Elucidating the scapulo-humeral rhythm calculation: 3D joint contribution method

Assessment of three-dimensional rotation of the shoulder complex and scapulohumeral rhythm during sagittal movement

BACKGROUND

Due to the influence of spinal and respiratory movements, it is difficult to accurately measure the range of motion of each joint.

OBJECTIVE

To conduct a three-dimensional (3D) measurement of each joint in the shoulder complex in different postures in the sagittal plane of the upper extremity.

METHODS

Thirteen healthy adults with no history of shoulder surgery for trauma or chronic pain were enrolled in the present study. The computed tomography (CT) imaging data of the shoulder complex were acquired in four postures via the reconstruction and alignment of 3D images. The angles of the postural changes were measured, and rotation vectors were used for descriptions and statistical analyses.

RESULTS

There was a statistical difference in the rotation angles between the dominant and non-dominant sides of the sternoclavicular joint when the posture changed from a resting position to a posterior inferior position. During the postural change from a resting position to a horizontal position, the regression coefficient (β) of the humerothoracic joint to the sternoclavicular joint was 0.191, and the β of the humerothoracic joint to the glenohumeral joint was 0.621. During the postural change from the horizontal position to the rear upper position, the β of the humerothoracic joint to the sternoclavicular joint was 0.316, and the β of the humerothoracic joint to the glenohumeral joint was 0.845. During the postural change from the resting position to the rear lower position, the β of the humerothoracic joint to the glenohumeral joint was 0.991.

CONCLUSION

The application of the image alignment technique enabled the direct and accurate measurement of the bony structures of the shoulder joint. The helical approach accurately described the scapulohumeral rhythm during 3D motion. There was a scapulohumeral rhythm of the shoulder complex during 3D composite sagittal movement, with different ratios for different joints and postures.

Optical Motion Capture Systems for 3D Kinematic Analysis in Patients with Shoulder Disorders

Shoulder dysfunctions represent the third musculoskeletal disorder by frequency. However, monitoring the movement of the shoulder is particularly challenging due to the complexity of the joint kinematics. The 3D kinematic analysis with optical motion capture systems (OMCs) makes it possible to overcome clinical tests' shortcomings and obtain objective data on the characteristics and quality of movement. This systematic review aims to retrieve the current knowledge about using OMCs for 3D shoulder kinematic analysis in patients with musculoskeletal shoulder disorders and their corresponding clinical relevance. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were used to improve the reporting of the review. Studies employing OMCs for 3D kinematic analysis in patients with musculoskeletal shoulder disorders were retrieved. Eleven articles were considered eligible for this study. OMCs can be considered a powerful tool in orthopedic clinical research. The high costs and organizing complexities of experimental setups are likely outweighed by the impact of these systems in guiding clinical practice and patient follow-up. However, additional high-quality studies on using OMCs in clinical practice are required, with standardized protocols and methodologies to make comparing clinical trials easier.

Kinematic coupling of the glenohumeral and scapulothoracic joints generates humeral axial rotation

Glenohumeral and scapulothoracic motion combine to generate humerothoracic motion, but their discrete contributions towards humerothoracic axial rotation have not been investigated. Understanding their contributions to axial rotation is important to judge the effects of pathology, surgical intervention, and physiotherapy. Therefore, the purpose of this study was to investigate the kinematic coupling between glenohumeral and scapulothoracic motion and determine their relative contributions towards axial rotation. Twenty healthy subjects (10 M/10F, ages 22-66) were previously recorded using biplane fluoroscopy while performing arm elevation in the coronal, scapular, and sagittal planes, and external rotation in 0° and 90° of abduction. Glenohumeral and scapulothoracic contributions towards axial rotation were computed by integrating the projection of glenohumeral and scapulothoracic angular velocity onto the humeral longitudinal axis, and analyzed using one dimensional statistical parametric mapping and linear regression. During arm elevation, scapulothoracic motion supplied 13-20° (76-94%) of axial rotation, mainly via scapulothoracic upward rotation. The contribution of scapulothoracic motion towards axial rotation was strongly correlated with glenohumeral plane of elevation during arm elevation. During external rotation, scapulothoracic motion contributed 10° (8%) towards axial rotation in 0° of abduction and 15° (15%) in 90° of abduction. The contribution of scapulothoracic motion towards humerothoracic axial rotation could explain the simultaneous changes in glenohumeral plane of elevation and axial rotation associated with some pathologies and surgeries. Understanding how humerothoracic motion results from the functional coupling of scapulothoracic and glenohumeral motions may inform diagnostic and treatment strategies by targeting the source of movement impairments in clinical populations.

