Shoulder Muscles Research Articles

Shoulder vibratory exercises improves shoulder external rotation muscle strength and shoulder function: Randomized comparison trial.

Based on electromyography measurements, shoulder vibratory exercises efficiently stimulate shoulder muscles activity. Yet very few studies have supported that shoulder vibratory exercises increased shoulder muscles strength and function, and the noninferiority compared with conventional elastic resistance exercises remains unknown. This study investigated the effect of vibratory exercises versus conventional elastic resistance exercises with elastic bands on shoulder external rotation muscles strength and functional performance in young adults. 26 young adults (7 males and 19 females, with age 23.89 ± 3.02) were recruited and randomly allocated to shoulder vibratory exercises with FLEXI-BAR (FLEXI-BAR group) or conventional resistance exercises with elastic band (TheraBand group) for 3 times/week, 4 weeks totally. Shoulder external rotator muscles strength test and Underkofler softball distance throw test (USDTT) were performed before and after the training period. After 4 weeks training, shoulder external rotator muscles strength increased 22.25 ± 15.06 N (P= 0.004, effect size = 1.48) within FLEXI-BAR group and 22.81 ± 14.94 N (P= 0.007, effect size = 1.53) within TheraBand group. There were no statistically significant differences between groups in the three muscle strength tests (P> 0.65). Regarding shoulder function, FLEXI-BAR exercises increased the throw distance 0.81 ± 0.92 meters in USDTT (P= 0.041, effect size = 0.88) while TheraBand exercise did not (P= 0.284), yet there was no statistically significant between group effects (P= 0.608). These findings suggest that shoulder vibratory exercises can improve shoulder muscles strength in young adults and can be a useful alternative to the conventional elastic resistance exercises to improve the shoulder muscles strength and function. This provides therapists with more options in terms of choosing training equipment for rehabilitation programs.

Upper Extremity Muscle Activation Pattern Prediction Through Synergy Extrapolation and Electromyography-Driven Modeling.

Patients with neuromuscular disease fail to produce necessary muscle force and have trouble maintaining joint moment required to perform activities of daily living. Measuring muscle force values in patients with neuromuscular disease is important but challenging. Electromyography (EMG) can be used to obtain muscle activation values, which can be converted to muscle forces and joint torques. Surface electrodes can measure activations of superficial muscles, but fine-wire electrodes are needed for deep muscles, although it is invasive and require skilled personnel and preparation time. EMG-driven modeling with surface electrodes alone could underestimate the net torque. In this research, authors propose a methodology to predict muscle activations from deeper muscles of the upper extremity. This method finds missing muscle activation one at a time by combining an EMG-driven musculoskeletal model and muscle synergies. This method tracks inverse dynamics joint moments to determine synergy vector weights and predict muscle activation of selected shoulder and elbow muscles of a healthy subject. In addition, muscle-tendon parameter values (optimal fiber length, tendon slack length, and maximum isometric force) have been personalized to the experimental subject. The methodology is tested for a wide range of rehabilitation tasks of the upper extremity across multiple healthy subjects. Results show this methodology can determine single unmeasured muscle activation up to Pearson's correlation coefficient (R) of 0.99 (root mean squared error, RMSE = 0.001) and 0.92 (RMSE = 0.13) for the elbow and shoulder muscles, respectively, for one degree-of-freedom (DoF) tasks. For more complicated five DoF tasks, activation prediction accuracy can reach up to R = 0.71 (RMSE = 0.29).

Changes in Neck and Shoulder Muscles Fatigue Threshold When Using a Passive Head/Neck Supporting Exoskeleton During Repetitive Overhead Tasks.

