Shoulder Function and Bone Mineralization in Children with Obstetric Brachial Plexus Injury After Neuromuscular Electrical Stimulation During Weight-Bearing Exercises.

OBJECTIVE: The purpose of this study was to evaluate the effects of neuromuscular electrical stimulation during weight-bearing exercises on shoulder function and bone mineral density (BMD) in children with obstetric brachial plexus injury (OBPI). DESIGN: This study was a randomized controlled trial. Forty-two children with OBPI were recruited. Their ages ranged from 3 to 5 years. They were randomly assigned either to control group (received a selected program) or study group (received the same program as the control group and neuromuscular electrical stimulation during weight bearing). Mallet grading system and dual-energy x-ray absorptiometry were used to evaluate shoulder function and BMD respectively at entry and after intervention (3 months later). RESULTS: No significant differences of the outcome measures were detected at entry. Significant differences were observed within both groups when the pre and post treatment scores within each group were compared. Finally, significant differences favoring the study group were recorded when their post treatment scores were compared. CONCLUSION: Neuromuscular electrical stimulation during weight bearing exercises is an effective and simple method to improve shoulder function and BMD in children with OBPI.

Anatomical structure and nerve branching pattern of the human infraspinatus muscle.

The function of the infraspinatus muscle, critical to rotator cuff function, is dependent upon the muscle's structure and innervation pattern. The morphology of the infraspinatus muscle has been inconsistently described in the literature. Additionally, the branching pattern of the suprascapular nerve in the infraspinous fossa has not been addressed in the literature. The purposes of this study were to determine: the arrangement of the infraspinatus muscle bellies; the branching patterns of the suprascapular nerve to the infraspinatus muscle; if the infraspinatus muscle was composed the neuromuscular compartments. Forty-eight infraspinatus muscles from 24 embalmed cadavers were studied using standard dissection techniques to determine morphological characteristics and innervation patterns. Results demonstrated that the infraspinatus muscles were comprised of three separate muscular partitions with each partition residing in a thin fascial compartment but all residing deep to the posterior scapular fascia. A first order suprascapular nerve branch was present in 91.6% of superior, 100% of middle, and 70.8% of inferior partitions. A first order nerve was present in all 3 muscular compartments of the same infraspinatus muscle in 62.5% of cases. Second order nerve branches were present in 8.3% of superior, 0% of middle, and 29.2% of inferior partitions. These findings help to determine a more complete and accurate understanding of the structure of the infraspinatus muscle. A better understanding of its structure could lead to a better understanding of the function of the muscle. Such information will enable more effective rehabilitation strategies for injuries involving the infraspinatus component of the rotator cuff.

Why does my shoulder hurt? A review of the neuroanatomical and biochemical basis of shoulder pain.

If a patient asks 'why does my shoulder hurt?' the conversation will quickly turn to scientific theory and sometimes unsubstantiated conjecture. Frequently, the clinician becomes aware of the limits of the scientific basis of their explanation, demonstrating the incompleteness of our understanding of the nature of shoulder pain. This review takes a systematic approach to help answer fundamental questions relating to shoulder pain, with a view to providing insights into future research and novel methods for treating shoulder pain. We shall explore the roles of (1) the peripheral receptors, (2) peripheral pain processing or 'nociception', (3) the spinal cord, (4) the brain, (5) the location of receptors in the shoulder and (6) the neural anatomy of the shoulder. We also consider how these factors might contribute to the variability in the clinical presentation, the diagnosis and the treatment of shoulder pain. In this way we aim to provide an overview of the component parts of the peripheral pain detection system and central pain processing mechanisms in shoulder pain that interact to produce clinical pain.

Active biofeedback changes the spatial distribution of upper trapezius muscle activity during computer work.

