Scapular Motion Research Articles

Effectiveness of Ayush Rasayana A and B on the Quality of Life of Older Adults: Protocol for a Cluster Randomized Controlled Trial.

With advancing age among older adults, the associated debilities increase, indicating a deteriorating health status as there is a gradual loss of muscle mass, strength, and functionality. Ayush Rasayana A and B are coded Ayurvedic medicines developed from herbal extracts. This study has been planned to prevent debilitating conditions and improve the quality of life (QOL) in older adults. This study aimed to assess the effectiveness of Ayush Rasayana A and B on the QOL, quality of sleep, and functionality of older adults, along with the tolerability of the intervention. This was a multicenter, open-label, cluster randomized controlled trial conducted with 720 participants aged 60 to 75 years. The participants were divided into 2 groups (intervention and control), with both receiving Ayurvedic ancillary treatment for 3 months. The intervention group additionally received 10 g of Ayush Rasayana A orally once daily at bedtime for 6 days, followed by 1.5 g of Ayush Rasayana B orally twice daily before food for the remaining 84 days. The assessment criteria included the Older People's Quality of Life Questionnaire Brief, Katz Index of Independence in Activities of Daily Living, Pittsburgh Sleep Quality Index, Five Times Sit-to-Stand Test, and shoulder and scapular movements. Any change in hematological and biochemical parameters and occurrence of treatment-emergent adverse events were also assessed during the study period. The recruitment of the participants started in December 2023, and the final follow-up was completed in April 2024. Out of the total 720 enrolled participants, 686 (95.3%) completed the study up to the last follow-up. This study may provide evidence-based data to establish preventive treatment protocols for enhancing the QOL and functionality among older adults. The study results may also be helpful for the planning of interdisciplinary health policies for improving the health conditions of different populations. DERR1-10.2196/58186.

Effectiveness of Retraction 30 over Gross Stretch For Relieving Pectoralis Minor Tightness Among College Students

Background: The Pectoralis minor muscle originates from different 3 ribs and converges into one attachment point. Pectoralis minor shortening can contribute to many syndromes and impairments, especially at the shoulder. Some of them are impingement of the soft tissues, adhesive capsulitis etc. The prevalence of pectoralis minor tightness is very high in college-going students. The gross stretch is the stretching procedure that increases the length of the pectoralis minor muscle. This shoulder position produces tension in the muscle insertion in a posterior direction in conjunction with the scapular motion that is performed at flexion and elevation in the scapular plane, thereby lengthening the muscle. Retraction 30 is stretching with scapular retraction at 30 degrees of shoulder flexion; the flexion angle at 30 degrees can lengthen the muscle along the muscle fiber direction in the coronal plane. 30 degrees of flexion is considered to be more comfortable than a higher angle of flexion, as well as the angle is closest to the line of force Objectives of the study: To compare the effectiveness of gross stretch and retraction 30 in relieving pectoralis minor muscle tightness which can be co-operated in further treatment protocols. Study Design: Comparative Study Methodology: Two group pre–test–post–test design was used with purposive sampling. Selected subjects were allocated to two groups. Fourty subjects (20 males and 20 females) who fulfilled inclusion and exclusion criteria were recruited for the study. The independent variables are gross stretch and retraction 30 whereas the dependent variables were PMI (pectoralis minor index), pectoralis minor length test and Cervical Curvature. Result: This study results imply that retraction 30 is better when compared to gross stretch for correcting pectoralis minor tightness. Hence should be included as an inevitable part of stretching treatment. Practicing clinicians should continue to use evidence-based decisions when treating pectoralis minor tightness.

Effects of scapular motion control training on treatment of patients with scapular fractures: An observational study.

To explore the effect of scapula motion control training on the rehabilitation effect of patients with scapular fracture. According to the random number table method, 61 patients were evenly divided into observation group 30 cases and control group 31 cases. The control group received routine postoperative functional exercise, and the observation group received functional exercise by adding scapula motion control training to the routine postoperative functional exercise. The pain, daily activity, range of shoulder movement, strength test, and total score were compared between the 2 groups of patients at 4 and 12 weeks after surgery. After 4 and 12 weeks of treatment, compared with the control group, the daily activities, range of shoulder movements, and total scores of the observation group increased, and there were no significant differences in pain and strength tests. After 12 weeks of treatment, compared with the control group, the daily activity, range of shoulder movements, and total score of the observation group were higher than those of the control group. Scapular motion control training can effectively improve the treatment of patients with scapular fractures and has clinical application value.

