Three-dimensional scapular kinematics during open and closed kinetic chain movements in asymptomatic and symptomatic subjects

External handheld loads affect scapular elevation and upward rotation during shoulder elevation tasks

Altered scapular kinematics is associated with shoulder pain. Resistance exercise is a common treatment; however, the effects of lifting an external load on scapular kinematics is limited. Understanding whether an external handheld load affects scapular kinematics in a healthy population can provide normal values utilized for comparison to individuals with shoulder pain. Currently, no studies have examined the effect of incrementally increased handheld loads. We defined the effects of varying external handheld loads on scapular kinematics during a shoulder elevation task. Healthy participants (n = 50) elevated their shoulder in the scapular plane over 4 trials. One trial of no loading (control) and 3 trials with incrementally increased external handheld loads. Scapular kinematic rotations and translations were measured during ascent and descent phases using 3D motion capture. Compared to no load, the highest external load during ascent increased scapular elevation [mean difference = 3.2 degrees (95%CI: 0.9, 5.4), p = 0.006], and during descent increased scapular elevation [mean difference = 3.9 degrees (95%CI: 2.8, 5.1), p < 0.001] and increased scapular upward rotation [mean difference = 4.5 degrees (95%CI: 2.4, 6.6), p < 0.001]. External handheld loads result in small increases in scapular elevation and scapular upward rotation. These results should be utilized as normal values to compare to individuals with shoulder pain.

Kinematic, electromyographic and isokinetic measurements for the management of shoulder subacromial pain syndrome: A systematic review

BACKGROUND

Subacromial shoulder pain syndrome is a very common and challenging musculoskeletal disorder. Kinematics, electromyographic muscle activity and isokinetic dynamometry are promising non-invasive movement analysis tools to improve understanding of this condition. No review has combined their results to provide a better understanding of the effects of subacromial pain syndrome on shoulder movement. This systematic review aimed to synthesise the associations between exposure to shoulder pain due to subacromial pain syndromes or subacromial impingement and changes in shoulder movement measures.

METHODS

The databases were Scholar google, Pubmed, Science Direct, Scopus and the Cochrane Library. We included studies that observed the association of the presence of subacromial pain syndromes or subacromial impingement with changes in shoulder motion measures.

FINDINGS

Seventeen studies with 943 participants were included. The main kinematic change was a lower scapular posterior during abduction in the subacromial pain syndrome group with a "low" level of evidence (standardised mean difference = -0.61, 95% confidence interval [-0.80; -0.43]). The main electromyographic change was an earlier onset of activation of the upper trapezius in the subacromial pain syndrome group, with a "moderate" level of evidence (standardised mean difference = 1.01, 95% confidence interval: [-2.97; 0.96]). The main isokinetic change was a lower peak internal rotator torque in the subacromial pain syndrome group, with a 'low' level of evidence (standardised mean difference = -0.41, 95% confidence interval: [-0.53; -0.29]).

INTERPRETATION

The variables measured during movement are associated with subacromial pain syndrome or subacromial impingement syndrome. Consistency between the results supports the importance of scapula biomechanics measurements in these conditions.

Could the Improvement of Supraspinatus Muscle Activity Speed up Shoulder Pain Rehabilitation Outcomes in Wheelchair Basketball Players?

