Arm Adduction Research Articles

Latarjet procedure without capsular repair produces favorable clinical results and avoids limitation in external rotation.

This study aimed at analyzing the range of motion (ROM) and other clinical outcomes in patients with > 20% glenoid bone loss who underwent the Latarjet procedure with or without anterior capsule repair. This retrospective study included 47 patients with > 20% glenoid bone loss who underwent the classic Latarjet procedure from 2016 to 2021. Of these, 25 did not undergo capsular repair (no-capsular-repair group; group I) whereas 22 patients did (capsular-repair group; group II). The Rowe score, American Shoulder and Elbow Surgeons score, Visual Analogue Scale, ROM, recurrence, and complications were evaluated before and 3, 6, and 12months after the surgery. A goniometer was used to measure the forward flexion and external rotation (arm adducted, 90° abducted) of both shoulders. The ROM deficit was measured as the difference from the contralateral healthy shoulder. The external rotation in arm adduction at 3 and 6months after surgery showedsignificantly better results in group I than group II(p = 0.002 at 3months; p = 0.005 at 6months). The deficit in external rotation with arm adduction was also significantly lower in group I at 3months (p = 0.001) and 6months (p = 0.001) after surgery. However, external rotation with arm adduction at 12months after surgery did not significantly differ between the groups. Moreover, the ROM in external rotation with 90° arm abduction was significantly better in group I than that in group II at 3, 6, and 12months postoperatively (p = 0.002, p = 0.001, and p = 0.005, respectively). The deficit in external rotation with 90° arm abduction gradually decreased with time after surgery and differed significantly between the groups. However, the difference in deficit between the two groups at 12months after surgery did not exceed the measurement error. All clinical scores significantly improved after surgery compared to before surgery; however, the improvement did not significantly differ between the two groups. The Latarjet procedure without capsular repair showed good laxity restoration and clinical results with less early postoperative external rotation limitation than that achieved by the same procedure with capsular repair. However, external rotation deficit at 1year after surgery did not show a clinically relevant difference difference between the two groups. Level III.

Determining factors for compensatory movements of the left arm and shoulder in violin playing.

Despite a large number of available ergonomic aids and recommendations regarding instrument positioning, violin players at any proficiency level still display a worrying incidence of task-specific complaints of incompletely understood etiology. Compensatory movement patterns of the left upper extremity form an integral part of violin playing. They are highly variable between players but remain understudied despite their relevance for task-specific health problems. This study investigated individual position effects of the instrument and pre-existing biomechanical factors likely determining the degree of typical compensatory movements in the left upper extremity: (1) left elbow/upper arm adduction ("Reference Angle α", deviation from the vertical axis), (2) shoulder elevation ("Coord x", in mm), and (3) shoulder protraction ("Coord y", in mm). In a group of healthy music students (N = 30, 15 m, 15 f, mean age = 22.5, SD = 2.6), "Reference Angle α" was measured by 3D motion capture analysis. "Coord x" and "Coord y" were assessed and ranked by a synchronized 2D HD video monitoring while performing a pre-defined 16-s tune under laboratory conditions. These three primary outcome variables were compared between four typical, standardized violin positions varying by their sideward orientation ("LatAx-CSP") and/or inclination ("LoAx-HP") by 30°, as well as the players' usual playing position. Selected biomechanical hand parameter data were analyzed as co-factors according to Wagner's Biomechanical Hand Measurement (BHM). Mean "Reference Angle α" decreased significantly from 24.84 ± 2.67 to 18.61 ± 3.12° (p < 0.001), "Coord x" from 22.54 ± 7.417 to 4.75 ± 3.488 mm (p < 0.001), and "Coord y" from 5.66 ± 3.287 to 1.94 ± 1.901) mm (p < 0.001) when increasing LatAx-CSP and LoAx-HP by 30°. Concerning the biomechanical co-factors, "Reference Angle α", "Coord y", but not "Coord x", were found to be significantly increased overall, with decreasing passive supination range (r = -0.307, p = <0.001 for "Passive Supination 250 g/16Ncm", and r = -0.194, p = <0.001 for "Coord y"). Compensatory movements were larger during tune sections requiring high positioning of the left hand and when using the small finger. Results may enable to adapt individually suitable instrument positions to minimize strenuous and potentially unhealthy compensation movements of the left upper extremity.