This study aimed to investigate the effects of a head/neck supporting exoskeleton (HNSE) on the electromyographic fatigue threshold (EMGFT) of the neck and shoulder muscles during a simulated overhead work task. Overhead work is a well-known risk factor for neck and shoulder musculoskeletal disorders due to the excessive strain imposed on the muscles and joints in these regions. Fourteen healthy males performed a repetitive overhead nut fastening/unfastening task to exhaustion while wearing and not wearing the HNSE at two neck extension angles (40% and 80% of neck maximum range of motion). Electromyographic signals were continuously recorded from the right and left sternocleidomastoid (SCMR, SCML), splenius capitis (SCR, SCL), upper trapezius (UTR, UTL), and anterior deltoid (ADR, ADL) muscles. The normalized electromyographic amplitude (nEMG) data was time normalized, and a bisegmental linear regression was applied to determine the muscle fatigue break point. The results showed a significant increase in fatigue threshold time in the SCMR (p < .001), SCML (p = .002), and UTR (p = .037) muscles when the HNSE was used. However, the EMGFT times for the right and left deltoid and left trapezius muscles showed a nonsignificant reduction due to the head/neck support exoskeleton use. In addition, the neck extension angle did not reveal a significant effect on muscles' EMGFT time. Overall, the findings confirmed a significant delay in fatigue onset in sternocleidomastoid muscles, as measured by the electromyographic fatigue threshold. This finding suggests that the HNSE can be an effective ergonomic intervention for reducing the risk of musculoskeletal disorders in overhead workers. However, further studies are needed to investigate the effect of the HNSE at other neck extension angles and more realistic tasks to ensure the generalizability of our results. The present findings emphasize the application of the fatigue onset time to evaluate the effectiveness of ergonomic interventions, including exoskeletons, which can subsequently be utilized to alleviate postural demands and reduce the risk of musculoskeletal disorders.

Reverse shoulder arthroplasty in obstetric brachial plexus injury: our experience with shoulder motion analysis

BackgroundObstetric brachial plexus injury (OBPI) is a weakening or paralysis of the upper arm caused by brachial plexus injury followed by a muscle paralysis with severe repercussions on the movement of the shoulder joint following a progressive glenohumeral joint deformity.This case series analyzes the clinical and radiological outcomes of reverse total shoulder arthroplasty (RSA) in OBPI patients with a follow-up of 2 years.Materials and methodsOBPI patients with secondary end-stage glenohumeral arthritis were enrolled in the study and they were treated with RSA. Patient demographics and clinical outcomes [Range of Motion (ROM), Visual Analog Scale (VAS), Oxford Shoulder Score (OSS)] were evaluated. A novel Shoulder motion analysis was carried out to investigate specific movement patterns of scapulothoracic movements in these patients. This study is a prospective cohort study.ResultsFour Patients (M: F = 1:3) were enrolled in the study, the mean age was 49.3 years (+ 2.75), the mean OSS (Oxford Shoulder Score) decreased from 48.8 (± 2.5) preoperatively to 18.30 (± 2.78), the mean VAS (Visual Analog Scale) decreased from 7.25 (± 0.5) to 1.7 (± 0.3) in the follow up (∆% relative pain reduction:− 76.5%), Shoulder ROM obtained an improvement (p < 0.05) except for abduction and external rotation. The average follow-up time was 26.3 months (+− 4.5). Shoulder motion analysis showed a complete loss of the scapular tilting above 90 degrees of flexion compared to the typical one of standard RSA with a pattern shifted towards scapular retraction (engaging trapezius and rhomboid muscles) to compensate the loss of the posterior tilting.ConclusionsRSA in OBPI patients demonstrated a significant improvement of pain symptoms and a moderate improvement in daily activities, anyway with a more appreciable quality of life over time even if the marked hypotrophy especially of the posterior shoulder muscles showed some limits in maintaining suspension of the upper limb and a minor external rotation, with an internal rotation attitude during the movements.Level of evidence: Level IV, Case series.

The Factors Influencing Shoulder Mobility Disorders in Patients after Radical Breast Cancer Surgery: A Cross-Sectional Study

Introduction: This study is a cross-sectional study that investigated the factors influencing shoulder mobility in terms of pain, grip strength, and supraspinatus muscle thickness in patients with impaired shoulder mobility during chemotherapy after radical breast cancer surgery. Methods: This study included 165 female patients with unilateral breast cancer who had shoulder joint mobility disorders during chemotherapy within 3 months after surgery. The clinical examination included the maximum active range of motion of the shoulder (flexion, extension, abduction, adduction, external rotation, and internal rotation), pain score (visual analog scale [VAS]), grip strength, and supraspinatus muscle thickness. Results: During shoulder abduction, supraspinatus muscle thickness was greatest at 90°, lowest at 0°, and higher at 60° than at 30° (p < 0.01). The factors influencing the active movement of shoulder flexion were the VAS score, body weight, grip strength, and supraspinatus contraction rate (R² = 0.295), while the factors influencing active shoulder abduction were the VAS score, body weight, grip strength, supraspinatus muscle thickness (drooping position), and supraspinatus contraction rate (R² = 0.295). Moreover, the factors influencing the active movement of shoulder external rotation were age, VAS score, body weight, grip strength, and supraspinatus muscle thickness (drooping position) (R² = 0.258). There were no significant results from multiple linear regressions for shoulder extension, adduction, or internal rotation. Conclusion: Pain, weight, grip strength, supraspinatus muscle thickness, and supraspinatus distensibility are the main factors affecting shoulder flexion, abduction, and external rotation. In addition, supraspinatus muscle thickness and contraction rate may be a new index for assessing shoulder dysfunction.

