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Background and purpose — Shoulder function may be changed after healing of a nonoperatively treated clavicular fracture, especially in cases of clavicular shortening or mal-union. We investigated scapular orientations and functional outcome in healed clavicular fractures with and without clavicular shortening. Patients and methods — 32 participants with a healed nonoperatively treated midshaft clavicular fracture were investigated. Motions of the thorax, arm, and shoulder were recorded by standardized electromagnetic 3D motion tracking. The DASH score and Constant-Murley score were used to evaluate functional outcome. Orientation of the scapula and humerus at rest and during standardized tasks, and strength and function of the affected shoulders were compared with corresponding values for the uninjured contralateral shoulders. Results — Mean clavicular shortening was 25 mm (SD 16). Scapula protraction had increased by mean 4.4° in rest position in the affected shoulders. During abduction, slightly more protraction, slightly more lateral rotation, and slightly less backward tilt was found for the affected shoulders. For anteflexion, the scapular orientations of the affected shoulders also showed slightly increased protraction, slightly increased lateral rotation, and slightly reduced backward tilt. Scapulohumeral kinematics, maximum humerus angles, and strength were not associated with the degree of clavicular shortening. All participants had excellent performance on the Constant-Murley score and DASH score. Interpretation — Scapulohumeral kinematics in shoulders with a healed clavicular fracture differ from those in uninjured shoulders, but these changes are small, do not result in clinically relevant changes in outcome, and do not relate to the amount of clavicular shortening. These findings do not support routine operative reduction and fixation of shortened midshaft clavicular fractures based on the argument of functional outcome. [ABSTRACT FROM AUTHOR]

Introduction: Tonic experimentally induced shoulder pain alters the activation of periscapular muscles1. However, tonic pain may not entirely reproduce the symptoms experienced by people with painful shoulder conditions2 since they commonly report an increase of symptoms during movement. In this study we adopted a novel experimental pain model3 to investigate motor control adaptations of the scapular muscles during movement-evoked pain. Methods: Fifteen healthy participants performed a repeated box-lifting task for twelve sets. Pain was induced over the posterior acromion using electrical stimulation, modulated to induce a pain intensity of 4/10 when the activity of the anterior deltoid was equal or higher than the peak activity measured at baseline, and of 1/10 when lower than 80%. Muscle activity from the Upper (UT), Middle (MT) and Lower (LT) divisions of the Trapezius, and elevation of the scapula, were compared between baseline (sets 1-2), early-and late adaptation (respectively sets 3-4 and 11-12) using a Friedman test and post-hoc comparisons. Results: Early adaptation was characterised by lower scapular elevation (p = 0.002) and decreased activation of the UT (p = 0.006). In the late adaptation phase, participants exhibited lower scapular elevation (p = 0.032), decreased MT activation (p = 0.032) and increased LT activation (p = 0.006). Discussion: Movement-evoked pain results in lower scapular elevation, and different muscle strategies may be responsible for the changes in scapular kinematics in the early-and late-adaptation phase. Those results may provide new insights about motor adaptations and motor control in clinical condition. Process evaluation: Stimulation artifacts in the EMG were removed by filtering. [ABSTRACT FROM AUTHOR]

Introduction: Individuals with shoulder pain commonly present changes in scapular movement and pathoanatomic alterations in the rotator cuff tendons. However, these may not be the main contributors or source of pain in the shoulder. This study compared scapular kinematics and the frequency of pathoanatomic findings across both shoulders of individuals with unilateral shoulder symptoms. Methods: One-hundred and twelve patients (38.1 ± 14.2 years) with unilateral shoulder pain completed the study. Three-dimensional scapular kinematics was measured during arm elevation. The presence of tendinopathy and partial tear of the supraspinatus and infraspinatus was evaluated using magnetic resonance imaging (MRI). A two-way ANOVA (side x angle of arm elevation) was conducted for each scapular rotation. Chi-square tests were used to compare MRI findings. A p-value <0.05 was considered significant. Results: The interactions and main effect of side for scapular internal rotation (mean difference; 95% confidence interval: 0.5°; -0.4°, 1.6°), upward rotation (-0.8°; -1.8°, 0.1°) and posterior tilt (0.3°; -0.6°,1.2°). Supraspinatus tendinopathy (~68%), infraspinatus tendinopathy (~7%), partial tear in the supraspinatus (~17%) and infraspinatus (~5%) tendons were equally present in both shoulders (p > 0.05). Discussion: Scapular movement and pathoanatomic abnormalities in the rotator cuff are similar across shoulders of individuals with unilateral shoulder pain. Process evaluation: Psychosocial aspects should be investigated to help decision-making in the management of patients with shoulder pain. [ABSTRACT FROM AUTHOR]

Three-dimensional finite element analysis is one of the best ways to assess stress and strain distributions in complex bone structures. However, accuracy in the results may be achieved only when accurate input information is given. A semi-automated method to generate a finite element (FE) model using data retrieved from computed tomography (CT) was developed. Due to its complex and irregular shape, the glenoid part of a left embalmed scapula bone was chosen as working material. CT data were retrieved using a standard clinical CT scanner (Siemens Somatom Plus 2, Siemens AG, Germany). This was done to produce a method that could later be utilized to generate a patient-specific FE model. Different methods of converting Hounsfield unit (HU) values to apparent densities and subsequently to Young's moduli were tested. All the models obtained were loaded using three-dimensional loading conditions taken from literature, corresponding to an arm abduction of 90 degrees. Additional models with different amounts of elements were generated to verify convergence. Direct comparison between the models showed that the best method to convert HU values directly to apparent densities was to use different equations for cancellous and cortical bone. In this study, a reliable method of determining both geometrical data and bone properties from patient CT scans for the semi-automated generation of an FE model is presented. [ABSTRACT FROM AUTHOR]

Extrapolating the figures from a previous study on FSHD in a province of The Netherlands to the entire Dutch population suggests that at present a nearly complete overview is obtained of all symptomatic kindred. In 139 families, dominant inheritance was observed in 97, a pattern compatible with germline mosaicism in 6, while sporadic cases were found in 36 families. A mutation frequency of 9.6% was calculated. Mental retardation and severe retinal vasculopathy were reported in low frequencies (1%). Early onset was seen more frequently in sporadic cases. Chromosome 4 linkage appeared excluded in 3 of 22 autosomal-dominant families. The clinical pictures in the linked and nonlinked families were identical.

The working career of 138 adult patients with autosomal dominant facioscapulohumeral muscular dystrophy (FSHD) was studied using a mailing questionnaire. Of 126 patients with an occupational history, the average female and male working career was 15 to 30 years, respectively. Of 61 respondents actually holding a job, only nine had adjustments for disease-related handicaps. Reaching above and below shoulder level was required in 24 jobs, although shoulder weakness is a presenting symptom of FSHD. In spite of these physical problems, 52 patients (85%) labelled their job as satisfying. The duration of their working career and the satisfaction with their work despite frequent physical problems warrant a careful vocational guidance of FSHD patients in order to prevent or postpone unemployment. Similar working career studies in patients with other neuromuscular disorders are worthwhile.