Speed differences between the two groups were probably due to the pain in some ranges of arm elevation. SSHR in the involved group probably changed in order to compensate downward rotation of the scapula in the resting position. Study of the AC upward rotation range can be misleading; therefore, the study of scapulohumeral rhythm is recommended.

A new description of scapulothoracic motion during arm movements in healthy subjects

The participation of scapula motion in arm movement is clinically well known and recent three dimensional (3D) analyses using kinematic techniques have confirmed its importance. Scapular motion relative to the thorax has a theoretical maximum of 6 degrees of freedom (DoF), resulting from rotations at both clavicular joints (3 rotational DoF each). However, most recent kinematic studies have only analysed the 3D rotations of the scapula relative to the thorax. In the present study, the 3D translations of the barycentre of the scapula were considered in order to complete the description of movement at the shoulder complex. Eight healthy subjects performed arm elevation in the sagittal and frontal planes, simulated activities of daily living (hair combing and back washing) and maximum voluntary scapula movement (forward and backward rolling). Measurements were recorded using a 6 DoF electromagnetic device and the acromial method of analysis was used. The results showed that 3D scapular rotations and translation of its barycentre were functionally consistent for all tasks. A principal component analysis (PCA) yielded three factors, explaining 97.6% of the variance. The first two factors (protraction and shrug, according to clinical descriptions) combined rotations and translations, consistent with the hypothesis that the scapula rolls over the curved thoracic surface. The third factor related to lateral-medial rotation, thus representing rotation in the plane tangential to the thorax. The PCA suggested that scapular motion can be described using these 3 DoF. This should be studied in a larger group of individuals, including patients with pathological conditions.

Intra-protocol repeatability and inter-protocol agreement for the analysis of scapulo-humeral coordination

Multi-center clinical trials incorporating shoulder kinematics are currently uncommon. The absence of repeatability and limits of agreement (LoA) studies between different centers employing different motion analysis protocols has led to a lack dataset compatibility. Therefore, the aim of this work was to determine the repeatability and LoA between two shoulder kinematic protocols. The first one uses a scapula tracker (ST), the International Society of Biomechanics anatomical frames and an optoelectronic measurement system, and the second uses a spine tracker, the INAIL Shoulder and Elbow Outpatient protocol (ISEO) and an inertial and magnetic measurement system. First within-protocol repeatability for each approach was assessed on a group of 23 healthy subjects and compared with the literature. Then, the between-protocol agreement was evaluated. The within-protocol repeatability was similar for the ST ([Formula: see text] = 2.35°, [Formula: see text] = 0.97°, SEM = 2.5°) and ISEO ([Formula: see text] = 2.24°, [Formula: see text] = 0.97°, SEM = 2.3°) protocols and comparable with data from published literature. The between-protocol agreement analysis showed comparable scapula medio-lateral rotation measurements for up to 120° of flexion-extension and up to 100° of scapula plane ab-adduction. Scapula protraction-retraction measurements were in agreement for a smaller range of humeral elevation. The results of this study suggest comparable repeatability for the ST and ISEO protocols and between-protocol agreement for two scapula rotations. Different thresholds for repeatability and LoA may be adapted to suit different clinical hypotheses.

Specific scapular kinematic patterns to differentiate two forms of dynamic scapular winging

BACKGROUND

Dynamic scapular winging (DSW) is a rare and misdiagnosed disorder causing considerable disability due to reduced scapular stability and abnormal motion. Two common causes are long thoracic nerve lesions resulting in serratus anterior muscle palsy and spinal accessory nerve lesions resulting in trapezius muscle palsy. The aim of this study was to analyse 3D scapular kinematic patterns in patients with DSW due to long thoracic (LTNL) or spinal accessory nerve lesions (SANL).

METHODS

3D scapular kinematics were assessed using a non invasive method involving an electromagnetic device during arm elevation in the frontal and sagittal planes in 9 patients (4 with SANL and 5 with LTNL) with unilateral DSW confirmed by electrical evidence. Within subject affected-unaffected differences were measured and compared between pathological groups (Mann-Whitney).

FINDINGS

Differences between affected and unaffected shoulders were significantly greater for scapular posterior tilt (at rest and 30° for sagittal arm elevation, at rest, 30° and 60° for frontal arm elevation) in the LTNL compared to the SANL group. Differences between affected and unaffected shoulders were significantly greater for scapular protraction (at rest and 60° of sagittal arm elevation, at rest, 30° and 60° of frontal arm elevation) and scapular lateral rotation at 60° for frontal arm elevation in the SANL compared to the LTNL group.

INTERPRETATIONS

These kinematic findings show two different scapular patterns that are specific to the neurological lesion. Moreover our kinematic data relate to specific clinical signs and the functional roles of the muscles involved.