Arm-support exoskeleton reduces shoulder muscle activity in ceiling construction

The objective of this study was to assess the efficacy and user’s impression of an arm-support exoskeleton in complex and realistic ceiling construction tasks. 11 construction workers performed 9 tasks. We determined objective and subjective efficacy of the exoskeleton by measuring shoulder muscle activity and perceived exertion. User’s impression was assessed by questionnaires on expected support, perceived support, perceived hindrance and future intention to use the exoskeleton. Wearing the exoskeleton yielded persistent reductions in shoulder muscle activity of up to 58% and decreased perceived exertion. Participants reported limited perceived hindrance by the exoskeleton, as also indicated by no increase in antagonistic muscle activity. The findings demonstrate the high potential of an arm-support exoskeleton for unloading the shoulder muscles when used in the dynamic and versatile working environment of a ceiling construction worker, which is in line with the consistent intention of the workers to use the exoskeleton in the future. Practitioner Summary: The majority of research focuses on the effect of using an arm-support exoskeleton during isolated postures and prescribed movements. We investigated the efficacy of an exoskeleton during a complex and realistic work, namely ceiling construction. Shoulder muscle activity was lower in almost all tasks when wearing the exoskeleton.

Effect of Indian clubbell exercises on cricket fast bowlers' shoulder kinematics.

The glenohumeral joint's rotational range of motion (ROM) and muscle strength are essential to execute the cricket bowling action. Performing shoulder rotation exercises may increase the rotator cuff muscle strength and rotational ROM. The aim of this study was to test the effect of a six-week exercise programme on shoulder rotational ROM and muscle strength. Twenty-one healthy male cricket fast bowlers were recruited, ranked and pair-matched on initial shoulder rotator muscle strength and assigned to either a shoulder exercise (SE) group or cricket training (CT) only group. The SE group incorporated Indian clubbell exercises in addition to their cricket training. Bowlers in both groups displayed a large increase on the dominant shoulder's internal rotation (IR) ROM, but only the SE group's bowlers displayed ROM improvements (p<0.001) bilaterally for both internal and external rotation. The CT group's fast bowler's non-dominant shoulder IR ROM significantly decreased (p=0.02) during the six weeks. Between groups, only the SE group's bowler's internal rotator muscle strength improved (p<0.001) bilaterally. The observed kinematic changes were statistically significantly greater at a 5% level for the SE group's bowlers (bilateral internal rotators muscle strength, non-dominant shoulder IR ROM and horizontal adduction ROM). Maintenance of the shoulder's rotational ROM and muscle strength is vital for a fast bowler. Cricket bowlers who perform regular clubbell exercises might increase their shoulder's ROM and internal rotator cuffs' muscle strength, which may aid in stabilising their glenohumeral joint while bowling.

Pork muscle profiling: pH and instrumental color of the longissimus thoracis is not representative of pH and instrumental color of shoulder and ham muscles

From a population of 351 pork carcasses, 3.0-cm thick chops from the 10th rib location of the longissimus thoracis, faced surfaces of the triceps brachii and serratus ventralis muscles from the boneless shoulder, and faced surfaces of the biceps femoris, semitendinosus, semimembranosus, adductor, rectus femoris, and vastus lateralis muscles from the boneless ham were evaluated for pH and instrumental color (Minolta CR-400). Evaluations were conducted for at least three different locations on each of the muscle samples and averaged before data analysis occurred. The longissimus thoracis had the lowest pH and the lightest and least red color compared with the other eight muscles evaluated in this study (mean differences ranged from 0.98 to 8.70 for L*, 3.98 to 12.56 for a*, and 0.026 to 0.409 for pH). Furthermore, regression analysis suggested that pH and color values for the longissimus thoracis were not adequate predictors for pH and color values obtained from other muscles and therefore consideration should be given to the individual muscles that are of interest.

