Shoulder Abduction Research Articles

Quantifying the Effects of American Football Shoulder Pads on Reach Distance and Player Perception of Comfort and Fit

Background: The majority of sports equipment research to date has focused on their protective capabilities, and not on how they impact player performance and comfort while using them. Objective: The purpose of this study was to quantify the reach distances of players wearing different football shoulder pads and determine player perceptions of shoulder pad comfort and fit. Methods: Football players (n=10) underwent a standardized reach distance protocol comprised of three trials of repeated shoulder flexion, extension, abduction, horizontal flexion, and horizontal extension in each of the three shoulder pad conditions (no shoulder pad, standard shoulder pad, prototype shoulder pad). Player perceptions of shoulder pad comfort and fit, breathability, restrictiveness, and weight were also evaluated using a questionnaire. Reach distances were recorded using five GoPro Hero 9 cameras and analyzed using ProAnalyst®3D motion tracking software. Results: Reach distances were significantly affected during several movements, but especially in the vertical direction, for flexion and abduction, with mean differences between the prototype pad and standard pad of 10.3 cm and 23.1 cm, respectively (P = 0.007 and P = 0.003). Differences in reach distance were greater for the standard shoulder pad than the prototype shoulder pad on average. This indicates that the prototype shoulder pad was less restrictive, which aligned with what players reported. There was significantly more discomfort reported in the neck collar and armpit regions for the standard shoulder pad compared to the prototype pad. Participants also found the prototype shoulder pad to be lighter, and more breathable (P0.05). Conclusion: These results provide manufacturers with valuable insights from a design standpoint, and offer athletes who are looking for superior sport protective equipment key evidence regarding shoulder pad performance, fit, and comfort.

Preoperative Planning for Reverse Shoulder Arthroplasty: Does the Clinical Range of Motion Match the Planned 3D Humeral Displacement?

The functional outcome after reverse shoulder arthroplasty (RSA) is closely linked to how much the humerus shifts because of the implants. While two-dimensional (2D) angle measurements have been used to capture this shift, it can be measured in three dimensions (3D) as the arm change position (ACP). In a previous study, the ACP was measured using 3D preoperative planning software with the passive virtual shoulder range of motion obtained after RSA. The main objective of this study was to evaluate the relationship between the ACP and the actual active shoulder range of motion measured after RSA. The hypothesis was that the ACP and the active clinical range of motion are related such that the ACP is a reliable parameter to guide the preoperative planning of an RSA. The secondary objective was to assess the relationship between 2D and 3D humeral displacement measurements. This prospective observational study enrolled 12 patients who underwent RSA and had a minimum follow-up of 2 years. The active range of motion in shoulder flexion, abduction, and internal and external rotation was measured. At the same time, ACP measurements were taken from a reconstructed postoperative CT scan, in addition to the radiographic measurements of humeral lateralization and distalization angles on AP views in neutral rotation. The mean humeral distalization induced by RSA was 33.3 mm (±3.8 mm). A non-statistically significant increase in shoulder flexion was observed for humeral distalization beyond 38 mm (R2 = 0.29, p = 0.07). This "threshold" effect of humeral distalization was also observed for the gains in abduction, as well as internal and external rotations, which seemed better with less than 38 mm or even 35 mm distalization. No statistical correlation was found between the 3D ACP measurements and 2D angle measurements. Excessive humeral distalization seems to be detrimental to joint mobility, especially shoulder flexion. Humeral lateralization and humeral anteriorization measured using the ACP seem to promote better shoulder range of motion, with no threshold effect. These findings could be evidence of tension in the soft tissues around the shoulder joint, which should be taken into consideration during preoperative planning.

Physical activity levels respiratory and peripheral muscle strength and pulmonary function in young post-COVID-19 patients : Across-sectional study.

Coronavirus disease 2019 (COVID-19) causes permanent problems, even mild severity. The long-term consequences of COVID-19 are still unknown. This study aimed to investigate physical activity levels, respiratory and peripheral muscle strength, and pulmonary function in the long term in young adult COVID-19patients who recovered from mild disease. This cross-sectional study was carried out at least 6 months after the COVID-19 diagnosis, 54 patients with COVID-19 (median age: 20years) and 46controls (median age: 21years) were compared. Functional status (post-COVID-19 functional status scale), respiratory (maximum inspiratory and expiratory pressures (MIP, MEP)) and peripheral muscle strength (dynamometer), pulmonary function (Spirometry), dyspnea and fatigue (modified Borg scale), and physical activity levels (International Physical Activity Questionnaire) were evaluated. NCT05381714. Patients with COVID-19 measured and percent predicted MIP and MEP were statistically decreased compared with the controls (p < 0.05). Shoulder abductors muscle strength (p < 0.001) and the number of individuals with low physical activity levels were significantly higher in patients compared with controls (p = 0.048). Pulmonary function, quadriceps muscle strength, exertional dyspnea, and fatigue scores were similar in groups (p > 0.05). Respiratory and peripheral muscle strength and physical activity levels are adversely affected in patients with COVID-19, even though the patients were mildly affected in the long term. Also, symptoms such as dyspnea and fatigue may persist. Therefore, these parameters should be evaluated in the long term, even in young adults who are mildly affected by COVID-19.