Scapulohumeral rhythm in patients after total shoulder arthroplasty compared to age-matched healthy individuals

PURPOSE

The coordination of the glenohumeral joint and the shoulder girdle has been known as scapulohumeral rhythm. The effects of anatomical total shoulder arthroplasty (aTSA) are still subject to research. Former studies showed a higher amount of scapula lateral rotation to compensate for reduced glenohumeral elevation. The purpose of the present study was to confirm this mechanism and examine additional effects on the sternoclavicular and acromioclavicular joints' kinematics.

METHODS

3D motion analysis was used to examine 23 shoulders of 16 patients with a mean age of 71.2 (SD: 5.2) years with a mean follow up of 5.4 (SD: 2.1) years after aTSA and to compare kinematics and coordination to 22 shoulders of 11 healthy age-matched individuals with a mean age of 69.6 (SD: 5.3) years while performing elevation movement in frontal and sagittal plane.

RESULTS

The ratio of glenohumeral to shoulder girdle contribution was reduced compared to healthy individuals: Shoulder girdle contribution to elevation was 36.5% (SD: 8.1) in the aTSA group vs. 28.5% (SD: 8.2) in the control group in the sagittal plane and 38.1% (SD: 9.1) vs. 30.2% (SD: 7.1) in the frontal plane. Kinematics of the sternoclavicular and acromioclavicular joints showed significantly different patterns.

CONCLUSION

Patients after aTSA showed altered shoulder girdle kinematics and higher contribution of the shoulder girdle towards elevation. Whether this is a result of the surgery, of limited glenohumeral range of motion or due to the preoperative status remains unclear. Further investigation with a prospective study design is necessary.

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.

Variation of the glenohumeral and scapulothoracic motion in progressive severity of glenohumeral osteoarthritis

INTRODUCTION

The aim of this study is to investigate the variation of the glenohumeral and scapulothoracic motion in progressive severity of glenohumeral osteoarthritis using a 3-D-motion analysis. Moreover, the variation of the Constant Score is evaluated.

HYPOTHESIS

The hypothesis is that the motion of the scapulothoracic joint may partly compensate for the loss of the glenohumeral joint movement in patients with increasing severity of glenohumeral osteoarthritis.

MATERIAL AND METHODS

A total of 21 patients with primary osteoarthritis of the glenohumeral joint were clinically examined, divided in three groups (SP1-SP3) according to size of their caudal osteophyte. The contribution of the scapulothoracic (acromioclavicular and sternoclavicular) joint to the total arm (humerothoracical) elevation in sagittal and frontal plane was measured with 3D motion analysis and the Constant Score was evaluated.

DISCUSSION

In sagittal plane elevation (anteversion) the contribution of the scapulothoracic joint to the total elevation was while arm raising 32.7% (SD 8.0%) in Group SP1, 36.6% (SD 11.0%) in Group SP2 and 49.6% (SD 9.0%) in Group SP3 (p=0.002). The contribution of the scapulothoracic joint to the total elevation while arm lowering was 31.4% (SD 9.0%) in Group SP1, 39.0% (SD 13.0%) in Group SP2 and 49.7% (SD 12.0%) in Group SP3 (p=0.043). In frontal plane elevation (abduction) the contribution of the scapulothoracic joint was while arm raising 33.7% (SD 8.0%) in Group SP1, 34.0% (SD 10.0%) in Group SP2 and 42.3% (SD 9.0%) in Group SP3 (p=0.071). While arm lowering the contribution of the scapulothoracic joint was 30.8% (SD 10.0%) in Group SP1, 36.3% (SD 12.0%) in Group SP2 and 44.8% (SD 8.0%) in Group SP3 (p=0.022). The group SP1 achieved a Constant Score of 78.00 (SD 9.823) points. The group SP2 achieved a Constant Score of 53.57 (SD 13.92) and the group SP3 38.64 (SD 10.40). There is a significant difference between the three groups (p<0.001). Increasing severity of glenohumeral osteoarthritis leads to a reduced motion of the glenohumeral joint. Instead the magnitude of the scapulothoracic motion increases.