No Evidence of Short-Term Changes in Muscle Activity Elicited by Dry Needling in Chronic Unilateral Shoulder Pain Patients.

The aim of the study was to assess short-term changes in shoulder muscle activity elicited by dry needling in chronic unilateral shoulder pain patients. A double-blind, placebo-controlled clinical trial was conducted, in which 30 volunteers with unilateral shoulder pain (USP) were recruited and randomly assigned to either real or sham dry needling conditions. Pain intensity scores, pressure pain threshold (PPT), glenohumeral internal rotation angles, and electromyographic activity during isotonic shoulder tasks (shoulder flexion and extension) were assessed before, immediately and 72 h after the intervention in the infraspinatus and deltoid muscles. A single application of real dry needling resulted in lower pain intensity scores and a larger range in glenohumeral internal rotation 72 h after the intervention in comparison with sham dry needling. No differences in PPT or muscle activity were observed due to the intervention. A single application of real dry needling resulted in clinically significant changes in the short-term. No differences were detected in muscle activation in the infraspinatus or deltoid muscles. Complementary interventions and longer follow-up times may be required to observe changes in muscle activity.

Effectiveness of Pulse Electromagnetic Field Therapy in Patients With Subacromial Impingement Syndrome: A Double-Blind Randomized Sham Controlled Study

ObjectivesTo evaluate the 3-month effects of pulsed electromagnetic field therapy (PEMF) in the treatment of subacromial impingement syndrome (SIS). DesignPlanned analysis of a randomized controlled trial with 4- and 12-week follow-ups. SettingPhysical medicine and rehabilitation clinic, treatment unit. ParticipantsOf the 250 individuals screened for eligibility, participants with a diagnosis of SIS (N=80) were randomized to intervention or control groups. InterventionThe first group received PEMF + exercise and the second group received sham PEMF + exercise 5 days a week for a total of 20 sessions. Main Outcome MeasuresVisual Analog Scale (VAS), Constant Murley Score (CMS), Shoulder Pain and Disability Index (SPADI), Short Form-36 (SF-36) Quality of Life Questionnaire, and shoulder muscle strength measurement with an isokinetic dynamometer. Evaluations were performed before treatment (T0), after treatment (T1), and 12th week (T2). ResultsEvaluation at T1 and T2 showed improvement in most parameters in both groups compared with baseline. In the comparison between the 2 groups at T1 and T2, more improvement was found in the PEMF group in most parameters. ConclusionsIn our study, PEMF was found to be superior to sham PEMF in terms of pain, ROM, functionality, and quality of life at the first and third months.

Dry needling versus muscle energy technique on shoulder adhesive capsulitis post mastectomy

Objectives. To compare the effect of dry needling and muscle energy technique on adhesive capsulitis post mastectomy. Design. A single-blinded randomized clinical study. Setting. Outpatient setting. Subjects. Fifty female patients diagnosed with shoulder adhesive capsulitis post mastectomy, ranging in age from 30 to 60 years, were randomly assigned to two groups. Participants in Group A were administered dry needling treatment, plus a traditional physical therapy program in the form of shoulder joint mobilization, shoulder muscle stretching, and ROM exercise; Group B received muscle energy technique, plus a traditional physical therapy program in the form of shoulder joint mobilization, shoulder muscle stretching, and ROM exercise. Intervention. Two sessions per week over five weeks. Outcome measures. Shoulder range of motion, pressure pain threshold, and shoulder dysfunction were measured pre-treatment and post-treatment. Results. There was no statistically significant difference observed in the age distribution between the groups (p &gt; 0.05). Following the treatment, there was a notable rise in the pressure pain threshold and a considerable decline in shoulder dysfunction when compared to the pre-treatment condition (p &lt; 0.001). There was a notable rise in the ranges of shoulder flexion, abduction, and external rotation after the treatment when compared to before the treatment in both group A and B (p &gt; 0.001). The percentage of change in flexion, abduction, and external rotation in group A was 125.03%, 76.43%, and 58.72%, respectively. In contrast, group B exhibited percentage changes of 137.48%, 97.51%, and 68.78% in flexion, abduction, and external rotation, respectively. There was no statistically significant difference seen between the groups prior to treatment, as shown by a p-value greater than 0.05. The analysis of the data after treatment demonstrated a statistically significant rise in the pressure pain threshold for group A in comparison to group B (p &lt; 0.001). However, there was no significant disparity observed in shoulder dysfunction between the two groups (p &gt; 0.05). Following the treatment, there was a notable rise in the range of motion (ROM) for flexion, extension, and abduction in group B when compared to group A (p &lt; 0.001). Conclusion. Application of either dry needling or muscle energy technique results in a notable enhancement in the severity of symptoms in adhesive capsulitis post mastectomy, with superiority for dry needling.