Shoulder pain (SP) is a common clinical complaint among wheelchair basketball (WB) players, since their shoulders are exposed to intense overload and overhead movements. The supraspinatus tendon is the most exposed to WB-related injuries and it is primarily responsible for SP in WB athletes. In these cases, SP rehabilitation remains the main treatment, but there is still a lack of specific protocols which should be customized to WB players' peculiarities and to the supraspinatus muscle activity monitor, and the improvement of rehabilitation outcomes is slow. Thus, the aim of this study was to verify if the improvement of supraspinatus muscle activity, monitored in real time with surface electromyography (sEMG) during the execution of therapeutic exercises, could speed up SP rehabilitation outcomes in WB players. Thirty-three athletes were enrolled. They were divided into two groups. Both groups underwent the same shoulder rehabilitation program, but only the Exercise Plus sEMG Biofeedback Group executed therapeutic exercises while the activity of the supraspinatus muscles was monitored using sEMG. Participants were evaluated at enrollment (T0), at the end of 4 weeks of the rehabilitation program (T1), and 8 weeks after T1 (T2), using the following outcome measures: supraspinatus muscle activity as root mean square (RMS), Wheelchair User's Shoulder Pain Index (WUSPI), shoulder abduction, and external rotation range of motion (ROM). The Exercise Plus sEMG Biofeedback Group improved more and faster for all the outcomes compared to the Exercise Group. The monitoring and improvement of supraspinatus muscle activity seems to be an effective way to speed up SP rehabilitation outcomes in WB players, since it makes the performance of therapeutic exercise more precise and finalized, obtaining better and faster results in terms of recovery of shoulder function.

Effect of elastic scapular taping on shoulder and spine kinematics in adolescents with idiopathic scoliosis

OBJECTIVE

The aim of this study was to investigate the short-term effects of scapular repositioning using an elastic taping technique on the three-dimensional (3-D) shoulder and thoracic kinematics during various activities of daily living (ADLs) in adolescents with idiopathic scoliosis (IS).

METHODS

Shoulder and spine kinematics during five ADL movement tasks were assessed in 24 adolescents with IS (3 males and 21 females; mean age: 15.8 years; age range: 14-17 years) before and 15 min after elastic scapular taping. All the participants had a moderate curve magnitude (Cobb angle: 20°-45°), with a primary thoracic curve. A 3-D electromagnetic tracking system (Ascension Technology Corporation, Shelburne, VT, USA) was used to record 3-D shoulder and thoracic kinematics. ADL movement tasks included touching the mouth/drinking, touching the back, touching the contralateral shoulder, reaching upward, and bilateral 4-kg weight lifting. Two separate strips of elastic tape were applied using the same correction technique for each shoulder and scapular region to control scapular alterations in the resting position.

RESULTS

Elastic scapular taping significantly improved scapular external rotation and scapular upward rotation. Similarly, humeral horizontal adduction, external rotation, thoracic flexion, and lateral bending significantly increased in the taped condition depending on the specific task (p<0.05).

CONCLUSION

Elastic scapular taping can change scapular orientations on the convex and concave sides, thereby affecting upper extremity and trunk kinematics. Thus, the dynamic stability of the scapula increases to produce larger movements during functional activities.

LEVEL OF EVIDENCE

Level IV, Therapeutic study.

Analysis of Scapular Kinematics and Muscle Activity by Use of Fine-Wire Electrodes During Shoulder Exercises

BACKGROUND

During nonoperative or postoperative rehabilitation after sports injuries, exercise selection is often based on minimal load on the injured/repaired glenohumeral structures, while optimally activating scapulothoracic muscles. Previous research explored scapular muscle activity during rehabilitation exercises using surface electromyography (EMG). However, limited information exists about the deeper lying muscle activity, measured with fine-wire electrodes, even more in combination with 3-dimensional scapular kinematics.

PURPOSE

To report scapular kinematics synchronously with surface and fine-wire EMG during specific shoulder exercises for early rehabilitation.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A total of 23 healthy male patients were recruited. Three-dimensional scapular kinematics were measured combined with EMG recording of 8 muscles during 4 commonly used shoulder exercises (inferior glide, low row, lawnmower, and robbery). Upper (UT), middle (MT), and lower (LT) trapezius and serratus anterior muscle activities were measured with bipolar surface electrodes. Intramuscular electrodes were placed in the levator scapulae (LS), rhomboid major (RM), pectoralis minor (Pm), and infraspinatus (IS) muscles. All data were normalized as a percentage of maximal voluntary isometric contraction (%MVIC). A linear mixed model with Bonferroni correction was applied for statistical analysis.