Seronegative Isaac Syndrome Presenting as Focal Limb Stiffness Responsive to Plasma Exchange Therapy (P8-8.015)

<h3>Objective:</h3> N/A <h3>Background:</h3> Isaac syndrome is an autoimmune disorder of peripheral nerve hyperexcitability characterized by neuromyotonia, myokymia, muscles stiffness, pseudomyotonia, and pseudotetany frequently accompanied by dysautonomia and neuropathic pain. Approximately 50% of cases are associated with antibodies against contactin-associated protein-like 2 (CASPR2) or less commonly leucine-rich glioma inactivated protein 1 (LGI1), both components of the voltage-gated potassium channel (VGKC) complex. Paraneoplastic, genetic, and toxic etiologies must be considered. Management includes membrane-stabilizing drugs as well as immunotherapy in more severe cases. <h3>Design/Methods:</h3> N/A <h3>Results:</h3> A 50-year-old woman presented with one year of left neck, shoulder, and upper extremity pain and stiffness that began one month after an upper respiratory illness. Her exam was notable for anterocollis, left shoulder elevation, impaired left shoulder abduction beyond 35–40 degrees, tonically contracted left biceps, and marked tenderness to palpation of the affected muscles. Symptomatic management with diazepam, lorazepam, baclofen, mexiletine, and trihexyphenidyl was ineffective. EMG demonstrated widespread neuromyotonic discharges throughout the proximal greater than distal left upper extremity, cervical and thoracic paraspinals, and right deltoid. Laboratory studies including CASPR2, LGI1, VGKC, GAD-65, and amphiphysin antibodies were unremarkable. Comprehensive screening for occult malignancy was unrevealing. She received partial benefit from carbamazepine, levetiracetam, cyclobenzaprine, and onabotulinumtoxinA injections, but symptoms remained debilitating. She was treated with IVIg 1g/kg Q2 weeks for three months with symptom progression to the jaw and lower extremities. She was started on plasmapheresis QOD for ten days every four weeks with rapid improvement in symptoms. <h3>Conclusions:</h3> We report a case of seronegative Isaac syndrome initially presenting with focal limb stiffness and dystonic posturing that was exquisitely responsive to plasmapheresis. This case highlights the need to consider peripheral nerve hyperexcitability syndromes in patients presenting with focal limb stiffness or painful dystonia and provides additional support for plasmapheresis as an effective treatment option for patients with debilitating symptoms. <b>Disclosure:</b> Dr. Khalil has received personal compensation in the range of $0-$499 for serving as a Resident and Fellow Council Member with American Association of Neuromuscular &amp; Electrodiagnostic Medicine. Dr. Khalil has received personal compensation in the range of $0-$499 for serving as a MS Mentorship Forum Participant with Foundation of the Consortium of Multiple Sclerosis Centers. Dr. Bradshaw has nothing to disclose.

Moderate-to-high Intensity Group Exercise Improves Function of Stroke Survivors (P12-8.009)