Mediating the Connection: The Role of Pain in the Relationship between Shoulder Muscle Strength, Joint Position Sense, and Sub-Acromial Impingement Syndrome

Sub-acromial Impingement Syndrome (SIS) is a prevalent shoulder pathology characterized by pain, muscle weakness, and altered joint position sense (JPS). This prospective study aimed to comprehensively assess the relationship between shoulder muscle strength, JPS, and pain in individuals with SIS. A total of 100 participants, including 50 with SIS and 50 healthy controls, underwent shoulder muscle strength testing and JPS evaluation in various directions (flexion, abduction, medial rotation, and lateral rotation). Pain intensity was quantified using a visual analog scale. Correlation analyses were conducted to explore the associations between muscle strength, JPS, and pain, with Cohen’s d values indicating the effect size. Individuals with SIS exhibited significantly lower shoulder muscle strength and greater JPS errors compared to the healthy controls (p &lt; 0.001, Cohen’s d = 0.51 to 0.84). The results showed strong positive correlations between muscle strength and JPS in all assessed directions (p &lt; 0.001, with r values ranging from 0.35 to 0.62). Mediation analysis revealed that pain partially mediated the relationship between muscle strength and JPS in all directions (p &lt; 0.005). This study highlights the multifaceted nature of SIS, emphasizing the coexistence of muscle weakness, proprioceptive impairments, and pain. The findings underscore the importance of addressing these factors in the comprehensive rehabilitation of individuals with SIS to optimize functional outcomes and enhance their quality of life.

Comparing Three Wearable Brassiere Braces Designed to Correct Rounded Posture.

Rounded shoulder posture (RSP) causes shoulder pain and can lead to shoulder impingement and thoracic outlet syndromes, ultimately resulting in a frozen shoulder. Altered scapular positions in RSP patients affect muscle activity. Many studies have explored methods to correct and prevent RSP, including shoulder braces, muscle strengthening, stretching, and inhibition techniques. Using a shoulder brace reduces RSP and improves shoulder discomfort and function, similar to conventional rehabilitation. However, despite their effectiveness, these braces are bulky and inconvenient, which makes continuous daily wear challenging. This is especially true for women who are sensitive to their appearance. To address this issue, methods have been developed to convert women's underwear bra straps into braces. This study aimed to evaluate the immediate effects of three underwear-mounted rounded shoulder braces and to identify the brace that is most effective in decreasing RSP and upper trapezius (UT) muscle activity and increasing lower trapezius (LT) muscle activity in patients with RSP. The study included 18 patients with an RSP. The RSP amount and UT and LT muscle activities were measured before and after three interventions. The interventions were scapular posterior tilting (SPT) exercises with the X strap, X + 8 strap, and inner brace. Compared with the baseline value, the RSP amount was significantly lower with the three braces. The RSP was significantly lower with the X + 8 strap and the inner brace than with the X strap. The inner brace showed significantly lower UT muscle activity than those with the X strap and X + 8 straps and significantly greater LT muscle activity than that with the X + 8 strap. These results show underwear-mounted braces as a potential RSP solution, but long-term sustainability and improving comfort, especially for those concerned about appearance, require further research and development.