RESULTS

Scapular kinematics revealed an anterior tilt position during the inferior glide, low row, and robbery (P < .05). An upward rotation position between 20° and 30° was reached in all exercises except low row. Inferior glide (31°) and low row (42°) represented a significantly increased internal rotation position compared with lawnmower and robbery. Lawnmower and robbery showed significantly (P < .05) more MT (lawnmower, 36% MVIC; robbery, 39% MVIC) and RM (lawnmower, 59% MVIC; robbery, 66% MVIC) activation compared with inferior glide and low row. Lawnmower and robbery showed significantly (P < .05) less Pm activation (9.5%-12% MVIC). LS was significantly more active during robbery (58% MVIC) compared with inferior glide and low row (27%-36% MVIC) (P < .05). IS showed moderate activity (24%-37% MVIC) for all exercises, except low row (13% MVIC).

CONCLUSION/CLINICAL RELEVANCE

This study provides new insights about scapular positions and activation of the deeper layer muscles during 4 commonly used shoulder rehabilitation exercises. The lawnmower showed a favorable position of the scapula with less Pm activity in contrast to the low row. The inferior glide, lawnmower, and robbery should not be implemented in early phases of shoulder rehabilitation because of their moderate muscle activity.

A three-dimensional scapular motion analysis in patients with arthroscopic anterior capsulolabral repair of the shoulder: The effect of scapular stabilization taping

BACKGROUND

The aim of this study was to investigate the scapular kinematics during dynamic humeral movements in patients with arthroscopic anterior capsulolabral repair of the shoulder along with the potential biomechanical corrective effects of scapular stabilization taping.

METHODS

Twenty patients with unilateral traumatic anterior shoulder instability and arthroscopic anterior capsulolabral repair participated in the study. Dynamic shoulder kinematics were assessed during the scapular plane shoulder elevation for both the operated and non operated shoulders and also under two conditions: no-taping and taping. Statistical analysis to compare sides and conditions was performed with analysis of variance models.

RESULTS

The scapula was more internally rotated position in operated shoulders than in non operated shoulders. Furthermore, the scapula was less internally rotated and more downwardly rotated at 120° of elevation in the taping condition.

CONCLUSIONS

Operated shoulders demonstrated kinematics alterations when compared to non operated shoulders underwent arthroscopic anterior capsulolabral repair. Additionally, changes in the scapular orientation with the taping was very small but followed a pattern, which would be suggested to be an orientation that potentially produce more scapular stability and to increase stress on the inferior glenohumeral ligament.

Comparison of the effects of sensorimotor training programs on pain, electromyography and kinematics in patients with scapular downward rotation syndrome

OBJECTIVES

Comparison of the effects of six weeks sensorimotor and sensorimotor with passive interventions programs on pain, electromyography (EMG) and kinematics in patients with scapular downward rotation syndrome (SDRS).

DESIGN

Randomized Controlled Trial.

SETTING

Institutional practice.

PARTICIPANTS

140 active subjects with unilateral SDRS were randomized to three groups. Group one received sensorimotor (n = 46), group two received sensorimotor with passive interventions (n = 48), and group three received active self-exercise as a control group (n = 46). Pain, EMG of the levator scapula (LS), upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA), as well as kinematics were measured at the baseline and after the interventions.

MAIN OUTCOME MEASURES

Primary outcome: Pain - Secondary outcomes: EMG and kinematics.

RESULTS

There were significant between-group differences between intervention groups one and two in pain, LS and SA onset activation favoring group two and LS muscle activity favoring group one. There were significant within-group changes in almost all dependent variables except LT muscle onset activation in both groups one and two.

CONCLUSIONS

The addition of passive interventions on the scapula and neck may be superior to conservative training alone on the scapula and neck for improving neck pain, EMG and kinematics in participants with SDRS.

