Electromyographic muscle activity and three‐dimensional scapular kinematics in patients with multidirectional shoulder instability

2020 ◽  
Author(s):  
Valentien Spanhove ◽  
Patrick Calders ◽  
Kelly Berckmans ◽  
Tanneke Palmans ◽  
Fransiska Malfait ◽  
...  
2002 ◽  
Vol 30 (4) ◽  
pp. 514-522 ◽  
Author(s):  
Ruediger M. O. von Eisenhart-Rothe ◽  
Alwin Jäger ◽  
Karl-Hans Englmeier ◽  
Thomas J. Vogl ◽  
Heiko Graichen

Background No quantitative data on glenohumeral translation exist allowing one to distinguish insufficiency of the active or passive stabilizers in different forms of shoulder instability. Hypothesis To determine whether 1) in traumatic or atraumatic shoulder instability an increase of glenohumeral translation can be observed in specific relevant arm positions, 2) muscle activity leads to recentering of the humeral head, and 3) there exist differences between traumatic and atraumatic instability. Study Design Prospective clinical trial. Methods In 12 patients with traumatic and 10 patients with atraumatic instability, both shoulders were examined in different arm positions—with and without muscle activity—by using open magnetic resonance imaging and a three-dimensional postprocessing technique. Results At 90° of abduction and external rotation, translation (anterior-inferior) was significantly higher in patients with traumatic unstable shoulders compared with their contralateral side (3.6 ± 1.5 versus 0.7 ± 1.6 mm). In patients with atraumatic instability, significantly increased translation (4.7 ± 2.0 mm) was observed, with the direction being nonuniform. Muscle activity led to significant recentering in traumatic but not in atraumatic instability. Conclusions In traumatic instability, increased translation was observed only in functionally important arm positions, whereas intact active stabilizers demonstrate sufficient recentering. In atraumatic instability, a decentralized head position was recorded also during muscle activity, suggesting alterations of the active stabilizers. Clinical Relevance Clinical Relevance: These data are relevant for optimizing diagnostics and therapeutic strategies.


Author(s):  
Valentien Spanhove ◽  
Matthias Van Daele ◽  
Aäron Van den Abeele ◽  
Lies Rombaut ◽  
Birgit Castelein ◽  
...  

Author(s):  
Kermit G. Davis

In industry, workers perform tasks requiring both lifting and lowering. During concentric lifting, the muscles are shortening as the force is being generated. Conversely, the muscle lengthens while generating force during eccentric lowering. While research on various lifting tasks is extensive, there has been limited research performed to evaluate the lowering tasks. Most of the research that does exist on lowering has investigated muscle activity and trunk strength. None of these studies have investigated spinal loading. The current study estimated the effects of lifting and lowering on spinal loads and predicted moments imposed on the spine. Ten subjects performed both eccentric and concentric lifts under sagittally symmetric conditions. The tasks were performed under isokinetic trunk velocities of 5, 10, 20, 40, and 80 deg/s while holding a box with weights of 9.1, 18.2, and 27.3 kg. Spinal loads and predicted moments in three dimensional space were estimated by an EMG-assisted model which has been adjusted to incorporate the artifacts of eccentric lifting. Eccentric strength was found to be 56 percent greater than during concentric lifting. The lowering tasks produced significantly higher compression forces but lower anterior-posterior shear forces than the concentric lifting tasks. The differences in the spinal loads between the two lifting tasks were attributed to the internal muscle forces and unequal moments resulting from differences in the lifting path of the box. Thus, the differences between the lifting tasks resulted from different lifting styles associated with eccentric and concentric movements


2021 ◽  
Vol 16 (01) ◽  
pp. e51-e55
Author(s):  
Jasmine J. Lin ◽  
Gromit Y.Y. Chan ◽  
Cláudio T. Silva ◽  
Luis G. Nonato ◽  
Preeti Raghavan ◽  
...  

