SciCombinator

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Concept: Latissimus dorsi muscle

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Thoracodorsal artery perforator (TAP) flaps without latissimus dorsi muscle - have been used for reconstruction of the extremities, head and neck as free style flaps, and as pedicled flaps for reconstruction of the chest wall and axillary wounds. This retrospective study aimed to analyse the clinical applications and relevant anatomic findings of TAP flaps.

Concepts: Heart, Latissimus dorsi muscle, Iliac crest, Thoracodorsal nerve, Subscapular artery

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BACKGROUND: In addition to prosthetic rehabilitation, maxillary defects can also be surgically reconstructed. Soft-tissue reconstruction employs a radial forearm or latissimus dorsi muscle flap, while bony reconstruction can be achieved using a fibula, iliac crest, or scapular flap. Reconstruction using a scapular flap is further divided into two subgroups: the traditional scapular flap with the circumflex scapular artery as the donor vessel and the scapular angle flap with the angular artery originating from the thoracodorsal artery as the donor vessel. MATERIALS AND METHODS: We report on four patients who underwent successful reconstruction with a free scapular angle flap between 2009 and 2011, following maxillary resection due to malignancy. RESULTS: Vertical positioning of the scapular angle flap enables reconstruction of the facial contour, whereas its horizontal alignment and microvascular anastomosis makes a bony reconstruction of the hard palate possible. CONCLUSIONS: The versatility, low rate of donor site morbidity and shape of the scapular angle flap-which resembles that of the hard palate-render it ideal for plastic reconstruction. The suitability of bone quality for dental rehabilitation with implants is a topic of controversial discussion. The scapular angle flap represents an alternative to obturator prosthesis for the reconstruction of maxillary defects ≥ grade I according to Okay et al.

Concepts: Reconstruction era of the United States, Reconstruction, Latissimus dorsi muscle, Iliac crest, Thoracodorsal nerve, Subscapular artery, Arteries of the upper limb, Palatal obturator

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The aim of the study was to review systematically the literature available on electromyographic (EMG) variables of the golf swing. From the 19 studies found, a high variety of EMG methodologies were reported. With respect to EMG intensity, the right erector spinae seems to be highly activated, especially during the acceleration phase, whereas the oblique abdominal muscles showed moderate to low levels of activation. The pectoralis major, subscapularis and latissimus dorsi muscles of both sides showed their peak activity during the acceleration phase. High muscle activity was found in the forearm muscles, especially in the wrist flexor muscles demonstrating activity levels above the maximal voluntary contraction. In the lower limb higher muscle activity of the trail side was found. There is no consensus on the influence of the golf club used on the neuromuscular patterns described. Furthermore, there is a lack of studies on average golf players, since most studies were executed on professional or low handicap golfers. Further EMG studies are needed, especially on lower limb muscles, to describe golf swing muscle activation patterns and to evaluate timing parameters to characterize neuromuscular patterns responsible for an efficient movement with lowest risk for injury.

Concepts: Muscle, Electromyography, Muscle contraction, Latissimus dorsi muscle, Human leg, Golf, Golf ball, Golf club

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BACKGROUND: Ablation of locally advanced head and neck cancers generally results in large composite oro-facial defects. Due to the often-large segment of mandible missing, as well as the need to provide skin coverage and oral lining, reconstructive options are limited. We present our experience in oncologic head and neck reconstruction using chimaeric subscapular system free flaps. METHODS: We performed a retrospective chart review of patients presenting important through-and-through oro-facial defects following ablation of T3, T4a or T4b tumours in two university centres between 2005 and 2011. All defects were reconstructed with a subscapular system free flap that was harvested in a dorsal decubitus position. RESULTS: Sixteen patients (15 M, 1 F; mean age = 60 years) underwent mandibular reconstruction with latissimus dorsi flaps with one or two skin paddles and one bony component based on the angular branch of the thoracodorsal artery. Fifteen patients received adjuvant radiotherapy. We experienced no flap loss. Donor-site complications were minimal, albeit a limitation of shoulder range of motion was found in four patients. Eight patients presented postoperative complications requiring re-intervention. Fourteen patients were able to recommence oral nutrition and their diction returned to normal in all but one. The mean follow-up period was 25 months. Aesthetic results were satisfactory upon atrophy of the latissimus dorsi muscle. CONCLUSIONS: In cases of extensive oro-facial defects involving a large mandibular segment, reconstruction with subscapular system free-tissue transfer is a safe and reliable technique that offers satisfactory functional and aesthetic results.