<h3>Objective:</h3> The aim of this study is to investigate the effect and feasibility of moderate-to-high intensity exercise in stroke survivors. <h3>Background:</h3> Post-stroke exercise need to be encouraged to facilitate optimal recovery and to improve both physical and mental health. However, stroke survivors are easily predisposed to sedentary lifestyle due to physical impairment and functional compromise. Moreover, many clinicians as well as patients tend to be discouraged by exercise-related risk of injury of falls or comorbidities. <h3>Design/Methods:</h3> This study is a randomized controlled trial. Subjects were randomly assigned to either intervention or control group. Subjects in intervention group completed 16 sessions of 90-minute moderate-to-high intensity group-based exercise for 8 weeks. Isometric muscle strength and grip strength of the affected and unaffected side, 10 repetition sit-to-stand test (STS10), 60 second sit-to-stand test (STS60), Short Physical Performance Battery (SPPB), multidirectional reach test, Berg’s Balance scale (BBS), 10-meter walk test, 6 minute walk test, Timed-up-and-go test, physiological cost index, Korean version of modified Barthel index, and Korean version of Montreal Cognitive Assessment (MoCA-K) were measured at baseline and postintervention. <h3>Results:</h3> Total 30 stroke survivors were enrolled in the study and 22 were randomized to group-based moderate-to-high exercise and 8 were randomzied to home-based low intensity exercise. Intervention group showed high compliance as well as high attendance rate. Adverse event was only 2 uneventful falls in 1 subject. After 8 weeks of moderate-to-high intensity group exercise, subjects showed significant improvement in isometric muscle strength of hip extensors and knee flexors and grip strength both in affected and unaffected limbs, and isometric muscle strength of affected shoulder abductor. Also, STS60, SPPB, BBS, and MoCA-K were significantly improved in the intervention group after 8-week of moderate-to-high intensity exercise. <h3>Conclusions:</h3> Moderate-to-high intensity group-based exercise is feasible and safe and improves physical and cognitive function of chronic stroke survivors. <b>Disclosure:</b> The institution of Prof. Jung has received research support from National Rehabilitation Center, Ministry of Health and Welfare, South Korea. Miss Cho has nothing to disclose. Mr. Yoon has nothing to disclose.

Annualized Rates of Change from A Phase 2, Randomized, Double-Blind, Placebo-Controlled, 48-Week Study of Losmapimod in Subjects with FSHD: ReDUX4 (S48.010)

<h3>Objective:</h3> Evaluate annualized clinical outcome changes in subjects with facioscapulohumeral muscular dystrophy (FSHD) treated with losmapimod compared with placebo. <h3>Background:</h3> FSHD is a relentless, variably progressive disease leading to accumulation of disability over decades. Fulcrum is developing losmapimod, a small molecule p38 α/β MAPK inhibitor, to treat FSHD. An annualized analysis provides data on the slope of disease progression and the potential for treatment with losmapimod to change that slope over time. <h3>Design/Methods:</h3> Subjects aged 18–65 years with FSHD1, CSS 2–4, and MRI-eligible muscles for biopsy were randomized 1:1; losmapimod (15 mg BID): placebo. Assessments included for analysis: MRI assessments of muscle health, reachable workspace (RWS), dynamometry and TUG. Annualized rate of change (%/yr) was calculated using a linear mixed-effects model to estimate slope and percent change per year. Annualized analysis of RWS (measured in Reachable Surface Area, RSA) was prespecified; all other analyses are post-hoc. <h3>Results:</h3> Eighty subjects (N=40/group), mean age 45.7 (±12.5) years, Ricci score 3.2 were enrolled. Annualized rate of change (%/yr) in total RSA for losmapimod vs. placebo dominant arm: −0.44 vs. −8.42; p=0.07; non-dominant arm: 4.88 vs. −4.02; p=0.01. This slowing or improvement is supported by structural measures via MRI and functional outcomes (dynamometry and TUG). MRI annualized rates of change for losmapimod vs. placebo were 0.31 vs 3.82 for MFI, 4.42 vs 5.96 for MFF, and −7.15 vs −4.50 for LMV. Maximum dynamometry in the shoulder abductors showed variability in annualized rate of change for losmapimod vs. placebo (L −1.98 vs 13.62; R −14.39 vs −8.49) and in hand grip (L −8.30 vs −13.44; R −13.95 vs −15.27). In TUG, the annualized rate of change was −0.93 vs 2.23% in the losmapimod vs placebo group. <h3>Conclusions:</h3> Annualized rates of change in clinical outcomes support disease slowing or improvement in losmapimod treated subjects compared to placebo. <b>Disclosure:</b> Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving as a Consultant for DYNE Therapeutics. Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Arrowhead Pharma. Dr. Tawil has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Fulcrum Therapeutics. Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Acceleron Pharma. Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for MT Pharma. Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche Pharma. Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for miRecule. The institution of Dr. Tawil has received research support from Friends of FSH Research. The institution of Dr. Tawil has received research support from FSH Society. The institution of Dr. Tawil has received research support from NIH. The institution of Dr. Tawil has received research support from Fulcrum. Dr. Tawil has received intellectual property interests from a discovery or technology relating to health care. Dr. Tawil has received publishing royalties from a publication relating to health care.

