Effect of a slump posture on pain, proprioception, and electrical activity of the muscles in office workers with chronic non-specific neck pain. A retrospective study.

BACKGROUND: The impact of computer typing in a slump posture on pain, proprioception and muscle recruitment has not been extensively investigated. Therefore, the purpose of this study was to evaluate the extent of pain, proprioception and muscle activity resulting from computer typing in a slump posture in women who already suffer from chronic neck pain. METHODS: This cross-sectional study was conducted between May 20 to July 10, 2021. A total of 15 female 42-(±4.96)-year-old office workers with chronic non-specific neck pain participated in this study. Before and after 60 min of computer typing in a slump posture, proprioception and pain were measured using an inclinometer and visual analog scale (VAS), respectively. The activity of the cervical erector spine (CES) and upper trapezius (UT) muscle was also measured before and after the slump-posture computer typing, in upright, forward, and slump postures. RESU: lts: Paired-samples t-tests showed that pain was increased and proprioception in all directions (flexion, extension, right and left lateral flexion, and right, and left rotation) was less accurate (P < 0.05) after 60 min computer typing. The CES and UT muscle activity were elevated more in the forward head and slump posture than in the upright posture (P < 0.05). CONCLUSION: Sixty minutes computer typing in a slump posture increased neck pain, resulted in a decreased proprioception in the neck and was accompanied by an increased activity of the neck musculature.

The difference in the upper trapezius deep fascia slides between individuals with and without myofascial pain syndrome: A case-control study.

INTRODUCTION: MPS is a chronic disorder caused by myofascial trigger points, leading to pain and limited neck movements due to impacted fascia. Studies have reported reduced fascia slides in chronic low back pain, but limited fascia slides in MPS patients are still unreported. AIM: We determined differences in upper trapezius' deep fascia slides between MPS and non-MPS participants. METHODS: Between January-August 2019, participants from diverse work sectors were recruited in Manila. An expert physiotherapist diagnosed MPS, while non-MPS participants performed full painless cervical movements. Participants underwent upper trapezius deep fascia scans on both shoulders while performing six cervical movements. An HS1 Konica Minolta ultrasound recorded the data. Two blinded physiotherapists used Tracker 5.0 © 2018 to analyze videos and quantify deep fascia slides by measuring the distance between two x-axis points. The Multivariate analysis of variance (MANOVA) assessed deep fascia slide differences in six active cervical movements. Pillai's Trace, with a range of 0-1 and a p-value of <0.05, was set. Effect sizes in individuals with and without MPS were calculated using Hedges' g and Cohen's d. RESULTS: Of the 327 participants (136 non-MPS, 191 MPS), 101 MPS participants had shoulder pain for <1 year and 103 experienced unilateral pain. The study examined 3800 ultrasound videos but found no significant difference in deep fascia slides across cervical movements between MPS and non-MPS groups (Pillai's Trace = 0.004, p = 0.94). Minor differences in deep fascia displacement were observed, with small effect sizes (g = 0.02-0.08). CONCLUSION: A limited deep fascia slide does not characterize MPS participants from non-MPS participants.

Reliability of quantitative sensory testing on myofascial trigger points in the upper trapezius muscle of individuals with chronic neck pain.

OBJECTIVE: The objective of this study was to measure the intra- and inter-rater reliability of the quantitative sensory testing for measuring the thermal pain threshold on myofascial trigger points in the upper trapezius muscle of individuals with chronic neck pain. METHODS: Thirty female participants were included, aged between 18 and 45 years and with bilateral myofascial trigger points, active and centrally located in the upper trapezius muscle. Two measurements with quantitative sensory testing were performed by each examiner at an interval of 1 week between them. RESULTS: We observed substantial reliability for the intra-rater analysis (intraclass correlation coefficient ranging between 0.876 and 0.896) and excellent reliability for the inter-rater analysis (intraclass correlation coefficient ranging between 0.917 and 0.954). CONCLUSION: The measurement of the thermal pain threshold on myofascial trigger points in individuals with chronic neck pain has acceptable reliability values, supporting the use of the quantitative sensory testing in the research setting and the clinical environment.

Effects of alternating heat and cold stimulation using a wearable thermo-device on subjective and objective shoulder stiffness.

