Scapular Upward Rotation Research Articles

BIOMECHANICAL ASSESSMENT OF SCAPULAR PLANE ELEVATION EXERCISE WITH DIFFERENT MODES OF RESISTANCE IN SUBJECTS WITH AND WITHOUT IMPINGEMENT SYNDROME.

Background: Strengthening the rotator cuff and scapular stabilizers is usually prescribed for subjects with shoulder pain and is done either using dumbbells or TheraBand. The resistance offered by elastic Theraband increases with increase in change from initial length and therefore the resistance offered by TheraBand, and dumbbell differs across the range of motion. Objectives: The purpose of the study is to evaluate the scapular kinematics and activity of prime mover (Anterior Deltoid) while using two different modes of resistance (TheraBand v/s dumbbell) in subjects with and without impingement syndrome. Methods: Twenty-two asymptomatic subjects and 12 subjects with impingement syndrome were included. 3D motion sensors were attached over the humerus, scapulae and trunk to capture movements of the shoulders as the subject performed scapular elevation without load, with yellow Theraband or 2 Kg Dumbbell. Simultaneous electromyography (EMG) activity of anterior Deltoid was measured and analyzed as percentage of maximum voluntary contraction. Results: During arm elevation, scapular Upward rotation was significantly greater at 90° with TheraBand® as compared to unloaded. It was also greater at 120° as compared to unloaded and dumbbell conditions (p<0.001) during elevation and lowering phase. Scapula upward rotation was significantly lesser at 30° with TheraBand® as compared to other conditions. Conclusion: This study found significant downward rotation and anterior tilt of scapula with TheraBand during lowering phase of exercise as compared to dumbbell and unloaded. The alterations of kinematics may help therapists make informed decisions while making exercise prescriptions.

Comparing and characterizing scapular muscle activation ratios in males and females during execution of common functional movements.

The shoulder complex relies on scapular movement controlled by periscapular muscles for optimal arm function. However, minimal research has explored scapular muscle activation ratios during functional tasks, nor how they might be influenced by biological sex. This investigation aims to characterize how sex impacts scapular muscle activation ratios during functional tasks. Twenty participants (ten females, ten males) were assessed with surface electromyography (EMG) and motion tracking during seven functional tasks. Activation ratios were calculated from normalized EMG for the three trapezius muscles and serratus anterior. Scapular angles were calculated using a YXZ Euler sequence. Two-way mixed methods ANOVAs (p<.05) were used to assess the effects of sex and humeral elevation level on ratios and angles. Sex-based differences were present in the Tie Apron task, with males exhibiting higher upper trapezius/lower trapezius and upper trapezius/middle trapezius ratios than females. Males also demonstrated decreased internal rotation in this task. Other tasks showcased significant sex-based differences in scapular upward rotation but not in activation ratios. Humeral elevation generally demonstrated an inverse relationship with scapular muscle activation ratios. This study highlights sex-based differences in scapular muscle activation ratios during specific functional tasks, emphasizing the need to consider sex in analyses of shoulder movements. Normative activation ratios for functional tasks were provided, offering a foundation for future comparisons with non-normative groups. Further research is warranted to confirm and explore additional influencing factors, advancing our understanding of shoulder activation and movement in diverse populations.

Scapula-Focused Exercises With or Without Biofeedback and Corticospinal Excitability in Recreational Overhead Athletes With Shoulder Impingement.