Three-Dimensional Motion Capture Data of a Movement Screen from 183 Athletes

Movement screens are widely used to identify aberrant movement patterns in hopes of decreasing risk of injury, identifying talent, and/or improving performance. Motion capture data can provide quantitative, objective feedback regarding movement patterns. The dataset contains three-dimensional (3D) motion capture data of 183 athletes performing mobility tests (ankle, back bend, crossover adduction, crossover rotation, elbows, head, hip turn, scorpion, shoulder abduction, shoulder azimuth, shoulder rotation, side bends, side lunges and trunk rotation) and stability tests (drop jump, hop down, L-cut, lunge, rotary stability, step down and T-balance) bilaterally (where applicable), the athletes’ injury history, and demographics. All data were collected at 120 Hz or 480 Hz using an 8-camera Raptor-E motion capture system with 45 passive reflective markers. A total of 5,493 trials were pre-processed and included in .c3d and .mat formats. This dataset will enable researchers and end users to explore movement patterns of athletes of varying demographics from different sports and competition levels; develop objective movement assessment tools; and gain new insights into the relationships between movement patterns and injury.

E032 Deficiency of Adenosine Deaminase 2: a rare diagnosis in a case of suspected vasculitis

Abstract Background/Aims Deficiency of adenosine deaminase 2 (DADA2) is a rare autosomal recessive condition first described in 2014 which is characterised by vasculitis, systemic inflammation, immunodeficiency and cytopenias. The vasculitis is difficult to differentiate from polyarteritis nodosa and typically presents with recurrent strokes. It can also affect the skin and present with livedo racemosa. Clinical presentation varies widely; from vasculitic manifestations which tend to present later in life to severe haematological abnormalities such as bone marrow failure which tend to present earlier in life. Treatment with TNF inhibitors reduces the risk of additional strokes and controls inflammation in the presence of vasculitis but is not very effective against bone marrow failure. Methods We present the case of a 44-year-old gentleman who was being investigated for possible vasculitis by the rheumatology team in view of a history of Raynaud’s, 20-year history of recurrent leg ulcers and a previous pontine infarct. He presented acutely to the emergency department with numbness below the midthoracic level, weakness of his lower limbs and hands and urinary retention. His symptoms had progressed over a period of a few hours. On examination power was 4/5 on the MRC power scale for shoulder abduction and elbow flexion, 2/5 for elbow extension, 3/5 for wrist extension and 1/5 for finger extension. Power was 1/5 on his lower limbs. Sensation to pain was reduced with a T6 sensory level. Proprioception and vibration sense were intact. Upper limb reflexes were brisk. Knee jerks and left ankle jerk were difficult to elicit. Plantars were downgoing. Cranial nerves were normal. Results Bloods showed a white cell count of 6.7x109/l, haemoglobin of 96g/l (microcytic), platelets of 243x109/l, creatinine 119μmol/l (baseline 85μmol/l) and CRP of 42.9mg/l. Vitamin B12 was 200ng/l and folate levels were 2.2μg/L. ANA, ANCA, cryoglobulins and hepatitis serology were negative. MRI brain showed a 4mm area of hyper-density in the left pons. MRI whole spine was unremarkable. CSF showed normal protein, white cell count and glucose level. The patient was transferred to a tertiary neurology centre and a diagnosis of anterior spinal cord infarction was made. A nerve biopsy was performed which showed evidence of vasculitis and he was pulsed with methylprednisolone and commenced on high dose oral steroids. Genetic testing showed a pathogenic mutation in the adenosine deaminase 2 gene. He is currently awaiting to commence treatment with TNF inhibitors. Conclusion We conclude that DADA2 is an important differential in a young patient with suspected vasculitis especially in the presence of infarction. Identification of DADA2 allows initiation of treatment with TNF inhibitors which reduces the risk of additional strokes. Disclosure M. Xenophontos: None. J. Gan: None. A.C. Seneviratne: None.

Startle-triggered responses indicate reticulospinal drive is larger for voluntary shoulder versus finger movements

Recent primate studies have implicated a substantial role of reticulospinal pathways in the production of various voluntary movements. A novel way to assess the relative reticulospinal contributions in humans is through the use of a “StartReact” paradigm where a startling acoustic stimulus (SAS) is presented during a simple reaction time (RT) task. The StartReact response is characterized by short-latency triggering of a prepared response, which is attributed to increased reticulospinal drive associated with startle reflex activation. The current study used a StartReact protocol to examine differences in reticulospinal contributions between proximal and distal effectors by examining EMG onset latencies in lateral deltoid and first dorsal interosseous during bilateral shoulder or finger abduction. The magnitude of the StartReact effect, and thus relative reticulospinal drive, was quantified as the difference in RT between startle trials in which startle-reflex related EMG activation in the sternocleidomastoid (SCM) was present (SCM +) versus absent (SCM −). A significantly larger StartReact effect was observed for bilateral shoulder abduction versus bimanual finger abduction and a higher incidence of SCM + trials occurred in the proximal task. Additionally, both startle reflex and response-related EMG measures were larger on SCM + trials for the shoulder versus finger task. These results provide compelling novel evidence for increased reticulospinal activation in bilateral proximal upper-limb movements.