BACKGROUND: Technological innovations have allowed the use of miniature apparatus that can easily control and program heat and cold stimulations using Peltier elements. The wearable thermo-device has a potential to be applied to conventional contrast bath therapy. This study aimed to examine the effects of alternating heat and cold stimulation (HC) using a wearable thermo-device on subjective and objective improvement of shoulder stiffness. METHODS: Twenty healthy young male individuals (20.3 ± 0.6 years) participated in this study. The interventions were randomly conducted under four conditions, including HC, heat stimulation, cold stimulation, and no stimulation on their bilateral trapezius muscle, after a 30-min typing task. Each intervention was administered at least 1 week apart. The analyzed limb was the dominant arm. Muscle hardness was assessed using a portable muscle hardness meter, as well as the skin temperature over the stimulated area. After each condition, the participants were asked for feedback regarding subjective improvement in refreshed feelings, muscle stiffness, and muscle fatigue using an 11-point numerical rating scale. RESULTS: With regard to muscle hardness, only the HC condition significantly decreased from 1.43 N to 1.37 N (d = 0.44, p < 0.05). Additionally, reduced muscle hardness in HC condition was associated with the degree of skin cooling during the intervention (cold max: r = 0.634, p < 0.01; cold change: r = -0.548, p < 0.05). Subjective improvement in refreshed feelings, muscle stiffness, and muscle fatigue was determined in the HC and heat stimulation conditions compared with the no stimulation condition (p < 0.01 and p < 0.05, respectively). Moreover, the HC condition showed significantly greater improvements in muscle stiffness and fatigue compared to the cold stimulation condition (p < 0.05). CONCLUSIONS: The current study demonstrated that HC promoted not only better subjective symptoms, such as muscle stiffness and fatigue, but also lesser muscle hardness. Furthermore, an association was observed between the degree of skin temperature cooling and reduced muscle hardness during HC. Further investigations on the ratio and intensity of cooling should be conducted in the future to establish the optimal HC protocol for muscle stiffness or fatigue. TRIAL REGISTRATION: UMIN000040620 . Registered 1 June 2020.

Reliability of quantitative sensory testing on myofascial trigger points in the upper trapezius muscle of individuals with chronic neck pain

SUMMARY OBJECTIVE: The objective of this study was to measure the intra- and inter-rater reliability of the quantitative sensory testing for measuring the thermal pain threshold on myofascial trigger points in the upper trapezius muscle of individuals with chronic neck pain. METHODS: Thirty female participants were included, aged between 18 and 45 years and with bilateral myofascial trigger points, active and centrally located in the upper trapezius muscle. Two measurements with quantitative sensory testing were performed by each examiner at an interval of 1 week between them. RESULTS: We observed substantial reliability for the intra-rater analysis (intraclass correlation coefficient ranging between 0.876 and 0.896) and excellent reliability for the inter-rater analysis (intraclass correlation coefficient ranging between 0.917 and 0.954). CONCLUSION: The measurement of the thermal pain threshold on myofascial trigger points in individuals with chronic neck pain has acceptable reliability values, supporting the use of the quantitative sensory testing in the research setting and the clinical environment.

Exploring the Underlying Mechanisms of Action of Dry Needling: What Is the Immediate Effect on Muscle Electrophysiology? An Experimental Randomized Controlled Trial.

OBJECTIVE: Dry needling is a commonly used treatment technique for myofascial pain syndromes, such as trapezius myalgia. Despite the shown positive clinical effects on pain, the underlying mechanisms of action, such as the effect on muscle electrophysiology, remain unclear. The aim of this study was to investigate the effect of dry needling, compared with sham needling, in the upper trapezius muscle on surface electromyography activity and the relation with pain in office workers with trapezius myalgia. DESIGN: For this experimental randomized controlled trial, 43 office workers with work-related trapezius myalgia were included. Surface electromyography activity was measured before and after a pain-provoking computer task and immediately after, 15, and 30 mins after treatment with dry or sham needling. Pain scores were evaluated at the same time points as well as 1, 2, and 7 days after treatment. RESULTS: No significant differences in surface electromyography activity between dry needling and sham needling were found. Significant positive low to moderate Spearman correlations were found between surface electromyography activity and pain levels after dry needling treatment. CONCLUSIONS: This study shows no immediate effects of dry needling on the electrophysiology of the upper trapezius muscle, compared with sham needling.

