Repetitive Shoulder Research Articles

A scoping review of shoulder kinesthetic function in individuals with diabetes mellitus, with and without frozen shoulder

Abstract Background: Kinesthesia, the ability to perceive movements, is diminished in individuals with type II diabetes mellitus. People with frozen shoulders also experience kinesthetic deficits. Thus, obtaining accurate information on shoulder kinesthetic function in individuals with diabetes mellitus, both with and without a frozen shoulder, will aid in developing preventive and therapeutic strategies to optimize shoulder function. Aim: The study aims to investigate kinesthetic deficits in the shoulder among individuals with diabetes mellitus, both with and without frozen shoulder. Materials and Methods: A thorough literature search was performed using PubMed, Cochrane, CINAHL, and Science Direct. Free full-text articles in English, published from 2010 to October 2020, were identified using keywords and MeSH terms. Inclusion and exclusion criteria were developed based on the PICO format. The search results were then screened to identify relevant articles for this scoping review. Results: This review included fourteen articles, encompassing systematic reviews, cross-sectional studies, and prospective studies. Six studies examined the impact of diabetes mellitus on shoulder kinesthesia. These kinesthetic deficits adversely affected basic daily activities, recreational pursuits, and occupational tasks. Conclusion: Reduced kinesthetic function in the shoulder is attributed to structural changes such as capsular tightness, alterations in the fascicle length of rotator cuff muscles, the long head of the biceps, and glenohumeral joint laxity. Factors contributing to the loss of kinesthetic function include muscular fatigue from repetitive shoulder motion, limited joint mobility, blood glucose levels, and decreased muscle strength. This study provides valuable insights for clinicians to design rehabilitation programs, enhance shoulder function, and prevent re-injury risk.

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.

Shoulder structures and strength in competitive preadolescent swimmers: A longitudinal ultrasonographic study.

Repetitive shoulder movements during competitive training may cause changes in the strength of periarticular shoulder structures in preadolescent swimmers. To prospectively determine the effects of training on shoulder periarticular structures and muscle strength in preadolescent swimmers. Prospective cohort study. Community-based natatorium. Twenty-four preadolescent swimmers aged 10-12 years. Not applicable. Measurements were repeated in three periods as preseason, midseason, and postseason. Ultrasonographic measurements (supraspinatus tendon thickness, humeral head cartilage thickness, deltoid muscle thickness, and acromiohumeral distance) were performed using a portable device and a linear probe. Shoulder (flexion, extension, abduction, internal and external rotation) and back (serratus anterior, lower, and middle trapezius) isometric muscle strength were measured with a handheld dynamometer. Supraspinatus tendon thickness and acromiohumeral distance were similar in all periods (all p > .05); however, deltoid muscle and humeral head cartilage thicknesses increased throughout the season (p = .002, p = .008, respectively). Likewise, whereas shoulder muscle strength increased (all p < .05), back muscle strength was similar in all periods (all p > .05). In preadolescent swimmers, acromiohumeral distance and supraspinatus tendon thickness seem to not change; but humeral head cartilage and deltoid muscle thicknesses as well as shoulder muscle strength increase throughout the season.

Incidence of Work-Related Cervical Pain Disorder on Neck Disability Index- Hairdresser Population Based Cross-Sectional Study

Purpose: The most frequent issue among workers who perform repetitive upper extremity activity in their line of work is neck pain. Hairdressers who cut hair frequently use their shoulders in their picking and holding of the scissors. The muscles, ligaments, and soft tissues of the musculoskeletal system are put under more strain by this repetitive activity. Consequently, the objective of the current study is to ascertain, how prevalent neck pain is among hairdressers. The study’s objective is to determine the frequency of neck pain in hairdressers of Multan.&#x0D; Methodology: Cross-sectional study design was employed in this investigation. Information was gathered from Multan hairdressers. The technique of simple random sampling was used to gather the data from hairdressers. A total of 100 hair stylists were included in the study. Workers between the ages of 20 and 40 who have been employed for more than six months without a neck injury, trauma, or neurological or musculoskeletal problem were included. Participants were given questionnaires, and the answers were recorded. Data was manually coded, entered, and analysed using SPSS version 21. Results were described using frequency distributions, percentages, means, and standard deviations.&#x0D; Findings: Non Parametric Test was used to analyze data. In this study, only 44% of hairdressers reported having neck pain, while the rest reported mild, moderate, or no pain. The study demonstrates that hairdressers between the ages of 31 and 40 with more than five years of experience in their field frequently experience neck pain, which may be brought on by repetitive shoulder motion and poor posture at the workplace.&#x0D; Recommendations: The results of this study showed that hairdressers in Multan frequently experience neck pain. Physiotherapy campaigns should be conducted to raise awareness among hairdressers. It is suggested to use a random sampling technique instead of convenience sampling in future research to enhance the generalizability of the findings. Considering that the study had a short duration, it is advisable to allocate a longer time frame for conducting future studies to obtain a more comprehensive understanding of the topic.&#x0D;