Abstract Background The trapezius muscle is often utilized as a muscle or nerve donor for repairing shoulder function in those with brachial plexus birth palsy (BPBP). To evaluate the native role of the trapezius in the affected limb, we demonstrate use of the Motion Browser, a novel visual analytics system to assess an adolescent with BPBP. Method An 18-year-old female with extended upper trunk (C5–6–7) BPBP underwent bilateral upper extremity three-dimensional motion analysis with Motion Browser. Surface electromyography (EMG) from eight muscles in each limb which was recorded during six upper extremity movements, distinguishing between upper trapezius (UT) and lower trapezius (LT). The Motion Browser calculated active range of motion (AROM), compiled the EMG data into measures of muscle activity, and displayed the results in charts. Results All movements, excluding shoulder abduction, had similar AROM in affected and unaffected limbs. In the unaffected limb, LT was more active in proximal movements of shoulder abduction, and shoulder external and internal rotations. In the affected limb, LT was more active in distal movements of forearm pronation and supination; UT was more active in shoulder abduction. Conclusion In this female with BPBP, Motion Browser demonstrated that the native LT in the affected limb contributed to distal movements. Her results suggest that sacrificing her trapezius as a muscle or nerve donor may affect her distal functionality. Clinicians should exercise caution when considering nerve transfers in children with BPBP and consider individualized assessment of functionality before pursuing surgery.


2020 ◽  
Vol 55 (3) ◽  
pp. 265-273
Author(s):  
Wan-Yu Du ◽  
Tsun-Shun Huang ◽  
Yuan-Chun Chiu ◽  
Szu-Jieh Mao ◽  
Li-Wei Hung ◽  
...  

Context Subacromial impingement syndrome (SIS) is associated with scapular dyskinesis, or imbalanced scapular muscle activity. Evidence has shown that feedback can improve scapular control in patients with SIS. However, it is unknown whether real-time video feedback or electromyography (EMG) biofeedback is optimal for improving scapular kinematics and muscle activity during a functional task. Objective To compare the effects of video and EMG feedback sessions on absolute muscle activity (upper trapezius [UT], lower trapezius [LT], serratus anterior), muscle balance ratios (UT/LT, UT/serratus anterior), and scapular kinematics (anterior-posterior tilt, external-internal rotation, upward rotation) in SIS participants during arm elevation and lowering. Design Randomized controlled clinical trial. Setting Research laboratory. Patients or Other Participants Overhead athletes who were diagnosed with SIS and who also exhibited scapular dyskinesis (N = 41). Main Outcome Measure(s) Three-dimensional kinematics and EMG were recorded before and after feedback training. Results Lower trapezius muscle activity increased (4.2%–18%, P < .011) and UT/LT decreased (0.56–1.17, P < .013) in the EMG biofeedback training group as compared with those in the video feedback training group. Scapular upward rotation during arm elevation was higher in the video group than in the EMG group after feedback training (2.3°, P = .024). Conclusions The EMG biofeedback improved muscle control and video feedback improved the correction of scapular upward rotation in patients with SIS. Trial Registration Number ClinicalTrials.gov: NCT03252444.


2018 ◽  
Vol 30 (01) ◽  
pp. 1850001
Author(s):  
Mei-Ying Kuo ◽  
Shih-Wun Hong ◽  
Jia-Da Li ◽  
Tung-Wu Lu ◽  
Horng-Chaung Hsu

Accurate measurement of the three-dimensional scapular kinematics is essential for a better understanding of the mechanical interactions between the scapula and the other segments of the shoulder complex. The purposes of the study were: (i) to development a marker-based scapular locator for measuring scapular poses, and (ii) to determine the intra- and inter-rater reliability of the locator in terms of intra-class correlations (ICC). Twenty-two healthy volunteers without shoulder pathologies participated in the current study. Each subject was tested separately by two raters using the marker-based scapular locator while performing static shoulder flexion at 20, 40, 60, 80, 100 and 120 degrees in the scapular plane. Two reliability models, ICC[Formula: see text] and ICC[Formula: see text], were used to analyze the intra- and inter-rater reliability for scapular rotations and translations. Good to excellent intra-user reliability for both examiners was found for the scapular rotations (range: 0.82–0.99) and displacements (range: 0.72–0.99) for different shoulder flexion conditions. Good to excellent inter-rater reliability was found for scapular rotations (range: 0.63–0.95) and translations (range: 0.70–0.95) for all conditions. The results showed that high intra- and inter-examiner reliability could be achieved for scapular rotations and translation using the marker-based scapular locator. The proposed new scapular locator with an optical tracking system will be helpful for future applications in basic and clinical studies of the shoulder complex during arm movements.


2010 ◽  
Vol 32 (4) ◽  
pp. 500-507 ◽  
Author(s):  
Annelies Vandenberghe ◽  
Oron Levin ◽  
Joris De Schutter ◽  
Stephan Swinnen ◽  
Ilse Jonkers

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