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The purpose of this study was to compare the concurrent validity of four questionnaires in the assessment of outcome after rotator cuff repair. Sixty-two patients, who were at least two years post-rotator-cuff repair, completed three upper extremity scales: the Western Ontario Rotator Cuff (WORC) index, the Disabilities of the Arm, Shoulder and Hand (DASH) and the Simple Shoulder Test (SST), and a measure of general health status (SF-36). Internal and external rotation ranges of motion and isometric strength were measured. Pearson correlations were used to evaluate the construct whereby scores should be related to the severity of measured impairments. One-way ANOVA was used to determine the ability of the questionnaires to discriminate between groups expected to have different outcomes based on measured impairment or worker's compensation status. The upper extremity questionnaires demonstrated similar response distributions and were highly correlated (0.88 < r < 0.91). The response distribution of the SF-36 was different from the other scales and its correlation with them was moderate (0.58 < r < 0.75). The upper extremity measures demonstrated better correlations with measured impairments (0.18 < r < 0.56) than the SF-36 (0 < r < 0.40). All the questionnaires were able to discriminate between levels of impairment and worker's compensation status. This study supported the validity of upper extremity scales to measure cuff-related disability and suggests that the use of both specific and general health measures provides a more comprehensive evaluation of patient outcome.

Anterior translation in the right shoulders of 23 volunteers was evaluated using ultrasound from an anterior approach with a 10 MHz, 6 cm wide linear transducer. A translatory force of 90 N was used to translate the humeral head in the adduction and internal rotation position, while a translatory force of 60 N was used in the more clinically relevant position of 90° abduction and external rotation position. The overall intra-observer coefficients of variation ranged from 0–13.0% (mean 3.8 ± 2.5%) for examiner I and 0.5–20.9% (mean 5.1 ± 3.9%) for examiner II. The overall inter-observer variation ranged from 0–29.8% (mean 9.3 ± 7.3%). The anterior translation of the humeral head in adduction and internal rotation following 90 N displacement force ranged from -2.6 to 12.9 mm (mean 2.1 ± 3.1 mm) for examiner I and from -4.1 to 4.7 mm (mean 1.1 ± 2.2 mm) for examiner II. The anterior translation of the humeral head in abduction and external rotation following 60 N displacement force ranged from -3.3 to 3.7 mm (mean 0.3 ± 1.9 mm) for examiner I and from -8.3 mm to 4.5 mm (mean -0.7 ± 2.6 mm) for examiner II. The intra-class correlation coefficients (r) for the measured anterior translation between the two examiners for the 2 positions were 0.029 and -0.058 respectively. We concluded that the inter-observer coefficient of variation remained excessive and the agreement in the measured anterior translation between the two examiners was poor. The finding of negative values in the measured anterior translation despite the use of 90 N and 60 N translatory force raises further concerns about the prospective clinical use of this technique at the present moment.

Tears of the rotator cuff tendons may occur as a result of tendon degeneration or from a single traumatic event but commonly a combination of these factors are in play. Rotator cuff tendon degeneration and accidental falls are both known to increase in incidence with increasing age. No study to date has sought to investigate the characteristic of accidental falls as a significant cause of injury in the rotator cuff tear population. We developed a 25 multi-step item questionnaire to investigate the source of injury in sixty rotator cuff tear patients. The majority, 32/60 (53.3%), reported a fall associated with their rotator cuff tear. The tears nearly always occurred on the same side as the fall. Most falls resulting in cuff tears were to the side and front rather than backwards. Our findings highlight that falls are the leading cause of injury in the rotator cuff tear patient population and describe characteristics of the previously under-recognized fall-related rotator cuff tear population.

Background and aims: To study possible interrelations of clinical and functional parameters with ultrasonographic findings of shoulders of hemiplegic stroke patients. This would assist in determining the need for a possible ultrasound evaluation of hemiplegic shoulders. Methods: Prospective case series were studied in the Department of Geriatric Medicine and Rehabilitation, at a university-affiliated referral hospital. We studied a total of 26 consecutive stroke patients with hemiplegic shoulders undergoing a standard rehabilitation course. Hemiplegic shoulders were studied by ultrasound and scored for the number of pathological (positive) findings. Shoulder scores were correlated with various clinical and functional parameters (Ashworth score, Fugl-Meyer score, Functional Independence Measure) as non-dependent variables. Results: No correlation was found between any of the parameters we have studied and the ultrasonographic score, except for shoulder pain (p = 0.012). A regression analysis documented painful shoulder (p = 0.002) and spasticity (p = 0.039) as significantly associated with higher ultrasonographic scores. Conclusions: Ultrasound investigation of hemiplegic upper extremities does not interrelate with any of the parameters associated with rehabilitation outcome and should be reserved for those suffering painful and spastic hemiplegic shoulders.

