Since manual palpation is a subjective procedure for identifying and differentiate Myofascial Trigger Points -MTrPs-, the use of Shear Wave Elastography -SWE- as an objective alternative is increasing. This study aimed to analyze pain pressure thresholds -PPTs- and SWE differences between active MTrPs, latent MTrPs and control points located in the upper trapezius to analyze the association of SWE features with clinical severity indicators (e.g., pain extension area, PPTs, neck pain and neck disability). An observational study was conducted to calculate the correlation and to analyze the differences of sociodemographic, clinical and SWE features on 34 asymptomatic subjects with latent MTrPs and 19 patients with neck pain and active MTrPs. Significant PPT differences between active with latent MTrPs (p < 0.001) and control points (p < 0.001) were found, but no differences between latent MTrPs and control points (p > 0.05). No stiffness differences were found between active MTrPs with latent MTrPs or control points (p > 0.05). However, significant control point stiffness differences between-samples were found (p < 0.05). SWE showed no significant correlation with clinical severity indicators (p > 0.05). No stiffness differences between active and latent MTrPs were found. Neck pain patients showed increased control point stiffness compared with asymptomatic subjects. SWE showed no association with clinical severity indicators.

Background and Objectives: Dry needling (DN) is a technique that involves inserting a thin filament needle through the skin to target myofascial trigger points for the treatment of musculoskeletal pain and dysfunction. Despite its efficacy in a broad plethora of musculoskeletal pain conditions, its safety remains a topic of debate among clinicians and researchers. The aim of this study was to provide an overview of the current practice of DN through a national survey, focusing on the frequency of its use and the incidence of adverse events (AEs), considering factors including physiotherapist experience, clinical workload, the extent of training received by practitioners, and the use of ultrasound guidance. Materials and Methods: An online cross-sectional survey was conducted. Respondents were licensed physical therapists (PTs) working in Spain. The survey covered demographics, professional data, frequency of adverse effects, and if they use ultrasound routinary for guiding interventions. Results: A total of 422 PTs participated in the study, mostly having 21–60 h of DN training (38.6%), less than 2 years of experience (36%), and not using ultrasound during the interventions (85.5%). Post-needling soreness and bent needles were the most common AEs, with most severe events rarely reported. Adverse event frequencies varied significantly based on training hours, experience, patient percentage treated with DN, and weekly clinical dedication. Clinicians with more hours of DN training or fewer years of experience reported higher incidences of certain complications. Conclusions: DN is a common intervention among PTs, with minor AEs frequently occurring and major AEs being less common but still significant. The accidental puncture of non-desired structures highlights the necessity for improve training on anatomical landmarks, needle insertion depth, cross-sectional anatomy education, and patient monitoring. To ensure safe practice, emphasize comprehensive training, adhere to safety protocols, exercise caution, and prioritize the use of ultrasound-guide is encouraged.

Background/Objectives: The quadratus lumborum (QL) muscle is a key structure involved in patients with low back pain (LBP). Since the discriminative capability of morphological descriptors is uncertain and considering the high prevalence of myofascial trigger points and the poor reliability of manual palpation in this condition, developing a reliable procedure for assessing the QL’s tenderness is needed for facilitating the diagnosis and monitoring changes over time. We aimed to analyze the intra- and inter-examiner reliability of SWE for calculating the QL tenderness in patients with LBP. Methods: Using a convex transducer, longitudinal shear wave elastography (SWE) images of the QL muscle were acquired bilaterally twice in 52 volunteers with moderate LBP and disability by one experienced examiner and one novel examiner to measure shear wave speed and Young’s modulus as stiffness metrics. Results: Intra-examiner reliability estimates demonstrated high consistency independently of the examiner’s experience (intraclass correlation coefficients (ICCs) > 0.930) for both metrics. However, experienced examiners showed smaller minimal detectable changes. Additionally, inter-examiner reliability was lower, with ICCs ranging from 0.57 to 0.68, and significant differences in mean values between examiners (p < 0.01) were found. Conclusions: This procedure exhibited excellent intra-examiner reliability for assessing QL muscle stiffness in patients suffering LBP, indicating high repeatability of measurements when performed by the same examiner. In addition, experienced examiners demonstrated greater sensitivity in detecting real changes not attributed to measurement errors. However, inter-examiner reliability was moderate, highlighting the need for consistent examiner use to avoid measurement variability and averaging multiple measurements to enhance the accuracy.

Background and Objectives: Low back pain (LBP) is highly prevalent and often associated with altered muscle function, including in the quadratus lumborum (QL) muscle. While some studies have highlighted the clinical relevance of QL muscle stiffness in LBP, the findings remain inconsistent, and the role of this parameter in relation to clinical severity indicators is not well understood. Considering the high prevalence of myofascial trigger points among patients, objectively and reliably quantifying QL stiffness and its association with other clinical parameters could improve the identification of early stages of the condition before other alterations become apparent. Therefore, this study aimed to explore the association between QL stiffness and multiple indicators of LBP severity. Materials and Methods: A cross-sectional observational study was conducted involving the participation of seventy-six patients suffering from chronic LBP. An ultrasound scanner with shear-wave elastography (SWE) was used to determine the participants’ QL stiffness. Additional information was collected on LBP-associated pain intensity, disability, central sensitization, and quality of life. Results: QL muscle stiffness was negatively correlated with pain intensity (p < 0.01) and central sensitization (p < 0.01), and it was positively correlated with physical quality of life (p < 0.01). Muscle stiffness influenced the variance in pain intensity along with physical quality of life, central sensitization, and chronicity (together explaining 49% of the variance) but did not explain the variance in central sensitization. Conclusions: Assessing QL muscle stiffness in patients with LBP is recommended, as greater muscle softness is linked to higher pain intensity, central sensitization, and poorer physical quality of life. Regression analyses further highlighted that QL stiffness helps explain the variance in pain intensity, physical quality of life, central sensitization, and chronicity, but it did not directly affect the central sensitization variance.

Objective: This study aimed to determine latent myofascial trigger points and asymptomatic surrounding areas differences in pain pressure thresholds and shear-wave elastography metrics differences. Design: Latent myofascial trigger points and asymptomatic control points were identified within the infraspinatus muscle. A blinded examiner assessed the pain pressure thresholds and acquired three shear-wave elastography images of each location. Pain pressure threshold and shear-wave elastography scores were compared by location (myofascial trigger point and control) and gender. Finally, correlations among demographics, pain pressure thresholds, and shear-wave elastography data were calculated. Results: Forty participants were analyzed. Pain pressure thresholds were significantly lower in latent myofascial trigger points compared with control points in males (P = 0.003) and females (P < 0.001), and lower in females compared with males (myofascial trigger point P < 0.001; control point P = 0.006). No significant shear-wave elastography differences were found between myofascial trigger points and control points (P > 0.05) nor between males and females (myofascial trigger point and control points, P > 0.05). In contrast with the accepted myofascial trigger point definition, those areas with greater pain pressure thresholds exhibited greater stiffness via shear-wave elastography (P < 0.01). Conclusions: Although pain pressure threshold scores indicated significant differences in hyperirritability between latent myofascial trigger points and control points, shear-wave elastography measurements revealed no significant differences in muscle stiffness. Furthermore, muscle stiffness was significantly associated with greater pain pressure threshold scores, challenging the hypothesis that stiffer areas can be identified as myofascial trigger points or sources of pain.