Concepts: Cancer, Oncology, Latissimus dorsi muscle, Iliac crest, Thoracodorsal nerve, Subscapular artery, Glenohumeral joint, Thoracodorsal artery

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BACKGROUND: To date breast assessment has been conducted mainly subjectively. However lately validated objective three-dimensional (3D) imaging was developed. The study aimed to assess breast reconstruction subjectively and objectively and conduct a comparison. METHODS: In forty-four patients after immediate unilateral breast reconstruction with solely the extended latissimus dorsi flap the breast was captured by validated 3D imaging method and standardized 2D photography. Breast symmetry was subjectively evaluated by six experts who applied the Harris score giving a mark of 1-4 for a poor to excellent result. An error study was conducted by examination of the intra and inter-observer agreement and agreement on controls. By Procrustes analysis an objective asymmetry score was obtained and compared to the subjective assessment. RESULTS: The subjective assessment showed that the inter-observer agreement was good or substantial (p-value: <0.0001). There was moderate agreement on the controls (p-value: <0.0001) and fair (p-values: 0.159, 0.134, 0.099) to substantial (p-value: 0.005) intra-observer agreement. The objective assessment revealed that the reconstructed breast showed a significantly smaller volume compared to the opposite side and that the average asymmetry score was 0.052, ranging from 0.019 to 0.136. When comparing the subjective and objective method the relationship between the two scores was highly significant. CONCLUSION: Subjective breast assessment lacked accuracy and reproducibility. This was the first error study of subjective breast assessment versus an objective validated 3D imaging method based on true 3D parameters. The substantial agreement between established subjective breast assessment and new validated objective method supported the value of the later and we expect its future role to expand.

Concepts: Evaluation, Assessment, Latissimus dorsi muscle, Conducting

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Combined single-stage reverse total shoulder arthroplasty (RTSA) plus latissimus dorsi transfer (LDT) has been reported to be a reliable treatment for pseudoparalysis of elevation and external rotation caused by irreparable rotator cuff tears. Secondary LDT in patients with pseudoparalysis of external rotation after previous RTSA has not yet been studied.

Concepts: Shoulder, Latissimus dorsi muscle, Rotator cuff, Rotator cuff tear, Shoulder replacement, Glenohumeral joint

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Background The lateral branch of the thoracodorsal nerve (LBTN) is used for nerve transfer in facial, musculocutaneous, axillary nerve injuries and for irreparable C5, C6 spinal nerve lesions and accessory nerve defects. For a successful surgical outcome, the nerve to be used in nerve transfer should be of adequate length and thickness for nerve coaptation. Aim Our objective was to evaluate the length of the LBTN that could be obtained as a donor nerve, externally and within the muscle. Method Eight (8) cadavers with intact upper limbs and thorax which could be positioned in the anatomical position were selected for the study. Cadavers with dissected axillae, brachial plexus or upper limbs were excluded. The thoracodorsal neurovascular bundle was dissected and the number of branches of the thoracodorsal nerve was identified along with its lateral branch. The lateral branch was dissected up to the latissimus dorsi muscle and further intramuscularly. All lengths were measured using a vernier caliper. Results The mean length of the LBTN, up to its first intramuscular branch, is 8.14 cm (range 5.99-12.29 cm). Beyond this, the intramuscular nerve branched further and was of very minute diameter. The mean unbranched intramuscular length of the nerve is 3.36 cm (range 1.3-7.71 cm) which is 41.28% of the total length of the LBTN. Conclusion A significant proportion of the LBTN is found within the latissimus dorsi muscle. This length could potentially be used for direct nerve coaptation by intrafascicular dissection.