Isolated humeral distalization in reverse total shoulder arthroplasty: a biorobotic shoulder simulator study

BackgroundHumeral distalization is inherent to reverse total shoulder arthroplasty (rTSA) and is often produced with concomitant humeral lateralization via the level of the humeral head cut, implant positioning, implant neck shaft angle, and polymer insert thickness. Biomechanical data on the isolated effects of humeral distalization remain limited but could be important to consider when optimizing postoperative rTSA shoulder function. This study investigated the effects of isolated humeral distalization on shoulder biomechanics using a biorobotic shoulder simulator. MethodsEight fresh-frozen cadaveric shoulders were tested using custom polymer inserts that translated the bearing surface 0, +5, +10, and +15 mm along the humeral stem axis, producing isolated distalization without lateralization. Specimens underwent passive elevation in the scapular plane with a static scapula to assess glenohumeral range of motion. Scapular plane abduction motion trajectories were then performed, driven by previously collected scapulothoracic and glenohumeral kinematics from rTSA patients. The effect of isolated distalization on passive elevation was tested using mixed-effects linear regression and the effect on muscle force, joint reaction force, and muscle excursion during active scapular-plane abduction was tested using statistical parametric mapping random effects analysis. ResultsMaximum passive scapular plane elevation increased with humeral distalization (4° per 5 mm distalization). During active elevation, deltoid and rotator cuff muscle forces, and joint reaction forces, increased up to 37% per 5 mm of distalization. Simulated deltoid muscle excursion was altered with increasing distalization but amounted to no more than 0.8 mm change from baseline per 5 mm of distalization. Rotator cuff muscles were consistently lengthened throughout abduction, up to 1.6 mm per 5 mm of distalization. These trends were observed across various patient motions. ConclusionsIsolated humeral distalization caused dramatic increases in the muscle forces required to perform scapular-plane abduction. Joint reaction forces increased correspondingly. These results suggest that implant and surgical strategies to generate deltoid muscle tension without humeral distalization may promote better active range of motion and more durable long-term outcomes over approaches that rely on distalization.

Repeatability of two methods for estimating scapular kinematics during dynamic functional tasks

Best practices for scapular motion tracking are still being determined. The repeatability of different scapular kinematic procedures needs to be evaluated. The purpose of this study was to assess the test-retest reliability of two scapular kinematic procedures: double calibration with AMC (D-AMC) and individualized linear modelling (LM). Ten healthy participants had their upper body movement tracked with optical motion capture in two identical sessions. Five scapular calibration poses were performed, and seven dynamic functional tasks were tested. Scapular angles were calculated from both procedures (D-AMC vs LM). The D-AMC approach uses two poses (neutral and maximum elevation) and tracks the scapula with a rigid cluster, while the LM approach predicts scapular positioning from humeral angles based on equations built from the calibration pose data. Angle waveforms and repeatability outcomes were compared. Internal and upward rotation angle waveforms were significantly different (p < 0.05) between kinematic procedures for some tasks, with maximum mean differences up to 17.3° and 23.2°, respectively. Overall, repeatability outcomes were similar between procedures, but the LM approach was slightly better for tilt and the D-AMC approach was notably improved for upward rotation in certain tasks. For example, minimal detectable changes during the Forward Transfer ranged from 6.9° to 11.9° for the D-AMC and 8.9° to 25.3° for the LM. Discrepancies between procedures may be a function of the calibration poses chosen. Additional calibration poses may improve the comparisons between procedures.

A confounding pediatric spinal cord injury: Anterior, central, or both?

Pediatric spinal cord injury (SCI) most commonly affects the cervical region. Central cord syndrome most often occurs in the lower cervical injury due to hyperextension injury, while anterior cord syndrome is primarily due to vascular infarction after hyperextension injury. An unusual case of a pediatric patient who physically presented with central cord syndrome but radiologically had evidence of anterior spinal artery syndrome is described. A two-year-old male presented after a fall from three feet with flaccid upper extremities and dysesthesias but maintained functional strength in bilateral lower extremities. Although his clinical presentation was that of central cord syndrome, he was found to have an anterior spinal artery infarct spanning from C2-T3 with a ligamentous injury at C3 and an incidental finding of Chiari I malformation on MRI. Given the negative evaluation for a cardiac or hematologic source of embolus and normal angiography, it was theorized that compression of vertebral arteries by previously undiagnosed Chiari I malformation in the setting of trauma could have made the patient more vulnerable to this complication. During inpatient rehabilitation, he regained scapular movement and shoulder flexion. However, he regained distal movement in supination, wrist extension, and finger flexion instead of the more usual proximal-to-distal motor recovery observed in SCI. While he had a relative sparing of strength in his legs, he had impaired proprioception and balance, leading to gait impairment. This case highlights the complexity of pediatric cervical SCI diagnosis and prognostication. While classic SCI subtypes are well described, many pediatric and adult patients will present and recover in unexpected ways. All with SCI should be evaluated thoroughly for common etiologies and transitioned to rehabilitation therapies to assist in recovery.