Experimental Studies of Latissimus Dorsi Detrusor Myoplasty for Bladder Acontractility: A Systematic Review.

Current therapies that allow patients with bladder acontractility to void are limited. The standard therapy is clean intermittent catheterization. Latissimus dorsi detrusor myoplasty (LDDM) has been shown to provide functional contraction and allow patients with bladder acontractility to void voluntarily. Our goal was to summarize experimental studies of LDDM. We hypothesized that experimental studies would show that latissimus dorsi muscle (LDM) flaps for detrusor myoplasty have superior outcomes when compared with other types of flaps. On January 17, 2020, we conducted a systematic review of the PubMed/MEDLINE, Cochrane Clinical Answers, Cochrane Central Register of Controlled Trials, and EMBASE databases, without time frame limitations, to identify articles on the use of LDDM. We excluded studies that investigated other treatments. Of 54 articles identified by the search, three fulfilled the eligibility criteria. A total of 24 dogs underwent procedures and were evaluated with a maximum follow-up of 9 months. Three types of procedures were performed: LDM in situ reconfiguration, LDM myoplasty, and augmentation cystoplasty after supratrigonal cystectomy. Electrical stimulation, cystography, urodynamic and hydrodynamic measurements, and microscopic examinations were performed. Innervated LDM flaps transferred to the bladder were able to contract and promote voiding in response to electrical stimulation. Experimental studies have shown the feasibility of LDDM in canine models. Although no comparison groups were included, innervated LDM flap transferred to the bladder showed promising results regarding contraction capable of voiding.

Avaliação eletromiográfica da musculatura mastigatória e da coluna cervical com uso de placa oclusal: relato de caso / Electromyographic evaluation of masticatory and cervical musculature with occlusal splint: case report

Objetivo: Avaliar a atividade elétrica de músculos mastigatórios e cervicais e sua inter-relação na estabilização da cadeia crânio cervico umeral com uso da placa oclusal, por meio da avaliação eletromiográfica. Relato de caso: Paciente sexo feminino, 39 anos, queixando-se de dores na cabeça, faciais e cervicais, com prejuízo em suas atividades diárias. Relatou apertar os dentes durante o dia e a noite e ser uma pessoa muito ansiosa. Pratica exercício físico de 5 a 6 vezes por semana. Foi submetida ao tratamento com placa oclusal estabilizadora. O exame eletromiográfico foi realizado nos músculos masseter e trapézio, bilateralmente. A coleta de dados foi realizada antes da instalação da placa e passados 90 dias de uso. Considerações finais: Após o tempo de tratamento, foi relatado redução do comportamento de apertamento noturno e diurno dos dentes, redução do nódulo muscular antes visível na região supraescapular, eliminação das dores e melhor rendimento muscular durante a prática de atividade física.(AU)

Objective: To evaluate the electrical activity of masticatory and cervical muscles and their relationship in the stabilization of the craniocervicohumeral chain using a occlusal splint, through electromyographic evaluation. Case report: Female patient, 39 years old, complaining of headaches, facial and cervical pain, with impairment in her daily activities. She reported teeth clenching during the day and night, and being a very anxious person. She practices physical exercise 5 to 6 times a week. She underwent treatment with a stabilizing occlusal splint. The electromyographic examination was performed on the masseter and trapezius muscles, bilaterally. Data was collected before occlusal splint installation and after 90 days of use. Final considerations: After the treatment period, it was reported a reduction in the behavior of nocturnal and daytime teeth clenching, reduction of the muscle nodule previously visible in the suprascapular region, elimination of pain and better muscle performance during the practice of physical activities.(AU)

Myofascial Pain Syndrome Focused on the Upper Trapezius Muscle: A Comparative Randomized Controlled Trial of the Court-Type Traditional Thai Massage versus the Thai Hermit.

