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Annals of Dermatology Oct 2023Botulinum toxin type A (BTX-A) injection is being widely used off-label for muscular hypertrophy, including deltoid muscle hypertrophy. However, very few studies have...
A Double-Blinded, Randomized, Dose-Comparison Pilot Study to Comparatively Evaluate Efficacy and Safety of Two Doses of Botulinum Toxin Type A Injection for Deltoid Muscle Hypertrophy.
BACKGROUND
Botulinum toxin type A (BTX-A) injection is being widely used off-label for muscular hypertrophy, including deltoid muscle hypertrophy. However, very few studies have evaluated the optimal dosage and its clinical response.
OBJECTIVE
This study aimed to assess the efficacy and safety of different doses of Prabotulinum toxin A (PBoNT) for treating deltoid muscle hypertrophy.
METHODS
Twelve particiapants with bilateral deltoid muscle hypertrophy were enrolled and randomly received either 16 U or 32 U of PBoNT. In each participant, the same dose was administered to both deltoid muscles. Both participants and evaluators were blinded. Deltoid muscle thickness and upper arm circumference were measured on day 0, and weeks 2, 4, and 12 after the PBoNT injection.
RESULTS
Upper arm circumference significantly decreased in both groups; however, deltoid muscle thickness was reduced in the 16 U group only. No major complications were reported in both groups. However, a few minor complications were reported in the 16 U injection group.
CONCLUSION
Both 16 U and 32 U of PBoNT intramuscular injections are safe and effective in treating deltoid hypertrophy.
PubMed: 37830417
DOI: 10.5021/ad.22.155 -
Frontiers in Physiology 2022Overhead press is commonly performed to reinforce the muscles surrounding the shoulders. However, many overhead press variations can be executed, thus varying the...
Overhead press is commonly performed to reinforce the muscles surrounding the shoulders. However, many overhead press variations can be executed, thus varying the stimuli to each muscle. Therefore, the current study compared the muscles excitation during overhead press performed with the barbell passing in front or behind the head or using a shoulder press machine. Eight competitive bodybuilders performed in random order front (front-BMP) or back barbell military press (back-BMP), and front (front-MSP) with neutral handgrip or back machine shoulder press (back-MSP). Normalized surface electromyographic root mean square (RMS) of anterior, medial and posterior deltoid, upper trapezius, pectoralis major and triceps brachii was recorded during both the ascending and descending phases. During the ascending phase, anterior deltoid showed greater RMS in back-BMP than back-MSP [ES: 1.42, (95% confidence interval 0.32/2.51)]. Medial deltoid showed greater RMS in back-BMP than front-BMP [ES: 3.68 (2.07/5.29)], and back-MSP [ES: 7.51 (4.73/10.29)]. Posterior deltoid showed greater RMS in back-BMP than front-BMP [ES: 9.00 (5.73/12.27)]. Pectoralis major showed greater RMS in front-BMP than back-BMP [ES: 3.11 (1.65-4.56)] and in front-MSP than back-MSP [ES: 20.52 (13.34/27.70)]. During the descending phase, anterior deltoid was more excited in back-BMP compared to front-BMP [ES: 7.66 (4.83/10.49). Medial deltoid showed greater RMS in back-BMP than front-BMP [ES: 4.56 (2.70/6.42)]. Posterior deltoid showed greater RMS in back-BMP than front-BMP [ES: 8.65 (5.50/11.80)]. Pectoralis major showed greater RMS in front-BMP than back-BMP [ES: 4.20 (2.44/5.95)]. No between-exercise difference was observed for upper trapezius. Performing back overhead press enhances the excitation of medial and posterior and partly anterior deltoid, while front overhead favors pectoralis major. Overhead press performed using barbell excites muscles more than using machine to stabilize the trajectory of the external load. Different variations of overhead press appear to provide different stimuli to the shoulder muscles and may be used accordingly during the training routine.