LEVEL OF PROOF

V, Case Series.

Sex differences in upper limb 3D joint contributions during a lifting task

Sex-related differences in work technique may contribute to increasing the risk of musculoskeletal joint disorders among women. In lifting tasks, sex differences have been reported for the trunk and lower limb, although women present a higher prevalence of shoulder disorders. We investigated sex differences in the upper limb technique during a lifting task. Trunk and upper limb kinematics were recorded in 27 women and 27 men lifting a box (6 or 12 kg) from hip to eye level. Work technique was quantified through the three-dimensional contribution of each joint to overall box height. The glenohumeral joint showed a higher contribution in women with a 6 kg box and wrist and elbow joints did with a 12 kg box, compared to men at either 6 or 12 kg. Sex differences occurred systematically above shoulder level. Our results argue for careful consideration of sex during ergonomic intervention, particularly during the overhead task. Practitioner Summary: We investigated the sex-related differences in upper limb technique during lifting tasks. Results highlight a sex-specific kinematic strategy above the shoulder level on the glenohumeral joint and on the wrist and elbow joints. To help reduce women's shoulder disorders in overhead task, ergonomic interventions should account for those differences. Abbreviations: DoF: degree-of-freedom; WR/EL: wrist and elbow; GH: glenohumeral; SC/AC: sternoclavicular and acromioclavicular; TR/PE: pelvo-thoracic.

A survey of human shoulder functional kinematic representations

In this survey, we review the field of human shoulder functional kinematic representations. The central question of this review is to evaluate whether the current approaches in shoulder kinematics can meet the high-reliability computational challenge. This challenge is posed by applications such as robot-assisted rehabilitation. Currently, the role of kinematic representations in such applications has been mostly overlooked. Therefore, we have systematically searched and summarised the existing literature on shoulder kinematics. The shoulder is an important functional joint, and its large range of motion (ROM) poses several mathematical and practical challenges. Frequently, in kinematic analysis, the role of the shoulder articulation is approximated to a ball-and-socket joint. Following the high-reliability computational challenge, our review challenges this inappropriate use of reductionism. Therefore, we propose that this challenge could be met by kinematic representations, that are redundant, that use an active interpretation and that emphasise on functional understanding.

Dynamic thoracohumeral kinematics are dependent upon the etiology of the shoulder injury

Obtaining kinematic patterns that depend on the shoulder injury may be important when planning rehabilitation. The main goal of this study is to explore whether the kinematic patterns of continuous and repetitive shoulder elevation motions are different according to the type of shoulder injury in question, specifically tendinopathy or rotator cuff tear, and to analyze the influence of the load handled during its assessment. For this purpose, 19 individuals with tendinopathy and 9 with rotator cuff tear performed a repetitive scaption movement that was assessed with stereophotogrammetry. Furthermore, static range of motion (ROM) and isometric strength were evaluated with a goniometer and a dynamometer, respectively. Dynamic measurements of maximum elevation (Emax), variablility of the maximum angle (VMA), maximum angular velocity (Velmax), and time to maximum velocity (tmaxvel) were found to be significantly different between the tendinopathy group (TG) and the rotator cuff tear group (RTCG). No differences were found in the ROM assessed with goniometry and the isometric strength. The effect of increasing the load placed in the hand during the scaption movement led to significant differences in Emax, VMA, tmaxvel and repeatability. Therefore, only the dynamic variables showed sufficient capability of detecting differences in functional performance associated with structural shoulder injury. The differences observed in the kinematic variables between patients with tendinopathy and rotator cuff tear seem to be related to alterations in thoracohumeral rhythm and neuromuscular control. Kinematic analysis may contribute to a better understanding of the functional impact of shoulder injuries, which would help in the assessment and treatment of shoulder pain.

Scapulohumeral rhythm relative to active range of motion in patients with symptomatic rotator cuff tears

BACKGROUND

Some patients with rotator cuff tears feel pain without functional limitation, whereas others show a decrease in range of motion. To investigate this distinction, the scapulohumeral rhythm was used to conduct a functional evaluation of shoulder joints' coordination. The objective was to characterize patients according to their active range of motion without pain and their scapulohumeral rhythm compared with healthy individuals.