Myofascial pain syndrome is a common problem that can develop at any age. This study compares the efficacy of the court-type traditional Thai massage (CTTM) to the Thai hermit exercise (THE) in improving the cervical range of motion (CROM) and reducing pain in the upper trapezius muscle. In this study, 46 patient subjects were randomized into 2 groups, with 1 group administered CTTM and the other administered THE. Prior to and following the experiment, their demographic characteristics, pain levels and CROM were measured using a visual analog scale (VAS) and a goniometer, respectively. Data was then analyzed using descriptive statistics, percentage, mean, and standard deviation, as well as inferential statistics. The findings indicate that subjects in both groups demonstrated significantly lower pain and significantly better CROM (P < 0.05). In terms of comparative treatment between the CTTM and THE groups, the results were not found to differ in the range of motion, but a clear difference in pain level measured by VAS was found, in which CTTM provides a better way of reducing pain at the trigger point than THE (P < 0.05). From the findings, it can be concluded that both CTTM and THE are comparably efficacious therapies for myofascial pain in the upper trapezius muscle.

Muscle network topology analysis for the classification of chronic neck pain based on EMG biomarkers extracted during walking.

Neuromuscular impairments are frequently observed in patients with chronic neck pain (CNP). This study uniquely investigates whether changes in neck muscle synergies detected during gait are sensitive enough to differentiate between people with and without CNP. Surface electromyography (EMG) was recorded from the sternocleidomastoid, splenius capitis, and upper trapezius muscles bilaterally from 20 asymptomatic individuals and 20 people with CNP as they performed rectilinear and curvilinear gait. Intermuscular coherence was computed to generate the functional inter-muscle connectivity network, the topology of which is quantified based on a set of graph measures. Besides the functional network, spectrotemporal analysis of each EMG was used to form the feature set. With the use of Neighbourhood Component Analysis (NCA), we identified the most significant features and muscles for the classification/differentiation task conducted using K-Nearest Neighbourhood (K-NN), Support Vector Machine (SVM), and Linear Discriminant Analysis (LDA) algorithms. The NCA algorithm selected features from muscle network topology as one of the most relevant feature sets, which further emphasize the presence of major differences in muscle network topology between people with and without CNP. Curvilinear gait achieved the best classification performance through NCA-SVM based on only 16 features (accuracy: 85.00%, specificity: 81.81%, and sensitivity: 88.88%). Intermuscular muscle networks can be considered as a new sensitive tool for the classification of people with CNP. These findings further our understanding of how fundamental muscle networks are altered in people with CNP.

Comparison of the effects of extracorporeal shockwave treatment with kinesiological taping treatments added to exercise treatment in myofascial pain syndrome.

BACKGROUND: Although studies examined kinesiological taping (KT) and extracorporeal shock wave therapy (ESWT) in myofascial pain syndrome (MPS), no study has yet compared these two treatments. OBJECTIVE: This study aimed to compare the efficacy of KT and ESWT on pain, pain threshold, functional level and neck movements in the treatment of MPS, which is an important cause of disability and constitutes 50-80% of chronic painful diseases. METHODS: Two hundred and sixty-two patients diagnosed with MPS in the upper part of the unilateral trapeze muscle were included in the study. The patients were divided into three groups according to the treatment they received: Group 1 (n= 75): ESWT + exercise, Group 2 (n= 82): KT + exercise, Group 3 (n= 105) and the latter receiving only exercise therapy (control group). Visual analog scale (VAS), pain threshold with algometer, Neck Disability Index (NDI), and neck contralateral lateral flexion angle were assessed before and three months after treatment. RESULTS: VAS, pain threshold, NDI and contralateral flexion angle values after treatment improved significantly in the ESWT and KT groups (p< 0.05) compared to the control group. The level of improvement in the ESWT group was higher (p< 0.05) than in the KT group in terms of VAS, pain threshold and NDI scores. CONCLUSION: Exercise, KT and ESWT applications in MPS were effective in all of the parameters examined. However, the ESWT + exercise therapy was more effective in terms of pain, pain threshold and disability.

Patients with episodic migraine show increased T2 values of the trapezius muscles - an investigation by quantitative high-resolution magnetic resonance imaging.