The collection of outcomes data is critical for conducting clinical studies in orthopaedic surgery. Both subjective outcome data [e.g. Short Form-12 (SF-12) and Western Ontario Rotator Cuff (WORC) index] and objective data (e.g. range of motion) are necessary. Numerous studies have been conducted on the collection of patient survey data through electronic means (e.g. personal digital assistant and tablet PC), but none of these studies have made use of a device with an intuitive touch-screen interface. Studies have also been conducted on the collection of physical examination data through research-grade accelerometers but few have focused on the use of commercially available electronic devices. The goal of our project was to develop a mobile computing touch-screen system for capturing subjective and objective outcome data for the assessment of patients with rotator cuff tears. We were able to accomplish this goal through the development of a novel iPad/iPod Touch tool. Intra-rater and inter-rater reliability of shoulder flexion and external rotation measurements were good.

Congenital absence of the long head of biceps tendon (LHBT) is a very rare entity. With its debatable role in shoulder stability, the literature provides few reports of absent LHBT and its association with shoulder instability or pain. Reports of instability are associated with labral tear or attenuation of glenohumeral ligaments. We are first time reporting a case of congenital absence of the LHBT and associated bony Bankart’s lesion and posterior labral tear.

Purpose: The knowledge of the normal geometrical characteristics of the proximal humerus is crucial to the success of its arthroplasty. This important information, is however, limited for the South African population. Therefore, this study investigates the three-dimensional morphometric parameters, specifically examining the intra-ancestral differences within the South African population. Methods: With the aid of geometry extraction techniques, various morphometric characteristics were measured on South African cadaveric humeri originating from three ethnicities including whites, blacks, and mixed in the ratio 1:2:4. Results: There is a significant mean difference in humeral head diameter between blacks and whites and between mixed and whites with a mean difference of $-$4.86, 95% CI ($-9.40$, $-0.32$) and $-4.50$, 95% CI ($-8.56$, $-0.44$), respectively. Similarly, for articular surface diameter, a significant mean difference of $-4.58$, 95% CI ($-9.10$, $-0.0646$) and $-4.32$, 95% CI ($-8.36$, $-0.2854$) were recorded between blacks and whites and between mixed and whites, respectively. Conclusion: The outcome of our study showed that the shape of the South African proximal humerus varies distinctively within the different ethnicities that were measured. The findings from this study may provide the data required to design and develop a new shoulder implant appropriate for South African patients.

Background: Surgical techniques for resection of tumors at proximal humerus and scapula has been described in literature along with different classification systems, however, these techniques have not been revised for a while and the classification systems which are currently in use neither respect the difference between bone and soft tissue tumors nor the anatomical location humeral vs scapular. Material and Methods: The author operated on 32 patients with shoulder girdle tumors, all are bone tumors, Ewings sarcoma ($n=14$), Osteosarcoma ($n=6$), Metastatic tumors ($n=6$), GCT ($n=3$), Chondrosarcoma ($n=3$). We assigned two separate classifications to humerus and scapula resection, since surgical approaches, techniques, and reconstruction options are totally different for the both sites. Resection of the humerus is classified into: Type I to Type IV, A: is added to the type when the majority of Deltoid is preserved, and B: when it is sacrificed. And we classify the scapula resection into: Type I to Type III, A: is added to the type when the majority of Deltoid is preserved, and B: when it is sacrificed. In extra articular humerus resection, we found that sacrificing the acromion and coracoid process is not necessary as part of routine resection. Preservation of these structures can improve the cosmetic appearance of the shoulder with at least equal functional outcome. Endoprosthesis was used in 26 patients for reconstruction, osteoarticular allograft was used in 2 patients, and Tichoff Lindberg technique for 4 patients. Results: At 30 month mean follow up period, 2 patients developed local recurrence (osteosarcoma $n=1$, Ewing Sarcoma $n=1$), 2 patients had wound infection, and one patient developed stem loosening. The average MSTS functional score for all patients was 83%. Conclusion: The modification of surgical techniques saved structures which were unnecessarily resected, and kept the integrity of muscles and their attachments which were sacrificed in previously described techniques. This might lead to fewer restrictions during the rehabilitation process and resulted in preservation of the shoulder contour. The new classification system is realistic, separates the humeral resection from the scapular one, easy to be recalled and applicable to all patients.

