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Concept: Clavicle


BACKGROUND: Sympathetic nervous activity contributes to the maintenance of muscle oxygenation. However, patients with chronic pain may suffer from autonomic dysfunction. Furthermore, insufficient muscle oxygenation is observed among workers with chronic neck and shoulder pain. The aim of our study was to investigate how muscle load tasks affect sympathetic nervous activity and changes in oxygenation of the trapezius muscles in subjects with chronic neck and shoulder pain. METHODS: Thirty females were assigned to two groups: a pain group consisting of subjects with chronic neck and shoulder pain and a control group consisting of asymptomatic subjects. The participants performed three sets of isometric exercise in an upright position; they contracted their trapezius muscles with maximum effort and let the muscles relax (Relax). Autonomic nervous activity and oxygenation of the trapezius muscles were measured by heart rate variability (HRV) and Near-Infrared Spectroscopy. RESULTS: Oxyhemoglobin and total hemoglobin of the trapezius muscles in the pain group were lower during the Relax period compared with the control group. In addition, the low frequency / high frequency (LF/HF) ratio of HRV significantly increased during isometric exercise in the control group, whereas there were no significant changes in the pain group. CONCLUSIONS: Subjects with neck and shoulder pain showed lower oxygenation and blood flow of the trapezius muscles responding to isometric exercise, compared with asymptomatic subjects. Subjects with neck and shoulder pain also showed no significant changes in the LF/HF ratio of HRV responding to isometric exercise, which would imply a reduction in sympathetic nervous activity.

Concepts: Energy, Muscle, Muscle contraction, Acetylcholine, Autonomic nervous system, Isometric exercise, Trapezius muscle, Clavicle


This study, conducted in a group of nine chronic patients with right-side hemiparesis after stroke, investigated the effects of a robotic-assisted rehabilitation training with an upper limb robotic exoskeleton for the restoration of motor function in spatial reaching movements. The robotic assisted rehabilitation training was administered for a period of 6 weeks including reaching and spatial antigravity movements. To assess the carry-over of the observed improvements in movement during training into improved function, a kinesiologic assessment of the effects of the training was performed by means of motion and dynamic electromyographic analysis of reaching movements performed before and after training. The same kinesiologic measurements were performed in a healthy control group of seven volunteers, to determine a benchmark for the experimental observations in the patients' group. Moreover degree of functional impairment at the enrolment and discharge was measured by clinical evaluation with upper limb Fugl-Meyer Assessment scale (FMA, 0-66 points), Modified Ashworth scale (MA, 0-60 pts) and active ranges of motion. The robot aided training induced, independently by time of stroke, statistical significant improvements of kinesiologic (movement time, smoothness of motion) and clinical (4.6 ± 4.2 increase in FMA, 3.2 ± 2.1 decrease in MA) parameters, as a result of the increased active ranges of motion and improved co-contraction index for shoulder extension/flexion. Kinesiologic parameters correlated significantly with clinical assessment values, and their changes after the training were affected by the direction of motion (inward vs. outward movement) and position of target to be reached (ipsilateral, central and contralateral peripersonal space). These changes can be explained as a result of the motor recovery induced by the robotic training, in terms of regained ability to execute single joint movements and of improved interjoint coordination of elbow and shoulder joints.

Concepts: Time, Scientific method, Evaluation, Measurement, Assessment, Joint, Upper limb, Clavicle


Changes in muscle activities are commonly associated with shoulder impingement and theoretically caused by changes in motor program strategies. The purpose of this study was to assess for differences in latencies and deactivation times of scapular muscles between subjects with and without shoulder impingement. Twenty-five healthy subjects and 24 subjects with impingement symptoms were recruited. Glenohumeral kinematic data and myoelectric activities using surface electrodes from upper trapezius (UT), lower trapezius (LT), serratus anterior (SA) and anterior fibers of deltoid were collected as subjects raised and lowered their arm in response to a visual cue. Data were collected during unloaded, loaded and after repetitive arm raising motion conditions. The variables were analyzed using 2 or 3 way mixed model ANOVAs. Subjects with impingement demonstrated significantly earlier contraction of UT while raising in the unloaded condition and an earlier deactivation of SA across all conditions during lowering of the arm. All subjects exhibited an earlier activation and delayed deactivation of LT and SA in conditions with a weight held in hand. The subjects with impingement showed some significant differences to indicate possible differences in motor control strategies. Rehabilitation measures should consider appropriate training measures to improve movement patterns and muscle control.