Concepts: Latissimus dorsi muscle, Brachial plexus, Axillary artery, Thoracodorsal nerve, Dissection, Axillary nerve, Nerves of the upper limb, Posterior cord

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The objective of this study is to clarify the functional roles of upper limb muscles during standing and seated cycling when power output increases. We investigated the activity of seven upper limb and trunk muscles using surface electromyography (EMG). Power outputs ranged from ~100-700 W with a pedalling frequency of 90 revolution per minute. Three-dimensional handle and pedal forces were simultaneously recorded. Using non-negative matrix factorisation, we extracted muscle synergies and we analysed the integrated EMG and EMG temporal patterns. Most of the muscles showed tonic activity that became more phasic as power output increased. Three muscle synergies were identified, associated with (i) torso stabilisation, (ii) compensation/generation of trunk accelerations and (iii) upper body weight support. Synergies were similar for seated and standing positions (Pearson’s r > 0.7), but synergy #2 (biceps brachii, deltoidus and brachioradialis) was shifted forward during the cycle (~7% of cycle). The activity levels of synergy #1 (latissimus dorsi and erector spinae) and synergy #2 increased markedly above ~500 W (i.e., ~+40-70% and +130-190%) and during periods corresponding to ipsi- and contralateral downstrokes, respectively. Our study results suggest that the upper limb and trunk muscles may play important roles in cycling when high power outputs are required.

Concepts: Muscle, Biceps brachii muscle, Triceps brachii muscle, Electromyography, Latissimus dorsi muscle, Upper limb, Brachioradialis, Glenohumeral joint

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Multiple studies have reported on the safety of nipple-sparing mastectomy and low complication rates associated with single-stage implant breast reconstruction. Yet many plastic surgeons continue to be resistant to change. This article presents the senior author’s (M.A.C.) experience during his transition period from the latissimus dorsi flap with adjustable implants to a “one-and-done” approach using shaped implants and fetal bovine acellular dermal matrix.

Concepts: Pregnancy, Surgery, Plastic surgery, Breast, Latissimus dorsi muscle, Breast reconstruction, Breast implant, Breast reduction

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The response to resistance training and protein supplementation in the latissimus dorsi muscle (LDM) has never been investigated. We investigated the effects of resistance training (RT) and protein supplementation on muscle mass, strength, and fiber characteristics of the LDM. Eighteen healthy young subjects were randomly assigned to a progressive eight-week RT program with a normal protein diet (NP) or high protein diet (HP) (NP 0.85 vs. HP 1.8 g of protein·kg(-1)·day(-1)). One repetition maximum tests, magnetic resonance imaging for cross-sectional muscle area (CSA), body composition, and single muscle fibers mechanical and phenotype characteristics were measured. RT induced a significant gain in strength (+17%, p < 0.0001), whole muscle CSA (p = 0.024), and single muscle fibers CSA (p < 0.05) of LDM in all subjects. Fiber isometric force increased in proportion to CSA (+22%, p < 0.005) and thus no change in specific tension occurred. A significant transition from 2X to 2A myosin expression was induced by training. The protein supplementation showed no significant effects on all measured outcomes except for a smaller reduction of 2X myosin expression. Our results suggest that in LDM protein supplementation does not further enhance RT-induced muscle fiber hypertrophy nor influence mechanic muscle fiber characteristics but partially counteracts the fast-to-slow fiber shift.

Concepts: Muscle, Cardiac muscle, Glycogen, Actin, Myosin, Muscular system, Cytoskeleton, Latissimus dorsi muscle