The safety and efficacy of 2 anterior-inferior portals for arthroscopic repair of anterior humeral avulsion of the glenohumeral ligament: cadaveric comparison.

Humeral avulsion of the glenohumeral ligament (HAGL) lesions are associated with shoulder instability. Arthroscopic repair of anterior HAGL lesions typically requires the placement of an anterior-inferior (5-o'clock) portal, with different variations of this portal described. The purpose of this study was to determine the efficacy of described anterior-inferior shoulder arthroscopy portals for arthroscopic anterior HAGL repair, as well as evaluate the safety of these portals with respect to the surrounding neurovascular structures. Additionally, we sought to evaluate the effect of arm adduction vs. standard abduction during anterior-inferior portal creation. HAGL lesions were created and repaired using an all-arthroscopic technique in 12 cadaveric shoulders (matched pairs). Half of the repairs were performed using a standard 5-o'clock portal, whereas the other half of the matched pairs were repaired using a medialized 5-o'clock portal. Repairs were timed, and the number of anchor pullouts was recorded. The shoulders were subsequently dissected to measure the proximity of the portal to the cephalic vein, musculocutaneous nerve, axillary nerve, and lateral cord of the brachial plexus. The average time for HAGL repair was 18.0 ± 4.6 minutes. Repair times using the medial 5-o'clock portal (19.0 ± 3.3 minutes) vs. standard 5-o'clock portal (16.2 ± 5.8 minutes) were not significantly different (P = .37). From abduction to adduction, the cephalic vein distance from the standard 5-o'clock portal increased from 4.1 ± 4.7 mm to 5.2 ± 5.4 mm (P = .02); musculocutaneous nerve distance, from 14.4 ± 9.8 mm to 18.1 ± 10.8 mm (P = .005); axillary nerve distance, from 19.2 ± 9.6 mm to 19.8 ± 9.2 mm (P= .12); and distance of the lateral cord of the brachial plexus, 13.8 ± 6.6 mm to 16.7 ± 6.4 mm (P = .0006). The arm abduction angle significantly affects the distance of the cephalic vein, musculocutaneous nerve, and lateral cord of the brachial plexus from the anterior-inferior portal, regardless of which portal-standard or medial 5-o'clock portal-is chosen. This portal should be created with the arm in adduction. Arthroscopic HAGL repair can be performed safely, although accurate anchor placement remains a challenge. There was no advantage to use of the medial 5-o'clock portal. With a curved guide, the standard 5-o'clock portal allows for reproducible anchor placement and is recommended for anterior HAGL repairs.

The Effect of Gender and Arm Anatomical Position on the Hand Grip Strength and Fatigue Resistance during Sustained Maximal Handgrip Effort.

Background: Handgrip or Grip strength (GS) is a common method used to evaluate muscle strength and affected by different factors, including age, gender, and arm’s positions.Objective: This study aims to investigate the effect of both the gender and arm’s positions on the handgrip strength and the fatigue resistance (FR), which is the time needed for the handgrip strength to drop to 75% (FR75), 50% (FR50), and 25% (FR25) of its maximum strength during sustained maximal handgrip effort.Material and Methods: In this experimental study, 59 male and 41 female participants were asked to grip forcefully on a dynamometer for the longest period. GS and FR75, FR50, and FR25 values were recorded for 7 different arm positions. Factorial ANOVA was used to find the main effect of gender and position and the interaction between them. Sidak and Tukey’s HSD tests were used to find the gender and arm position effects, respectively.Results: The results showed a significant effect for gender and arm position on GS and FR and a significant interaction effect for GS that was significantly higher in males than females for all positions. The gender difference in FR depends on arm’s positions and the level at which the FR was measured. GS was higher when arm adduction with 90 ͦ forward at the elbow as compared to arm abduction with 180 ͦ at the shoulder and 90 ͦ at the elbow.Conclusion: The results confirmed the significant effect of the gender and arm’s positions on the maximal handgrip strength and fatigue resistance during sustained maximal handgrip effort.