Case report of idiopathic scapular dyskinesia: Revisiting involuntary scapular movements from a neurologist’s perspective

Abstract Scapular dyskinesia, one of the rare forms of focal dyskinesia, is usually considered a peripheral induced movement disorder (PIMD), occurring in the background of previous trauma or surgery. Different terms are used interchangeably with scapular dyskinesia, many of which are misleading. In this article, we present 2 cases of patients with abnormal involuntary scapular movement suggestive of scapular dyskinesia. In both cases, there is no history of preceding trauma or surgical intervention. We will review the literature and try to understand the fundamental difference between the various terms used for abnormal scapular movement in literature. Our cases highlight the difference between the two commonly used terms for scapular movement, i.e., scapular dyskinesia and scapular dyskinesis. We further suggest that shoulder girdle dyskinesia should be preferred over scapular dyskinesia. Although scapular dyskinesia is often considered PIMD, not all cases of scapular dyskinesia are peripherally induced.

Innervation of the human sternoclavicular joint.

The sternoclavicular joint (SCJ) functions as the basal joint of the entire upper limb and must move in the proper pattern for normal scapular motion. Afferent sensations from joints, such as proprioception and pain sensation, are important for maintaining the proper motion and condition of joints. Detailed anatomical data are useful for discussing injuries or surgeries that impair the afferent nerve to the SCJ. Nerve branches to SCJs were examined on 12 sides, and the subclavian nerve was investigated on six sides to clarify whether it innervates this joint. On seven of the 12 sides, the SCJ was innervated by two nerves, (1) a branch from the medial supraclavicular nerve that ran medially along the clavicle and (2) a branch from the lateral pectoral nerve that innervated the clavicular head and upper part of the sternocostal head of the pectoralis major. This branch ran medially behind the clavicular head of the pectoralis major and reached the SCJ. In the remaining five sides, the SCJ was innervated solely by the branch from the medial supraclavicular nerve. Subclavian nerves ended within the subclavius muscle or periosteum of the clavicle and were separate from the SCJs. Our data on the route of nerve branches to the SCJ suggest that injury or surgery, such as clavicle fracture or resection of the clavicular head of the pectoralis major for myocutaneous flap transfer, can impair the SCJ's afferent nerve supply.

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.

Breaking the operator variability in Kibler’s scapular dyskinesis assessment

IntroductionAlterations of scapular kinematics are generically reported as scapular dyskinesis (SD), and are a nonspecific response to various shoulder pathologies. The most widely used classification is Kibler’s (K), which is, however, characterized by poor sensitivity. To overcome this limit, using a 3D motion analysis system, we identified a specific pattern for each type of SD according to Kibler.Materials and methodsWe analyzed 34 patients with a total of 68 shoulders who came to our observation for shoulder pain. All patients underwent clinical examination, video-recording and motion analysis with SHoW Motion 3D kinematic tracking system (SM). Three independent observers classified SD into K types I, II and III. Only patients with concordant classification among the 3 operators were studied to identify a characteristic graphic pattern by type of SD.ResultsTypical patterns emerged from the examination with SM. K. type 1 consists of decreased or reversed posterior tilt and increased protraction in flexion–extension (FE) in early degrees of motion. K. type 2 consists of increased protraction and marked reversal of lateral rotation in abduction–adduction (Ab–Ad) in early degrees of movement. K. type 3 has been subdivided into two subgroups: K. type 3-A, composed of patients with massive rotator cuff lesions, shows an increase in all scapular movements in both FE and Ab–Ad. K. type 3-B, composed of patients with scapular stiffness and/or impingement, presents a slight increase in posterior tilt and lateral rotation in the final grades of FE and Ab–Ad.ConclusionsThe SM system allows reproducible dynamic analyses with low intra- and intra- operator variability. In our study, we demonstrated its applicability in the classification of SD. It also provides an objective and quantitative assessment of motor pattern alteration that is essential in the follow-up of patients to evaluate the effectiveness of rehabilitation and/or surgical treatment.Level of Evidence 3According to "The Oxford 2011 Levels of Evidence".