Repositioning the scapula with taping following distal radius fracture: Kinematic analysis using 3-dimensional motion system

STUDY DESIGN

Cross-sectional and controlled laboratory study using pretest-posttest design.

INTRODUCTION

Patients with distal radius fracture (DRfx) report proximal segment problems. Taping is commonly recommended because it provides improved posture and function.

PURPOSE OF THE STUDY

This study aimed to investigate the 3-dimensional scapular kinematics and the effect of taping on the kinematics in participants with DRfx.

METHODS

Twenty participants with a unilateral history of DRfx and 20 healthy controls participated. Scapular kinematics was assessed using an electromagnetic system. Three separate strips of elastic taping were applied for participants with DRfx over the arm, scapula, and middle and lower trapezius muscles through the paravertebral muscles. Afterward, the scapular kinematics was reassessed in taped condition.

RESULTS

When participants with DRfx and healthy controls compared, the scapula was more downwardly rotated at 120° of humerothoracic elevation (mean difference [MD], 9.06°) and at 120° (MD, 9.04°), 90° (MD, 5.6°) of humerothoracic lowering, more upwardly rotated at 30° of humerothoracic lowering (MD, 5.1°). Taping showed a significant effect on kinematics; specifically, the scapula was more externally rotated (38.9° untaped vs 31.1° taped) and posteriorly tilted (-9.2° untaped vs -4.8° taped) during humerothoracic elevation and lowering for participants with DRfx.

DISCUSSION

Participants with DRfx showed different scapular kinematics and taping resulted in changes on tested kinematic parameters during humeral movements. Differences in scapular motion during elevation with taping showed a specific pattern.

CONCLUSIONS

Overall, taping maintained a position likely to produce optimal rotator cuff function during early rehabilitation of patients with DRfx.

LEVEL OF EVIDENCE

N/A.

Analysis of the kinetic chain in asymptomatic individuals with and without scapular dyskinesis

BACKGROUND

This study measured strength of the trunk and hip, and compared Y Balance Test and Upper Quarter Y Balance Test in individuals without and with scapular dyskinesis. Strength and endurance of the scapulothoracic muscles were also assessed.

METHODS

Forty-four individuals without shoulder pain were divided in 2 groups: without scapular dyskinesis (age 26.00, SD 4.10 years) and scapular dyskinesis (age 23.68, SD 4.20 years). Scapular dyskinesis was assessed by clinical observation of the scapular motion during arm elevation, and was classified as present or absent. A handheld dynamometer was used to measure the isometric strength of the trunk flexors and lateral flexors, hip extensors and abductors, lower trapezius, serratus anterior, and latissimus dorsi. Y and Upper Quarter Y Balance Tests were performed with the individual in single-limb and 3-point plank position, respectively. Endurance of the scapulothoracic muscles was assessed with the individuals in prone with the arm at 135° abduction. Independent t-test and Mann-Witney test were used for comparison between groups. A P < 0.05 was considered significant. Effect sizes between groups were also calculated.

FINDINGS

No differences (P > 0.05) were demonstrated between groups for all variables. Moderate effect size (d ~ 0.40) was found for the trunk flexors and hip extensors, and endurance of the scapulothoracic muscles, whereas the scapular dyskinesis group showed less strength and endurance in relation to the group without dyskinesis.

INTERPRETATION

Strength of the trunk flexors and hip extensors, and endurance of the scapulothoracic muscles seem to have influence in scapular dyskinesis in non-athletes without shoulder pain.

Effect of flexibility deficit on scapular asymmetry in individuals with and without shoulder pain

BACKGROUND

Many studies have investigated the relationship between soft tissue tightness and shoulder kinematics. However, there is a lack of information on the dynamic properties responsible for side-to-side differences such as scapular asymmetry.

OBJECTIVE

To determine the relationship between a deficit in soft tissue flexibility and scapular asymmetry.

