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Concept: Trapezius muscle

171

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

28

Restoration of stability and movements at the shoulder joint are the 2 most important goals in the management of brachial plexus injuries. The 2 nerves that are preferentially targeted for this purpose are the suprascapular (SSN) and the axillary (AXN) nerves. These nerve transfers have conventionally been performed by the anterior approach, but recently transfers performed by posterior incisions have been gaining popularity, by virtue of being selective and located close to the target muscles. Herein, we describe the technical details of spinal accessory nerve (SAN) to SSN and triceps branch to AXN for upper plexus injuries, both performed by the posterior approach.

Concepts: Cranial nerves, Brachial plexus, Suprascapular nerve, Trapezius muscle, Axillary nerve, Radial nerve, Accessory nerve

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BACKGROUND: Multiple variations of the musculocutaneous trapezius flap have been described, each of which use a single composite musculocutaneous unit in their designs. The limitation of such designs is the ability to use the components in a 3-dimensional manner, with only 1 vector existing in the geometry of the musculocutaneous unit. METHODS: A review of the literature was undertaken with regard to designs of the musculocutaneous trapezius flap, and we present a new technique for flap design. With identification of individual perforators to each of the muscle and fasciocutaneous portions of the trapezius flap, the 2 components can act in a chimeric fashion, able to fill both a deep and complex 3-dimensional space while covering the wound with robust skin. RESULTS: A range of flap designs have been described, including transverse, oblique, and vertical skin paddles accompanying the trapezius muscle. We describe a technique with which a propeller-style skin paddle based on a cutaneous perforator can be raised in any orientation with respect to the underlying muscle. In a presented case, separation of the muscular and fasciocutaneous components of the trapezius flap was able to obliterate dead space around exposed cervicothoracic spinal metalwork and obtain robust wound closure in a patient with previous radiotherapy. CONCLUSIONS: This concomitant use of a muscle and fasciocutaneous perforator flap based on a single perforator, a so-called chimeric perforator flap, is a useful modification to trapezius musculocutaneous flap design.

Concepts: Dimension, Euclidean space, Vector space, Graphic design, Analytic geometry, Dorsal scapular artery, Manner of articulation, Trapezius muscle

27

Study Design Descriptive, laboratory based, cross sectional study. Objectives To describe scapular musculature strength, endurance, and change in thickness in individuals with unilateral lateral epicondylalgia (LE) compared to their uninvolved limb and the corresponding limb of a matched comparison group. Background Reported poor long term outcomes for the non-surgical management of individuals with LE suggests a less than optimal rehabilitation process. Knowledge of scapular muscle function in a working population of individuals with LE may help further refine conservative management of this condition. Methods Twenty eight patients with symptomatic LE and 28 controls matched by age and gender were recruited to participate in the study. Strength of the middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) was measured with a hand held dynamometer. A scapular isometric muscle endurance task was performed in prone. Changes in muscle thickness of the SA and LT were measured with ultrasound imaging (USI). ANOVA models were used to determine within and between group differences. Results The involved side of the group with LE had significantly lower values for MT strength (P = .031), SA strength (P<.001), LT strength (P = .006), endurance (P = .003), and change in SA thickness (P = .028) when compared to the corresponding limb of the control group. The involved side of the group with LE had significantly lower strength of the LT (P = .023) and SA (P = .016) when compared to their uninvolved limb, however these differences were small and of potentially limited clinical significance. Conclusion When compared to a matched comparison group, there were impairments of scapular musculature strength and endurance in patients with LE, suggesting that the scapular musculature should be assessed and potentially treated in this population. Cause and effect cannot be established as the weakness of the scapular musculature could be a result of LE. J Orthop Sports Phys Ther, Epub 10 Jan 2015. doi:10.2519/jospt.2015.5290.