Intensity of arm swing exercise with music-movement synchrony in untrained young adults

IntroductionThe research aimed to study the intensity of arm swing exercise (ASE) with different tempi of music-movement synchrony in untrained young adults and to investigate the effect of different music tempi on heart rate and oxygen consumption.MethodsParticipants were 30 healthy volunteers (15 males and 15 females), 20.67 ± 1.37 years and low-to-moderate physical activity. They performed ASE synchronised with music at a tempo of 60 and 140 bpm with a random sequence. They were measured for heart rate and oxygen consumption using a Quark SPIRO (COSMED) before and after the ASE for 6 minutes of each tempo. They rested for at least 15 minutes between music tempi during the ASE. The intensity of ASE with music-movement synchrony of each tempo was calculated as a percentage of maximum heart rate (%HRmax) and percentage maximum oxygen consumption (%VO&lt;sub&gt;2max&lt;/sub&gt;).ResultsThe %HRmax of all participants post-ASE at 60 and 140 bpm were 58.64 ± 8.82 and 60.12 ± 8.95%, respectively. The %VO&lt;sub&gt;2max&lt;/sub&gt; of all participants post-ASE at 60 and 140 bpm were 38.65 ± 11.36 and 40.17 ± 10.71%, respectively. There was no significant difference in HR and VO2 of ASE between music tempi.ConclusionsThe ASE with music-movement synchrony at 60 and 140 bpm is a low-intensity aerobic exercise, so is a suitable choice for people with low physical activity. Furthermore, the faster tempo did not significantly alter the intensity, therefore, we recommend selecting the slower music tempo at 60 bpm to avoid repetitive shoulder joint injury.

The Relationship Between Maximum Shoulder Horizontal Abduction and Adduction on Peak Shoulder Kinetics in Professional Pitchers.

Repetitive horizontal shoulder abduction during pitching can cause increased contact between the posterosuperior aspect of the glenoid and the greater tuberosity of the humeral head, theoretically putting baseball pitchers at increased risk of shoulder internal impingement and other shoulder pathologies. Increased shoulder horizontal abduction is associated with increased shoulder anterior force, while increased horizontal adduction is associated with increased shoulder distraction force. Descriptive laboratory study. Level 4. A total of 339 professional baseball pitchers threw 8 to 10 fastball pitches using 3D motion capture (480 Hz). Pitchers were divided into 2 sets of quartiles based on maximum shoulder horizontal abduction and adduction. Elbow flexion, shoulder external rotation, and peak shoulder kinetics were compared between quartiles with post hoc linear regressions conducted for the entire cohort. At maximum shoulder horizontal abduction, there was no difference in ball velocity between quartiles (P = 0.76). For every 10º increase in maximum shoulder horizontal abduction, shoulder anterior force decreased by 2.2% body weight (BW) (P < 0.01, B = -0.22, β = -0.38), shoulder adduction torque decreased by 0.5%BW × body height (BH) (P < 0.01, B = -0.05, β = -0.19), and shoulder horizontal adduction torque decreased by 0.4%BW × BH (P < 0.01, B = -0.04, β = -0.48). For every 10º increase in maximum shoulder horizontal adduction, shoulder anterior force increased by 2%BW and ball velocity decreased by 1.2 m/s (2.7 MPH). Professional pitchers with the least amount of maximum horizontal adduction had faster ball velocity and decreased shoulder anterior force. Pitchers with greater maximum shoulder horizontal abduction had decreased shoulder anterior force, shoulder adduction torque, and shoulder horizontal adduction torque. To maximize ball velocity as a performance metric while minimizing shoulder anterior force, pitchers can consider decreasing maximum shoulder adduction angles at later stages of the pitch. Identifying risk factors for increased throwing shoulder kinetics (ie, shoulder anterior force, shoulder adduction torque) has potential implications in injury prevention. Specifically, mitigating shoulder anterior forces may be beneficial in reducing risk of injury.