Concepts: Muscle, Humerus, Shoulder, Deltoid muscle, Clavicle, Glenohumeral joint, Scapula, Serratus anterior muscle


PurposeIn this retrospective study we investigated the clinical and radiological outcome after operative treatment of acute Rockwood III-V injuries of the AC-joint using two acromioclavicular (AC) cerclages and one coracoclavicular (CC) cerclage with resorbable sutures. METHODS: Between 2007 and 2009 a total of 39 patients fit the inclusion criteria after operative treatment of acute AC joint dislocation. All patients underwent open reduction and anatomic reconstruction of the AC and CC-ligaments using PDS® sutures (Polydioxane, Ethicon, Norderstedt, Germany). Thirty-three patients could be investigated at a mean follow up of 32+/-9 months (range 24–56 months). RESULTS: The mean Constant score was 94.3+/-7.1 (range 73–100) with an age and gender correlated score of 104.2%+/-6.9 (88-123%). The DASH score (mean 3.46+/-6.6 points), the ASES score (94.6+/-9.7points) and the Visual Analogue Scale (mean 0.5+/-0,6) revealed a good to excellent clinical outcome. The difference in the coracoclavicular distance compared to the contralateral side was <5 mm for 28 patients, between 5-10 mm for 4 patients, and more than 10 mm for another patient. In the axial view, the anterior border of the clavicle was within 1 cm (ventral-dorsal direction) of the anterior rim of the acromion in 28 patients (85%). Re-dislocations occured in three patients (9%). CONCLUSION: Open AC joint reconstruction using AC and CC PDS cerclages provides good to excellent clinical results in the majority of cases. However, radiographically, the CC distance increased significantly at final follow up, but neither the amount of re-dislocation nor calcifications of the CC ligaments or osteoarthritis of the AC joint had significant influence on the outcome.Level of evidenceCase series, Level IV.

Concepts: Osteoarthritis, Joint, Joints, Ligament, Joint dislocation, Clavicle, Acromioclavicular joint, Acromion


Training the bench press exercise on a traditional flat bench does not induce a level of instability as seen in sport movements and activities of daily living. Twenty participants were recruited to test two forms of instability: using one dumbbell rather than two and lifting on the COR bench compared to a flat bench. Electromyography (EMG) amplitudes of the pectoralis major, middle trapezius, external oblique, and internal oblique were recorded and compared. Differences in range of motion (ROM) were evaluated by measuring an angular representation of the shoulder complex. Four separate conditions of unilateral bench press were tested while lifting on a: flat bench with one dumbbell, flat bench with two dumbbells, COR Bench with one dumbbell, and COR Bench with two dumbbells. The results imply that there are no differences in EMG amplitude or ROM between the COR bench and traditional bench. However, greater ROM was found to be utilized in the single dumbbell condition, both in the COR bench and the flat bench.

Concepts: Fundamental physics concepts, Muscle, Electromyography, Bench press, Abdominal external oblique muscle, Pectoralis major muscle, Clavicle, Barbell


Study Design Case report. Background Prognosis for adhesive capsulitis has been described as self-limiting and can persist for 1-3 years. Conservative treatment including physical therapy is commonly advised. Case Description The patient was a 54 year old female with primary symptoms of shoulder pain and loss of motion consistent with adhesive capsulitis. Manual physical therapy intervention initially consisted of joint mobilizations of the shoulder region and thrust manipulation of the cervicothoracic region. Although manual techniques seemed to cause some early functional improvement, continued progression was limited by pain. Subsequent examination identified trigger points in the upper trapezius, levator scapula, deltoid and infraspinatus muscles that were treated with dry needling to decrease pain and allow for higher grades of manual intervention. Outcomes The patient was treated for a total of 13 visits over a 6 weeks period. After trigger point dry needling was introduced on the third visit, improvements in pain-free shoulder range of motion and functional outcome measures, including SPADI and QuickDASH, exceeded the minimal clinically important difference after 2 treatment sessions. At discharge the patient had achieved significant improvements in shoulder range of motion in all planes and outcome measures were significantly improved. Discussion This case report describes the clinical reasoning behind the use of trigger point dry needling in the treatment of a patient with adhesive capsulitis. The rapid improvement seen in this patient following the initiation of dry needling to the upper trapezius, levator scapula, deltoid and infraspinatus muscles suggests that surrounding muscles may be a significant source of pain in this condition. Level of Evidence Therapy, level 4. J Orthop Sports Phys Ther, Epub 21 November 2013. doi:10.2519/jospt.2014.4915.