The influence of gender on shoulder kinematics and head-hip technique during non-level transfers in full-time wheelchair users

BackgroundNon-level transfers are some of the most demanding tasks for manual wheelchair users. Safely performing these transfer tasks may be needed for maintaining long-term upper limb health. This cross-sectional study aimed to examine the influence of gender on the head-hip technique and lead arm kinematics during multi-height transfers in manual wheelchair users. MethodsMotion analysis was used to obtain lead-arm shoulder kinematics (flexion/extension and abduction/adduction) and trunk flexion during level, uphill, and floor-to-table transfers in full-time manual wheelchair users. FindingsTwelve male (N = 12) and fifteen female (N = 15) manual wheelchair users with a mean age of 23 ± 5 years and no signs of shoulder pain participated in the study. Lead-arm shoulder flexion and abduction increased as vertical displacement requirements increased during the various transfer tasks (p < 0.01). Women displaced greater trunk flexion during level transfers at approaching significant levels (p = 0.07). During uphill transfers, women displayed significantly greater trunk flexion than men (p < 0.05). InterpretationManual wheelchair users use unique kinematic requirements when using the head-hip during level and non-level transfers. Women may be at decreased risk of chronic shoulder pain due to a greater use of the head-hip technique during non-level transfers. Nonetheless, more research that integrates kinetics and strength assessments during non-level transfer biomechanical analyses is needed to better understand technical requirements of non-level transfers in manual wheelchair users.

Effects of Uni- vs. Bilateral Upper Limb Robot-Assisted Rehabilitation on Motor Function, Activities of Daily Living, and Electromyography in Hemiplegic Stroke: A Single-Blinded Three-Arm Randomized Controlled Trial.

To evaluate if bilateral or unilateral upper limb robot-assisted rehabilitation training using a new three-dimensional end-effector robot that targets shoulder and elbow flexion and abduction is superior to conventional therapy with regard to upper extremity motor function recovery and neuromuscular improvement in stroke patients. Randomized, controlled, parallel, assessor-blinded, three-arm clinical trial. Southeast University Zhongda Hospital Nanjing, Jiangsu, China. Seventy patients with hemiplegic stroke were randomly assigned to conventional training (Control, n = 23) or unilateral (URT, n = 23), or bilateral robotic training (BRT, n = 24). The conventional group received routine rehabilitation, 60 min/day, 6 days/week, for 3 weeks. For URT and BRT upper limb robot-assisted rehabilitation training was added. This was 60 min/day, 6 days/week, for 3 weeks. The primary outcome was upper limb motor function assessed with Fugl-Meyer-Upper Extremity Scale (FMA-UE). Secondary outcomes were activities of daily living (ADL) assessed with the Modified Barthel Index (MBI), Motor Evoked Potential (MEP) to assess corticospinal tract connectivity, Root Mean Square (RMS) value, and integrate Electromyography (iEMG) value recorded by surface electromyography to evaluate muscle contraction function. The primary outcome indicator FMA-UE (least square mean (LSMEAN): 31.40, 95% confidence interval (95% CI): 27.74-35.07) and the secondary outcome indicator MBI (LSMEAN: 69.95, 95% CI: 66.69-73.21) were significantly improved in BRT as opposed to control (FMA-UE, LSMEAN: 24.79, 95% CI: 22.23-27.35; MBI, LSMEAN: 62.75, 95% CI: 59.42-66.09); and unilateral (FMA-UE, LSMEAN: 25.97, 95% CI: 23.57-28.36; MBI, LSMEAN: 64.34, 95% CI: 61.01-67.68). BRT also showed greater improvement in the anterior deltoid bundle with regard to muscle contraction function indicated by RMS (LSMEAN: 257.79, 95% CI: 211.45-304.12) and iEMG (LSMEAN: 202.01, 95% CI: 167.09-236.94), as compared to the controls (RMS, LSMEAN: 170.77, 95% CI: 148.97-192.58; iEMG, LSMEAN: 132.09, 95% CI: 114.51-149.68), and URT (RMS, LSMEAN: 179.05, 95% CI: 156.03-202.07; iEMG, LSMEAN: 130.38, 95% CI: 107.50-153.26). There was no statistically significant difference between URT and conventional training for any outcome. There was no significant difference in MEP extraction rate after treatment between groups (p = 0.54 for URT, p = 0.08 for BRT). A 60 min daily training for upper extremities using a three-dimensional end-effector targeting elbow and shoulder adding conventional rehabilitation appears to promote upper limb function and ADL in stroke patients only if delivered bilaterally. URT does not seem to result in better outcomes than conventional rehabilitation. Electrophysiological results suggest that training using a bilateral upper limb robot increases the recruitment of motor neurons rather than improving the conduction function of the corticospinal tract.