PubMed: 35936912
DOI: 10.3389/fphys.2022.825880 -
Pediatric Physical Therapy : the... 2016Pain relief after exercise, exercise-induced hypoalgesia (EIH), is established across the lifespan. Conditioned pain modulation (CPM: pain inhibits pain) may be a... (Clinical Trial)
Clinical Trial
PURPOSE
Pain relief after exercise, exercise-induced hypoalgesia (EIH), is established across the lifespan. Conditioned pain modulation (CPM: pain inhibits pain) may be a mechanism for EIH.
METHODS
In 55 adolescents, pressure pain thresholds were measured before and after exercise (deltoid, quadriceps, and nail bed) and during CPM at the nail bed and deltoid test stimulus sites. The relationship between EIH and CPM was explored.
RESULTS
EIH occurred at deltoid and quadriceps; CPM occurred at nail bed and deltoid. CPM and EIH correlated at deltoid; adolescents with greater CPM experienced greater pain relief after exercise. At this site, CPM predicted 5.4% of EIH. Arm lean mass did not add a significant effect. Peak exercise pain did not influence EIH. Adolescents with none, minimal, moderate, or severe peak exercise pain experienced similar EIH.
CONCLUSIONS
A potential relationship exists between CPM and EIH in adolescents. Pediatric physical therapists should consider the CPM response when prescribing exercise as a pain management tool.
Topics: Adolescent; Body Weights and Measures; Deltoid Muscle; Exercise; Humans; Male; Nails; Pain; Pain Management; Pain Measurement; Pain Perception; Pain Threshold; Pressure; Quadriceps Muscle
PubMed: 27661245
DOI: 10.1097/PEP.0000000000000312 -
Neurology Jun 2020To test the hypothesis that neurophysiologic biomarkers of muscle activation during convulsive seizures reveal seizure severity and to determine whether automatically...
OBJECTIVE
To test the hypothesis that neurophysiologic biomarkers of muscle activation during convulsive seizures reveal seizure severity and to determine whether automatically computed surface EMG parameters during seizures can predict postictal generalized EEG suppression (PGES), indicating increased risk for sudden unexpected death in epilepsy. Wearable EMG devices have been clinically validated for automated detection of generalized tonic-clonic seizures. Our goal was to use quantitative EMG measurements for seizure characterization and risk assessment.
METHODS
Quantitative parameters were computed from surface EMGs recorded during convulsive seizures from deltoid and brachial biceps muscles in patients admitted to long-term video-EEG monitoring. Parameters evaluated were the durations of the seizure phases (tonic, clonic), durations of the clonic bursts and silent periods, and the dynamics of their evolution (slope). We compared them with the duration of the PGES.
RESULTS
We found significant correlations between quantitative surface EMG parameters and the duration of PGES ( < 0.001). Stepwise multiple regression analysis identified as independent predictors in deltoid muscle the duration of the clonic phase and in biceps muscle the duration of the tonic-clonic phases, the average silent period, and the slopes of the silent period and clonic bursts. The surface EMG-based algorithm identified seizures at increased risk (PGES ≥20 seconds) with an accuracy of 85%.
CONCLUSIONS
Ictal quantitative surface EMG parameters correlate with PGES and may identify seizures at high risk.
CLASSIFICATION OF EVIDENCE
This study provides Class II evidence that during convulsive seizures, surface EMG parameters are associated with prolonged postictal generalized EEG suppression.
Topics: Adolescent; Adult; Algorithms; Child; Deltoid Muscle; Electroencephalography; Electromyography; Epilepsy, Tonic-Clonic; Female; Hamstring Muscles; Humans; Male; Middle Aged; Risk Assessment; Seizures; Young Adult
PubMed: 32398358
DOI: 10.1212/WNL.0000000000009492 -
Journal of Nuclear Medicine : Official... Jan 2022With hundreds of millions of coronavirus disease 2019 (COVID-19) messenger RNA (mRNA)-based vaccine doses planned to be delivered worldwide in the upcoming months, it is...