Individuals with shoulder impingement syndrome (SIS) exhibit changes in corticospinal excitability, scapular kinematics, and scapular muscle-activation patterns. To restore the scapular kinematics and muscle-activation patterns in individuals with SIS, treatment protocols usually include scapula-focused exercises, such as scapular-orientation and strength training. To investigate whether scapular-orientation and strength training can reverse the altered corticospinal excitability of recreational overhead athletes with SIS. Randomized controlled clinical trial. University laboratory. Forty-one recreational overhead athletes with SIS: 20 in the scapular-orientation group (age = 26.45 ± 4.13 years, height = 171.85 ± 7.88 cm, mass = 66.70 ± 10.68 kg) and 21 in the strengthening group (age = 26.43 ± 5.55 years, height = 171.62 ± 5.87 cm, mass = 68.67 ± 10.18 kg). Both groups performed a 30-minute training protocol consisting of 3 exercises to strengthen the lower trapezius (LT) and serratus anterior muscles without overactivating the upper trapezius muscles. Participants in the scapular-orientation group were instructed to consciously activate their scapular muscles with electromyographic biofeedback and cues, whereas the strengthening group did not receive biofeedback or cues for scapular motion. Corticospinal excitability was assessed using transcranial magnetic stimulation. Scapular kinematics and muscle activation during arm elevation were also measured. After training, both groups demonstrated an increase in motor-evoked potentials in the LT (P = .004) and increases in scapular upward rotation (P = .03), LT activation (P < .001), and serratus anterior activation (P < .001) during arm elevation. Moreover, the scapular-orientation group showed higher LT activation levels during arm elevation after training than the strengthening group (P = .03). With or without biofeedback and cues, scapula-focused exercises improved scapular control and increased corticospinal excitability. Adding biofeedback and cues for scapular control during exercise helped facilitate greater LT activation, so feedback and cues are recommended during scapula-focused training.

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

Backgroundthe 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. Objectivesto compare muscle strength, scapular kinematics, proprioception, and blood glucose levels within patients with FS and to asymptomatic individuals. Designcross-sectional study. MethodThirty-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. ResultsPatients 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. ConclusionA 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.

Preparation For Flight: The Physical Profile of Pre-Professional and Professional Circus Artists in the United States.

Established norms for fitness and performance measures are lacking in circus arts. These would assist healthcare professionals and coaches to screen for readiness to participate in training or performance, determine post-injury return to performance, and develop targeted conditioning programs. The purpose of this research was to establish norms for trunk and extremity physical exam and performance measures in circus artists by professional status, assigned sex at birth (ASAB), and age. Descriptive laboratory study. Circus artists (n=201; ages 13-69y; 172 females ASAB, 29 males ASAB) from 10 cities across the United States underwent a baseline physical examination including shoulder, hip and trunk measures of passive (PROM) and active (AROM) range of motion, measures of flexibility (shoulder and hip), strength (manual muscle tests, grip strength), cardiovascular fitness (3 minute-step test), balance (single limb and handstand), and performance, (pull-ups, and the closed kinetic chain upper extremity stability test [CKCUEST]). ANOVAs were used to determine between group differences by age and T-tests to discern differences by ASAB or professional status. Differences existed by professional status for shoulder external rotation PROM, hip PROM, hip flexibility, shoulder and abdominal strength, and cardiovascular fitness. Sex differences were seen in active scapular upward rotation, hip and shoulder PROM and flexibility, hip and grip strength, and for functional performance measures (pull-ups, CKCUEST). Differences by age were limited to active scapular upward rotation, shoulder PROM, flexibility and strength, cardiovascular fitness, and balance. Overall, professionals outperformed pre-professionals for lower abdominal strength, pull-ups, handstand balance, cardiovascular fitness, hamstring, and straddle flexibility. Generally, males ASAB demonstrated greater shoulder flexibility and upper body functional strength while females ASAB had greater hip and lumbar flexibility and hip strength. No measures showed consistent declines with increasing age, though some showed differences between adolescents and adults. These normative values for physical characteristics and functional performance in pre-professional and professional circus artists may be used to guide screening for readiness to participate in advanced training or performance, return to performance after injury, and the development of targeted strength and conditioning programs. 3.

Neuromuscular electrical stimulation of humeral adductors in subjects with rotator cuff tear.