Clinical significance of anti-NT5c1A autoantibody in Korean patients with inflammatory myopathies.

To explore the clinical significance of anti-cytosolic 5'-nucleoditase 1A (NT5c1A) antibody seropositivity in inflammatory myopathies, we measured anti-NT5c1A antibodies and analyzed their clinical features. Anti-NT5c1A antibodies were measured in the sera of 103 patients with inflammatory myopathies using an enzyme-linked immunosorbent assay. Positivity for anti-NT5c1A antibody was found in 13 (12.6%) of 103 patients with inflammatory myopathy. Anti-NT5c1A antibody was most frequently identified in patients with inclusion body myositis (IBM) (8/20, 40%), followed by dermatomyositis (2/13, 15.4%), immune-mediated necrotizing myopathy (2/28, 7.1%), and polymyositis (1/42, 2.4%). In eight patients with the anti-NT5c1A antibody-seropositive IBM, the median age at symptom onset was 54 years (interquartile range [IQR]: 48-57 years), and the median disease duration was 34 months (IQR: 24-50 months]. Knee extension weakness was greater than or equal to hip flexion weakness in eight (100%) patients, and finger flexion strength was less than shoulder abduction in three (38%) patients. Dysphagia symptoms were found in three (38%) patients. The median serum CK level was 581 IU/l (IQR: 434-868 IU/L]. Clinically significant differences were not found between anti-NT5c1A antibody-seropositive and seronegative IBM groups with respect to gender, age at symptom onset, age at diagnosis, disease duration, serum CK values, presence of other autoantibodies, dysphagia, and the pattern of muscle impairment. Although anti-NT5c1A antibody is known to be associated with IBM, seropositivity has also been noted in non-IBM inflammatory myopathies, and is insufficient to have clinical significance by itself. These findings have important implications for interpreting anti-NT5c1A antibody test results as the first study in Korea.

The AIUM Practice Parameter for the Performance of the Musculoskeletal Ultrasound Examination.

The AIUM Practice Parameter for the Performance of the Musculoskeletal Ultrasound Examination.

The preferable shoulder position can isolate supraspinatus activity superior to the classic empty can test: an electromyographic study

BackgroundSupraspinatus (SSP) strength tests are an important shoulder examination tool for clinical evaluations of patients with a suspected SSP tear. While the empty can (EC) test is widely used to diagnose SSP dysfunction, the test cannot selectively activate SSP activity. The aim of this study was to access the electromyographic (EMG) activity within SSP, deltoid, and surrounding periscapular muscles after resisted abduction force to determine which shoulder position helps best isolate SSP from deltoid activity.MethodsA controlled laboratory EMG study was conducted. Specifically, we conducted an EMG analysis of the seven periscapular muscles (i.e., the middle deltoid, anterior deltoid, SSP, upper trapezius, posterior deltoid, infraspinatus, and pectoralis major) in 21 healthy participants, without any history of shoulder disorder, aged 29 ± 0.9 years old with a dominant-right arm. EMG activities were measured during resisted abduction force according to comprehensive shoulder positions in abduction, horizontal flexion, and humeral rotation. The supraspinatus to middle deltoid (S:D) ratio was calculated using the standardized weighted EMG and the maximum voluntary isometric contraction of the SSP and middle deltoid muscles, for each shoulder position to determine the best isolated SSP muscle strength test position. Results were analyzed with the Kruskal–Wallis test for non-normally distributed data.ResultsShoulder abduction, horizontal flexion, and humeral rotation significantly affected the activity of the middle deltoid, SSP, and S:D ratio (P < 0.05). The S:D ratio increased significantly in lower degrees of shoulder abduction, lower degrees of horizontal flexion, and external humeral rotation over internal rotation. The greatest S:D ratio (3.4 (0.5–9.1)) occurred at the shoulder position of 30° shoulder abduction combined with 30° horizontal flexion and external humeral rotation. Conversely, the classic EC position manifested nearly the smallest S:D ratio (0.8 (0.2–1.2)).ConclusionApplication of the SSP strength test in the shoulder position of 30 degrees abduction, 30 degrees horizontal flexion, and external humeral rotation offers the best position to isolate the abducting activity of the SSP from that of the deltoid, which could help with diagnosis among patients with chronic shoulder pain with a suspected SSP tear condition.