Context: Shoulder Impingement Syndrome (SIS) is a common clinical condition in general practice and overhead athletes. Alterations in the scapular position can lead to shoulder impingement syndrome. The effect of exercises on shoulder impingement syndrome is studied but the effect of Kinesiotape is not well explored.

Methods: A total of 42 participants were included in the study. The subjects were assessed for SPADI, pain, proprioception, lateral scapula slide test, and pectoral minor length test at the baseline and the subjects were randomly divided into two groups. The intervention group ($n$ = 18) received scapular taping and scapular exercises and the control group ($n$ = 17) received scapular exercises only. Post-outcome measures were taken at 4 weeks and 12 weeks during the intervention. Repeated measures ANOVA was used for the outcome measures and Bonferroni’s test was used to determine the pairwise comparisons at different measurement levels amongst experimental and control groups.

Results: The study consisted of 17 males and 18 females. There was statistical significance in both groups ($p$ < 0.01) over the 4th and 12th weeks. Pain ($p$ < 0.01) and proprioception ($p$ = 0.017) was also statistically significant between both the groups at 4 weeks.

Conclusion: This study concludes that scapular taping can be used as an adjunct with scapular involvement.

Reduced shoulder endurance in rotator cuff tear patients has been observed clinically. A simple and inexpensive shoulder endurance test protocol was developed. This study reports the test-retest reliability of the protocol. Twenty healthy volunteers without a history of shoulder pathology participated in the study. Each subject was tested twice, each on a separate day. Test-retest correlation coefficients of the arm endurance times were 0.59 and 0.60 for the dominant and nondominant sides, respectively. The protocol appears promising for assessing shoulder function.

Numerical simulations were conducted to validate computational and constitutive models for steel materials through dynamic material tests involving both tension and compression. These simulations involved the numerical modeling of the split Hopkinson pressure bar (SHPB) apparatus, with the appropriate loading applied directly in compression and indirectly in tension. To induce a tensile wave within the specimen, a shoulder, such as a coupler or collar, was interposed between the bars. The simulations were carried out using the LS-DYNA finite element code. In these numerical simulations of the SHPB tests, the MAT-15 Johnson–Cook material model was applied to represent mild steel. The resulting stress–strain relationships obtained under both compression and tension conditions were subsequently compared to corresponding experimental data. The primary objectives of these simulations were to determine the optimal placement of strain gauges on both the input and output bars of the tensile SHPB setup. Additionally, the simulations aimed to assess the influence of the gauge length-to-diameter ratio on the behavior of the mild steel specimen subjected to dynamic tension and compression. The results showed that the pulse produced due to the mechanical mismatch of the element at boundaries can be avoided using the length of the input bar smaller than the output bar. Further, the location of the strain gauge in the case of the output bar should be toward the output bar-shoulder interface, while in the case of the input bar, it should be considered at the center of the span of the bar.

Glenoid failure is one of the major indications for revision in total shoulder arthroplasty. Glenoid components should be carefully designed to improve the reliability of the prostheses, and mechanical testing can be a key tool to compare the performances of different designs. The most relevant guidelines for mechanical testing of glenoid prostheses are included in the ASTM F2028-05 Standard. The Standard refers to glenoid subluxation tests, designed to evaluate the intrinsic stability of the prosthesis system, and to glenoid edge displacement tests, which estimate the risk of micro-motions at the bone-glenoid interface. However, some indications given by the Standard are not mandatory, leaving the possibility to choose some parameters of the testing set-up and procedure. The main goal of this study was to investigate how different testing parameters (i.e. loads, velocities and bone-glenoid conformity) may affect the test results. In order to reach this target an experimental apparatus was developed and mechanical tests were performed on a keeled glenoid. The study showed that the applied load and the bone-glenoid conformity have a significant effect on the tests results, because of bone and glenoid deformation. Contrarily, the testing velocity was not found to be an influencing testing parameter.