The nerve to the levator scapulae muscle as donor in brachial plexus surgery: an anatomical study and case series.

Nerve transfers are commonly used in treating complete injuries of the brachial plexus, but donor nerves are limited and preferentially directed toward the recovery of elbow flexion and shoulder abduction. The aims of this study were to characterize the anatomical parameters for identifying the nerve to the levator scapulae muscle (LSN) in brachial plexus surgery, to evaluate the feasibility of transferring this branch to the suprascapular nerve (SSN) or lateral pectoral nerve (LPN), and to present the results from a surgical series. Supra- and infraclavicular exposure of the brachial plexus was performed on 20 fresh human cadavers in order to measure different anatomical parameters for identification of the LSN. Next, an anatomical and histomorphometric evaluation of the feasibility of transferring this branch to the SSN and LPN was made. Lastly, the effectiveness of the LSN-LPN transfer was evaluated among 10 patients by quantifying their arm adduction strength. The LSN was identified in 95% of the cadaveric specimens. A direct coaptation of the LSN and SSN was possible in 45% of the specimens (n = 9) but not between the LSN and LPN in any of the specimens. Comparison of axonal counts among the three nerves did not show any significant difference. Good results from reinnervation of the major pectoral muscle (Medical Research Council grade ≥ 3) were observed in 70% (n = 7) of the patients who had undergone LSN to LPN transfer. The LSN is consistently identified through a supraclavicular approach to the brachial plexus, and its transfer to supply the functions of the SSN and LPN is anatomically viable. Good results from an LSN-LPN transfer are observed in most patients, even if long nerve grafts need to be used.

Arm mobilization provokes deformity of long-term indwelling ports implanted via the jugular vein

BackgroundThe incidence of totally implantable catheter fracture ranges from 0.48% to 5.00%, and these fractures represent a potentially fatal complication. The fracture mechanism of catheters implanted via the jugular vein is unclear, and whether extreme arm movements represent an additional risk factor for repetitive stress of the material remains unknown. The aim of this study was to demonstrate and classify catheter deformations caused by extreme arm mobilization and associations with changes in catheter function and displacement. MethodsWe analyzed the fluoroscopy images of 60 consecutive patients undergoing long-term indwelling port implantation via the jugular vein. Three images were taken: arm in maximal abduction, maximal frontal elevation, and maximal adduction. The images were compared with an image of the remainder of the arm. We analyzed three catheter regions to classify the deformity: A, connection between catheter and reservoir; B, the catheter's subcutaneous tunnel; and C, the catheter's entrance in the jugular vein. The deformations were classified in comparative manner as follows: 0 (no changes), 1 (minor changes, new slightly curvatures with an angle of >90°), and 2 (major changes, new severe curvatures with angles of ≤90°). In each position, catheter function (injection and aspiration) and displacement of the reservoir and tip were analyzed. ResultsOnly 15% of patients did not show a deformity; 33.3% had a deformity in only one position, 47.7% in two positions, and 10% in three positions. Minor deformities were observed in 70% of patients and major deformities in 40%. Moreover, 25% of patients presented both major and minor deformities. Major deformities were observed in 25.0% of patients on maximal frontal elevation, in 23.3% on maximal adduction and in none on maximal abduction. Region B was the most affected, with 57.8% of all minor deformities and 78.1% of all major deformities. No change in function was noted in 91.7% of the catheters. Maximal arm adduction resulted in greater vertical and horizontal displacement of the catheter tip and horizontal displacement of the reservoir. Higher body mass index values were associated with major deformities. ConclusionsMaximal frontal elevation and maximal adduction were associated with major catheter deformities, and the subcutaneous tunnel region was the most deformed catheter region. An association between major catheter deformity and high body mass index was noted; in contrast, no association between the severity of catheter deformity, tip or reservoir displacement, or worsened functioning was observed.