Long head of biceps transfer to augment Bankart repair in chronic anterior shoulder instability with and without subcritical bone loss: a biomechanical study.

Treating recurrent anterior shoulder instability in participants in collision sports, patients with capsulolabral defects, and patients with bipolar bone loss remains challenging. The study purpose was to investigate the effect of long head of the biceps transfer (LHBT) on load-to-dislocation biomechanics in a repetitive serial shoulder dislocation cadaveric model comparing LHBT with the Latarjet and Bankart procedures-the first-line treatment methods for chronic traumatic anterior shoulder instability with and without anterior glenoid bone loss, respectively. In this controlled laboratory study, 8 fresh-frozen cadaveric shoulders with different conditions were dislocated in sequence using a custom test frame. The muscle loading configuration simulated the arm in the apprehension position, and biceps loads of 20 N and 40 N were used for the static glenohumeral position analysis to evaluate the sling effect. Sequential experimental conditions consisted of the intact state, second and third dislocations, chronic instability, Bankart repair, first LHBT, subcritical glenoid bone loss, second LHBT, and Latarjet procedure. The pectoralis major and joint reaction loads to dislocation sequentially decreased with serial dislocations in all specimens, with the lowest value in the subcritical glenoid bone defect condition. In the setting of chronic instability, the pectoralis load to dislocation was significantly higher with the Bankart repair (P = .031) and LHBT (P < .001), at 71% and 85% of the intact value, respectively. Direct comparison of the pectoralis load to dislocation favored LHBT over Bankart repair (P = .015). In the subcritical defect scenario, LHBT did not significantly increase the load to dislocate, and the Latarjet procedure demonstrated a higher load to dislocate than LHBT (P < .001). All 3 surgical procedures tested significantly increased the angle of horizontal abduction at the time of dislocation and restored the glenohumeral position to closer to the intact state. Doubling the biceps load leveraged the sling effect, pulling the humeral head farther posterior-superiorly, but this was not enough to overcome the effect of a 20% subcritical glenoid bone defect. In a serial dislocation model, LHBT effectively stabilized the glenohumeral joint in a simulated chronic instability scenario, increasing the pectoralis major load-to-dislocate and glenohumeral joint reaction force components at the time of dislocation and restoring relative glenohumeral positioning to close to the intact state. The Latarjet procedure outperformed LHBT in stabilizing shoulders in the 20% subcritical glenoid bone defect condition.

Isokinetic strength testing of shoulder rotators in collegiate throw ball players

Background and Objectives: Throwball involves repetitive shoulder rotations leading to the overuse of shoulder rotators causing several internal risk factors for shoulder problems. Reduction in the range and strength of shoulder rotators is major risk or cause for shoulder injuries. Hence, the primary objective of the study is to determining isokinetic strength of shoulder rotators in collegiate throwball payers. The secondary objectives are to determine the rotator strength on shoulder rotators in non-players and compare the strength between the two groups. Methods: Sample size was estimated to be 60 females between 18-25years, 30players (20.05+1.39) and 30 nonplayers (19.96+1.33); height (157.36+5.92 players; 158.18+5.38 non-players); weight (59.66+14.60 players; 63.24+12.63 non-players) participated in this cross-sectional study. Concentric and concentric peak torque of internal and external rotator ROM and strength was assessed. Three speeds of 1800/s, 1200/s and 600/s was used. Results: The dominant side presented higher mean values for peak torque for IR in players at all three speeds; the non-dominant side presented higher mean peak for in ER in both the groups at all three speeds. In the non-players group, the dominant limb presented higher mean peak torque values in IR at 1800/s and 600/s whereas the non-dominant limb presented higher peak for IR at 1200/s. However, only the mean peak torque of IR at 600/s had significant difference (15.65+3.23 for players; 13.2+3.54 for non-players) with p=0.02 and t-value=2.32. Interpretation and Conclusion: There was no significant difference between the players and non-players which implies that the players need to be trained for rotator strengthening especially external rotators as muscle strength imbalance between the agonist and antagonist is one of the major risk factors for shoulder injuries. The values obtained for the strength of the players can be used as reference for further studies for population-specific isokinetic data profile for both rehabilitation and prevention.