MATERIALS AND METHODS

Fourteen patients with rotator cuff tears and 14 healthy individuals were set up with 35 reflective markers on the trunk and upper limb tracked by an optoelectronic system to measure the scapulohumeral rhythm. Five scapular plane maximal arm elevations were executed without pain. Patients were separated by maximal arm elevation of 85° (category A) and 40° (category B). Three-way mixed-design analysis of variance with factors of group (patients and healthy), arm elevation, and motion direction was applied to the scapulohumeral rhythm.

RESULTS

A main effect of group (P = .032) was observed in patients in category A, who showed inferior scapulohumeral rhythm. An interaction between group and arm elevation (P = .044) was observed for patients in category B, where their scapulohumeral rhythm increased more during arm elevation than in the healthy individuals.

CONCLUSIONS

Patients who reached at least 85° compensated for the loss of glenohumeral motion by increased scapulothoracic contribution, suggesting that structural damage interferes with motion mechanics. In contrast, patients who reached less range of motion underused the scapulothoracic joint, which is likely to create subacromial impingement at low arm elevation. A patient's maximal range of motion without pain may indicate a pattern of scapulohumeral rhythm alteration.

The effects of plane and arc of elevation on electromyography of shoulder musculature in patients with rotator cuff tears

BACKGROUND

Arm elevations in different planes are commonly assessed in clinics and are included in rehabilitation protocols for patients with rotator cuff pathology. The aim of this study was to quantify the effect of plane and angle of elevation on shoulder muscles activity in patients with symptomatic rotator cuff tear to be used for rehabilitation purposes.

METHODS

Eight symptomatic patients with rotator cuff tears were assessed by using EMG (11 surface and 2 fine wire electrodes) synchronized with a motion analysis. The subjects completed five elevations in full can position (arm externally rotated and thumb up) in frontal, scapular and sagittal planes. Muscle activity in three elevation arcs of 20° (from 0° to 60°) was presented as the percentage of mean activity. Data were analyzed by mixed linear models (α=0.003), and Tuckey Post-hoc comparisons for significant effects (α=0.05).

FINDINGS

The effect of plane was significant for supraspinatus, middle trapezius, anterior, middle, and posterior deltoid, triceps, and pectoralis major (P<0.001). Supraspinatus was more active during abduction than scaption and flexion (P<0.05), and its activity did not increase significantly after 40° of elevation (P>0.05). Infraspinatus had similar activity pattern in the three planes of elevation (P>0.003) with increasing trend in accordance with the elevation angle.

INTERPRETATION

In any rehabilitation protocol, if less activity of supraspinatus is desired, active arm elevation should be directed toward flexion and scaption and postponed abduction to prevent high level of activity in this muscle.

Shoulder Coordination During Full-Can and Empty-Can Rehabilitation Exercises

CONTEXT

Supraspinatus tear is a common rotator cuff injury. During rehabilitation, debate persists regarding the most appropriate exercises. Whereas shoulder coordination is part of normal arm function, it has been infrequently considered in the context of exercise selection.

OBJECTIVE

To assess shoulder-motion coordination during 2 common supraspinatus rehabilitation exercises and to characterize load and motion-direction influences on shoulder coordination.

DESIGN

Descriptive laboratory study.

SETTING

Motion-analysis laboratory. Patient or Other Participants :  Fifteen asymptomatic right-hand-dominant men (age = 26 ± 4 years, height = 1.77 ± 0.06 m, mass = 74.3 ± 7.7 kg).

INTERVENTION(S)

Full-can and empty-can exercises with and without a 2.27-kg load.

MAIN OUTCOME MEASURE(S)

We recorded motion with an optoelectronic system. Scapulohumeral rhythm and complete shoulder joint kinematics were calculated to quantify shoulder coordination. The effects of exercise type, load, motion direction, and humerothoracic-elevation angle on the scapulohumeral rhythm and shoulder-joint angles were assessed.

