Fig 15 - uploaded by Stephen M Levin
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2 Fixing a point in space. Four vectors of restraint define a minimum system in which a point is fixed in space (D). However, turbining is still possible (E). An additional eight restraints are needed to rigidly fix a point. (Adapted from Fuller 1975.)
Source publication
The paradigm
According to conventional wisdom, the human spine behaves as
an architectural column or pillar and transfers the superincumbent
weight through the sacrum, to the ilium, through the hips and
down the lower extremities. The pillar holds the base in place
with the pressing weight of gravity. In this model, the sacrum, as
the base, lo...
Citations
... Варто зазначити, що деякі учені не погоджуються з ідеєю тенсегріті-моделі, вважаючи її неправдивою моделлю будови тіла та рухів людини [5,25]. Проте ортопед Стівен Леві, який ввів поняття «біотенсегріті» більше 30 років тому, навпаки розглядає тіло людини як цілісну кон-струкцію, яка являє собою ієрархічну систему, компоненти якої на всіх рівнях побудовані за принципом тенсегріті [16][17][18]. Але існуючі моделі та уявлення про опорно-руховий апарат людини як механічну систему із стиснутих та розтягнутих зав'язків (представлених кістками та м'язами відповідно) не є досконалою та потребує подальших досліджень і доопрацювань [5]. ...
Резюме. Надлишкова маса тіла є важливим фактором ризику утворення болю, переважно у колінних суглобах, внаслідок надмірного систематичного механічного навантаження та обмеження фізичної активності, що призводить до слабкості м’язово-зв’язкового апарату й порушення конгруентності суглобових поверхонь. Збільшення маси тіла створює передумови перенавантаження колінних суглобів. Мета. Висвітлення актуальності проблеми виникнення болю у колінах, спричинених збільшенням маси тіла, тобто внаслідок збільшення осьового навантаження на колінні та суміжні із ними суглоби, а також розгляд способів підвищення ефективності фізичної терапії жінок із надмірною масою тіла шляхом розробки удосконаленої фізико-математичної моделі нижньої кінцівки, що сприятиме більш точному аналізу впливу надмірної ваги на колінні та суміжні суглоби. Методи. Аналіз науково-методичної літератури, інтрументальні методи, діагностика. Результати. Відомо, що втрата ваги призводить до зменшення навантаження на суглоби, а отже, потенційно затримує прогресування запальних процесів і у колінних суглобах. Основна причина розвитку болю у колінах – невідповідність між механічним навантаженням на суглобову поверхню хряща та її здатністю чинити опір цьому навантаженню, що викликає явища дегенерації та деструкцій. Робота містить огляд того, як за допомогою методів геометричного формоутворення й чисельного моделювання можна вдосконалити тенсегріті-модель нижньої частини тіла для того, щоб оцінити сили натягу та стискання у колінному й суміжних суглобах. Для реалістичної побудови моделі нижньої частини опорно-рухового апарату знадобиться провести ретельний аналіз специфіки розподілу внутрішніх зусиль у м’язах та кістках ніг і таза людини. Це дасть змогу зрозуміти яким саме чином надмірна вага, розподілена в різних частинах тіла, призводить до задіяння відповідних груп м’язів та їх комбінацій у непритаманний для людини зі збалансованою вагою спосіб, що спричиняє неправильний характер розподілу внутрішніх зусиль у суглобах. Проаналізовано, як удосконалена тенсегріті-модель нижньої частини опорно-рухового апарату людини буде сприяти покращенню розуміння розподілу навантажень на колінний та суміжні з ним суглоби, допомагати наочності вивчення та оцінювання впливу надмірної ваги тіла на колінні суглоби та створювати передумови для вдосконалення програм з фізичної терапії, що допоможе підвищити показники фізичного та психоемоційного стану, покращити якість життя. Ключові слова: надмірна вага, колінний суглоб, навантаження, біль, тансегріті-модель, опорно-руховий апарат, фізична терапія.
... In normal pelvic kinematics, the sacrum is suspended between the ligaments and muscles of the posterior pelvis (29). The primary aim of SIJ arthrodesis is to relieve pain of the SIJ by immobilizing the joint within the pelvis. ...
Background:
Sacroiliac joint arthrodesis is an ultima ratio treatment option for sacroiliac joint dysfunction. Fusion drastically reduces sacroiliac joint movement providing long-lasting pain-relief associated with tension-relief to the innervated sacroiliac joint structures involved in force closure.