Research progress on the relationship between shoulder instability and superior labrum anterior posterior lesion

To summarize the relationship between shoulder instability and superior labrum anterior posterior (SLAP) lesion. The characteristics of shoulder instability and SLAP lesion were analyzed, and the relationship between them in pathogenesis, clinical symptoms, and biomechanics was discussed by referring to relevant domestic and foreign literature. Shoulder instability and SLAP lesion can occur both spontaneously and respectively. SLAP lesion destroys the superior labrum integrity and the long head of biceps tendon (LHBT) insertion, causing excessive humeral head displacement against glenoid, and leading to shoulder instability. While chronic repetitive or acute high-energy traumatic shoulder instability can in turn aggravate SLAP lesion, resulting in expansion and increased degree of the original lesion. SLAP lesion destroys mechanisms of shoulder stability, while shoulder instability causes tears of the upper labrum and the LHBT, showing a connection between shoulder instability and SLAP lesion. However, the existing evidence can only demonstrate that shoulder instability and SLAP lesion induce and promote the development of each other, instead of a necessary and sufficient condition. Therefore, the specific causal relationship between the two remains unknown and needs to be further studied.

Development of shoulder pain with job-related repetitive load: mechanisms of tendon pathology and anxiety.

The paucity of longitudinal clinical studies limits our understanding of the development of shoulder pain with repetitive shoulder tasks, and its association with underlying mind and body mechanisms. Tendon thickening characterizes painful shoulder supraspinatus tendinopathy, and the perception of pain can be affected by the presence of psychological factors such as anxiety and depression. This study determined the incidence of shoulder pain in novice individuals exposed to repetitive shoulder tasks, and the associated change in outcomes of supraspinatus tendon morphology and measures of anxiety and depression. We recruited dental hygiene (DH) students (n = 45, novice and exposed to shoulder repetitive tasks) and occupational therapy (OT) students (n = 52, novice, but not exposed to shoulder repetitive tasks), following them over their first year of training. We measured shoulder pain, supraspinatus morphology via ultrasonography, and psychosocial distress via the Hospital Anxiety and Depression Scale. We compared the incidence of shoulder pain (defined as a change of visual analog scale for pain score greater than the minimal clinically important difference) between DH and OT students using Fisher exact test. We used mixed effects models to longitudinally compare the change in outcomes between 3 groups: DH students who develop and did not develop shoulder pain, and OT students. The incidence of shoulder pain is higher in DH students (relative risk = 4.0, 95% confidence interval [CI] 1.4, 11.4). After 1 year, DH students with pain had the greatest thickening of the supraspinatus (0.7 mm, 95% CI 0.4, 0.9). The change in supraspinatus thickness of DH students with pain was greater than both DH students with no pain (0.4 mm, 95% CI 0.1, 0.8) and OT students (0.9 mm, 95% CI 0.5, 1.2). Anxiety score increased 3.8 points (95% CI 1.6, 5.1) in DH students with pain, and 43% of DH students with pain had abnormal anxiety score at 1 year (relative risk = 2.9, 95% CI 1.0, 8.6). Our results provide support for the theoretical model of repetitive load as a mechanism of tendinopathy. The supraspinatus tendon thickens in the presence of repetitive tasks, and it thickens the most in those who develop shoulder pain. Concurrently, anxiety develops with shoulder pain, indicating a potential maladaptive central mechanism that may impact the perception of pain.

Dynamic Joint Motions in Occupational Environments as Indicators of Potential Musculoskeletal Injury Risk.

The objective of this study was to test the feasibility of using a pair of wearable inertial measurement unit (IMU) sensors to accurately capture dynamic joint motion data during simulated occupational conditions. Eleven subjects (5 males and 6 females) performed repetitive neck, low-back, and shoulder motions simulating low- and high-difficulty occupational tasks in a laboratory setting. Kinematics for each of the 3 joints were measured via IMU sensors in addition to a "gold standard" passive marker optical motion capture system. The IMU accuracy was benchmarked relative to the optical motion capture system, and IMU sensitivity to low- and high-difficulty tasks was evaluated. The accuracy of the IMU sensors was found to be very good on average, but significant positional drift was observed in some trials. In addition, IMU measurements were shown to be sensitive to differences in task difficulty in all 3 joints (P < .05). These results demonstrate the feasibility for using wearable IMU sensors to capture kinematic exposures as potential indicators of occupational injury risk. Velocities and accelerations demonstrate the most potential for developing risk metrics since they are sensitive to task difficulty and less sensitive to drift than rotational position measurements.