The aim of this study was to investigate the spatio-temporal effects of advanced biofeedback by inducing active and passive pauses on the trapezius activity pattern using high-density surface electromyography (HD-EMG). Thirteen healthy male subjects performed computer work with superimposed feedback either eliciting passive (rest) or active (approximately 30% MVC) pauses based on fuzzy logic design and a control session with no feedback. HD-EMG signals of upper trapezius were recorded using a 5 x 13 multichannel electrode grid. From the HD-EMG recordings, two-dimensional maps of root mean square (RMS), relative rest time (RRT) and permuted sample entropy (PeSaEn) were obtained. The centre of gravity (CoG) and entropy of maps were used to quantify changes in the spatial distribution of muscle activity. PeSaEn as a measure of temporal heterogeneity for each channel, decreased over the whole map in response to active pause (P < 0.05) underlining a more homogenous activation pattern. Concomitantly, the CoG of RRT maps moved in caudal direction and the entropy of RMS maps as a measure of spatial heterogeneity over the whole recording grid, increased in response to active pause session compared with control session (no feedback) (P < 0.05). Active pause compared with control resulted in more heterogeneous coordination of trapezius compared with no feedback implying a more uneven spatial distribution of the biomechanical load. The study introduced new aspects in relation to the potential benefit of superimposed muscle contraction in relation to the spatial organization of muscle activity during computer work.

Comparison of the outcomes of two different exercise programs on frozen shoulder.

OBJECTIVES: The aim of the study was to compare the effects of two different exercise programs on pain, range of motion (ROM), and functional results in frozen shoulder. METHODS: Twenty-two female and 7 male patients [mean age 52.1 years (range 38-65 years)] were randomly allocated into two groups: 14 in the first group and 15 in the second group. The patients were treated for 6 weeks (30 sessions) at hospital under the supervision of physical therapist. Both groups were treated with transcutaneous electrical nerve stimulation, cold pack, and nonsteroidal antiinflammatory drugs; and were given glenohumeral ROM exercises. The scapulothoracic exercises were performed only by the second group. Functional results were assessed using the modified Constant score, pain was assessed using visual analog scale (VAS), and ROM was measured with a goniometer. Assessments were performed before treatment and repeated at 6 and 12 weeks of treatment. RESULTS: In both groups, the Constant score and ROM were increased, and VAS was decreased at the end of 6 and 12 weeks. The modified Constant score was not significantly different between the groups before and after treatment. VAS score was better in the second group at 6 weeks (p<0.01). Improvement in ROM was significantly better in the second group at 12 weeks (p=0.005). CONCLUSION: In addition to glenohumeral ROM exercises, scapulothoracic exercises contribute to decreasing pain and increasing ROM in patients with frozen shoulder.

Musculoskeletal model-guided, customizable selection of shoulder and elbow muscles for a C5 SCI neuroprosthesis.

Individuals with C5/C6 spinal cord injury (SCI) have a number of paralyzed muscles in their upper extremities that can be electrically activated in a coordinated manner to restore function. The selection of a practical subset of paralyzed muscles for stimulation depends on the specific condition of the individual, the functions targeted for restoration, and surgical considerations. This paper presents a musculoskeletal model-based approach for optimizing the muscle set used for functional electrical stimulation (FES) of the shoulder and elbow in this population. Experimentally recorded kinematics from able-bodied subjects served as inputs to a musculoskeletal model of the shoulder and elbow, which was modified to reflect the reduced muscle force capacities of an individual with C5 SCI but also the potential of using FES to activate paralyzed muscles. A large number of inverse dynamic simulations mimicking typical activities of daily living were performed that included 1) muscles with retained voluntary control and 2) many different combinations of stimulated paralyzed muscles. These results indicate that a muscle set consisting of the serratus anterior, infraspinatus and triceps would enable the greatest range of relevant movements. This set will become the initial target in a C5SCI neuroprosthesis to restore shoulder and elbow function.

Ultrasound-guided suprascapular nerve block technique.