In symptomatic patients with rotator cuff tear, MRI and radiographic studies have ascribed the pain symptom to insufficient humeral head depression during arm elevations. The arm adductors such as the teres major and pectoralis major may contribute to depression of the humerus head during arm elevations. Researchers have demonstrated that neuromuscular electrical stimulation (NMES) of the serratus anterior and lower trapezius can control scapular motions and improve acromiohumeral distance. It is unknown, however, if adductor neuromuscular training could help patients with rotator cuff tear. A cross-sectional study of NMES of the teres major and pectoralis major was conducted on 30 symptomatic subjects with rotator cuff tear. We measured the acromiohumeral distance by ultrasonography and scapular kinematics during arm elevation with a three-dimensional motion tracking system. The acromiohumeral distance significantly increased during NMES of the teres major (0.73mm, p < 0.001). However, the distance significantly decreased with NMES of the pectoralis major (0.78mm, p < 0.001). Additionally, scapular upward rotation was greater during NMES of the teres major than during NMES of the pectoralis major (3.4°, p < 0.001). Scapular external rotation decreased significantly more during NMES of the pectoralis major than during NMES of the teres major (1.6°, p = 0.003). NMES of the teres major can increase acromiohumeral distance and scapular upward rotation during arm elevation. However, the decreased upward and external rotation of the scapula during arm elevation with NMES of the pectoralis major may be associated with subacromial impingement.

Scapular Motor Control and Upper Limb Movement Quality in Subjects with and without Chronic Shoulder Pain: A Cross-Sectional Study

Despite the existence of several studies about the scapula’s position and motion, in shoulder pain conditions, there are still conflicting findings regarding scapular adaptations and reduced research about the scapula’s role during functional tasks. The present study aimed to compare scapular-related kinematic and electromyographic outcomes during different shoulder movements (with and without load) and the drinking task, between symptomatic and asymptomatic subjects. Forty subjects (divided into two groups) participated in this cross-sectional observational study. Scapulothoracic motion, scapulohumeral rhythm, and movement quality (considering trunk compensation, time-to-peak acceleration, and smoothness), as well as the relative surface electromyographic activity and muscle ratio considering the trapezius, serratus anterior, and levator scapulae (LS), were assessed. The symptomatic group presented the following: (1) changes in scapular upward rotation (p = 0.008) and winging (p = 0.026 and p = 0.005) during backward transport and drink phases; (2) increased muscle activity level of the middle trapezius (MT) in all tasks (p &lt; 0.0001 to p = 0.039), of LS during shoulder elevation with load (p = 0.007), and of LS and LT during most of the drinking task phases (p = 0.007 to p = 0.043 and p &lt; 0.0001 to p = 0.014, respectively); (3) a decreased serratus anterior lower portion activity level (SAlow) during shoulder lowering with load (p = 0.030) and drink phase (p = 0.047); and (4) an increased muscular ratio between scapular abductors/adductors (p = 0.005 to p = 0.036) and elevators/depressors (p = 0.008 to p = 0.028). Compared to asymptomatic subjects, subjects with chronic shoulder pain presented scapular upward rotation and winging adaptations; increased activity levels of MT, LT, and LS; decreased activity levels of SAlow; and increased scapular muscle ratios.

The effect of kinesio® tape on scapulothoracic joint kinematics in young healthy participants