BACKGROUND: Neck pain is frequent in patients with migraine. Likewise, evidence for inflammatory processes in the trapezius muscles is accumulating. However, non-invasive and objectively assessable correlates are missing in vivo. METHODS: Twenty-one subjects with episodic migraine (mean age: 24.6 ± 3.1 years, 18 females) and 22 controls (mean age: 23.0 ± 2.2 years, 17 females) without any history of headache prospectively underwent physical examination and quantitative magnetic resonance imaging of the trapezius muscles. A T2-prepared turbo spin-echo sequence was acquired for manual segmentation of the trapezius muscles and extraction of mean T2 values. RESULTS: There were no statistically significant differences regarding age, sex, body mass index, or number of myofascial trigger points (mTrPs) between groups. All patients with migraine presented with mTrPs in the trapezius muscles. T2 of the entire trapezius muscles was significantly higher in the migraine group when compared to controls (31.1 ± 0.8 ms vs. 30.1 ± 1.1 ms; p = 0.002). CONCLUSIONS: Elevated T2 values of the trapezius muscles may indicate subtle inflammatory processes within musculature among patients with migraine because T2 increase is likely to stem from edematous changes. Future work may validate this finding in larger cohorts, but muscle T2 might have potential to develop into a viable in vivo biomarker for muscular affection in migraine.

Can a metric combining arm elevation and trapezius muscle activity predict neck/shoulder pain? A prospective cohort study in construction and healthcare.

OBJECTIVE: To determine whether a composite metric of arm elevation and trapezius activity (i.e. neck/shoulder load) is more strongly associated with the 2-year course of neck and shoulder pain intensity (NSPi) among construction and healthcare workers than each exposure separately. METHODS: Dominant arm elevation and upper trapezius muscle activity were estimated in construction and healthcare employees (n = 118) at baseline, using accelerometry and normalized surface electromyography (%MVE), respectively. At baseline and every 6 months for 2 years, workers reported NSPi (score 0-3). Compositions of working time were determined for arm elevation (< 30°; 30-60°; > 60°), trapezius activity (< 0.5%; 0.5-7.0%; > 7.0%MVE), and a composite metric "neck/shoulder load" (restitution, low, medium, and high load). Associations between each of these three compositions and the 2-year course of NSPi were determined using linear mixed models. RESULTS: Associations between exposure compositions and the course of NSPi were all weak and in general uncertain. Time spent in 0.5-7.0%MVE showed the largest and most certain association with changes in NSPi during follow-up (ß = - 0.13; p = 0.037; corresponding to a -0.01 change in NPSi every 6 months). Among pain-free workers at baseline, medium (ß = - 0.23; p = 0.039) and high (ß = 0.15; p = 0.031) neck/shoulder load contributed the most to explaining changes in NSPi. CONCLUSION: The composite metric of neck/shoulder load did not show a stronger association with the course of NSPi than arm elevation or trapezius activity alone in the entire population, while some indications of a stronger association were found among those who were pain-free at baseline.

Reliability of shoulder muscle stiffness measurement using strain ultrasound elastography and an acoustic coupler.

PURPOSE: Abnormal increases in muscle tone can be caused by various musculoskeletal disorders. The objective of this study was to evaluate intratester and intertester reliabilities in measuring the stiffness of the shoulder muscles using strain ultrasound elastography (USE) and an acoustic coupler. METHOD: Tissue stiffness was measured in the trapezius muscle and in the supraspinatus muscle of healthy young volunteers. RESULTS: The mean strain ratios measured by two experienced shoulder surgeons were significantly higher in the trapezius muscle than in the supraspinatus muscle (P < 0.001). Intratester reliability was rated as moderate to substantial for the trapezius muscle and substantial for the supraspinatus muscle. Intertester reliability was substantial for both muscles, with an intraclass correlation coefficient (2,1) of 0.62 [95% confidence interval (CI) 0.28-0.82] for the trapezius muscle and 0.69 (95% CI 0.40-0.86) for the supraspinatus muscle. CONCLUSIONS: We found substantial intratester and intertester reliabilities for the trapezius and supraspinatus muscles, suggesting that USE represents a promising modality for measuring the stiffness of shoulder muscles. However, the clinical application of this method will require the development of a device that can standardize the scanning technique to further increase the reliability.

Influence of quantified dry cupping on soft tissue compliance in athletes with myofascial pain syndrome.