Precision of 3D scapular kinematic measurements for analytic arm movements and activities of daily living

Electromagnetic devices allow the non invasive and accurate measurement of 3D scapula kinematics. The acromial method allows continuous dynamic measurement using a skin surface sensor fixed to the acromion. Inter-session intra and inter-observer repeatability of 3D scapular kinematics have only been partially assessed for analytical movements and never for functional tasks. Inter-session intra and inter-observer repeatability of 3D scapular kinematics were assessed for arm elevation in the sagittal and frontal planes and for two activities of daily living (ADL), hair combing and back washing, in both shoulders of 15 healthy subjects, using the intraclass correlation coefficient (ICC), the standard error of measurement (SEM), the small real difference (SRD) and the Bland and Altman's graphical method. Intra-observer repeatability was good to excellent for every scapular rotation for both arm elevation in isolated planes and ADL (ICC ranged from 0.64 to 0.95). Inter-observer repeatability of scapular rotations was fair to excellent for arm elevation in isolated planes (ICC ranged from 0.49 to 0.92) and poor to excellent for ADL (ICC ranged from 0.35 to 0.89). Inter-observer repeatability of scapular protraction/retraction had the lowest ICC. For both inter-session intra and inter-observer reliability, the SEM and SRD remained low and Bland and Altman's graphical method showed a good repeatability of the measurement method. Longitudinal monitoring of a subject's scapular kinematics by a trained observer is reliable. The inter-observer repeatability of scapular protraction/retraction must be improved.

MEASURING SCAPULAR MOVEMENT USING THREE-DIMENSIONAL ACROMIAL PROJECTION

Background

The current jig standard for measuring scapulohumeral movement of the shoulder complex only allows for static measurements of scapular positioning.

Methods

We compared scapular positioning as determined by a scapular jig with that projected from a marker triad placed on the acromion process of the scapula using an infrared motion capture system. Nine individuals performed abduction and scaption shoulder movements while arm and shoulder positioning were recorded during static and dynamic trials. Virtual scapulae were projected from surface marker triads on participants' acromia and compared with the position of three scapular landmarks identified by placement of a customized plastic jig. Static and dynamic positioning at a series of angles was compared to the jig standard to determine validity of the technique.

Results

There were no statistically significant differences between the virtual projections and jig standard for scapular external rotation, upward rotation, and anterior-posterior tilt planar measurements. Dynamic positioning correlated well with static projections, but virtual scapular projections generally overestimated upward rotation of the scapulae, as compared to the jig. This could potentially be corrected through the development of a linear correction factor.

Conclusion

Acromial projection allows for reproducible, non-invasive dynamic video motion capture of the scapula.

The acute effects of two passive stretch maneuvers on pectoralis minor length and scapular kinematics among collegiate swimmers

PURPOSE/BACKGROUND

To compare the acute effects of two passive stretches on pectoralis minor length and scapular kinematics among a group of collegiate swimmers.

METHODS

The study was a descriptive design with repeated measures. All procedures were conducted in a biomechanics laboratory and collegiate swimming facility. Fifty asymptomatic shoulders from 29 NCAA swimmers were used (15 control shoulders, 17 focused stretch shoulders, 18 gross stretch shoulders). Pre- and post-test linear pectoralis minor length, as well as scapular kinematics (upward/downward rotation, external/internal rotation, anterior/posterior tilt) were measured as dependent variables. Pectoralis minor length was measured using a standard tape measure and three-dimensional scapular kinematics were measured using an electromagnetic capture system.

RESULTS

The gross stretch shoulders had a significant increase in pectoralis minor length compared to the control shoulders (P=.007). There were no other significant changes in length for either the focused stretch or control shoulders (P>.07). No statistically significant (P>.08) differences for all three scapular kinematic variables were found among any of the three groups (P>.08).

CONCLUSIONS

Our results revealed no acute improvements of scapular upward rotation, external rotation, or posterior tilt after the application of either passive stretch maneuver to the pectoralis minor muscle.

LEVEL OF EVIDENCE

2b.

Development of a method for analyzing three-dimensional scapula kinematics

BACKGROUND

Scapula mobility complicates upper extremity kinematics assessment. Existing methods are diverse, providing inconsistent results. The current gold standard (bone pins) is prohibitively invasive. The purposes of the current study are to describe a virtual projection alternative to surface markers for video motion capture (VMC) of the scapula and to compare the results of the projection and surface marker methods to the results of similar existing methods.

METHODS

Ten participants were evaluated using VMC. Surface markers were applied to the trunk and arm in accordance with existing guidelines. Three markers were affixed to plastic base on the skin over the acromion process. Other scapular landmarks were digitized in a neutral position. These landmarks' locations were defined in reference to the acromion cluster and used to generate the projection. Humerothoracic, glenohumeral, and scapulothoracic kinematics were evaluated during shoulder abduction, flexion, and scaption. Joint angles produced by the surface markers and the projection were compared by Bonferroni-adjusted t tests. The results were compared to prior findings in the literature.

RESULTS

The projection resulted in greater scapulothoracic upward rotation, internal rotation, and anterior-posterior tilt and less glenohumeral elevation (p < .0055) than did surface markers. The virtual scapula produced greater estimates of scapular mobility than did surface markers, corresponding to pre-existing results from similar methodologies.

CONCLUSIONS

The result is a noninvasive measurement tool that produces different and superior results than do scapula surface markers. Measuring scapula kinematics via VMC without bone pins will facilitate future investigations into interactions between upper extremity injury, kinematics, and activity performance.