With hundreds of millions of coronavirus disease 2019 (COVID-19) messenger RNA (mRNA)-based vaccine doses planned to be delivered worldwide in the upcoming months, it is important to recognize PET/CT findings in recently vaccinated immunocompetent or immunocompromised patients. We aimed to assess PET/CT uptake in the deltoid muscle and axillary lymph nodes of patients who received a COVID-19 mRNA-based vaccine and to evaluate its association with patient age and immune status. All consecutive adults who underwent PET/CT scans with any radiotracer at our center during the first month of a national COVID-19 vaccination rollout (between December 23, 2020, and January 27, 2021) and had received the vaccination were included. Data on clinical status, laterality, and time from vaccination were prospectively collected, retrospectively analyzed, and correlated with deltoid muscle and axillary lymph node uptake. Of 426 eligible subjects (median age, 67 ± 12 y; 49% female), 377 (88%) underwent PET/CT with F-FDG, and positive axillary lymph node uptake was seen in 45% of them. Multivariate logistic regression analysis revealed a strong inverse association between positive F-FDG uptake in ipsilateral lymph nodes and patient age (odds ratio [OR], 0.57; 95% CI, 0.45-0.72; < 0.001), immunosuppressive treatment (OR, 0.37; 95% CI, 0.20-0.64; = 0.003), and presence of hematologic disease (OR, 0.44; 95% CI, 0.24-0.8; = 0.021). No such association was found for deltoid muscle uptake. The number of days from the last vaccination and the number of vaccine doses were also significantly associated with increased odds of positive lymph node uptake. After mRNA-based COVID-19 vaccination, a high proportion of patients showed ipsilateral lymph node axillary uptake, which was more common in immunocompetent patients. This information will help with the recognition of PET/CT pitfalls and may hint about the patient's immune response to the vaccine.
Topics: Adult; Aged; COVID-19; Female; Humans; Lymph Nodes; Male; Middle Aged; Positron Emission Tomography Computed Tomography; Retrospective Studies
PubMed: 33893188
DOI: 10.2967/jnumed.121.262194 -
International Journal of Sports... 2023The lower trapezius (LT) muscle, which stabilizes the scapula posteriorly during arm elevation, has been interesting to both clinicians and researchers for its...
BACKGROUND
The lower trapezius (LT) muscle, which stabilizes the scapula posteriorly during arm elevation, has been interesting to both clinicians and researchers for its importance in throwing-related shoulder rehabilitation and injury prevention.
PURPOSE
The purpose of this study was to investigate the electromyographic activity of the LT and other relevant muscles during scapular and shoulder activities in the side-lying position.
METHODS
Twenty collegiate baseball players volunteered to participate in this study. Electromyographic (EMG) output of the lower trapezius, infraspinatus, posterior deltoid, middle deltoid, serratus anterior, and upper trapezius muscles were collected. All the subjects performed isometric resistance exercises in four arm positions: 0° horizontal abduction from the coronal plane (NEUT) with protraction (NEUT-PRO), 15° horizontal adduction from the coronal plane (HADD) with protraction (HADD-PRO), and NEUT with retraction (NEUT-RET), and HADD-RET in a side-lying isometric abduction exercise with two external loads: a 9.1 kg dumbbell and 40% of the manual muscle test (MMT). The subjects also performed two more isometric resistance exercises: supine protraction and side-lying external rotation (ER) of the glenohumeral (GH) joint in GH adduction at 90° of GH ER or with as much ER as possible. All raw EMG data were normalized to maximal voluntary isometric contraction (% MVIC) of the corresponding muscle.
RESULTS
LT activity was significantly greater in HADD-RET with 9.1 kg than that of HADD-PRO (p < 0.001) (55 vs 21% MVIC) while middle deltoid muscle activity was significantly decreased in both NEUT and HADD-RET compared to that of NEUT and HADD-PRO (p < 0.001). In contrast, IS muscle activity was significantly increased in HADD-RET with 9.1 kg compared with that 40% MMT (p < 0.001) (41 vs 22% MVIC).
CONCLUSION
LT activity was modulated by changes in scapulothoracic and glenohumeral joint positioning during a side-lying isometric abduction exercise. These findings may help clinicians to select exercises to improve scapular muscle balance ratios during rehabilitation of the shoulder complex.
LEVEL OF EVIDENCE
Level 3b, Controlled laboratory study.