Double trouble-unveiling the hidden pain: bilateral paediatric parsonage-turner syndrome: an unprecedented encounter

Parsonage-turner syndrome (PTS), also known as idiopathic brachial neuritis, is a rare disorder characterized by sudden-onset severe shoulder pain followed by weakness and atrophy of the shoulder and arm muscles. This case report presents the clinical scenario of an 11-year-old girl diagnosed with PTS, highlighting the unique challenges and considerations in the paediatric population. In our case, a 11-year-old girl presented with sudden-onset severe bilateral shoulder pain, followed by weakness and atrophy of the shoulder and upper arm muscles. The clinical examination revealed muscle wasting and limited range of motion. The diagnosis of PTS was confirmed through MRI and electromyography (EMG) showing denervation in the affected shoulder muscles. Patient was managed with symptomatic supportive treatment in the form of analgesics and physical therapy. Patient is on the road to recovery and on regular follow up. We concluded that prompt recognition and appropriate management of PTS are crucial to optimize outcomes and prevent long-term disability, particularly in the paediatric population.

How Do People with Limited Movement Personalize Upper-Body Gestures? Considerations for the Design of Personalized and Accessible Gesture Interfaces.

Always-on, upper-body input from sensors like accelerometers, infrared cameras, and electromyography hold promise to enable accessible gesture input for people with upper-body motor impairments. When these sensors are distributed across the person's body, they can enable the use of varied body parts and gestures for device interaction. Personalized upper-body gestures that enable input from diverse body parts including the head, neck, shoulders, arms, hands and fingers and match the abilities of each user, could be useful for ensuring that gesture systems are accessible. In this work, we characterize the personalized gesture sets designed by 25 participants with upper-body motor impairments and develop design recommendations for upper-body personalized gesture interfaces. We found that the personalized gesture sets that participants designed were highly ability-specific. Even within a specific type of disability, there were significant differences in what muscles participants used to perform upper-body gestures, with some pre-dominantly using shoulder and upper-arm muscles, and others solely using their finger muscles. Eight percent of gestures that participants designed were with their head, neck, and shoulders, rather than their hands and fingers, demonstrating the importance of tracking the whole upper-body. To combat fatigue, participants performed 51% of gestures with their hands resting on or barely coming off of their armrest, highlighting the importance of using sensing mechanisms that are agnostic to the location and orientation of the body. Lastly, participants activated their muscles but did not visibly move during 10% of the gestures, demonstrating the need for using sensors that can sense muscle activations without movement. Both inertial measurement unit (IMU) and electromyography (EMG) wearable sensors proved to be promising sensors to differentiate between personalized gestures. Personalized upper-body gesture interfaces that take advantage of each person's abilities are critical for enabling accessible upper-body gestures for people with upper-body motor impairments.

Changes in neuromuscular activation, heart rate and rate of perceived exertion over the course of a wheelchair propulsion fatigue protocol.

Shoulder pain is common in persons with spinal cord injury and has been associated with wheelchair use. Fatigue related compensation strategies have been identified as possibly impacting the development of shoulder injury and pain. The purpose of this study was to investigate the progression of performance fatigability (i.e., decline in objective measure of performance including neuromuscular activation and increase in heart rate) and perceived fatigability (i.e., increased perceived exertion) during a 15-min fatigue protocol including maximum voluntary overground wheelchair propulsion. Fifty participants with paraplegic spinal cord injury completed three 4-min rounds of wheelchair propulsion, separated by 90s of rest, on a figure-8 course consisting of two turns and full stops per lap in their manual wheelchairs (ClinicalTrials.gov: NCT03153033). Electromyography (EMG) signal of five muscles acting on the shoulder joint, heart rate (HR), and rate of perceived exertion (RPE) were measured at the beginning and end of every 4min of propulsion. Root Mean Square (RMS) and Mean Power Frequency were calculated from EMG data. There was a significant increase in %RMS of the pectoralis major pars sternalis and trapezius pars descendens, HR, and RPE with greatest changes during the first 4min of the protocol. The observed changes in neuromuscular activation in only two of the shoulder muscles may impact muscular imbalances and the development of shoulder injuries and should be further studied. The current study gives clearer insight into the mechanisms of performance fatigability and perceived fatigability throughout a wheelchair propulsion fatigue protocol.

Cluster Analysis of Subjective Shoulder Stiffness and Muscle Hardness: Associations with Central Sensitization-Related Symptoms.