Fatigue, induced via repetitive upper-limb motor tasks, influences trunk and shoulder kinematics during an upper limb reaching task in a virtual reality environment.

BackgroundEfficient shoulder movement depends on the ability of central nervous system to integrate sensory information and to create an appropriate motor command. Various daily encountered factors can potentially compromise the execution of the command, such as fatigue. This study explored how fatigue influences shoulder movements during upper limb reaching.MethodsForty healthy participants were randomly assigned to one of two groups: Control or Fatigue Group. All participants completed an upper limb reaching task at baseline and post-experimental, during which they reached four targets located at 90° of shoulder abduction, 90° external rotation at 90° abduction, 120° scaption, and 120° flexion in a virtual reality environment. Following the baseline phase, the Fatigue Group completed a shoulder fatigue protocol, while Controls took a 10-minute break. Thereafter, the reaching task was repeated. Upper limb kinematic (joint angles and excursions) and spatiotemporal (speed and accuracy) data were collected during the reaching task. Electromyographic activity of the anterior and middle deltoids were also collected to characterize fatigue. Two-way repeated-measures ANOVA were performed to determine the effects of Time, Group and of the interaction between these factors.ResultsThe Fatigue group showed decreased mean median power frequency and increased electromyographic amplitudes of the anterior deltoid (p < 0.05) following the fatigue protocol. Less glenohumeral elevation, increased trunk flexion and rotation and sternoclavicular elevation were also observed in the Fatigue group (Group x Time interaction, p < 0.05). The Control group improved their movement speed and accuracy in post-experimental phase, while the Fatigue group showed a decrease of movement speed and no accuracy improvement (Group x Time interaction, p < 0.05).ConclusionIn a fatigued state, changes in movement strategy were observed during the reaching task, including increased trunk and sternoclavicular movements and less glenohumeral movement. Performance was altered as shown by the lack of accuracy improvement over time and a decrease in movement speed in the Fatigue group.

Tourette disorder: A case report.

Tourette disorder: A case report.

Acuity of goal-directed arm movements and movement control; evaluation of differences between patients with persistent neck/shoulder pain and healthy controls

Background The main aim was to examine whether patients with persistent upper quadrant pain have higher end-point variability in goal directed pointing movements than pain-free controls when the pointing task is performed in total darkness and under full vision. An additional aim was to study associations between the magnitude of end-point variability and a clinical movement control test battery and self-rated functioning among patients. Methods Seventeen patients and 17 age- and gender-matched pain-free controls performed a pointing task that evaluated end-point variability of repetitive shoulder movements in horizontal adduction and abduction with full vision, and abduction with no visual information, completed a movement control test battery of neck and shoulder control tests and answered questionnaires. Results Patients had higher end point variability for horizontal abduction when performed with no visual information. For horizontal adduction the variability was higher, but only when it was controlled for movement time. No significant correlations were found between end-point variability and self-rated functioning, nor between end-point variability and neuromuscular control of the glenohumeral joint. Conclusions This study provides preliminary evidence that patients with persistent neck/shoulder pain can partly compensate proprioceptive deficits in goal-directed arm movement when visual feedback is present.

No Pain, No Gain: Normalizing Attitudes Associated with Shoulder Pain in Adolescent Swimmers

Introduction: “Swimmer’s shoulder” is the colloquial phrase describing pain and injury in the anterolateral region of the shoulder and is reported by 40-91% of adolescent competitive swimmers (1-3). Early detection of shoulder pain is beneficial to long-term health of athletes across similar sports requiring repetitive overhead shoulder motions as shoulder pain can signal imminent overuse injury (4). However, prior studies indicate that 86% of athletes implicitly or explicitly endorse swimming through practice pain, and 84% express reluctance towards the idea of taking time off (5). Such normalization is likely derived from theories that relate …

Effects of Scapular Motor Control Training versus Scapular Retraining Along With Mobilization on Pain and Functional Status among Construction Workers