METHODS

A total of 58 individuals (29 patients with shoulder pain and 29 asymptomatic participants) were enrolled. Bilateral shortening of the pectoralis minor muscle and posterior shoulder tightness were assessed. Additionally, side-to-side flexibility deficit was calculated. Scapular kinematics were measured with an electromagnetic tracking device while individuals were standing in a resting position and during arm elevation. The symmetry angle was calculated to quantify scapular asymmetry.

RESULTS

The pectoralis minor and the posterior capsule flexibility deficit showed a significant positive relationship with the symmetry angle in the resting position separately for both asymptomatic (r=0.47, r=0.37 relatively) and symptomatic groups (r=0.58, r=0.38 relatively), indicating that the increased deficit in the pectoralis minor and posterior capsule flexibility were associated with increased scapular asymmetry. However, no significant relationship was found between flexibility deficit and scapular asymmetry during arm elevation and lowering for both asymptomatic and symptomatic groups.

CONCLUSION

The findings of the study provided information on the relationship of a flexibility deficit on the scapular position and orientation in asymptomatic and symptomatic populations.

Scapular kinematics in adolescent idiopathic scoliosis: A three-dimensional motion analysis during multiplanar humeral elevation

The scapula plays a critical role in supporting shoulder function. Considering the closed anatomical relationship between the scapula and the thoracic cage, the presence of postural disturbances could be linked to alterations in the scapular position and orientation in adolescent idiopathic scoliosis (AIS). However, currently there is a lack of descriptive research and detailed assessment of scapular kinematics in AIS. The aim of this study was to investigate the three-dimensional scapular kinematics in AIS. Nineteen AIS patients and fourteen healthy controls participated in this study. Bilateral shoulder kinematics were measured with an electromagnetic tracking device during shoulder elevation in the sagittal, scapular, and frontal planes. Data for the scapular orientation were analyzed in the resting position and at 30°, 60°, 90°, and 120° of humerothoracic elevation. Scapular behavior was different in participants with AIS, compared to healthy controls, with different patterns observed on convex and concave sides. While examining all three planes of elevation, the scapula was more internally and anteriorly tilted on the convex side, while the scapula was more externally, downwardly rotated, and posteriorly tilted on the concave side in participants with AIS. Furthermore, there was a decreased peak humerothoracic elevation and altered scapular posterior tilt in participants with AIS in the resting position. These findings increase our knowledge and understanding of scapular alterations and the reported scapular alterations can be considered as adaptive compensation strategies in AIS.

Subacute effects of cervicothoracic spinal thrust/non-thrust in addition to shoulder manual therapy plus exercise intervention in individuals with subacromial impingement syndrome: a prospective, randomized controlled clinical trial pilot study

OBJECTIVES

To determine the subacute effects of cervicothoracic spinal thrust/non-thrust in addition to shoulder non-thrust plus exercise in patients with subacromial pathology.

METHODS

This was a randomized, single blinded controlled trial pilot study. This trial was registered at ClinicalTrials.gov (NCT01753271) and reported according to Consolidated Standards of Reporting Trials requirements. Patients were randomly assigned to either shoulder treatment plus cervicothoracic spinal thrust/non-thrust or shoulder treatment-only group. Primary outcomes were average pain intensity (Numeric Pain Rating Scale) and physical function (Shoulder Pain and Disability Index) at 2 weeks, 4 weeks, and patient discharge.

RESULTS

18 patients, mean age 43.1(15.8) years satisfied the eligibility criteria and were analyzed for follow-up data. Both groups showed statistically significant improvements in both pain and function at 2 weeks, 4 weeks, and discharge. The between-group differences for changes in pain or physical function were not significant at any time point.

DISCUSSION

The addition of cervicothoracic spinal thrust/non-thrust to the shoulder treatment-only group did not significantly alter improvement in pain or function in patients with subacromial pathology. Both approaches appeared to provide an equally notable benefit. Both groups improved on all outcomes and met the criteria for clinical relevance for both pain and function.

LEVEL OF EVIDENCE

2b.