Background Pelvic girdle pain (PGP) and sacroiliac joint (SIJ) dysfunction/pain are considered frequent contributors to low back pain (LBP). Like other persistent pain conditions, PGP is increasingly recognized as a multifactorial problem involving biological, psychological, and social factors. Perspectives differ between experts and a diversity of treatments (with variable degrees of evidence) have been utilized. Objective To develop a collaborative model of PGP that represents the collective view of a group of experts. Specific goals were to analyze structure and composition of conceptual models contributed by participants, to aggregate them into a metamodel, to analyze the metamodel's composition, and to consider predicted efficacy of treatments. Design To develop a collaborative model of PGP, models were generated by invited individuals to represent their understanding of PGP using fuzzy cognitive mapping (FCM). FCMs involved proposal of components related to causes, outcomes, and treatments for pain, disability, and quality of life, and their connections. Components were classified into thematic categories . Weighting of connections was summed for components to judge their relative importance. FCMs were aggregated into a metamodel for analysis of the collective opinion it represented and to evaluate expected efficacy of treatments. Results From 21 potential contributors, 14 (67%) agreed to participate (representing six disciplines and seven countries). Participants' models included a mean (SD) of 22 (5) components each. FCMs were refined to combine similar terms, leaving 89 components in 10 categories . Biomechanical factors were the most important in individual FCMs. The collective opinion from the metamodel predicted greatest efficacy for injection, exercise therapy, and surgery for pain relief. Conclusions The collaborative model of PGP showed a bias toward biomechanical factors. Most efficacious treatments predicted by the model have modest to no evidence from clinical trials, suggesting a mismatch between opinion and evidence. The model enables integration and communication of the collection of opinions on PGP.

Synopsis Although biomechanics plays a role in the development and perhaps the persistent or recurrent nature of low back pain (LBP), whether biomechanics alone can provide the basis for intervention is debated. Biomechanics, which refers to the mechanics of the body, including its neuromuscular control, has been studied extensively in LBP. But, can gains be made in understanding LBP by research focused on this component of biology in the multifactorial biopsychosocial problem of LBP? This commentary considers whether biomechanics research has the potential to advance treatment of LBP, and how likely it is that this research will lead to better treatment strategies. A point-counterpoint format is taken to present both sides of the argument. First, the challenges faced by an approach that considers biomechanics in isolation are presented. Next, we describe 3 models that place substantial emphasis on biomechanical factors. Finally, reactions to each point are presented as a foundation for further research and clinical practice to progress understanding of the place for biomechanics in guiding treatment of LBP. J Orthop Sports Phys Ther 2019;49(6):425–436. Epub 15 May 2019. doi:10.2519/jospt.2019.8825

The principles of form and force closure were introduced to describe the complex mechanism of sacroiliac joint (SIJ) stability. Form closure refers to a theoretical stable state of a joint with close fitting articular surfaces, where no extra forces are needed to maintain the stable state of the system during loading and unloading situations. If the sacrum would fit in the pelvis with perfect form closure, no lateral compressional forces would be needed to maintain stability. However, such a construction would make mobility practically impossible. Force closure is the theoretical state where lateral force and friction resulting in joint compression, are required for the joint to withstand a vertical load. Structures that contribute to SIJ stability via “form closure” include (1) the configuration of the interfacing joint surfaces, along with dorsocranial “wedging” of the sacrum into the ilia; (2) the corresponding ridges and grooves of the articular surfaces of the SIJs and resultant high coefficient of friction; and (3) the integrity of the binding ligaments, which are among the strongest in the body. Shearing forces absorbed in the SIJ occur because of a combination of person‐specific anatomical features. This results in unique form and force closure situations that provide effective and tailored joint accommodation that balance both friction and compression in the joint. Force closure occurs because of altered joint reaction force via taut ligaments, fascia, muscles, and the ground reaction force they are reacting to at the moment. In the ideal state, force closure creates a perpendicular compressive reaction force to the SIJ to adapt and overcome the forces of gravity. In order for force closure to be effective, sacral nutation must occur and is considered to be anticipatory for joint loading. Sacral nutation results in tensing all of the dorsal SIJ ligaments (interosseous, dorsal sacroiliac) with the exception of one, the long dorsal ligament (LDL). This prepares the pelvis to absorb and increase in load. As a result, the posterior ilium are pressed together causing an increase in SIJ compression. This review will discuss the importance of understanding form and force closure principles because they are related to understanding the relationship of anatomy and function of the SIJ.

Overuse injuries are suggested to result from repetitive microdamage eliciting pain in the affected tissue. Therapy commonly focuses on the area of symptom localization; however, such approach may oversimplify the true etiopathology. This review hypothesizes that the development of some sports-related soft tissue disorders, such as plantar fasciitis or lumbago, is promoted by pathologically altered force transmission from anatomically connected structures.