Background and aim: Fatigue of internal or external rotators of the glenohumeral may alter proprioception in the shoulder joint. Fatigue of shoulder muscles can affect the three-dimentional kinematics of the scapula, and may also alter the glenohumeral and scapular movement pattern, with changes in the scapulohumeral rhythm. Previous studies have shown that with arm elevation, there is a decreased upward rotation of the scapula as well as reduced posterior tilt and external rotation movements with shoulder rotator cuff muscle fatigue. Our aim is to examine the effect of internal rotator fatigue on the proprioception of glenohumeral and scapular active repositioning. Methods: Twenty young healthy subjects with an average age of 20 years were recruited. Each subject performed repetitive concentric exercise (internal rotation) to induce muscles fatigue, which was confirmed by a muscle strength testing using a hand-held dynamometer. Measurement of active repositioning with glenohumeral and scapula repositioning were examined before and after internal rotator fatigue via the three-dimensional (3D) electromagnetic motion analysis system. Results: Fatigue of internal rotators did not affect the glenohumeral and thoracoscapluar joint proprioception (P > 0.05). Conclusion: The findings showed that fatigue of shoulder internal rotators did not contribute to alteration in glenohumeral and scapular proprioception.

The aim of this study is to quantify the relative contributions of two muscle energy consumption processes (the detachment of cross-bridges and calcium-pumping) incorporated in a recently developed muscle load sharing cost function, namely the energy-based criterion, by using in vivo measured glenohumeral-joint reaction forces (GH-JRFs). Motion data and in vivo GH-JRFs were recorded for four patients carrying an instrumented shoulder implant while performing abduction and forward flexion motions up to their maximum possible arm elevations. Motion data were used as the input to the delft shoulder and elbow model for the estimation of GH-JRFs. The widely used stress as well as the energy-based cost functions were adopted as the load sharing criteria. For the energy-based criterion, simulations were run for a wide range of different weight parameters (determining the relative contribution of the two energy processes) in the neighborhood of the previously assumed parameters for each subject and motion. The model-predicted and in vivo-measured GH-JRFs were compared for all model simulations. Application of the energy-based criterion with new identified parameters resulted in significant (two-tailed p < 0.05, post-hoc power ~ 0.3) improvement (on average ~20%) of the model-predicted GH-JRFs at the maximal arm elevation compared to when using either the stress or the pre-assumed form of the energy-based criterion. About 25% of the total energy consumption was calculated for the calcium-pumping process at maximal muscle activation level when using the new parameters. This value was comparable to the corresponding ones reported in the previous literature. The identified parameters are recommended to be used instead of their predecessors.

The importance of core stabilization exercises for extremities associated with dynamic spinal stabilization prior to movement has been demonstrated. However, no previous studies have investigated the muscle-coordinated effects on the upper trapezius (UT), anterior deltoid (AD), pectoralis major (PM), bilateral transverse abdominis (TrA), bilateral internal oblique (IO), and bilateral external oblique (EO) in healthy adults. The purpose of this study was to compare the effects of the dynamic neuromuscular stabilization (DNS) breathing technique and the abdominal bracing (AB) technique on UT, AD, PM, bilateral IO/TrA, and bilateral EO motor control in healthy participants during horizontal shoulder adduction. Thirty-six participants, eight of whom were female, were randomized into an AB and a DNS group and performed horizontal shoulder adduction with loads (8 and 17 lb). The clinical outcomes were UT, AD, and PM muscle activation and TrA/IO and EO muscle activation. Paired t-tests were used to analyze electromyography (EMG) data to determine statistically significant differences in muscle activity between the two techniques. For the EMG analysis, the maximal voluntary isometric contraction was measured for normalization and then divided by the EMG amplitude value. The results showed that UT, AD, and PM muscle amplitudes were lower and TrA/IO and EO muscle amplitudes were higher with DNS than with AB ($P<0.05$). Our findings provide clinical evidence that core exercise with DNS is more effective in lessening UT, AD, and PM muscle activation and improving bilateral TrA/IO motor control than with AB.

Object: In this paper, eight male basketball players were tested for physical fitness using the method of sports biology. The content of the physical examination is the isokinetic muscle strength of the shoulder joint. This paper aims to investigate the effect of shoulder isokinetic muscle strength on athletic performance. Methods: This paper uses the principles of sports biology and the isokinetic muscle strength test system to measure the shoulder torque and fatigue index of eight basketball players. At the same time, this paper analyzes the obtained data using the method of mathematical statistics. Results: There were significant differences in the test data of eight male basketball players (P < 0.05). The fatigue of basketball players is mainly in the middle and late stages of sports. At average speed, the fatigue index of the shoulder is the lowest at 180°/s. Conclusion: Basketball players have stronger shoulder extensors than flexors. The balance of strength in the shoulder flexors is greater than the balance in the extensors.