IntroductionThe purpose of this study was to investigate the effects of Kinesio® tape on scapulothoracic joint kinematics during humerothoracic elevation and lowering in asymptomatic participants. MethodSixteen males and 24 females participated in data collection using the Polhemus G4 3D electromagnetic motion capture system. Dominant shoulder kinematics were collected while the participant performed three repetitions of elevation in the frontal, sagittal, and scapular planes. Initial data collection occurred with and subsequent data collection without Kinesio® tape. Scapular upward rotation and posterior tilting were compared between the two conditions between 30 and 90 degrees of elevation. ResultsDuring abduction elevation, participants demonstrated 3.40° more posterior tilting (p = 0.001), and 2.58° less upward rotation (p = 0.006) with Kinesio® tape. During lowering in the scapular plane, participants demonstrated 2.05° less downward rotation (p = 0.008) with Kinesio® tape. DiscussionPeople with subacromial impingement and multidirectional instability demonstrate decreased upward rotation. People with subacromial impingement also demonstrate decreased posterior tilting. Posterior tilting differences found during elevation as well as upward rotation differences found during lowering in this study indicate Kinesio® tape may be beneficial to patients with impingement or multidirectional instability. ConclusionKinesio® tape significantly alters scapulothoracic kinematics during humerus to trunk elevation. The clinical significance of this remains to be investigated.

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

ABSTRACT 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.

Differences in Osseous Shoulder Morphology, Scapulothoracic Orientation, and Muscle Volume in Patients With Constitutional Static Posterior Shoulder Instability (Type C1) Compared With Healthy Controls

Background: Constitutional static posterior humeral decentering (type C1 according to ABC Classification) has been recognized as a pre–osteoarthritic deformity that may lead to early-onset posterior decentering osteoarthritis at a young age. Therefore, it is important to identify possible associations of this pathologic shoulder condition to find more effective treatment options. Purpose: To perform a comprehensive analysis of all parameters reported to be associated with a C1 shoulder—including the osseous shoulder morphology, scapulothoracic orientation, and the muscle volume of the shoulder girdle in a single patient cohort. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A retrospective, comparative study was conducted analyzing 17 C1 shoulders in 10 patients who underwent magnetic resonance imaging (MRI) with the complete depiction of the trunk from the base of the skull to the iliac crest, including both humeri. The mean age of the patients was 33.5 years, and all patients were men. To measure and compare the osseous shoulder morphology (glenoid version, glenoid offset, humeral torsion, anterior acromial coverage, posterior acromial coverage, posterior acromial height, and posterior acromial tilt) and scapulothoracic orientation (scapular protraction, scapular internal rotation, scapular upward rotation, scapular translation, scapular tilt, and thoracic kyphosis), these patients were matched 1 to 4 according their age, sex, and affected side with shoulder-healthy patients who had received positron emission tomography (PET)-computed tomography. To measure and compare the muscle volume of the shoulder girdle (subscapularis, infraspinatus/teres minor, supraspinatus, trapezius, deltoid, latissimus dorsi/teres major, pectoralis major, and pectoralis minor), patients were matched 1 to 2 with patients who had received PET-MRI. Patients with visible pathologies of the upper extremities were excluded. Results: The C1 group had a significantly higher glenoid retroversion, increased anterior glenoid offset, reduced humeral retrotorsion, increased anterior acromial coverage, reduced posterior acromial coverage, increased posterior acromial height, and increased posterior acromial tilt compared with controls (P < .05). Decreased humeral retrotorsion showed significant correlation with higher glenoid retroversion (r = −0.742; P < .001) and higher anterior glenoid offset (r = −0.757; P < .001). Significant differences were found regarding less scapular upward rotation, less scapular tilt, and less thoracic kyphosis in the C1 group (P < .05). The muscle volume of the trapezius and deltoid was significantly higher in the C1 group (P < .05). Conclusion: Patients with C1 shoulders differ from healthy controls regarding osseous scapular and humeral morphology, scapulothoracic orientation, and shoulder girdle muscle distribution. These differences may be crucial in understanding the delicate balance of glenohumeral centering.