The Relationship Between Frailty and Functional Outcomes, Range of Motion, and Reoperation After Reverse Total Shoulder Arthroplasty for Proximal Humerus Fracture.

The objective of this study was to investigate whether frailty is associated with functional outcomes, motion, and reoperation at a minimum of 2 years after reverse total shoulder arthroplasty (rTSA) for proximal humerus fracture. We performed a retrospective study of 153 patients who underwent rTSA for proximal humerus fracture at two level 1 trauma centers from 2003 to 2018 with minimum 2-year follow-up. Frailty was assessed using the modified 5-item frailty index (mFI). The primary outcome variable was the American Shoulder and Elbow Surgeons (ASES) shoulder score at minimum 2-year follow-up. The secondary outcome variables were the Shoulder Pain and Disability Index (SPADI), the Shoulder Subjective Value (SSV), the 0 to 10 numeric rating scale (NRS) pain score, surgical complication, and reoperation. Bivariate comparisons were made between mFI and outcome variables. The mean age of the 153 patients was 70 years, and 76% were women. Forty patients (26%) had a mFI score of 0, 65 patients (42%) had a mFI score of 1, 40 patients (26%) had a mFI score of 2, and 8 patients (5%) had a mFI score of 3. Twenty-seven patients (18%) had complications, and 21 patients (14%) underwent reoperation. At minimum 2-year follow-up, mFI was not associated with ASES shoulder score, SPADI, SPADI pain or disability subscales, SSV, NRS pain score, active and passive shoulder forward flexion, abduction, and external rotation, complication, or reoperation. Provided they survive the initial physiologic insults of trauma and surgery, patients with higher mFI scores treated with rTSA for proximal humerus fracture can expect similar medium-term restoration of shoulder function. [Orthopedics. 2023;46(5):274-279.].

Perception of Torque is Impacted by a Subset of Features Related to the Motor Command.

Accurate perception of one's self-generated torques is integral to sensorimotor control. Here, we examined how features of the motor control task, specifically the variability, duration, muscle activation pattern, and magnitude of torque generation, relate to one's perception of torque. Nineteen participants generated and perceived 25% of their maximum voluntary torque (MVT) in elbow flexion while simultaneously abducting at their shoulder to 10%, 30%, or 50% of their MVT in shoulder abduction (MVT[Formula: see text]). Subsequently, participants matched the elbow torque without feedback and without activating their shoulder. The shoulder abduction magnitude affected the time to stabilize the elbow torque (p 0.001), but did not significantly impact the variability of generating the elbow torque (p = 0.120) or the co-contraction between the elbow flexor and extensor muscles (p = 0.265). The shoulder abduction magnitude influenced perception (p = 0.001) in that the error in matching the elbow torque increased with an increased shoulder abduction torque. However, the torque matching errors neither correlated with the time to stabilize and variability in generating the elbow torque, nor the co-contraction of the elbow muscles. These findings suggest that the total torque generated during a multi-joint task impacts the perception of a torque about a single joint; yet, effective and efficient generation of the torque about a single joint does not impact the torque percept.

147 The Impact of Tming of Primary Nerve Surgery on Shoulder Recovery in Neonatal Brachial Plexus Palsy

INTRODUCTION: Neonatal brachial plexus palsy (NBPP) almost universally impacts shoulder abduction, forward flexion, and external rotation. While nerve reconstruction options are available for restoration of these movement, the outcomes for nerve surgery for shoulder have lagged behind those at other joints. Operative timing is a potentially modifiable variable but remains controversial. METHODS: We interrogated a prospective database of all patients with NBPP who underwent primary nerve surgery at a single tertiary referral center between 2005-2020. The cohort was divided into those who underwent surgery ≤6 months old, 6-9 months old, and &gt;9 months old. AROM for shoulder abduction, forward flexion, and external rotation was plotted over time for each group and a logistic regression and 95% confidence interval fit to each plot to visualize both absolute and rate of recovery of AROM for each group. RESULTS: 99 children with 2196 AROM measurements were included in the analysis with average follow-up of 46 months. 26 underwent surgery ≤6 months old, 47 between 6-9 months, and 26 &gt;9 months old. Those who underwent surgery ≤9 months old had more rapid and better overall recovery of shoulder abduction and forward flexion than those who had surgery &gt;9 months. Timing of operation did not clearly impact recovery of external rotation. Patients who presented to a multidisciplinary clinic earlier were more likely to have earlier operations. CONCLUSIONS: Surgery prior to 9 months old may improve long-term recovery of shoulder AROM in NBPP. Early referral should be encouraged to optimize timing of operative intervention.