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.

Effects of the open Latarjet procedure on shoulder kinematics and periscapular muscle activity 3 months postoperatively

BackgroundThe debate surrounding the influence of the open Latarjet procedure on postoperative scapular motions persists, and there is no evidence regarding its effects on periscapular muscle activation. This study aimed to assess the short-term influence of open Latarjet procedure on scapular kinematics and periscapular muscle activity during arm raising and lowering based on comparisons between patient and healthy athletes. Methods22 healthy male athletes and 22 male athletes scheduled for glenohumeral stabilization surgery by open Latarjet procedure were included. Scapular kinematics, periscapular muscle activities and shoulder-related quality of life were recorded prior to surgery and 3 months postoperatively for the Latarjet group. For the healthy group, same assessments were performed 3 months apart. Bilateral differences in both scapular kinematics and periscapular muscle activation ratios, and Western Ontario Shoulder Instability (WOSI) index were defined as dependent variables. ResultsScapular kinematics of the operated shoulder, namely scapular upward/downward rotation, internal/external rotation and anterior/posterior tilt recorded between 20° and 120° of humerothoracic elevation, showed no alterations 3 months post-surgery (p>0.05), and did not differ from those observed in healthy athletes (p>0.05). Similarly, all periscapular muscle activations were not different within time and between groups (p>0.05). WOSI index of the operated shoulder was significantly improved postoperatively (871.9 ± 443.7 vs. 1346.3 ± 552.3) but remained higher than the WOSI indices of the non-operated shoulder or those of the healthy group (52.7±75.6). ConclusionThis study emphasizes the short-term effects of the open Latarjet procedure, demonstrating an improvement in the shoulder-related quality of life 3 months after surgery. Notably, during this period, both kinematics and periscapular muscle activity remained consistent, and similar to the patterns observed for healthy athletes.

Comparison of glenohumeral and scapulothoracic kinematics between fastballs and curveballs during baseball pitching

ABSTRACT Shoulder injuries are common in baseball pitchers and primarily involve the glenohumeral joint. Past analyses have examined shoulder biomechanics during different pitch types simply as the motion of the upper arm relative to the thorax. In this study, glenohumeral and scapulothoracic kinematics were compared between fastballs and curveballs at key timepoints throughout a pitch. Upper extremity kinematics of thirteen collegiate pitchers were collected during fastball and curveball pitches with motion capture. A linear model approach was utilised to estimate scapular kinematics based on measurable humerothoracic motion. Glenohumeral kinematics were computed from the scapular and humeral motion data. Comparisons of scapulothoracic and glenohumeral kinematic variables at times of maximum glenohumeral external rotation, ball release, and maximum glenohumeral internal rotation between pitch types were made using paired t-tests with Benjamini-Hochberg corrections. There were no significant differences in glenohumeral kinematics. Fastballs elicited significantly less scapulothoracic internal rotation and more posterior tilt at maximum glenohumeral external rotation. Fastballs produced significantly less scapulothoracic internal rotation and anterior tilt at maximum glenohumeral internal rotation. This study provides further evidence that risk of injury to the glenohumeral joint may be consistent between fastballs and curveballs and offers insights into subtle differences in scapular kinematics between pitch types.

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.

Three-dimensional measurements of scapular kinematics: Interrater reliability and validation of a skin marker-based model against an intracortical pin model

A skin marker-based motion capture model providing measures of scapular rotations was recently developed. The aim of this study was to investigate the concurrent validity and the interrater reliability of the model. Shoulder range of motion (RoM) and activities of daily living (ADL) were tested in healthy volunteers with reflective markers on the scapula and thorax. To investigate the validity, the model was compared to simultaneous data collection from markers on a scapular intracortical pin. The interrater reliability was tested by comparing the skin marker-based protocol performed by two investigators. The mean root mean square error (RMSE) and the intraclass correlation coefficient (ICC(2,1)) were calculated to determine the validity and the interrater reliability, respectively. Eight subjects were included in the validity test: female/male = 2/6, mean (SD) age 35.0 (3.0) and BMI 23.4 (3.3). The mean RMSE of all scapular rotations ranged 2.3–6.7° during shoulder RoM and 2.4–7.6° during ADL. The highest errors were seen during sagittal and scapular plane flexions, hair combing and eating. The reliability test included twenty subjects: female/male = 8/12, mean (SD) age 31.4 (4.9) and BMI 22.9 (1.7). The ICC(2,1) for measuring protraction ranged 0.07–0.60 during RoM and 0.27–0.69 for ADL, for upward rotation the corresponding ICC(2,1) ranged 0.01–0.64 and 0.38–0.60, and anterior tilt 0.25–0.83 and 0.25–0.62. The validity and interrater reliability of the model are task dependent, and interpretation should be made with caution. The model provides quantitative measurements for objective assessment of scapular movements and can potentially supplement the clinical examination in certain motion tasks.