Analysis of the three-dimensional scapular kinematics and associated scapular muscle activity during scapular muscle exercises

ObjectiveTo compare scapular kinematics and muscle activity among various scapular muscle exercises. DesignA cross-sectional study. SettingA university research laboratory. ParticipantsEighteen healthy men participated in this study. Main outcome measuresThree-dimensional scapular kinematics was measured with an electromagnetic motion capture system. Activities of the upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA) were measured by using surface electromyography (EMG). In addition, the ratio of LT to the UT (LT/UT) and SA to the UT (SA/UT) was calculated. A repeated one-way analysis of variance and Shaffer's post-hoc analysis were used to detect the differences in each outcome during five exercises. ResultsThe scapula was rotated upwardly during all exercises except push-up plus. The LT/UT ratio during side-lying external rotation and side-lying flexion were significantly higher than that for scapular plane elevation (P < .05), although the highest activity of the lower trapezius was produced during scapular plane elevation. The activities of the serratus anterior and SA/UT ratio during horizontal adducted elevation and push-up plus were significantly higher than that during scapular plane elevation (P < .05). ConclusionHorizontal adducted elevation might be more appropriate for increasing scapular upward rotation with high serratus anterior activity and SA/UT ratio than push-up plus.

Effects of manual therapy in addition to stretching and strengthening exercises to improve scapular range of motion, functional capacity and pain in patients with shoulder impingement syndrome: a randomized controlled trial

BackgroundThe current study aimed to measure the effectiveness of manual therapy in addition to stretching and strengthening exercises in patients with shoulder impingement syndrome to improve functional capacity, pain, and scapular range of motion.MethodsThis is a single-blinded randomized controlled trial. Thirty-two participants with chronic shoulder impingement syndrome were randomly allocated into two groups. Both groups received stretching and strengthening exercises while the treatment group was given manual therapy additionally. Treatment was started after the patients signed an informed consent form. The data were collected from the University of Lahore Teaching Hospital between March 2022 and December 2022. The study aimed to measure pain using a numeric pain rating scale, functional capacity was assessed by the disability of the arm and shoulder, and goniometry was used for scapular ranges, i.e., scapular protraction and upward rotation. Each treatment session lasted 45 min for the treatment group and 30 min for the control group. The treatment comprised five days a week for four weeks, after which post-intervention measurements were taken.ResultsThirty-two participants were enrolled in the study, and 16 were divided into each group. The mean age of the participants in the treatment group was 38.19 ± 7.31 while the comparison group was 35.69 ± 7.98. An independent sample t-test was run on the data with a 95% confidence interval, statistically significant results were obtained, i.e., p-value < 0.05, post-intervention in the treatment group. Both groups have significantly improved functional capacity and scapular protraction (p < 0.005), however, pain and scapular upward rotation were not found statistically significant in the control group (p > 0.05).ConclusionThe addition of manual therapy along with exercise therapy showed clinical and statistical significant results for pain, functional capacity, and scapular range of motion. It demonstrated superior effects than exercise therapy alone for the chronic condition of SIS.Trial RegistrationThe trial was registered in the Iranian Registry of Clinical Trials (https://www.irct.ir/) with the registration number: IRCT20230526058291N1, (Date: 12/08/2023).

In Vivo 3-Dimensional Dynamic Evaluation of Shoulder Kinematics After the Latarjet Procedure: Comparison With the Contralateral Healthy Shoulder.