Human Gait Indicators of Carrying a Concealed Firearm : A Skeletal Tracking and Data Mining Approach

There has been an increase in crimes involving illegal firearms in the last couple of years. Previous studies have found that most illegal firearms are carried in a concealed manner. The detection therefore of persons carrying concealed firearms is critical in maintaining security especially in public places. Literature indicates that disruption in gait is a major indicator used by security personnel to detect persons carrying concealed firearms especially those tucked on the hip. However, the specific gait parameters that are indicative have not yet been quantitatively determined. The purpose of this study therefore is to analyze the gait of persons carrying a concealed firearm tucked on the right hip and to quantitatively determine the gait characteristics associated with carrying the firearm. A simulation of persons walking while carrying a concealed firearm and when unarmed was recorded using Kinect V2 depth camera. The depth camera provided 3D spatial skeletal joint position features of tracked joints for the armed and unarmed scenario. Paired t-tests were conducted to compare these features. Further, the results of the t-tests were related to the anatomical planes of Motion. Results showed that persons carrying a firearm demonstrated disrupted gait characterized by right arm abduction, left arm adduction, right leg adduction and extension. These findings extend existing gait indicators which can be employed by security personnel to identify persons carrying concealed firearms.

A Collapse that Led to Shoulder Pain

HISTORY: A 55 year old female presents for right shoulder pain. She has a history of multiple sclerosis, recent falls complicated by a right 6th rib fracture and a right 4th phalanx fracture, a 35 pack year history of tobacco use, and an unknown fracture of her right shoulder sustained at age 16. Her current shoulder pain began four weeks prior to her visit while reaching behind her back in the shower. She felt like her shoulder popped out of place. She has achy pain, worse when touching her shoulder or using her walker. It improves with lying down and with a sling. Acetaminophen and ibuprofen do not provide relief. Physical therapy as part of her multiple sclerosis treatment has not helped. PHYSICAL EXAMINATION: BP: 122/82, Pulse: 69, Respirations: 16, SpO2: 96%. Shoulder: - No gross abnormality, no step-offs along the clavicle. - Tender over the entire humeral head and anterior shoulder. - No swelling, warmth, or erythema. - ROM: o Right flexion 85 degrees active, 95 degrees passive. o Right abduction 90 degrees active, 100 degrees passive. o Adduction, internal rotation, external rotation and extension were full and equal bilaterally. - 5/5 strength - Special tests: positive empty can, Hawkin’s, O’Brien’s, and Speed’s test. Negative crossed arm adduction, AC compression, and sulcus sign. Unable to perform Neer’s test due to pain. DIFFERENTIAL DIAGNOSIS: Torn rotator cuff Glenohumeral arthritis Humeral head fracture as part of Osteogenesis Imperfecta Avascular necrosis AC joint arthritis Shoulder dislocation/subluxation Elder Abuse TEST AND RESULTS: Shoulder 3 view XR: - Extensive posttraumatic deformity of proximal right humerus with marked irregularity of articular surface. - Possible non-displaced superimposed acute or subacute fracture - Slightly displaced posterolateral right 4th and 5th rib fractures Shoulder MRI: - Marked abnormality of the right humeral head with contour deformity - Progressive collapse of superior articular surface, with focal marrow edema. This may be posttraumatic or relate to avascular necrosis - No rotator cuff tear. FINAL WORKING DIAGNOSIS: Avascular necrosis of the humeral head TREATMENT AND OUTCOMES: - Placed in arm sling for pain control - Referred for surgical replacement of the humeral head - Referred for workup for osteogenesis imperfecta, given multiple fractures