Functional Outcome following Phrenic Nerve Transfer in Brachial Plexus Injury

BackgroundBrachial plexus injuries are debilitating injuries resulting in paralyzed shoulder to global paralysis of the upper extremity. Treatment strategies have evolved over the years with nerve transfer forming the mainstay of surgical management. Phrenic nerve provides certain advantages as donor over other options but has been less preferred due to fear of pulmonary complications. In this study, we assess the functional outcomes of phrenic nerve transfer in brachial plexus injuries. Materials and MethodsA retrospective study was performed on 18 patients operated between 2012 and 2017. The mean duration of injury to surgery was 4.56 months and mean follow-up was for 3.66 years. Phrenic nerve was used as donor to neurotize either biceps and brachialis branch of musculocutaneous nerve or suprascapular nerve. Assessment was done through Waikakul score for elbow flexion and Medical Research Council grading for shoulder abduction. Respiratory function assessment was done through questionnaire. ResultsTwelve (80%) patients recovered grade 3 and above elbow flexion with 6 patients having a positive endurance test according to Waikakul and a “very good” result. In phrenic to suprascapular transfer group (3 patients), all patients had more than grade 3 recovery of shoulder abduction. No patient complained of respiratory problems. ConclusionPhrenic nerve can be used as a reliable donor with suitable patient selection with good results in regaining muscle power without any anticipated effects on respiratory function.

Brachial Plexus Birth Injury: A Single-Center Study.

Infants can sustain traction injury to brachial plexus nerves during birth, called brachial plexus birth injury (BPBI). While spontaneous recovery is possible, upper extremity weakness can linger. We report our experience at a brachial plexus clinic from a retrospective chart review of infants with BPBI from September 2017 to September 2019. We determined Narakas Classification (NC) and Active Movement Scale (AMS) at predetermined follow-up points. Of 15 patients, 8 presented with NC-I, 5 with NC-II, and 2 with NC-III without Horner's syndrome. By 7 months, 3 had spontaneous recovery, and 4 achieved all and another 4 achieved most AMS5-7 scores. Eleven patients undergoing surgery had little-to-no improvement of shoulder abduction and shoulder external rotation AMS categories by 6 months. Our small sample size prevents us from making definitive conclusions but gave beneficial insight into our clinic barriers to follow-up, data collection, and collaboration with physical and occupational therapy.

Comparison of shoulder functions between assembly workers with and without subacromial pain syndrome.

The occurrence of subacromial pain syndrome (SPS) is associated with the frequent handling and lifting of heavy loads and excessive repetitive work. Thus, assembly workers have a high prevalence of SPS. The purpose of this study was to investigate differences in shoulder ROM, muscle strength, asymmetry ratio, function, productivity, and depression between workers with and without SPS. Sixty-seven male workers (35 workers with SPS and 32 workers without SPS) participated in this study. Shoulder internal rotation (SIR), shoulder external rotation (SER), shoulder abduction (SAB), shoulder horizontal adduction ROM and SIR, SER, elbow flexion (EF), scapular depression and adduction, scapular protraction strength were measured. The asymmetry ratio was calculated using the asymmetry ratio formula; shoulder functions were measured using the shoulder pain and disability index (SPADI), disabilities of the arm, shoulder, and hand (DASH), and visual analogue scale (VAS); and Endicott work productivity scale (EWPS). The SPADI (p = 0.001), DASH (p = 0.001), and VAS (p = 0.001) values of workers with SPS were higher than those of workers without SPS. Also, workers with SPS had lower SIR (p = 0.001) and SAB (p = 0.002) ROM compared to workers without SPS. In addition, workers with SPS exhibited lower SIR (p = 0.012) strength than workers without SPS. Workers with SPS had higher asymmetry ratio in SIR (p = 0.015), SER (p = 0.005), and EF (p = 0.008) strength than workers without SPS. The SIR, SAB ROM, SIR strength, and the asymmetry ratio of SIR, SER, EF strengths could provide an important baseline comparison for the workers with SPS.