Researchers have attempted to understand the underlying mechanism of the Latarjet procedure; however, its effects on shoulder kinematics have not been well studied. The purpose was to analyze shoulder kinematics after the Latarjet procedure. It was hypothesized that the nonanatomic transfer of the coracoid process during the procedure would affect normal shoulder kinematics. Controlled laboratory study. The study included 10 patients (age range, 20-52 years) who underwent the modified Latarjet procedure between June 2016 and November 2021. Computed tomography and fluoroscopy were conducted on both shoulder joints of all patients, and 3-dimensional models were reconstructed. The 3-dimensional coordinates were encoded on the reconstructed models, and shoulder kinematics were analyzed through a 3-dimensional-2-dimensional model-image registration technique. Scapular rotation parameters (scapular upward rotation, posterior tilt, external rotation, and scapulohumeral rhythm) were compared between the Latarjet and the nonsurgical contralateral sides during humeral abduction, as was anteroposterior (AP) translation relative to the glenoid center during active humeral external rotation. The Latarjet side displayed significantly higher values of scapular upward rotation at higher degrees of humeral elevation (130°, 140°, and 150°) compared with the nonsurgical side (P = .027). Posterior tilt, external rotation, and scapulohumeral rhythm were not significantly different between sides. AP translation at maximal humeral rotation was not significantly different between sides (Latarjet, -0.06 ± 5.73 mm vs nonsurgical, 5.33 ± 1.60 mm; P = .28). Interestingly, on the Latarjet side, AP translation increased until 40° of humeral rotation (4.27 ± 4.64 mm) but began to decrease from 50° of humeral rotation. The Latarjet side demonstrated significant changes in scapular upward rotation during higher degrees of humeral elevation compared with the contralateral shoulder. Posterior movement of the humeral head at >50° of humeral rotation could be the desired effect of anterior stabilization; however, researchers should evaluate long-term complications such as osteoarthritis. Analysis of shoulder kinematics after the Latarjet procedure could provide information regarding long-term outcomes and whether the procedure would affect the daily activities of patients.

Effects of Scapular Angular Deviations on Potential for Rotator Cuff Tendon Mechanical Compression.

One proposed mechanism of rotator cuff disease is scapular motion impairments contributing to rotator cuff compression and subsequent degeneration. To model the effects of scapular angular deviations on rotator cuff tendon proximity for subacromial and internal mechanical impingement risk during scapular plane abduction. Descriptive laboratory study. Three-dimensional bone models were reconstructed from computed tomography scans obtained from 10 asymptomatic subjects and 9 symptomatic subjects with a clinical presentation of impingement syndrome. Models were rotated to average scapular orientations from a healthy dataset at higher (120°) and lower (subject-specific) humeral elevation angles to investigate internal and subacromial impingement risks, respectively. Incremental deviations in scapular upward/downward rotation, internal/external rotation, and anterior/posterior tilt were imposed on the models to simulate scapular movement impairments. The minimum distance between the rotator cuff insertions and potential impinging structures (eg, glenoid, acromion) was calculated. Two-way mixed-model analyses of variance assessed for effects of scapular deviation and group. At 120° of humerothoracic elevation, minimum distances from the supraspinatus and infraspinatus insertions to the glenoid increased with ≥5° changes in upward rotation (1.6-9.8 mm, P < .001) or external rotation (0.9-5.0 mm, P≤ .048), or with ≥10° changes in anterior tilt (1.1-3.2 mm, P < .001). At lower angles, ≥20° changes in most scapular orientations significantly increased the distance between the supraspinatus and infraspinatus insertions and the acromion or coracoacromial ligament. A reduction in scapular upward rotation decreases the distance between the rotator cuff tendon insertions and glenoid at 120° humerothoracic elevation. Interpretation is complicated for lower angles because the humeral elevation angle was defined by the minimum distance. These results may assist clinical decision making regarding the effects of scapular movement deviations in patients with rotator cuff pathology and scapular dyskinesia and may help inform the selection of clinical interventions.

Towards in-field assessment of humeral and scapular kinematics: a comparison between laboratory and field settings using inertial sensors.