PURPOSE: This study aimed to develop a quantitative dry cupping system that can monitor negative pressure attenuation and soft tissue pull-up during cupping to quantify soft tissue compliance. METHODS: Baseball players with myofascial pain syndrome were recruited to validate the benefits of cupping therapy. Nine of 40 baseball players on the same team were diagnosed with trapezius myofascial pain syndrome; another nine players from the same team were recruited as controls. All participants received cupping with a negative pressure of 400 mmHg for 15 minutes each time, twice a week, for 4 weeks. Subjective perception was investigated using upper extremity function questionnaires, and soft tissue compliance was quantified objectively by the system. RESULTS: During the 15-minute cupping procedure, pressure attenuation in the normal group was significantly greater than that in the myofascial group (p = 0.017). The soft tissue compliance in the normal group was significantly higher than that in the myofascial group (p = 0.050). Moreover, a 4-week cupping intervention resulted in an obvious increase in soft tissue lift in the myofascial pain group (p = 0.027), although there was no statistical difference in the improvement of soft tissue compliance. Shoulder (p = 0.023) and upper extremity function (p = 0.008) were significantly improved in both groups, but there was no significant difference between the two groups. CONCLUSION: This quantitative cupping monitoring system could immediately assess tissue compliance and facilitate the improvement of soft tissues after cupping therapy. Hence, it can be used in athletes to improve their functional recovery and maintain soft tissues health during the off-season period.

Interrater and Intrarater Reliability and Minimum Detectable Change of Ultrasound for Active Myofascial Trigger Points in Upper Trapezius Muscle in Individuals With Shoulder Pain.

OBJECTIVE: We sought to investigate the interrater and intrarater reliability of ultrasound and the minimum detectable change (MDC) for the trigger points (TrPs) active in the upper trapezius (UT) muscle in individuals with shoulder pain. METHODS: Forty individuals with shoulder pain were investigated for the presence of active TrPs in the UT muscle by means of ultrasound for the parameters of gray scale, muscle thickness of UT muscle at rest, and contraction and area of TrPs. The intrarater reliability was performed on 2 days, and interrater reliability on the same day. For the gray scale, the reliability was evaluated using the kappa coefficient (κ), while the other parameters were measured by the intraclass correlation coefficient (ICC), standard error of measurement (SEM), and MDC. RESULTS: For the gray scale, the intrarater agreement was almost perfect (κ = 1.00) and the interrater agreement was substantial (κ = 0.75). The intrarater and interrater reliability were excellent for most of the parameters, except for the area of TrPs (intrarater: ICC = 0.71, substantial; interrater: ICC = 0.52, substantial). The MDC for intrarater reliability varied between 0.04 and 0.05 (SEM% between 2.4% and 38.87%), and that for interrater reliability ranged from 0.05 to 0.07 (SEM% between 3.18% and 55.10%), with a higher value for area. CONCLUSION: Parameters such as gray scale, resting muscle thickness, and muscle contraction of the UT muscle, obtained through ultrasound, showed excellent intrarater and interrater reliability with low SEM%. The intrarater and interrater reliability for the area deserves a caveat regarding their use.

Shoulder pain and scapular dyskinesis associated with lower trapezius dysplasia - A case report.

BACKGROUND: Scapular dyskinesis (SD) has been associated with shoulder soft-tissue tightness as well scapular muscle strength and/or activation deficits. Inadequate development of the trapezius muscle (trapezius dysplasia) is a relatively rare condition inconsistently associated with shoulder dysfunction. CASE DESCRIPTION: a 24-year old male complaining of left scapular area pain associated with SD and scapular muscle weakness was noted to present with a smaller ipsilateral lower trapezius (LT). Further inquiry including electromyography, rehabilitative ultrasound imaging (RUSI) and magnetic resonance imaging ruled out nerve palsy and demonstrated a hypoplastic left LT. This led to a greater emphasis on serratus anterior (SA) training along with the addition of neuromuscular electrical stimulation of the LT. OUTCOMES: Following 12 sessions over a 5-month period the patient reported no pain or functional deficits, and was able to resume all recreational activities. The patient's subjective shoulder value increased from 55% to 80%, and LT strength was markedly improved. DISCUSSION: Scapular muscle dysplasia may represent a less recognized cause of SD. A more thorough inspection of scapular muscle shape and orientation, possibly augmented by RUSI may be indicated in patients presenting with SD. Neuromuscular electrical stimulation is a potentially useful modality for addressing scapular muscle activation and strength deficits and future research into its efficacy under these circumstances may be warranted.

Association of Both Scapular Upward Rotation and Scapulothoracic Muscle Lengths With Shoulder Pain, Function, and Range of Movement.