Repetitive or sustained shoulder elevation during occupational tasks has been identified as a significant risk factor for shoulder tendinitis or non–specific shoulder pain. Dysfunction in any of the structure that surrounds shoulder joint can cause shoulder pathology. Impingement is thought to be due to inadequate subacromial space for clearance of the rotator cuff tendons as the arm is elevated. In Construction workers, abnormal motion during arm elevation may lead to impingement syndrome. Aim of the study was to analyze the effects of Scapular motor control training versus Scapular retraining along with mobilization on pain and functional status among construction workers. According to the inclusion criteria, a total of 20 subjects were selected and divided into two groups, Group A subjects received Scapular motor control training and Group B subjects received Scapular retraining, in addition both the group received mobilization over 6 weeks period. The subjects were assessed for Pain and Functional status using Numerical Pain Rating Scale and Disabilities of the Arm, Shoulder and Hand Score. Scores were evaluated before and after 6 weeks of duration. There was a difference between the groups with post test means 2.4 & 3.5 for NPRS and 46.1 & 55.3 for DASH respectively. A statistically significant improvement was obtained in Group A on Pain and Functional status in construction workers with Shoulder impingement syndrome (p<0.05). The result concluded and suggests that the Scapular Motor Control training when compared to the Scapular retraining was effective on improving Pain and Functional status among constructional workers.

Improving the realism of a wheelchair simulator through tracking of upper body movements

Introduction Safe and efficient use of a manual wheelchair (MWC) requires appropriate training. New MWC users should learn how to maneuver in different environments (restricted spaces, uneven surfaces, etc.). Learning of appropriate balance skills is also crucial, to avoid falls when handling forward or side slopes. Moreover, long-term MWC use can lead to repetitive shoulder strain injuries, which can be avoided through adequate propulsion technique (increasing push amplitude, while decreasing cadence). We have developed a virtual reality MWC simulator for the training of MWC skills. The velocities of the rear wheels control a virtual MWC in a 3D scene presented on a computer screen in front of the participant, while force feedback simulates the effects of gravity and inertia. Our objective was to improve the realism of our existing wheelchair simulator, through the addition of upper body motion tracking that will provide feedback on trunk posture and propulsion movement. Material and methods Ten MWC users participated in the study. They propelled the virtual MWC while their trunk and arm movements were simultaneously recorded by three systems: – five inertial sensors placed on the trunk, arms and forearms; – a markerless, 3D depth camera system; – a high-precision motion capture system (gold standard). Upper body position as measured by the two low-cost approaches (inertial system and depth camera) was compared to the motion capture system. Results and conclusion Findings from this interdisciplinary study will optimize mobility of MWC users, through better MWC skills (balance and propulsion techniques), while possibly decreasing the incidence of falls and shoulder injuries.

Sex differences in perceptual responses to experimental pain before and after an experimental fatiguing arm task

BackgroundThe incidence and prevalence of musculoskeletal disorders (MSDs) is about twice as high in women compared to men, and those of the neck/shoulder region are particularly high among women. Fatigue and responses towards pain are known risk factor for MSDs. However, women have been shown to be less fatigable than men, but more sensitive to experimental pain. From a general standpoint, sex differences in the relationships between the fatigue and pain pathways are poorly understood. This may be due to differences in how men and women conceptually define the sensations of fatigue and pain. The objective of this study was to compare physical and verbal descriptors of fatigue and pain between men and women undergoing an experimental protocol where fatigue and pain were manipulated.MethodsHealthy adult volunteers (14 men and 14 women) underwent experimental pain tests to identify pressure pain threshold (PPT) at biceps brachii (BIC), anterior deltoid (AD), and upper trapezius (UT) followed by the Short-form McGill Pain Questionnaire (SF-MPQ) and Pain Catastrophizing Scale (PCS) before and after a repetitive arm task performed at shoulder height until reaching a rating of neck/shoulder perceived exertion, using the Borg Category Ratio 10 (CR10), greater than 8/10. PPT and MPQ data were analyzed using repeated measures analyses of variance (ANOVA) (time × sex). Correlational analyses were used to investigate relationships between pain measures with time and fatigue.ResultsUT PPT was reduced following the fatiguing task (p ≤ 0.01). Men overall reported higher AD PPT levels compared to women (p ≤ 0.05). MPQ and PCS magnification scores were significantly higher after the fatiguing task (p ≤ 0.05), with no sex differences. Time to fatigue correlated with changes in AD PPT in men and with PCS scores in women.ConclusionsFindings suggest that mechanisms underlying the sensation of acute pain following a repetitive shoulder height task are closely linked with PPT changes in shoulder stabilizers (UT) irrespective of sex, and more so with physical pain responses in men and in attitudes towards pain in women. Sex differences in pain perception may contribute to a better understanding of sex-specific mechanisms underlying neck/shoulder MSDs.