Reproducibility of a 3-dimensional gyroscope in measuring shoulder anteflexion and abduction

Background

Few studies have investigated the use of a 3-dimensional gyroscope for measuring the range of motion (ROM) in the impaired shoulder. Reproducibility of digital inclinometer and visual estimation is poor. This study aims to investigate the reproducibility of a tri axial gyroscope in measurement of anteflexion, abduction and related rotations in the impaired shoulder.

Methods

Fifty-eight patients with either subacromial impingement (27) or osteoarthritis of the shoulder (31) participated. Active anteflexion, abduction and related rotations were measured with a tri axial gyroscope according to a test retest protocol. Severity of shoulder impairment and patient perceived pain were assessed by the Disability of Arm Shoulder and Hand score (DASH) and the Visual Analogue Scale (VAS). VAS scores were recorded before and after testing.

Results

In two out of three hospitals patients with osteoarthritis (n = 31) were measured, in the third hospital patients with subacromial impingement (n = 27).

There were significant differences among hospitals for the VAS and DASH scores measured before and after testing. The mean differences between the test and retest means for anteflexion were −6 degrees (affected side), 9 (contralateral side) and for abduction 15 degrees (affected side) and 10 degrees (contralateral side).

Bland & Altman plots showed that the confidence intervals for the mean differences fall within −6 up to 15 degrees, individual test - retest differences could exceed these limits.

A simulation according to ‘Generalizability Theory’ produces very good coefficients for anteflexion and related rotation as a comprehensive measure of reproducibility. Optimal reproducibility is achieved with 2 repetitions for anteflexion.

Conclusions

Measurements were influenced by patient perceived pain. Differences in VAS and DASH might be explained by different underlying pathology. These differences in shoulder pathology however did not alter the reproducibility of testing. The use of a tri axial gyroscope is a simple non invasive and reproducible method for the recording of shoulder anteflexion and abduction. Movements have to be repeated twice for reproducible results.

Assessment of scapulohumeral rhythm for scapular plane shoulder elevation using a modified digital inclinometer

AIM: To develop a better understanding of scapulohumeral rhythm during scapular plane shoulder elevation.

METHODS: Thirteen healthy, college-aged subjects participated in this study. Subjects were free from any upper extremity, neck or back pathology. A modified digital inclinometer was utilized to measure scapular upward rotation of the subject’s dominant shoulder. Upward rotation was measured statically as subjects performed clinically relevant amounts of shoulder elevation in the scapular plane. Testing order was randomized by arm position. Scapular upward rotation was assessed over the entire arc of motion and over a series of increments. The percent contributions to shoulder elevation for the scapula and glenohumeral joint were calculated. Scapulohumeral rhythm was assessed and represented the ratio of glenohumeral motion to scapulothoracic motion (glenohumeral elevation: scapular upward rotation). A one-way ANOVA was used to compare scapular upward rotation between elevation increments.

RESULTS: Scapulohumeral rhythm for the entire arc of shoulder elevation was equal to a ratio of 2.34 :1 and ranged from 40.01:1 to 0.90:1 when assessed across the different increments of humeral elevation. Total scapular motion increased over the arc of shoulder elevation. The scapula contributed 2.53% of total motion for the first 30 degrees of shoulder elevation, between 20.87% and 37.53% for 30^o-90^o of shoulder elevation, and 52.73% for 90^o-120^o of shoulder elevation. Statistically significant differences in scapular upward rotation were identified across the shoulder elevation increments [F_(3,48) = 12.63, P = 0.0001].

CONCLUSION: Clinically, we must recognize the usefulness of the inclinometer in documenting the variable nature of scapulohumeral rhythm in healthy and injured shoulders.

Effectiveness of the end-range mobilization and scapular mobilization approach in a subgroup of subjects with frozen shoulder syndrome: a randomized control trial

Treatment strategies targeting abnormal shoulder kinematics may prevent pathology or if the pathology develops, shorten its duration. We examined the effectiveness of the end-range mobilization/scapular mobilization treatment approach (EMSMTA) in a subgroup of subjects with frozen shoulder syndrome (FSS). Based on the kinematics criteria from a prediction method, 34 subjects with FSS were recruited. Eleven subjects were assigned to the control group, and 23 subjects who met the criteria were randomly assigned to the criteria-control group with a standardized physical therapy program or to the EMSMTA group. Subjects attended treatment sessions twice a week for 8 weeks. Range of motion (ROM), disability score, and shoulder complex kinematics were obtained at the beginning, 4 weeks, and 8 weeks. Subjects in the EMSMTA group experienced greater improvement in outcomes compared with the criteria-control group at 4 weeks (mean difference=0.2 of normalized hand-behind-back reach) and 8 weeks (mean difference=22.4 degrees humeral external rotation, 0.31 of normalized hand-behind-back reach, 7.5 disability, 5 degrees tipping and 0.32 rhythm ratio). Similar improvements were found between the EMSMTA group and control group. The EMSMTA was more effective than a standardized physical therapy program in a subgroup of subjects who fit the criteria from a prediction method.