Concepts: Improve, Injuries, Acupuncture, Shoulder, Massage, Supraspinatus muscle, Clavicle, Trigger point


McAllister, MJ, Schilling, BK, Hammond, KG, Weiss, LW, and Farney, TM. Effect of grip width on electromyographic activity during the upright row. J Strength Cond Res 27(1): 181-187, 2013-The upright row (URR) is commonly used to develop the deltoid and upper back musculature. However, little information exists concerning muscle recruitment during variations of this exercise. Sixteen weight-trained men completed 2 repetitions each in the URR with 3 grip conditions: 50, 100, and 200% of the biacromial breadth (BAB). The load was the same for all grip conditions and was equal to 85% of the 1RM determined at 100% BAB. Repeated measures analyses of variance were used to compare the maximal activity of the anterior deltoid (AD), lateral deltoid (LD), posterior deltoid (PD), upper trapezius (UT), middle trapezius (MT), and biceps brachii (BB) during the 3 grip widths for eccentric and concentric actions. Significant differences (p < 0.05) were noted in concentric muscle activity for LD (p < 0.001) and PD (p < 0.001), and in eccentric muscle activity for AD (p = 0.023), LD (p < 0.001), UT (p < 0.001), MT (p < 0.001), and BB (p = 0.003). Bonferroni post hoc analysis revealed significant pairwise differences in the concentric actions from the LD (50% vs. 200% BAB and 100% vs. 200% BAB) and PD (50% vs. 200% BAB and 100% vs. 200% BAB), and eccentric actions of the LD (all comparisons), UT (all comparisons), MT (50% vs. 200% BAB and 100% vs. 200% BAB), and BB (50% vs. 200% BAB), with large-to-very-large effect sizes (ESs). Moderate-to-large ESs were noted for several nonsignificant comparisons. The main findings of this investigation are increased deltoid and trapezius activity with increasing grip width, and correspondingly less BB activity. Therefore, those who seek to maximize involvement of the deltoid and trapezius muscles during the URR should use a wide grip.

Concepts: Muscle, Biceps brachii muscle, Electromyography, Muscle contraction, Deltoid muscle, Muscles of the upper limb, Clavicle, Glenohumeral joint


: During resistance training protocols, people are often encouraged to target the scapular stabilizing musculature (middle and lower trapezius and serratus anterior) while minimizing shoulder prime mover activation (upper trapezius and large glenohumeral muscles) in their training regime, especially in overhead athletes with scapular dyskinesis. In order to increase the activation levels in the stabilizing muscles without drastically increasing the activation in the prime movers, unstable surfaces are frequently used during closed kinetic chain exercises (CKC). However, the specific influence of Redcord slings (RS) as an unstable surface tool on the shoulder muscle activation levels have rarely been investigated, despite these results may be used for adequate exercise selection. Therefore, a controlled laboratory study was performed on 47 healthy subjects (22 ± 4.31 yr; 176 ± 0.083 cm; 69± 8.57 kg) during four CKC exercises without and with RS: half push-up, knee push-up, knee prone bridging plus, and pull-up. When using RS, serratus anterior muscle activation decreased during the knee push-up and knee prone bridging plus exercise. In addition, a drastic increase in pectoralis major muscle activation was found during the half push-up and knee prone bridging plus exercise. Consequently, the use of RS does not necessarily imply that higher levels of scapular stabilizer muscle activation will be attained. These findings suggest RS might be an appropriate training tool when used within a general strengthening program, but should not be preferred over a stable base of support when training for specific scapular stabilization purposes.

Concepts: Stabilizer, Muscle, Physical exercise, Exercise, Exercise physiology, Pectoralis major muscle, Clavicle, Serratus anterior muscle


The deltoid is a fascinating muscle with a significant role in shoulder function. It is comprised of three distinct portions (anterior or clavicular, middle or acromial, and posterior or spinal) and acts mainly as an abductor of the shoulder and stabilizer of the humeral head. Deltoid tears are not infrequently associated with large or massive rotator cuff tears and may further jeopardize shoulder function. A variety of other pathologies may affect the deltoid muscle including enthesitis, calcific tendinitis, myositis, infection, tumors, and chronic avulsion injury. Contracture of the deltoid following repeated intramuscular injections could present with progressive abduction deformity and winging of the scapula. The deltoid muscle and its innervating axillary nerve may be injured during shoulder surgery, which may have disastrous functional consequences. Axillary neuropathies leading to deltoid muscle dysfunction include traumatic injuries, quadrilateral space and Parsonage-Turner syndromes, and cause denervation of the deltoid muscle. Finally, abnormalities of the deltoid may originate from nearby pathologies of subdeltoid bursa, acromion, and distal clavicle.

Concepts: Humerus, Shoulder, Rotator cuff, Deltoid muscle, Axillary nerve, Clavicle, Scapula, Acromion


Malunion after displaced fractures of the clavicle can result in varying degrees of scapular malalignment and potentially scapular winging. The purpose of our study was to quantify the scapular malalignment in patients with midshaft clavicle malunions showing scapular winging.

Concepts: Bone fracture, Clavicle fracture, Clavicle