Inertial measurement units allow for quantitative assessment of body motion in many environments. Determining the ability to measure upper limb motion with inertial measurement units, leveraging procedures traditionally used in the lab such as scapular calibration procedures and humeral axial rotation calculation, would expand the opportunities to assess upper limb function in externally valid environments. This study examined if humeral and scapular motion measured in different field settings is consistent with motion measured in a lab setting in similar tasks. Twenty-eight adults participated in the study (14 field setting, 14 lab setting). Three different types of field settings were included: home (n = 5), work (n = 4), and sports (n = 5). Field participants were matched to lab participants based on sex and body height. All participants were equipped with five inertial and magnetic measurement units (Xsens Awinda, Xsens Technlogies, NL, Fs = 100 Hz) on the torso, humeri, and scapulae. Humeral and scapular angles were measured during a functional task protocol consisting of seven tasks. Data from all three field settings were combined. Statistical parametric mapping (α = .05) was used to assess differences in waveforms between the lab and field data. Five out of seven tasks displayed no differences for humeral elevation and humeral axial rotation, while scapular upward rotation and tilt were not statistically different for any tasks. Scapular internal rotation variability was very high for the field setting, but not for the lab setting. Task-based differences in humeral elevation and humeral axial rotation may be related to equipment modifications for the field protocol and between subjects' variability in task performance. Data indicate that humeral elevation, humeral axial rotation, and scapular upward rotation can be measured in externally valid field settings, which is promising for the evaluation of upper limb movement in natural environments.

Scapular motion during shoulder joint extension movement

A few reports on scapular motion during shoulder joint extension exist. Understanding the normal motion of shoulder joint extension may be useful in evaluating and treating patients with diminished or minimal shoulder joint extension. Therefore, this study aimed to identify scapular motion during shoulder joint extension movement in a sitting position. Shoulder joint extension movement in the sitting position were measured in 22 healthy adults (age, 25.8 ± 2.7 years). Shoulder joint extension, scapular upward rotation, anterior tilt, external rotation angles, and the acromion position were investigated using a three-dimensional motion analyzer. The difference from each value of 10° to 50° shoulder joint extension to each value of 0° shoulder joint extension were checked. The results were compared using multiple comparison method. In most participants, the scapula tilted posteriorly up to 30° of the shoulder joint extension and anteriorly after 30°. Scapular upward and external rotation continued to increase with shoulder extension. Furthermore, the acromion was displaced upward and backward. Thus, scapular posterior tilt is necessary for shoulder joint extension during the initial movement, followed by anterior tilt. The acromion may have been displaced posteriorly because of clavicular retraction, causing the scapula to tilt posteriorly. After 30° of shoulder joint extension, the scapular anterior tilt may have prevailed over the scapular posterior tilt.

Does scapular dysfunction alter scapular muscles activity and kinematics during swim stroke motion on adolescent swimmers?

ABSTRACT Scapular dyskinesis (SD) indicates dysfunction of the scapular muscle activity during the arm elevation, resulting in altered scapular kinematics. This study examined whether SD alters scapular muscle activity and kinematics during swim stroke motion. Seventeen swimmers (mean age: 13 ± 1 years) were divided into SD (n = 8) and control (n = 9) groups. Scapular muscle activity (the upper, middle, and lower trapezius and the serratus anterior muscle) and kinematics data were collected and time-normalised (0–100%) during swim stroke motion by swim-bench on land. Scapular kinematics were calculated for upward rotation, internal rotation, posterior tilt, and arm elevation angles. To compare patterns of muscle activity and kinematics with and without SD, statistical parametric mapping unpaired t-test was used. The scapular upward rotation angle was decreased in SD compared to control in the 0–10% of the swim stroke phase (p = 0.041, t* = 3.018), and the internal rotation angle was increased in 0–15% of the phase (p = 0.033, t* = 2.994). Scapular posterior tilt and muscle activity showed no significant differences. These results suggested that SD altered scapular upward rotation and internal rotation at the initial phase of the swim stroke motion in adolescent swimmers and might potentially provoke a risk of subacromial impingement.