BACKGROUND: In this article, we describe a case report of using real-time, high-resolution ultrasound guidance to facilitate blockade of the suprascapular nerve. We describe a case report and technique for using a portable ultrasound scanner (38 mm broadband (13-6 MHz) linear array transducer (SonoSite Micromaxx SonoSite, Inc. 21919 30th Drive SE Bothwell W. A..)) to guide suprascapular nerve block. METHODS: A 44-year old male patient presented with severe, painful osteoarthritis with adhesive capsulitis of his right shoulder. The ultrasound transducer in a transverse orientation was placed over the scapular spine. Moving the transducer cephalad the suprascapular fossa was identified. While imaging the supraspinatus muscle and the bony fossa underneath, the ultrasound transducer was moved laterally (maintaining a transverse transducer orientation) to locate the suprascapular notch. The suprascapular nerve was seen as a round hyperechoic structure at 4 cm depth beneath the transverse scapular ligament in the scapular notch. The nerve had an approximate diameter of 200 mm. Real-time imaging was used to direct injection in the scapular notch. Ultrasound scanning confirmed local anesthetic spread. RESULTS: The patient's pain intensity decreased. Shoulder movement and function improved. These improvements were maintained at 12 weeks. CONCLUSION: Ultrasound guidance does not expose patients and personnel to radiation. It is also less expensive than other imaging modalities. This technique has applications in both acute and chronic pain management.

Accessory nerve to suprascapular nerve transfer to restore shoulder exorotation in otherwise spontaneously recovered obstetric brachial plexus lesions.

OBJECTIVE: A systematic follow-up of infants with an obstetric brachial plexus lesion of C5 and C6 or the superior trunk showing satisfactory spontaneous recovery of shoulder and arm function except for voluntary shoulder exorotation, who underwent an accessory to suprascapular nerve transfer to improve active shoulder exorotation, to evaluate for functional recovery, and to understand why other superior trunk functions spontaneously recover in contrast with exorotation. METHODS: In 54 children, an accessory to suprascapular nerve transfer was performed as a separate procedure at a mean age of 21.7 months. Follow-up examinations were conducted before and at 4, 8, 12, 24, and 36 months after operation and included scoring of shoulder exorotation and abduction. Intraoperative reactivity of spinatus muscles and additional needle electromyographic responses were registered after electrostimulation of suprascapular nerves. Histological examination of suprascapular nerves was performed. Trophy of spinatus muscles was followed by magnetic resonance imaging scanning. The influence of perinatal variables and results of ancillary investigations on outcome were evaluated. RESULTS: Exorotation improved from 70 degrees to functional levels exceeding 0 degrees, except in two patients. Abduction improved in 27 patients, with results of 90 degrees or more in 49 patients. Electromyography at 4 months did not show signs of denervation in 39 out of 40 patients. Intraoperative electrostimulation of suprascapular nerves elicited spinatus muscle reaction in 44 out of 48 patients. Histology of suprascapular nerves was normal. Preoperative magnetic resonance imaging scans showed only minor wasting of spinatus muscles in contrast with major wasting after successful operations. CONCLUSION: An accessory to suprascapular nerve transfer is effective to restore active exorotation when performed as the primary or a separate secondary procedure in children older than 10 months of age. Contradictory spontaneous recovery of other superior trunk functions and integrity of suprascapular nerves, as well as absence of spinatus muscle wasting direct to central nervous changes are possible main causes for the lack of exorotation.

The frozen shoulder syndrome. Description of a new technique and five case reports using the subscapular nerve block and subscapularis trigger point infiltration.

BACKGROUND AND OBJECTIVES: A frozen shoulder is considered by some authors to be a common stage of many disorders affecting the shoulder, while others regard it as an independent idiopatic condition. A consistent finding is that subscapularis muscle trigger points play a key role in the development of the frozen shoulder syndrome. Apart from the conventional treatment, a selective subscapularis fossa nerve block combined with subscapularis trigger points infiltration, may be an effective treatment in preventing chronic pain. METHODS: In this manuscript the posterior injection technique of the subscapularis fossa nerve block is described. RESULTS: Five patients with typical symptoms of frozen shoulder, who did not respond to conventional treatment, but obtained pain relief after a combination of a subscapularis nerve block with the infiltration of trigger points, are presented. CONCLUSION: The results of this block in various painful situations of the shoulder region suggest the importance of subscapularis muscle in the etiology of the frozen shoulder. Using this technique, we could demonstrate that a subscapular nerve block and subscapularis trigger points infiltration have both a diagnostic and therapeutic value for the treatment of the frozen shoulder.