Posterior Shoulder Pain in a High School Football Lineman

HISTORY: 16yo high school football lineman presented with right shoulder pain. He initially noticed moderate pain after squatting 350lbs and placing the weight back down. The pain was sharp and painful when turning his head to the left. He was evaluated at an urgent care facility and felt to have a muscular injury and placed on muscle relaxants and anti-inflammatories. His pain improved transiently. He then re-injured this area when he was in gym class running hurtles and brought his arms across his chest in the front of him. He states that he heard a pop in his shoulder and had excruciating pain, and presented to the sports medicine clinic for further evaluation. The pain was pleuritic and still localized to the posterior shoulder. PHYSICAL EXAMINATION: BMI 33.5RR 17O2 Sat 99% He appeared moderately uncomfortable. He had full motion at the neck with no tenderness of the cervical spine. Bending to the left was mildly painful. He had a negative Spurling’s maneuver. He had tenderness over the medial rhomboids, trapezius, and overlying the scapular body. He had no scapular winging. He had full range of motion at the shoulder and 5/5 rotator cuff strength. He had no AC tenderness or pain with cross arm adduction. His lung fields were clear to auscultation with good air movement throughout. DIFFERENTIAL DIAGNOSIS: 1. Strain or partial tear of scapular stabilizer 2. Snapping Scapula (scapulothoracic bursitis) 3. First Rib Fracture TEST AND RESULTS: Three views of the right shoulder (AP, scapular Y, and lateral axillary) -Nondisplaced, oblique fracture through mid-portion of the first right rib Two views of clavicles (AP and 15 degree cephalic) -Fracture confirmed; no pneumothorax is visualized FINAL WORKING DIAGNOSIS: 1st Rib Stress Fracture secondary to scalene and serratus anterior contraction TREATMENT AND OUTCOMES: 1. Patient was placed in sling and provided with narcotic analgesia; pendulum exercises were emphasized. 2. At three weeks, repeat XR showed minimal displacement of the fracture. His sling was discontinued and he was allowed to start back light weight training (30lbs max). Physical therapy was ordered. 3. At 7 weeks, he was pain free with normal strength and allowed to resume normal weight lifting. 4. At 3 month follow up, repeat XR showed some callus formation. He was allowed to resume contact sports, such as football.

Palpation Versus Ultrasound-Guided Acromioclavicular Joint Intra-articular Corticosteroid Injections: A Retrospective Comparative Clinical Study

Background: Primary osteoarthritis (OA) is the most common cause of pain arising from the acromioclavicular (AC) joint. The true incidence is unknown because of differences in the criteria used to define arthritis in various studies. The proper diagnosis of AC joint OA requires a thorough physical examination, radiographic findings, and a diagnostic local anesthetic injection. Objective: The goal of this study was to assess the effects and safety of ultrasound (US) versus palpation-guided acromioclavicular (AC) joint intra-articular (IA) corticosteroid injection for patients with osteoarthritis (OA) of the AC joint. Study Design: Retrospective, compared clinical study. Setting: University hospital outpatient pain clinic. Method: We retrospectively reviewed the charts of patients with AC joint degenerative OA who had undergone US or palpation-guided AC joint IA corticosteroid injection between January 2012 and December 2013 at our outpatient clinic. One hundred consecutive patients identified from chart review met inclusion criteria. Patients (N = 50) in US guide AC joint IA steroid injection group were administered a mixture of 0.5% lidocaine (1 mL) with triamcinolone (20 mg/mL; 0.5 mL) and radiographic contrast material (0.5 mL) and patients (N = 50) in palpation-guided AC joint IA steroid injection group were administered a mixture of 0.5% lidocaine (1 mL) with triamcinolone (20 mg/mL; 0.5 mL) and 0.5 mL of radiographic contrast material. Results were measured using the Shoulder Pain and Disability Index (SPADI), Verbal Numeric pain Scale (VNS) at rest (VNSar), under local pressure (VNSlp) ,and the arm adduction test (VNSaat) at the joint space area before injections and at one, 3, and 6 months after the injections. Successful treatment occurred when patients obtained significant pain relief (as measured by &gt; 50% improvement in the VNS score and 20 point improvement in the SPADI) at one, 3, and 6 months after the injections. Univariable analysis was performed to evaluate the relationship between possible outcome predictors and therapeutic effect by using a chi-square test. Logistic regression analysis was performed to assess whether injection method, injection accuracy, patients’ age, gender, and duration of the disease were independent predictors of successful outcome. Results: SPADI, VNSaat, VNSlp, and VNSar improved at one, 3, and 6 months after the injections in both groups. There was a statistically significantly greater improvement in the VNSlp score and SPDAI at 6 months and in the VNSaat score at 3 months and 6 months for US-guided group as compared with the palpation group. Successful treatment is defined as significant differences found between the groups or from the 3-month to 6-month outcomes. Multiple logistic regression and univariable analysis showed that the significant outcome predictors at 6-month follow-up was the injection accuracy. Limitations: Limitations include the retrospective nature of the study, lack of evaluation of longterm effects , most of the injections were performed in patients with a BMI of less than 30 kg/m2, and the treatment procedures were conducted by the same physician. Conclusion: US-guided AC joint IA injection for the treatment of symptomatic AC joint OA resulted in better pain and functional status improvement than palpation-guided IA injection at the 6-month follow-up. Key Words: Ultrasound, injection, acromioclavicular joint, steroid