PubMed: 37425105
DOI: 10.26603/001c.74969 -
Shoulder & Elbow Feb 2022Deltoid muscle function is paramount to the success of reverse total shoulder arthroplasty. The purpose of this study was to investigate the role of deltoid volume on...
Effect of deltoid volume on range of motion and patient-reported outcomes following reverse total shoulder arthroplasty in rotator cuff-intact and rotator cuff-deficient conditions.
BACKGROUND
Deltoid muscle function is paramount to the success of reverse total shoulder arthroplasty. The purpose of this study was to investigate the role of deltoid volume on shoulder range of motion and patient-reported outcomes following reverse total shoulder arthroplasty in rotator cuff-intact and rotator cuff-deficient conditions.
METHODS
Retrospective review of records identified 107 patients who met inclusion criteria. The rotator cuff integrity was evaluated by two musculoskeletal-trained radiologists. Volumetric deltoid measurements were calculated from preoperative computed tomography or magnetic resonance imaging scans. Satisfactory outcomes were defined as forward elevation of at least 135°, external rotation of at least 35°, and American Shoulder and Elbow Surgeons and Single Assessment Numerical Evaluation scores of at least 70.
RESULTS
Mean total deltoid muscle volume was significantly higher in patients with satisfactory forward elevation (57.8 ± 18.1 cm³) versus unsatisfactory forward elevation (48.6 ± 19.5 cm³) (p = 0.013). When separated by rotator cuff integrity, total deltoid volume was significantly higher (p = 0.030) in patients who achieved satisfactory forward elevation in the rotator cuff-deficient group but not the rotator cuff-intact group (p = 0.533).
DISCUSSION
Preoperative deltoid volume directly correlated with achieving satisfactory forward elevation after reverse total shoulder arthroplasty in rotator cuff-deficient conditions and may be one factor in determining the ability to achieve satisfactory outcomes in the rotator cuff-deficient patient.
PubMed: 35154397
DOI: 10.1177/1758573220925046 -
Cureus Nov 2023The procedure of nasotracheal intubation (NI) has long been performed utilizing the Magill forceps as developed by Sir Ivan Magill in the 1920s. While used for nearly a...
INTRODUCTION
The procedure of nasotracheal intubation (NI) has long been performed utilizing the Magill forceps as developed by Sir Ivan Magill in the 1920s. While used for nearly a century, several serious patient safety concerns remain including torn tube cuffs, vocal cord trauma, and inefficient tube placement. The Tylke forceps have been developed as a modification to the largely unchanged form of Magill forceps.
METHODS
In the present investigation we compared the efficacy, number of clasps, and muscle activation involved in NI using the Tylke forceps versus the Magill forceps in previously untrained individuals.
RESULTS
Tylke forceps showed faster successful NI over the standard Magill forceps at an average intubation time of 6.54s vs. 13.73s, respectively. Tylke forceps also had fewer clasps per intubation over the Magill. The trapezius, deltoid, and brachioradialis muscle activation was also compared in Tylke vs Magill forceps intubation trials. Tylke forceps required less lower muscle activation in the brachioradialis and trapezius over the Magill forceps with Tylke forceps resulting in higher deltoid muscle activation.
CONCLUSION
Tylke forceps were more efficacious and reduced the number of clasps over the Magill forceps when used in successful NI with different muscle activation patterns.
PubMed: 38106711
DOI: 10.7759/cureus.48857 -
Journal of Clinical Medicine Jan 2020Although reverse shoulder arthroplasty (RSA) has shown successful postoperative outcomes, little is known about compensatory activation patterns of remaining shoulder...