Spiral nerve cuff electrodes for an upper extremity neuroprosthesis.

Four nerve cuff electrodes were implanted in the shoulder and arm of one subject with high tetraplegia. Stimulation produced shoulder abduction, elbow flexion and extension, and wrist and finger extension. Recruitment properties were quantified using twitch EMG recruitment curves and tetanic moment measurements. The chronic qualitative 'function' of each channel of stimulation could be predicted from the intraoperative data collection. The average threshold was 11.3 +/- 9 nC and stabilized to this value over the 35 weeks of testing. The moment production of most muscles increased over the testing period due to exercise of the atrophied muscles. No muscle decreased its moment and most appeared to plateau after 15 weeks. Sensation was also evaluated since this subject had an incomplete injury and nerve stimulation was not found to painful throughout the range of muscle activation. Nerve electrodes have been shown to be a stable, effective means of activating muscles for neuroprosthetics.

Cortical involvement in the induction, but not expression, of thalamic plasticity.

The present study examined the role of the somatosensory cortex in the plasticity of thalamic sensory maps. Thalamic plasticity was induced by the disruption of hindlimb input by unilateral destruction of nucleus gracilis. Unilateral somatosensory cortex lesions were performed either on the same day as or a week after the removal of hindlimb input. Multiple electrode penetrations enabled us to measure the volume of somatosensory thalamus devoted to hindlimb, forepaw, and shoulder body regions. Cortical lesions alone did not change the volume of the shoulder, forepaw, or hindlimb representations in the thalamus relative to controls. However, these lesions blocked the increase in shoulder representation resulting from the nucleus gracilis lesion. In contrast, if thalamic reorganization caused by removal of hindlimb input was allowed to occur, subsequent somatosensory cortex lesions 1 week later did not prevent reorganization. Thus, an intact somatosensory cortex is necessary for the occurrence of sensory map reorganization at the thalamic level (induction) in response to nucleus gracilis lesions, but not for the maintenance of such changes once they are present (expression).

Prevention of shoulder subluxation after stroke with electrical stimulation.

BACKGROUND AND PURPOSE: Subluxation is a significant problem in poststroke hemiplegia, resulting in pain and loss of function. Current treatments are not proved and not considered effective. It has been demonstrated that cyclical electrical stimulation of the shoulder muscles can reduce existing subluxation. The purpose of this study was to determine whether electrical stimulation could prevent subluxation in both the short and long terms. METHODS: A prospective, randomized controlled study was used to determine the efficacy of electrical stimulation in preventing shoulder subluxation in patients after cerebrovascular accidents. Forty patients were selected and randomly assigned to a control or treatment group. They had their first assessment within 48 hours of their stroke, and those in the treatment group were immediately put on a regimen of electrical stimulation for 4 weeks. All patients were assessed at 4 weeks after stroke and then again at 12 weeks after stroke. Assessments were made of shoulder subluxation, pain, and motor control. RESULTS: The treatment group had significantly less subluxation and pain after the treatment period, but at the end of the follow-up period there were no significant differences between the 2 groups. CONCLUSIONS: Electrical stimulation can prevent shoulder subluxation, but this effect was not maintained after the withdrawal of treatment.

[Assessment of the functional origin of shoulder pain in chronic polyarthritis by diagnostic local anesthesia of inflamed distal joints. A pilot study]. / Nachweis der funktionellen Genese von Schulterschmerzen bei chronischer Polyarthritis durch diagnostische Lokalanästhesie entzündeter distaler Gelenke. Eine Pilotstudie.

We examined 40 patients with rheumatoid arthritis suffering from painful shoulder. While the shoulder itself was not treated, Mepivacain was injected into an arthritic joint of wrist or elbow. In 36 out of 40 patients we achieved full or partial improvement of pain and movement of the shoulder. We conclude that pain in the shoulder of these patients was caused by a regulatory mechanism, triggered by nociceptors in an arthritic distal joint in order to protect this damaged structure. The therapeutic consequence implies treatment of the distal joint rather than treatment of the painful shoulder itself.