OBJECTIVE: Our aim was to analyze whether shoulder pain is related to scapular upward rotation (SUR) or to the lengths of the pectoralis minor and levator scapulae muscles. METHODS: This cross-sectional, observational study was carried out in 3 primary-care centers; 54 individuals with chronic shoulder pain participated. Scapular upward rotation and the lengths of the pectoralis minor and levator scapulae muscles were assessed. RESULTS: The level of association was small between shoulder pain and function and (1) the lengths of the pectoralis minor (r = 0.08, P = .93) and levator scapulae (r = -0.01, P = .57) muscles and (2) SUR at 45° (r = 0.17, P = .21), 90° (r = 0.08, P = .57), and 135° (r = 0.10, P = 0.45) of shoulder elevation. CONCLUSION: The relationship was small between shoulder pain and function and (1) SUR (45°, 90°, and 135° of shoulder elevation) and (2) the lengths of the pectoralis minor and levator scapulae muscles. Thus, the use of SUR and pectoralis minor and levator scapulae lengths in shoulder assessment should be undertaken with caution. Other factors such as psychological factors, central/peripheral sensitization, and intrinsic properties of the tissue have to be taken into account.

Electromyographic analysis of selected shoulder muscles during a series of exercises commonly used in patients with symptomatic degenerative rotator cuff tears.

BACKGROUND: In the nonoperative treatment of degenerative rotator cuff (RC) tears, exercise therapy is advocated. Exercises focusing on strengthening the anterior deltoid (AD) and the scapular muscles are proposed to compensate for RC dysfunction. However, the amount of electromyographic (EMG) activity in these muscles during these exercises remains unclear. Moreover, it is unknown whether muscle activity levels during these exercises alter with increasing age. Therefore, the purpose of this study was to evaluate EMG activity in the deltoid and scapular muscles during 2 series of commonly used shoulder rehabilitation exercises and assess possible age-related changes in muscle activity. METHODS: Fifty-five healthy participants (aged 18-60 years) participated in this study. Surface EMG activity was measured in 8 shoulder girdle muscles during a progression of a closed chain elevation program (bench and wall slides) and during a progression of previously published AD exercises. In addition, muscle activity was compared between 3 age categories (18-32 years, 33-46 years, and 47-60 years). RESULTS: The proposed progressions exhibited increasing activity from <10% of maximal voluntary isometric contraction to >20% of maximal voluntary isometric contraction for the AD for both exercise programs and for the middle deltoid, upper trapezius, and middle trapezius during the closed chain elevation exercises. Activity levels in the other muscles remained <20% throughout the progression. Age-related analysis revealed increased activity in the AD, infraspinatus, and middle trapezius and decreased lower trapezius activity during the bench and wall slides. No age-related changes were noted for the AD exercises. CONCLUSION: These findings may assist the clinician in prescribing appropriate progressive exercise programs for patients with symptomatic RC tears.

Relationship between trapezius muscle hardness and transverse cervical artery flow in association with neck and upper-back stiffness.

Neck and upper-back stiffness is a common discomfort encountered occasionally in daily life among otherwise healthy subjects. The pathogenesis of this condition could be attributable to increased tension in muscles such as the trapezius muscle (TM). The transverse cervical artery (TCA) is one of the feeding arteries for the TM, and TCA flow is reportedly related to symptoms of neck and upper-back stiffness. This study quantitatively investigated relationships between TM hardness and TCA hemodynamics as evaluated on Doppler sonography. Questionnaires regarding neck and upper-back stiffness, muscle hardness measurements obtained using a muscle hardness meter and examinations of TCA hemodynamics using Doppler sonography were performed on 55 healthy young adults (25 males, 30 females; mean age, 22 ± 2 years). Subjects displaying neck and upper-back stiffness actually exhibited high muscle hardness (median, 14.0; interquartile range (IQR), 12.9-18.0) compared to those without the symptom (median, 12.0; IQR, 9.9-14.0; p = .002). Peak systolic velocity in the TCA on Doppler sonography was lower in subjects with the symptom (median, 65.1 cm/s; IQR 59.6-72.5 cm/s) than in those without the symptom (median, 72.5 cm/s; IQR 66.5-84.2 cm/s; p = .012). Resistive index in the TCA was high (r2  = .605, p = .014) with increasing TM hardness, particularly among male subjects with the symptom. The present study suggests that high resistance and low blood flow velocity in the TCA could be closely associated with the underlying pathogenesis of neck and upper-back stiffness.