Objectives:
To display the bone mineralization distribution patterns of the subchondral bone plate in 3 distinct regions (superior, anterior, and inferior) of the sacral and iliac counterparts of the sacroiliac joint pre- and post-sacroiliac joint arthrodesis and compare patterns of sacroiliac joint dysfunction post-sacroiliac joint fusion with sacroiliac joint dysfunction pre- arthrodesis patterns and those from healthy controls.
Study design:
An observational study.
Setting:
The research took place at the University of Basel, Switzerland, where the specific image analysis program (Analyze, v7.4, Biomedical Imaging Resources, Mayo Foundation, Rochester, NY, USA) was made available.
Methods:
Mineralization densitograms of 18 sacroiliac joint dysfunction patients pre- and post-sacroiliac joint arthrodesis (>= 6, >= 12, and >= 24 months post-surgery) were obtained using computed tomography osteoabsorptiometry. For each patient, pre- vs. post-surgery statistical comparisons were undertaken, using the Hounsfield unit values derived from the subchondral mineralization of superior, anterior, and inferior regions on the iliac and sacral auricular surfaces. Post-operative values were also compared to those from a healthy control cohort (n = 39).
Results:
In the pre-operative cohort at all 3 follow-up times, the superior iliac region showed significantly higher Hounsfield unit values than the corresponding sacral region (P < 0.01). Mineralization comparisons were similar for the sacrum and ilium in the anterior and inferior regions at all follow-up points (P > 0.5) with no surgery-related changes. Sacral density increased significantly in the post-operative state; not observed on the ilium. Post-operative sacroiliac joints showed a significantly increased mineralization in the superior sacrum after >= 6 months (P < 0.05), not replicated after >= 12 nor >= 24 months. Further comparison of post-operative scans versus healthy controls revealed significantly increased mineralization in the superior sacral region at (>=) 6, 12, and 24 months (P < 0.01), likely related to bone grafting, and in the anterior and inferior regions in post-operative scans at >= 12 and >= 24 months follow-up (P < 0.05).
Limitations:
The given study is limited in sample size. Post-operative computed tomography scans had screws which may have left artifacts or partial volume effects on the surfaces. Healthy controls were different patients to the sacroiliac joint dysfunction and post-operative cohorts. Both cohorts were age-matched but this comparison did not take into account potential population differences. Size differences in the regions may have also been an influencing factor of the results as the regions were based on the size and shape of the articular surface.
Conclusions:
Sacroiliac joint arthrodesis results in an increased morpho-mechanical conformity in the anterior and inferior sacrum and reflects variable morpho-mechanical density patterns compared to the healthy state due to permanent alterations in the kinematics of the posterior pelvis.
... Further soft tissues, including the dense SIJ ligaments, also play a crucial role in suspending the sacrum within the ilia (Hammer et al., 2009(Hammer et al., , 2013Rosatelli et al., 2006;Steinke et al., 2010). The 'tensegrity model' describes the sacrum as being suspended between meshes of ligaments and muscles, with the irregularity of the auricular surfaces aiding with the suspension (Levin, 2007). These suspensory structures provide the pelvic ring with structure and stability and allow the transmission of forces through the pelvis through active compression and tension (Pardehshenas et al., 2014). ...
... Since then, biotensegrity has been described in the cranium (Scarr, 2008), shoulder (Levin, 1997), elbow (Scarr, 2012), spine (Levin, 2002), pelvis (Levin, 2007;Pardehshenas et al., 2014), knee (Hakkak et al., 2015), foot (Wilson and Kiely, 2016), cellular cytoskeleton (Ingber et al., 2014), extra-cellular matrix and fascia (Guimberteau and Armstrong, 2015;Tadeo et al., 2014), molecules (Edwards et al., 2012) and the haptic perceptual system (Turvey and Fonseca, 2014); and applied in the development of prosthetic limbs (Lessard et al., 2016) and robotics (Lian et al., 2012;Caluwaerts et al., 2014). Levin (2002) introduced the term biotensegrity to distinguish this structural system in living tissues from the field of tensegrity engineering, which is related but contains some fundamental differences that do not apply in biology (Scarr, 2014 p 65). ...