Axillary Pain in a Collegiate Rower

HISTORY: A 19 year old right-handed NCAA Division I rower with history of migraines, anxiety, and depression presented with one year of progressively worsening right axillary pain and swelling. The pain was described as aching with episodic sharp, stabbing and pulsating pain. Symptoms were worst in the morning and exacerbated by rowing, working out and arm adduction, and alleviated by rest. Minimal relief with Motrin. Denied neck pain, numbness, tingling, arm swelling, or dizziness. PHYSICAL EXAMINATION: R Upper Extremity: Mildly tender 5 x 8 cm collection of scattered, soft, bluish spider-like vessels on volar surface of arm, adjacent to the axilla. No increased signal on Doppler, no edema, bruits, or lymphadenopathy. Radial pulses 2+. Shoulder with full motion and strength. HEENT, cardiac, respiratory, skin, and neuro exams were normal. DIFFERENTIAL DIAGNOSIS: 1. Non-involuting congenital hemangioma 2. Venous malformation 3. Arteriovenous malformation 4. Lymphatic malformation 5. Venous thromboembolism TESTS AND RESULTS: CT angiogram, R Upper Extremity — 11 x 3 x 4.3 cm subcutaneous fat-containing mass superficial to the brachial veins MRI angiogram, R Upper Extremity — Area of increased vascularity (8.9 x 1.7 cm in axial plane, 5.5 x 2.1 cm in coronal plane) draining into at least one branch of the R brachial vein — No evidence of AV shunting, intramuscular, or intraosseous involvement FINAL/WORKING DIAGNOSIS: Venous malformation TREATMENT AND OUTCOMES: 1. Underwent IR-guided embolization with sclerosing agent 2. Initially reported improvement, but by 6 wks, had recurrent/worsening pain in axilla 3. Repeat MRI angiogram at 12 wks with evidence of sclerosing agent and thrombus occlusion in the mid-portion of the malformation, but no change in size 4. Underwent surgical excision — 8 x 10 cm multiloculated lesion with numerous feeding vessels was excised — Pathology consistent with venous malformation 5. Superficial wound dehiscence 2 wks post-op, requiring healing by secondary intent 6. Stationary bike started 3 wks post-op 7. Unable to tolerate elliptical at 6 wks post-op due to axillary pain 8. Wound fully healed, with hypertrophic scarring, at 12 wks; referred to OT for scar mobilization 9. Ultimately unable to return to sport due to persistent discomfort and exacerbation of chronic depression and anxiety

Osteomyelitis with a twist: Streptococcus pneumoniae causing sternoclavicular septic arthritis.