This paper describes a design for a humanoid shoulder complex that replicates human shoulder girdle motion. The goal here is to use the minimum number of actuators to keep the mechanism as light as possible to help ensure that a humanoid is not too top heavy. The human shoulder girdle has two degrees-of-freedom (DOF), which means the minimum number of actuators is also two. The proposed mechanism is a novel parallel platform with two DOF that acts as a pointing mechanism. As the mechanism is articulated the end-effector moves, which results in contraction or elongation, mimicking the natural motion of the human shoulder girdle. A parallel platform was chosen because of the inherent rigidity and a large workspace is not necessary. The mechanism presented here was chosen because of its simplicity and ability to track human shoulder girdle motion. Motion studies were conducted to collect data representing human shoulder girdle motion, which was used to optimize the mechanism for tracking human shoulder girdle motion as closely as possible. A second optimization was performed to ensure that the mechanism avoids singularities throughout its entire range of motion. The results show that this design closely replicates human shoulder girdle motion and is well-suited for use as a humanoid shoulder girdle to increase the range of motion for a humanoid arm.

Background: The objective of this study was to determine prognostic factors affecting the clinical outcome of septic arthritis of the shoulder.

Methods: We retrospectively reviewed 34 shoulders from 32 patients, two of which had bilateral involvement. Arthroscopic (22 shoulders) or open surgery (12 shoulders) was performed by a single surgeon. The mean follow-up period was 32.4 ± 17.0 months. Clinical outcomes according to the University of California at Los Angeles (UCLA) score, American Shoulder and Elbow Surgeons (ASES) score, and Subjective Shoulder Value (SSV) were assessed at the final follow-up period. Various factors were included for statistical analysis.

Results: The mean UCLA, ASES scores, and SSV were 28.9 ± 7.2, 81.3 ± 21.0, 79.7 ± 2.5%, respectively. Positive culture was observed in only 13 shoulders (38.2%) and the most common organism was Staphylococcus aureus (seven shoulders). Five shoulders (14.7%) required two or three operations. Age and comorbidity were negatively correlated with the UCLA, ASES score, and/or SSV (p < 0.05). There was no correlation between clinical outcome and various parameters, including gender, location of lesion, history of previous steroid injection, interval between onset of symptoms and surgical intervention, bacterial organisms, operative method, and presence of rotator cuff tear and reoperation (p > 0.05).

Conclusions: Both arthroscopic and open surgery for septic shoulders showed satisfactory clinical outcomes. Old age and comorbidity were poor prognostic factors of clinical outcomes after treatment.

Background: Trapezius transfer has shown promise to restore shoulder movements and has stood through the passage of time. We here in describe a modification of trapezius transfer technique and review the current literature available.

Methods: The modified trapezius transfer in which the trapezius muscle is extended with folded tensor fascia lata graft and attached as distally possible to the deltoid insertion was done in twelve patients at tertiary health care centre in India. Post-operative splinting and staged physiotherapy were given.

Results: Results were described in the form of improvement in degree of shoulder abduction and Disabilities of the Arm, Shoulder and Hand (DASH) score. Six months post-surgery there were improvement in shoulder abduction and DASH score with mean 116 degrees (10–180 degree) and 38 (23–58) respectively. One patient showed poor results due to poor compliance in post-operative period. There were no major complications observed.

Conclusions: The modified technique of trapezius transfer described here is a feasible option with good biomechanical outcomes. The technique is simple and can be adopted easily by emerging brachial plexus surgeon as a technique for secondary reconstruction of shoulder joint.

The objective of this study was to provide a normative database of dynamic upper-extremity (shoulder and elbow) joint strengths to fill the current void in literature for multidimensional strength capacity profiles. The isokinetic strength of the elbow and shoulder joints was tested for twenty normal males and females. The independent variables consisted of joint angular position, joint angular velocity, direction of exertion, and gender. The measured joint strength (torque, Nm) was the only defined dependent variable. The majority of existing joint strength prediction models and normative databases are static (isometric) in nature. The few available dynamic models are reported in the form of torque as a function of joint angle. Since joint strength is a function of both the joint angular position and angular velocity, descriptive models should take this interaction into consideration. The dynamic joint strengths of the subjects were studied using the KIN_COM 125E Plus. A second-order multiple regression analysis was used to model the dynamic 3-D strength surface response of each joint in each direction of exertion. Analysis of variance (ANOVA) with repeated measures design was used to test for the effects of gender, angular position, angular velocity, and direction on the dynamic strength of each joint, joint strength was significantly influenced by dynamic parameters such as the angular velocity. The interaction between angular position and velocity was highly significant. 3-D strength surface representation may be used as a "performance capacity envelope" to comprehensively characterize an individual's dynamic joint strength performance.