Evaluation of Scapular Dynamics in Sports Trainees

Background: The scapula provides stability and mobility for efficient upper-limb movement. Optimal scapular kinematics are essential for efficient force generation and injury prevention. Sports trainees, particularly those involved in sports requiring repetitive or high-intensity shoulder movements, are susceptible to injuries and performance limitations if associated with aberrant scapular mechanics. Understanding the intricacies of scapular dynamics is essential for designing tailored training interventions that enhance athletic performance. Rationale and objectives: Previous research has emphasized the need for sports-specific training protocols. The measurement of scapular rotation has gained significant attention. Evaluating asymmetries in scapular dynamics across various sports trainee populations is a step forward for the need for tailored interventions and injury prevention strategies in preventing injury and planning better exercise programs. The study uses a PALM meter for the measurement of scapular rotation. Methodology: 40 Subjects 19 to 24 years old from the sports authority of Andhra Pradesh, India, were studied after obtaining written informed consent. Scapular rotation measured in a neutral and with hands on the hip position. Root of the scapula (RSS), inferior angle of the scapula (IAS), and spinous processes (Sp) of C7 to T8 are taken as the anatomical landmarks. Measurements of scapular position taken in two arm positions: shoulder neutral, hands on hip. A right-angle triangle created by dropping a perpendicular line from the scapula's root to intersect the horizontal line between the scapula's inferior angle and the thoracic spine's closest spinous process (IAS-Sp). The hypotenuse represents the distance IAS to RSS, while the side opposite the angle θ is the distance IAS-Sp minus RSS-Sp. A positive result indicates upward scapular rotation, while a negative result indicates downward scapular rotation. Results and Conclusion: This cross-sectional study revealed variations in scapular rotation and the distances from spinous processes in the scapular position in neutral and hands-on Hip positions from right to left and male to female. Further studies are required to understand scapular rotation variations concerning various sports involving overhead activity, heavy weight lifting, endurance sports and anatomical variations, muscle activation patterns, or task demands. KEYWORDS: Scapular Rotation, Sports Trainees, Shoulder Movements, Scapular Mechanics, Athletic Performance.

Effect of a physiotherapy-directed rehabilitation programme on patients with multidirectional instability of the glenohumeral joint: a multimodal interventional MRI study protocol

IntroductionAltered neuromuscular control of the scapula and humeral head is a typical feature of multidirectional instability (MDI) of the glenohumeral joint, suggesting a central component to this condition. A previous...

Ab. No. 153 Comparison of 3d Scapular Kinematics of the Affected and Unaffected Shoulder in Subjects With Unilateral Adhesive Capsulitis

Introduction: The purpose of the study is to compare 3D scapular kinematics and scapulohumeral rhythm of affected and unaffected side in subjects with unilateral adhesive capsulitis at various degrees of elevation and lowering during flexion. Improving precise measurement of all scapular rotations will enhance comprehension of shoulder dysfunction and may aid in the development of targeted rehabilitation strategies. Methods: 20 subjects with unilateral adhesive capsulitis, average age (51.7±7.6 years) with symptoms since 4.3±2.5 months using purposive sampling were included. 3-dimensional Euler angles using the International Society of Biomechanics standards were estimated during flexion via Ascension trakSTAR sensors integrated with Motion Monitor Software. The scapular movements (upward/downward rotation, internal/external rotation and anterior/posterior tilt) were measured at rest(0°), 30°, 60°, 90° and 120° of arm elevation and the scapulohumeral rhythm was calculated between these motion increments. The kinematic variables at rest were compared using paired t-tests and scapular kinematic variables were compared across angles of elevation and sides for each phase separately using 2-way repeated measures ANOVA. In case of significant interactions, post hoc testing was done using Tukey Kramer test for pairwise comparisons. Results: The affected side was 6.81° more upwardly rotated than unaffected at 90°. There was statistical difference between phases of elevation and lowering for upward rotation at 60° and 90°, anterior tilt at 30°, 60° and 90° and scapular internal rotation at 90° and 120°. The differences at 120 degrees could not be measured in all subjects. The scapulohumeral rhythm was different between sides only for 60°-90° during flexion. Conclusion: There was a more substantial scapular substitution beyond the middle region of arm elevation during shoulder flexion. Beyond correcting the scapular shrug that would have increased scapular tilt, therapists may focus on reducing scapular upward rotation.