CASE PRESENTATION An 80-year-old woman of Caribbean descent with a history of type 2 diabetes mellitus, gout, osteoarthritis, gastrointestinal reflux and atrial fibrillation, presented with a 12 h history of left-sided shoulder, neck and back pain. Her temperature was 38.0°C and her white blood cell count was 15×109 cells/L. She experienced tenderness in the left sternoclavicular and sternomanubrial regions associated with warmth and erythema, but without an effusion. Her neck range of motion was restricted by pain on the left side, including neck deviation to the right, which was compatible with torticollis. She could not abduct her shoulder beyond 60 degrees. She had a III/VI systolic ejection murmur at the left upper sternal border, but no stigmata of infectious endocarditis. Her gastrointestinal, dermatological and respiratory examinations were within normal limits. On admission, she was empirically started on ceftriaxone for suspected shoulder joint septic arthritis. An unsuccessful attempt was made to aspirate the left shoulder joint. The pain progressed toward her anterior chest wall and within 72 h C-reactive protein levels had increased from 11 mg/L to 240 mg/L. Blood cultures were positive in three of three sets for penicillin-susceptible Streptococcus pneumoniae. Aspiration of the sternoclavicular joint (SCJ) was unsuccessful. Transesophageal echocardiography did not reveal evidence of endocarditis. The chest radiograph did not reveal evidence of pneumonia. Despite prolonged antibiotic therapy, the patient never experienced full recovery of function, primarily with respect to arm adduction, which was limited by pain at the SCJ. Repeat computed tomography (CT) scan after therapy revealed arthritic changes related to her treated infection. Avoidance of pain led to the patient’s torticollis, which was the most distressing clinical feature for her. This persisted for months despite regular physiotherapy sessions.

The control of twisting somersaults

In the takeoff and early flight phase of a twisting somersault, joint coordination is based on feed-forward control whereas in the late stages of the flight phase configuration adjustments are made using feedback control to ensure accurate completion of the movement and appropriate landing orientation. The aim of this study was to use a computer simulation model of aerial movement to investigate the extent to which arm and hip movements can control twist and somersault rotation in the flight phase of a twisting somersault. Two mechanisms were considered for the control of twist in simulated target trampoline movements with flight times of 1.4s. In the first case a single symmetrical arm adduction correction was made using delayed feedback control based on the difference between the twist rate in a perturbed simulation and the twist rate in a target movement comprising a forward somersault with 1½ twists. Final corrections were made using symmetrical arm abduction and hip flexion to adjust the twist and somersault angles. In the second case continual asymmetrical arm adduction/abduction adjustments were used to remove the tilt from a perturbed full twisting backward somersault using delayed feedback control based on twist angle and angular velocity. The first method was able to cope with perturbations to a forward somersault with 1½ twists providing the feedback time delay was less than 200ms. The second method was able to correct a perturbed full twisting backward somersault providing the feedback time delay was less than 125ms.

Three-dimensional shoulder kinematics after total claviculectomy: A biomechanical investigation of a single case

Since total claviculectomy is an uncommon surgical procedure, few case reports exist in the literature. This report describes the three-dimensional scapulothoracic kinematics in a subject with unilateral total claviculectomy. Kinematic data were collected during shoulder protraction with arms at the side of the body, horizontal arm adduction at 90° of elevation, humeral internal/external rotation with the arm at 90° of elevation in the frontal plane, and elevation and lowering of the arm in the sagittal plane. Descriptive data were compared to the subject's contralateral shoulder. Scapulohumeral rhythm during arm elevation in the sagittal plane was calculated for both sides. Overall the subject demonstrated excessive scapular mobility. However, kinematics during elevation were similar to the contralateral side during elevation. The subject demonstrates good muscle control despite the lack of normal sternoclavicular and acromioclavicular joint articulations. His relatively well-preserved shoulder biomechanics belied his ongoing symptoms, especially involving pain with activities that required use of the arm away from the side.

Being ambulatory does not secure respiratory functions of Duchenne patients

Aim:The aim of this work was to assess the respiratory functions of ambulatory Duchenne patients and to propose an earlier time period for intervention.Materials and Methods:Lung functions and North Star Ambulatory Assessment (NSAA) scores of Duchenne patients were evaluated simultaneously.Results:Thirty ambulatory Duchenne patients were included in this study. NSAA scores of the patients were directly correlated with arm abduction, arm adduction, and shoulder flexion strengths. Forced expiratory volume in 1 second percent predicted and forced vital capacity (FVC) percent predicted correlated inversely to age and to the NSAA score. Twelve of 13 patients with FVC values lower than 80% of predicted had NSAA scores below 24 points. None of the patients who were younger than 7 years had FVC values lower than 80% of predicted.Conclusion:Annual spirometry is necessary for Duchenne patients older than 6 years regardless of the ambulatory status.