RESULTS

We observed multivariate interactions between exercise type and humerothoracic elevation and between load and humerothoracic elevation. Scapulohumeral rhythm increased by a mean ratio of 0.44 ± 0.22 during the full-can exercise, whereas the addition of load increased mean glenohumeral elevation by 4° ± 1°.

CONCLUSIONS

The full-can exercise increased the glenohumeral contribution, as hypothesized, and showed normal shoulder coordination. During the empty-can exercise, the increased scapulothoracic contribution was associated with a compensatory pattern that limits the glenohumeral contribution. Using loads during shoulder rehabilitation seems justified because the scapulohumeral rhythm is similar to that of unloaded arm elevation. Finally, motion direction showed a limited effect during the exercises in healthy individuals.

Studying upper-limb kinematics using inertial sensors: a cross-sectional study

Background

In recent years, there has been a great interest in analyzing upper-limb kinematics in order to investigate scapulohumeral rhythm, as its alteration has been associated with shoulder joint complex injuries. The use of inertial sensors is presented as a convenient and portable analysis method for studying kinematics in terms of angular mobility and linear acceleration. The aim of this study was to analyze upper-limbs kinematics in the three anatomical axes, obtained by inertial sensors.

Results

Descriptive graphics of analytical tasks performed were obtained. The main difference in mobility between the scapula and humerus was found in pitch axis for abduction (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\bar{\text{X}}}$$\end{document}X¯ = 107.6°, SD = 9.3°) and flexion (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\bar{\text{X}}}$$\end{document}X¯ = 113.1°, SD = 9.3°).

Conclusion

The use of inertial sensors for human kinematics analysis is favorable. Although this study identified movement patterns, and supports inertial sensors as a useful device to analyze upper-limb kinematics, further studies with subjects with shoulder pathology to establish differences in movement patterns and scapulohumeral rhythm between healthy and pathological shoulders should be carried out.

Botulinum Toxin Injection for Spastic Scapular Dyskinesia After Stroke: Case Series

Spastic scapular dyskinesia after stroke is rare, which causes impaired shoulder active range of motion (ROM). To date, there has been no report about botulinum toxin injection to spastic periscapular muscles. This study presents botulinum toxin A injection for management of spastic periscapular muscles after stroke in 2 cases.This is a retrospective study of 2 cases of spastic scapular dyskinesia after stroke. Spasticity of periscapular muscles including rhomboid and lower trapezius was diagnosed by physical examination and needle electromyographic study. Botulinum toxin was injected into the spastic periscapular muscles under ultrasound imaging guidance.During the 3-week follow-up visit after injection, both patients showed increased shoulder active ROM, without any sign of scapular destabilization.The results suggest that botulinum toxin injection to spastic periscapular muscles can increase shoulder active ROM without causing scapular destabilization in patients with poststroke spastic scapular dyskinesia.

Studying Upper-Limb Kinematics Using Inertial Sensors Embedded in Mobile Phones

BACKGROUND

In recent years, there has been a great interest in analyzing upper-limb kinematics. Inertial measurement with mobile phones is a convenient and portable analysis method for studying humerus kinematics in terms of angular mobility and linear acceleration.

OBJECTIVE

The aim of this analysis was to study upper-limb kinematics via mobile phones through six physical properties that correspond to angular mobility and acceleration in the three axes of space.

METHODS

This cross-sectional study recruited healthy young adult subjects. Humerus kinematics was studied in 10 young adults with the iPhone4. They performed flexion and abduction analytical tasks. Mobility angle and lineal acceleration in each of its axes (yaw, pitch, and roll) were obtained with the iPhone4. This device was placed on the right half of the body of each subject, in the middle third of the humerus, slightly posterior. Descriptive statistics were calculated.

RESULTS

Descriptive graphics of analytical tasks performed were obtained. The biggest range of motion was found in pitch angle, and the biggest acceleration was found in the y-axis in both analytical tasks. Focusing on tridimensional kinematics, bigger range of motion and acceleration was found in abduction (209.69 degrees and 23.31 degrees per second respectively). Also, very strong correlation was found between angular mobility and linear acceleration in abduction (r=.845) and flexion (r=.860).

CONCLUSIONS

The use of an iPhone for humerus tridimensional kinematics is feasible. This supports use of the mobile phone as a device to analyze upper-limb kinematics and to facilitate the evaluation of the patient.