Although reverse shoulder arthroplasty (RSA) has shown successful postoperative outcomes, little is known about compensatory activation patterns of remaining shoulder muscles following RSA. The purpose of this experimental case control series was to investigate shoulder muscle strength and neuromuscular activation of deltoid and teres minor muscles 2 years after RSA. Humerus lengthening, center-of-rotation medialization, maximal voluntary strength, and electromyographic (EMG) activity were compared between the operated and the non-operated side of 13 patients (mean age: 73 years). Shoulder muscle strength was significantly lower on the operated side for external rotation (-54%), internal rotation (-20%), and adduction (-13%). Agonist deltoid EMG activity was lower on the operated side for shoulder flexion, extension, and internal and external rotation ( < 0.05). Antagonist deltoid coactivation was higher on the operated side for external rotation ( < 0.001). Large correlation coefficients were observed between shoulder adductor strength asymmetry and both center-of-rotation medialization (r = -0.73) and humerus lengthening (r = 0.71). Shoulder abduction strength and neuromuscular activation were well preserved 2 years after RSA, while persistent strength and activation deficits were observed for shoulder adduction and internal and external rotation. Additional studies are required to elucidate shoulder neuromuscular activation patterns before and after RSA to support decision making for surgical, implant design, and rehabilitation choices.
PubMed: 32013074
DOI: 10.3390/jcm9020365 -
Journal of Neuroengineering and... May 2021Falls commonly occur due to losses of balance associated with vertical body movements (e.g. reacting to uneven ground, street curbs). Research, however, has focused on...
BACKGROUND
Falls commonly occur due to losses of balance associated with vertical body movements (e.g. reacting to uneven ground, street curbs). Research, however, has focused on horizontal perturbations, such as forward and backward translations of the standing surface. This study describes and compares muscle activation patterns following vertical and horizontal perturbations during standing and walking, and investigates the role of vision during standing postural responses.
METHODS
Fourteen healthy participants (ten males; 27±4 years-old) responded to downward, upward, forward, and backward perturbations while standing and walking in a virtual reality (VR) facility containing a moveable platform with an embedded treadmill; participants were also exposed to visual perturbations in which only the virtual scenery moved. We collected bilateral surface electromyography (EMG) signals from 8 muscles (tibialis anterior, rectus femoris, rectus abdominis, external oblique, gastrocnemius, biceps femoris, paraspinals, deltoids). Parameters included onset latency, duration of activation, and activation magnitude. Standing perturbations comprised dynamic-camera (congruent), static-camera (incongruent) and eyes-closed sensory conditions. ANOVAs were used to compare the effects of perturbation direction and sensory condition across muscles.
RESULTS
Vertical perturbations induced longer onset latencies and shorter durations of activation with lower activation magnitudes in comparison to horizontal perturbations (p<0.0001). Downward perturbations while standing generated earlier activation of anterior muscles to facilitate flexion (for example, p=0.0005 and p=0.0021 when comparing the early activators, rectus femoris and tibialis anterior, to a late activator, the paraspinals), whereas upward perturbations generated earlier activation of posterior muscles to facilitate extension (for example, p<0.0001 and p=0.0004, when comparing the early activators, biceps femoris and gastrocnemius, to a late activator, the rectus abdominis). Static-camera conditions induced longer onset latencies (p=0.0085 and p<0.0001 compared to eyes-closed and dynamic-camera conditions, respectively), whereas eyes-closed conditions induced longer durations of activation (p=0.0001 and p=0.0008 compared to static-camera and dynamic-camera, respectively) and larger activation magnitudes. During walking, downward perturbations promptly activated contralateral trunk and deltoid muscles (e.g., p=0.0036 for contralateral deltoid versus a late activator, the ipsilateral tibialis anterior), and upward perturbations triggered early activation of trunk flexors (e.g., p=0.0308 for contralateral rectus abdominis versus a late activator, the ipsilateral gastrocnemius). Visual perturbations elicited muscle activation in 67.7% of trials.
CONCLUSION
Our results demonstrate that vertical (vs. horizontal) perturbations generate unique balance-correcting muscle activations, which were consistent with counteracting vertical body extension induced by downward perturbations and vertical body flexion induced by upward perturbations. Availability of visual input appears to affect response efficiency, and incongruent visual input can adversely affect response triggering. Our findings have clinical implications for the design of robotic exoskeletons (to ensure user safety in dynamic balance environments) and for perturbation-based balance and gait rehabilitation.
Topics: Adult; Electromyography; Female; Humans; Male; Muscle, Skeletal; Postural Balance; Posture; Walking
PubMed: 33957953
DOI: 10.1186/s12984-021-00836-0