A Biomechanical Assessment of Isometric Handgrip Force and Fatigue at Different Anatomical Positions

The present work examined the handgrip force at different anatomical positions for both hands. Anthropometrics, handgrip force, and fatigue were obtained from a representative sample of 20 males randomly selected from the German Jordanian University students. The hand dynamometer first was calibrated with respect to the volunteer's maximal grip strength, and he was then asked to squeeze maximally until the grip force decreased to 50% of its maximal due to fatigue; this test was performed for both hands at different anatomical positions with 2 min of rest for recovery of muscle function. The results showed differences in the handgrip force between subjects of the same anatomical positions and for the different anatomical positions, differences in the time for 50% of the force maximal for both right hand and left hand, higher time required to achieve 50% of maximal handgrip force for the nondominant hand, and maximal handgrip force was obtained when arm adduction with 90 degrees forward at the elbow joint. Recommendations for future work are to measure fatigue time at different percentages, 25%, 50%, 60%, and 75% of maximal force and to investigate the factors affecting handgrip force over a larger sample.

Rupture of the Latissimus Dorsi Muscle in a Tennis Player

Spontaneous rupture of the latissimus dorsi muscle is a rare injury, and few reported cases were avulsion injuries at their humeral insertion. Seven cases of spontaneous rupture of the latissimus dorsi muscle have been reported, but only 1 occurred at the myotendinous junction. The mechanism of this injury is reported to be forceful resisted arm adduction or extension, and reported injuries were rock climbing and attempting to pull up on an overhead handhold, waterskiing injury during pull-up with ski rope, overuse in golf in the leading arm, and abduction-external rotation with horizontally extended arm during a professional steer wrestling performance. The latissimus dorsi muscle is not a critical muscle for activities of daily living; however, the significance of the muscle is increased in professional or elite athletes. This article presents a case of rupture of the latissimus dorsi muscle at the myotendinous junction that occurred during a sports activity.

Recipient Vessel Exposure in the Axilla during Microvascular Breast Reconstruction

Over the years, the favored recipient vessels for microvascular breast reconstruction have changed from the thoracodorsal to the internal mammary vessels, mainly due to the deep position and poor exposure of the vessels in the axilla and all the technical difficulties this reflects. We used the simple maneuver of arm adduction during microvascular anastomoses in the axilla and compared it with the conventional method of abducted arm regarding the exposure of the vessels, the position of the operator and the assistant, and the operative time. We found that this innovation considerably improved the exposure of the vessels and the operator's position, facilitating easier and faster anastomoses.

Traumatic rupture of the sternal origin of pectoralis major in a female patient

We present the case of a 34-year-old lady who sufferedavulsion of the sternal origin of her left pectoralis majormuscle, secondary to blunt chest trauma. As far as we areaware, such an injury is yet to be reported, and certainly notin a female patient, through this type of insult.Our patient was the passenger in a motor vehicle and waswearing a seat-belt at the time of a head-on impact in a roadtrafficaccident.Shesustainedseat-beltbruisingbutnootherinjuries. Chest X-rayand sternal X-rays werealsoclear.Someweeks later, she continued to complain of left anterior chestdiscomfort when using her left arm, accompanied by abnor-mal breast movement. By the time of her consultation withus, her chest discomfort had resolved and no loss of armfunction was reported. Examination showed normal contourof her chest wall at rest. However, on arm adduction, retrac-tion of the medial breast with asymmetric widening of thecleavage could be seen. The pectoralis muscle could be felttoretract awayfromtheleft sternal edgewith theclavicularheadremainingintact.Theresidualaestheticoutcomeoftheinjurywasawideningoftheinter-mammarysulcusonadduc-tion of the arm on the affected side (see Fig. 1a and b).

Isometric torque of arm abduction and adduction muscles in men

Isometric torque of arm abduction and adduction muscles in men