Concepts: Causality, Cross-sectional study, Muscle, Muscle contraction, Muscular system, Hand strength, Trapezius muscle, Serratus anterior muscle

27

BACKGROUND: Shoulder pain and dysfunction can occur following neck dissection surgery for cancer. These conditions often are due to accessory nerve injury. Such an injury leads to trapezius muscle weakness, which, in turn, alters scapular biomechanics. OBJECTIVE: The aim of this study was to assess which strengthening exercises incur the highest dynamic activity of affected trapezius and accessory scapular muscles in patients with accessory nerve dysfunction compared with their unaffected side. DESIGN: A comparative design was utilized for this study. METHODS: The study was conducted in a physical therapy department. Ten participants who had undergone neck dissection surgery for cancer, with signs of accessory nerve injury, were recruited. Surface electromyographic activity of the upper trapezius, middle trapezius, rhomboid major, and serratus anterior muscles on the affected side was compared dynamically with that of the unaffected side during 7 scapular strengthening exercises. RESULTS: Electromyographic activity of the upper and middle trapezius muscles of the affected side was lower than that of the unaffected side. The neck dissection side affected by surgery demonstrated higher levels of upper and middle trapezius muscle activity during exercises involving overhead movement. The rhomboid and serratus anterior muscles of the affected side demonstrated higher levels of activity compared with the unaffected side. LIMITATIONS: Exercises were repeated 3 times on one occasion. Muscle activation under conditions of increased exercise dosage should be inferred with caution. CONCLUSIONS: Overhead exercises are associated with higher levels of trapezius muscle activity in patients with accessory nerve injury following neck dissection surgery. However, pain and correct scapular form must be carefully monitored in this patient group during exercises. Rhomboid and serratus anterior accessory muscles may have a compensatory role, and this role should be considered during rehabilitation.

Concepts: Muscle, Physical exercise, Neurology, Electromyography, Trapezius muscle, Scapula, Accessory nerve, Serratus anterior muscle

13

Winged scapula is defined as the prominence of the medial border of the scapula. The classic etiopathology of scapular winging are injuries to the spinal accessory or long thoracic nerves resulting respectively in trapezius and serratus anterior palsy. To the best of our knowledge, there are only few reports of scapular lesions being mistaken for winging of the scapula. We report a rare case of a large scapular osteochondroma arising from the medial border and causing a pseudowinging of the scapula.

Concepts: Cranial nerves, Philosophy of science, Trapezius muscle, Scapula, Accessory nerve, Serratus anterior muscle, Winged scapula, Long thoracic nerve

6

Massage is commonly believed to be the best modality for relieving muscle soreness. However, actively warming up the muscles with exercise may be an effective alternative. The purpose of this study was to compare the acute effect of massage with active exercise for relieving muscle soreness. Twenty healthy female volunteers (mean age 32 years) participated in this examiner-blind randomized controlled trial (ClinicalTrials.gov NCT01478451). Participants performed eccentric contractions for the upper trapezius muscle on a Biodex dynamometer. Delayed onset muscle soreness (DOMS) presented 48 hours (h) later, at which participants 1) received ten minutes (min) of massage of the trapezius muscle or 2) performed ten min of active exercise (shoulder shrugs 10 x 10 reps) with increasing elastic resistance (Thera-Band). First, one treatment was randomly applied to one shoulder while the contralateral shoulder served as passive control. Two hours later the contralateral resting shoulder received the other treatment. Participants rated intensity of soreness (scale 0-10) and a blinded examiner took measures of pressure pain threshold (PPT) of the upper trapezius immediately before treatment and 0, 10, 20 and 60 min after treatment 48 h post eccentric exercise. Immediately prior to treatment intensity of soreness was 5.0 (SD 2.2) and PPT was 138 (SD 78) kPa. In response to treatment, a significant treatment by time interaction was found for intensity of soreness (P<0.001) and PPT (P<0.05). Compared with control, both active exercise and massage significantly reduced intensity of soreness and increased PPT (i.e. reduced pain sensitivity). For both types of treatment the greatest effect on perceived soreness occurred immediately after treatment, while the effect on PPT peaked 20 min after treatment. In conclusion, active exercise using elastic resistance provides similar acute relief of muscle soreness as compared with massage. Coaches, therapists and athletes can use either active warm-up or massage to reduce DOMS acutely, e.g. before competition or strenuous work, but should be aware that the effect is temporary, i.e. the greatest effects occurs during the first 20 min after treatment and diminishes within an hour.