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.

Association of Breast-Feeding Positions with Scapular Dyskinesia in Postpartum Females

Background: Breastfeeding is a vital activity for the nurturing and development of infants. However, the postures adopted during breastfeeding may have implications for the physical well-being of postpartum females, particularly concerning scapular dyskinesia—a condition characterized by altered scapular movement and positioning, which can affect shoulder function. Objective: This study aimed to investigate the association between different breastfeeding positions and the prevalence of scapular dyskinesia among postpartum females, providing insights into the potential musculoskeletal implications of breastfeeding practices. Methods: An observational cross-sectional study was conducted involving 111 postpartum females aged 18-45 years, who had been breastfeeding for six months or more. Participants were recruited using non-probability convenient sampling from various hospitals in Lahore, Pakistan. Data on breastfeeding positions and the occurrence of scapular dyskinesia were collected through self-administered questionnaires and the Scapular Dyskinesia Test (SDT) by McClure, respectively. Descriptive statistics were used to summarize participant demographics and breastfeeding practices, while the chi-square test was employed to examine the association between breastfeeding positions and scapular dyskinesia. Results: Among the participants, the cradle hold was the most commonly used breastfeeding position (82.0%), followed by the cross cradle (13.5%), side-lying (3.6%), and laid-back positions (0.9%). The prevalence of scapular dyskinesia was 41.4%, with no statistically significant association found between breastfeeding positions and scapular dyskinesia (p-value = 0.06). Additionally, upper back pain was reported by 39.6% of the participants, indicating a notable presence of musculoskeletal discomfort. Conclusion: The study concluded that there is no significant association between breastfeeding positions and scapular dyskinesia among postpartum females. Despite the high prevalence of scapular dyskinesia and musculoskeletal discomfort, the type of breastfeeding position does not appear to influence the likelihood of developing scapular dyskinesia. These findings suggest the need for further research into the factors contributing to musculoskeletal health in postpartum females and the development of guidelines for breastfeeding practices that promote maternal comfort and physical well-being.

Clinical Diagnosis of Scapular Dyskinesis in a Youth Softball Pitcher: A Case Report.

Effective rehabilitation strategies for upper extremity injuries in softball pitchers are scarce in current literature, especially among youth athletes. Additionally, there continues to be ambiguity regarding the interpretation and clinical practicality when treating an overhead athlete with scapular dyskinesis. The purpose of this case report is to highlight the examination and treatment of a youth softball pitcher referred to physical therapy with the diagnosis of scapular dyskinesis. This case report presents data and outcomes for a 14-year-old female who experienced chronic right shoulder discomfort related to performing the windmill softball pitch (WSP). The subject was clinically diagnosed with scapular dyskinesis by her referring physician and demonstrated abnormal scapular movement when elevating and lowering her upper extremity. Internal and external rotator isokinetic strength testing and the Athletic Shoulder Test (ASH) were used as primary objective measures. Both were performed six days after the initial evaluation and again six weeks later. Initial testing demonstrated decreased peak torque and total work. Initial treatment involved periscapular and shoulder strengthening with progression to overhead loading. Later rehabilitation strategies focused on neuromuscular control, functional training, and sport-specific activities. The subject initially demonstrated improved peak torque and total work of the shoulder with isokinetic strength testing but continued to have symptoms with pitching, even though the Scapular Dyskinesis Test had become negative. After changing the focus to neuromuscular and functional training the subject had fewer symptoms and became comfortable with self-management. This case matches previous research that endorses scapular dyskinesis being a normal finding in overhead athletes with and without shoulder pain. Neuromuscular control and functional training after a period of scapular strengthening were beneficial in improving symptoms in this athlete. 5.