FIGURE 1. A metamodel illustrating factors (colored circles) contributing to low back pain, disability, quality of life, and other outcomes (white circles) and their interactions (colored lines). This metamodel was constructed with input from the multidisciplinary panel of 27 experts in preparation for the symposium at the 26th Annual Meeting of the North American Spine Society (2017). Diameters of the circles are proportional to the number of experts identifying these factors and the number and strength of connections with other factors.

The fascial system builds a three-dimensional continuum of soft, collagen-containing, loose and dense fibrous connective tissue that permeates the body and enables all body systems to operate in an integrated manner. Injuries to the fascial system cause a significant loss of performance in recreational exercise as well as high-performance sports, and could have a potential role in the development and perpetuation of musculoskeletal disorders, including lower back pain. Fascial tissues deserve more detailed attention in the field of sports medicine. A better understanding of their adaptation dynamics to mechanical loading as well as to biochemical conditions promises valuable improvements in terms of injury prevention, athletic performance and sports-related rehabilitation. This consensus statement reflects the state of knowledge regarding the role of fascial tissues in the discipline of sports medicine. It aims to (1) provide an overview of the contemporary state of knowledge regarding the fascial system from the microlevel (molecular and cellular responses) to the macrolevel (mechanical properties), (2) summarise the responses of the fascial system to altered loading (physical exercise), to injury and other physiological challenges including ageing, (3) outline the methods available to study the fascial system, and (4) highlight the contemporary view of interventions that target fascial tissue in sport and exercise medicine. Advancing this field will require a coordinated effort of researchers and clinicians combining mechanobiology, exercise physiology and improved assessment technologies.

To investigate coronal plane trunk asymmetry (TA) and its association with sagittal postural alignment in healthy subjects before pubertal peak growth.

Objective: Examine whether implementing an active lumbopelvic control strategy during high load prone lumbar extension exercises affects posterior extensor chain recruitment and lumbopelvic kinematics.Methods: Thirteen healthy adults acquired an optimal active lumbopelvic control strategy during guided/home-based training sessions. During the experimental session electromyography was used to evaluate the activity of the posterior extensor chain muscles during high load trunk/bilateral leg extension exercises with/without application of the strategy. Video-analysis was used to evaluate thoracic/lumbar/hip angles.Results: Implementing the active lumbopelvic control strategy decreased the lordotic angle during trunk (p = 0.045; -3.2 degrees) and leg extension exercises (p = 0.019; -degrees 10). The hip angle was solely affected during trunk extension (p < 0.001; +9.2 degrees). The posterior extensor chain (i.e. mean of the relative activity of all muscles (%MVIC) was recruited to a higher extent (p = 0.026; + 9%) during trunk extension exercises performed with active lumbopelvic control. Applying the strategy during leg extension exercises lead to less activity of longissimus thoracic (p = 0.015; -10.2%) and latissimus dorsi (p = 0.010; -4.4%), and increased gluteus maximus activity (p <= 0.001; +16.8%).Conclusions: When healthy people are taught/instructed to apply an active lumbopelvic control strategy, this will decrease the degree of lumbar (hyper)lordosis and this influences the recruitment patterns of trunk and hip extensors. Hence, the possible impact on predetermined training goals should be taken into account by trainers.

Manual therapy for musculoskeletal pain syndromes : , Manual therapy for musculoskeletal pain syndromes : , کتابخانه دانشگاه علوم پزشکی و خدمات بهداشتی درمانی کرمان

To investigate the factors related to the 1-month period prevalence of low back pain (LBP), neck pain (NP) and thoracic spine pain (TSP) in young adolescents, thereby considering potential correlates from the physical, sociodemographic, lifestyle, psychosocial and comorbid pain domains.

Trunk extension exercises are used to train endurance and strength of the trunk extensor muscles. Appropriate exercise dosage is crucial to achieve specific training effects, however literature describing the relation between the predetermined exercise intensity and the actual trunk extensors activity is scarce and inconclusive. To examine whether the actual activity of the thoracic and lumbar extensors during extensions exercises correspond with the predetermined intensity, electromyographic evaluation of the trunk extensors was performed during trunk extension exercises at various intensities expressed as percentages of 1-RM. The 1-RM was predetermined using 2 different methods: (1) through direct estimation by determining the maximum isometric force produced during semi-seated trunk extension on a Tergumed rehabilitation device, (2) through indirect estimation calculated based on the relation between the maximum number of repetitions of trunk extension from prone lying on a variable angle chair and the submaximal resistance at which the repetitions were performed as presented on the Holten-diagram. The total trunk muscle activity during extension exercises performed semi-seated on a rehabilitation device or from prone lying corresponds with the predetermined dosage using both estimation methods. The indirect estimation method more accurately predicts the actual trunk extensor activity for low load training than for high load training. However, the direct estimation method is suitable to closely predetermine the load and actual trunk extensors activity during high load exercises. A shift from a differential recruitment between the thoracic and lumbar extensors at low intensities to a more homogenous recruitment at high intensities is observed during semi-seated trunk extension exercises. During prone extension exercises both muscle groups equally contribute to the total muscle work regardless of the exercise intensity. Based on these findings suggestions regarding the appropriate choice of estimation and performance method are made.