Concepts: Exercise physiology, Stretching, Trapezius muscle, Delayed onset muscle soreness

4

The aim of this review was to describe the effects of ischemic compression and dry needling on trigger points in the upper trapezius muscle in patients with neck pain and compare these two interventions with other therapeutic interventions aiming to inactivate trigger points. Both PubMed and Web of Science were searched for randomized controlled trials using different key word combinations related to myofascial neck pain and therapeutic interventions. Four main outcome parameters were evaluated on short and medium term: pain, range of motion, functionality, and quality-of-life, including depression. Fifteen randomized controlled trials were included in this systematic review. There is moderate evidence for ischemic compression and strong evidence for dry needling to have a positive effect on pain intensity. This pain decrease is greater compared with active range of motion exercises (ischemic compression) and no or placebo intervention (ischemic compression and dry needling) but similar to other therapeutic approaches. There is moderate evidence that both ischemic compression and dry needling increase side-bending range of motion, with similar effects compared with lidocaine injection. There is weak evidence regarding its effects on functionality and quality-of-life. On the basis of this systematic review, ischemic compression and dry needling can both be recommended in the treatment of neck pain patients with trigger points in the upper trapezius muscle. Additional research with high-quality study designs are needed to develop more conclusive evidence.

Concepts: Evidence-based medicine, Systematic review, Randomized controlled trial, Effectiveness, Acupuncture, Massage, Trapezius muscle, Trigger point

3

BACKGROUND: Myofascial trigger points (MTrPs) are hyperirritable spots located in taut bands of muscle fibres. Electrophysiological studies indicate that abnormal electrical activity is detectable near MTrPs. This phenomenon has been described as endplate noise and it has been purported to be associated MTrP pathophysiology. Thus, it is suggested that MTrPs will be overlap the innervation zone (IZ). The purpose of this work was to describe the location of MTrPs and the IZ in the right upper trapezius. METHODS: We screened 71 individuals and eventually enrolled 24 subjects with neck pain and active MTrPs and 24 neck pain-free subjects with latent MTrPs. Surface electromyography (sEMG) signals were detected using an electrode matrix during isometric contraction of the upper trapezius. A physiotherapist subsequently examined the subject’s trapezius to confirm the presence of MTrPs and establish their location. IZ locations were identified by visual analysis of sEMG signals. IZ and MTrPs locations were described using an anatomical coordinate system (ACS), with the skin area covered by the matrix divided into four quadrants. RESULTS: No significant difference was observed between active and latent MTrPs locations (P = 0.6). Forty-five MTrPs were in the third quadrant of the ACS, and 3 were included in second quadrant. IZs were located approximately midway between the seventh cervical vertebrae and the acromial angle in a limited area in the second and third quadrants. The mean distance between MTrP and IZ was 10.4 +/- 5.8 mm. CONCLUSIONS: According to the acquired results, we conclude that IZ and MTrPs are located in well-defined areas in upper trapezius muscle. Moreover, MTrPs in upper trapezius are proximally located to the IZ but not overlapped.

Concepts: Muscle, Electromyography, Cervical vertebrae, Quadrant, Trapezius muscle, Clavicle, Trigger point, Myofascial release

2

This study investigated the characteristics of arm elevation via principal component analysis in symptomatic overhead athletes with scapular dyskinesis. One hundred-thirty-four overhead athletes with scapular dyskinesis [24: inferior angle prominence (pattern I); 46: medial border prominence (pattern II), 64: pattern I + II] were evaluated by three-dimensional electromagnetic motion and electromyography to record the scapular kinematics (upward rotation/posterior tipping/exterior rotation) and muscle activation (upper trapezius: UT; middle trapezius: MT; lower trapezius: LT; serratus anterior: SA) during lowering phase of arm elevation. The results showed: (1) for pattern I and II, the first 3 principal component (PCs) explained 41.4% and 42.6% of total variance of movement; (2) the first PCs were correlated with MT, LT activity (r = 0.41~0.61) and upward rotation, posterior tipping (r = -0.59~-0.33) in pattern I, and UT, MT, SA (r = 0.30~0.70) activity in pattern II; (3) contour plots of muscle activity demonstrated that muscle activities varied with dyskinesis patterns. In summary, for the pattern I, the major characteristics are coactivation of MT and LT and corresponding scapular posterior tipping and upward rotation. For the pattern II, the major characteristics are coactivation of UT, MT and SA without corresponding scapular external rotation.

Concepts: Electromyography, Principal component analysis, Singular value decomposition, Major, Trapezius muscle, Scapula, Serratus anterior muscle, Law of total variance