Corpus callosotomy might have reduced epileptic seizure-induced repetitive shoulder joint dislocation in two patients with medically intractable epilepsy who were not focus resection candidates.

PurposeTreatment options appear lacking for patients with epileptic seizure-induced shoulder dislocations who are not candidates for shoulder and focus resection surgeries. To reduce shoulder joint dislocations caused by epileptic seizures and simultaneously reduce the frequency and intensity of seizures, we performed corpus callosotomy for two patients with medically intractable epilepsy that induced repetitive shoulder joint dislocations.Materials and methodsA 21-year-old man (Patient 1) with bilateral temporal lobe epilepsy [Focal onset impaired awareness seizure (FIAS), 1/month; focal to bilateral tonic-clonic seizure (BTCS), 1/2–3 months], autism and intellectual disorder and a 34-year-old man (Patient 2) with left multi-lobar epilepsy (BTCS, 3–4/month; status epilepticus, 1/2–3 months), autism and intellectual disorder had suffered from repetitive seizure-induced shoulder dislocations (1/2–3 months for Patient 1; 3–4/month for Patient 2). Due to frequent seizures and uncooperativeness, they were not candidates for shoulder joint dislocation surgery. They were also not candidates for focus resection surgery due to multiple foci and uncooperativeness for invasive monitoring. We performed corpus callosotomy for both patients.ResultsPostoperatively, frequencies of both shoulder dislocations (2 in 5 years of follow-up for Patient 1; 1 in 5 months of follow-up for Patient 2) and epileptic seizures were drastically reduced.ConclusionsFor patients who are not candidates for focus resection and shoulder joint surgeries but who suffer from frequent shoulder joint dislocations, corpus callosotomy could be a treatment of last resort.

The effects of comorbid Tourette symptoms on distress caused by compulsive-like behavior in very young children: a cross-sectional study

BackgroundMany children 4 to 6 years old exhibit compulsive-like behavior, often with comorbid Tourette symptoms, making this age group critical for investigating the effects of having comorbid Tourette symptoms with compulsive-like behavior. However, these effects have not yet been elucidated: it is unclear whether having comorbid tics with compulsive-like behavior leads to lower quality of life. This cross-sectional study aims to investigate the effect of comorbid Tourette symptoms on distress caused by compulsive-like behavior in very young children.MethodsSelf-administered questionnaires were distributed to guardians of children aged 4 to 6 attending any of the 59 public preschools in a certain ward in Tokyo, Japan. The questionnaire contained questions on the presence of Tourette symptoms, the presence of specific motor and vocal tics, frequency/intensity of compulsive-like behavior, and the distress caused by compulsive-like behavior, which was rated on a scale of 1 to 5. Additionally, questions on autism spectrum disorder (ASD) traits, attention-deficit/hyperactivity disorder (ADHD) traits, internalizing behavior traits, and externalizing behavior traits were included in the questionnaire as possible confounders of distress caused by compulsive-like behavior. Wilcoxon rank-sum tests were conducted to compare the distress caused by compulsive-like behavior and frequency/intensity of compulsive-like behavior between children in the Tourette symptoms group and the non-Tourette symptoms group. Furthermore, a stepwise regression analysis was performed to assess the effects of the independent variables on distress caused by compulsive-like behavior. Another stepwise regression analysis was performed to assess the relationship between distress caused by compulsive-like behavior and the presence of five specific motor and vocal tics.ResultsOf the 675 eligible participants, distress due to compulsive-like behavior was significantly higher in children in the Tourette symptoms group compared to the non-Tourette symptoms group (2.00 vs 1.00, P < 0.001). Stepwise regression analysis showed that frequency/intensity of compulsive-like behavior, being in the Tourette symptoms group, ASD traits, and internalizing behavior traits were predictors of distress due to compulsive-like behavior. Two specific tics, repetitive noises and sounds and repetitive neck, shoulder, or trunk movements, were significant predictors of distress due to compulsive-like behavior.ConclusionsComorbid Tourette symptoms may worsen distress caused by compulsive-like behavior in children 4 to 6 years old, and specific motor and vocal tics may lead to greater distress.