Background and Objectives: Understanding the relationships between subjective shoulder stiffness, muscle hardness, and various factors is crucial. Our cross-sectional study identified subgroups of shoulder stiffness based on symptoms and muscle hardness and investigated associated factors. Materials and Methods: measures included subjective stiffness, pain, muscle hardness, and factors like physical and psychological conditions, pressure pain threshold, postural alignment, heart rate variability, and electroencephalography in 40 healthy young individuals. Results: Three clusters were identified: Cluster 1 with high stiffness, pain, and muscle hardness; Cluster 2 with low stiffness and pain but high muscle hardness; and Cluster 3 with low levels of all factors. Cluster 1 had significantly higher central sensitization-related symptoms (CSS) scores than Cluster 2. Subjective stiffness is positively correlated with psychological factors. Conclusions: our results suggest that CSS impacts subjective symptom severity among individuals with similar shoulder muscle hardness.

Descriptive study of the intrinsic muscles of the shoulder and brachium in kinkajou (Potos flavus) and an evolutionary analysis within the suborder Caniformia

Abstract The kinkajou (Potos flavus) is a carnivoran of the suborder Caniformia and the family Procyonidae, inhabiting regions throughout Central and South America. Potos flavus has arboreal preferences and exhibits unique anatomical adaptations that facilitate movement within trees. Its pelvic limbs enable hindfoot reversal, while its thoracic limbs possess remarkable prehensile capabilities. Previous anatomical studies in Potos flavus have presented discrepancies in the description of the intrinsic shoulder and brachial muscles. Therefore, this study aims to provide a comprehensive anatomical description of these muscles in five specimens. The findings are compared with descriptions reported for other caniforms. The application of the Density-Based Spatial Clustering of Application with Noise (DBSCAN) algorithm aids in identifying relationships among caniforms based on the presence or absence of specific muscles. Our analysis reveals several key differences, including the presence of a biceps brachii with two capita (longum and breve), two coracobrachiales muscles (longus and brevis), a tensor fasciae antebrachii with two distinct parts (cranialis and caudalis), and an anconeus medialis. The caput breve of the biceps brachii and coracobrachialis longus muscles are absent in some individuals, with prevalence rates of 10% and 20%, respectively. One specimen exhibited an accessory caput laterale of the m. triceps brachii bilaterally. The comparative analysis suggests that the shoulder and brachial muscles of Potos flavus share more similarities with those of Ailurus fulgens and ursids of the genera Ursus and Tremarctos. These findings suggest the retention of muscles that may have been present in the common ancestor of the infraorder Arctoidea.

The effect of deep neck flexor endurance on craniovertebral angle changes and neck and shoulder muscle activities during a computer task

ABSTRACT The deep neck flexors are important for maintaining neck posture by stabilizing and supporting it through low-intensity contraction, ensuring static endurance. The subjects performed computer tasks after having their deep neck flexor endurance measured using a pressure biofeedback unit. The craniovertebral angle (CVA) and the muscle activities were measured while participants were completing computer tasks for 10 min. The deep neck flexor endurance was significantly negatively correlated with CVA changes at 0–2 min. The deep neck flexor endurance was significantly negatively correlated with sternocleidomastoid muscle and upper trapezius activity at 0–2 min. The deep neck flexor endurance negatively predicted CVA changes at 0–2 min and explained 28.8% of the variance in the CVA changes. The lower the deep neck flexor endurance, the earlier the simultaneous changes occurred in the CVA and the neck and shoulder muscle activities during computer tasks.

Acute Effect of KinesioTaping on Technical Skills of Wheelchair Basketball Players

The purpose of this research kinesiology taping (KT) is to increase the blood and lymph circulation under the skin and provide the athlete with a comfortable movement capacity. For this purpose, we aim to examine the effect of KT on the shoulder and supraspinatus muscles of wheelchair basketball players on the technical skills of athletes. Ten male wheelchair basketball players between the ages of 20 and 40 participated in the study. In the study, kinesiology tape was applied to the shoulder and supraspinatus muscle regions of the athletes. To evaluate the effect of KT regional shooting (2p), tourniquet, slalom, and sprint tests were applied before and after taping. SPSS 25 statistical program was used for the analysis of the data. The significance value for the analysis was accepted as 0.05. According to the research findings, it was determined that KT was effective in the 2nd, 3rd, and 4th regions in shooting from 5 regions, and KT was also effective in 20m sprint, right tourniquet throw, and slalom skills with and without the ball (p&amp;lt;0.05). We can say that KT affects shots made from positions that see the basket from the opposite and diagonal, increasing the dribbling skill and sprint performance. During the competition, it is recommended that the athletes do it on the shoulder and supraspinatus muscle areas.