The temporo-mandibular joint is a characteristic feature of mammalian development, and essential to mastication and speech, yet it causes more problems than any other joint in the body and remains the least understood. While it is generally accepted that the normal joint is loaded under compression, the problems and controversies surrounding this view remain unresolved and the disparity in opinion over its treatment continues. Although difficulties in the acquisition of reliable information have undoubtedly contributed to this situation, it is now considered that deficits in neural control and shortcomings in the underlying biomechanical theory and analysis have also played a part, and that a re-assessment from a different perspective could resolve these.
... The biotensegrity concept is based on the rules of physics first and from which everything else is derived (Levin, 1982(Levin, , 2006Scarr, 2014); and thus escapes the controversies surrounding the TMJ by revealing the flaws in current biomechanical theory. It has already been described in the shoulder (Levin, 1997), elbow (Scarr, 2012) spine (Levin, 2002), cranium (Scarr, 2008), pelvis (Levin, 2007;Pardehshenas et al., 2014), knee (Hakkak et al., 2015), cellular architecture (Huang et al., 2006;Ingber et al., 2014), etc. Biotensegrity is a structural design principle in biology that considers bones as compressional elements suspended within a global network of tensioned muscles, ligaments and fascial tissues, and that enables the structure itself to control complex mandibular movements and decompress the joint. A paper to follow will then provide a more complete explanation of biotensegrity principles and develop a new model of mandibular physiology that can be used to guide future research. ...
The temporo-mandibular joint causes more problems than any other in the body and is the least understood with the high incidence of associated symptomatology remaining a major cause for concern. This lack of knowledge is partly due to the difficulties in acquiring information as it is not easy to access and practical and ethical constraints have ensured the almost complete absence of reliable in vivo data on joint loading and muscle forces. Whilst the issue of joint compression was debated throughout much of the twentieth-century, it is now considered that short-comings in the underlying biomechanical theory and analysis have contributed to this uncertainty and stifled progress, and that a reassessment of mandibular motion from a different perspective could resolve this.
... Notwithstanding this, there is abundant and relevant theoretical research considering anatomical structures as tensegrities (e.g., Refs. 9,14,15,17,53); however, controversy exists. 16,54 Mathematical models of biotensegrity are simplified and sparse, but generally demonstrate feasibility of macroscopic tensegrity analysis, and yield results positively comparable to invivo force measurements. ...
Background: Tensegrity has been proposed as a unifying mechanism between structures at cellular, connective tissue and whole body level. Originating in the fields of sculpture and architecture, tensegrity has recently received increasing attention from practitioners and researchers of manual therapy. Notwithstanding this, evidence regarding the role of the tensegrity principle to manual therapy practice is lacking. Objective: This qualitative study explored the conception of tensegrity amongst manual therapy practitioners and how knowledge of the physical principle of tensegrity may influence manual therapy practitioners' clinical decision-making. Methods: Eight semi-structured interviews were conducted with participants from manual therapy, fascia research and/or manual therapy education fields, and analysed using grounded theory methods. Results: Data from this study indicates that tensegrity may inform clinical decision-making in manual therapy. A theory has been constructed that may help to explain aspects of manual therapy practitioners' approaches to tensegrity. Four such approaches to tensegrity were identified and elaborated on. Conclusion: This study suggests that apart from being of importance as a scientific model in the fields of architecture, engineering and biology, tensegrity may also be useful to the practice of manual therapy. Here, tensegrity may serve as a theoretical underpinning of previously conceived clinical models and subjective clinical experience, and may also inform decision-making processes by providing a biomechanical model of the human body.
... In contrast to the pelvic arch theory, some anatomists (Kapandji et al 1982;Grant 1989) and some clinicians (Dijkstra 2007;DonTigny 2007) theorize that the sacrum is hanging from the iliac bones. Levin (2007) proposes a suspensory system for the stability of the SI joints, a "wire-spoke bicycle wheel" model. In a bicycle wheel, tension-loaded spokes transmit compressive loads from the frame and the ground. ...
Purpose:
According to the conventional arch model of the pelvis, stability of the sacroiliac joints may require a predominance of form and force closure mechanisms: the greater the vertical shear force at the sacroiliac joints, the greater the reliance on self-bracing by horizontally or obliquely oriented muscles (such as the internal oblique). But what happens to the arch model when a person stands on one leg? In such cases, the pelvis no longer has imposts, leaving both the arch, and the arch model theory, without support. Do lumbopelvic muscle activation patterns in one-legged stances under load suggest compatibility with a different model? This study compares lumbopelvic muscle activation patterns in two-legged and one-legged stances in response to four levels of graded trunk loading in order to further our understanding the stabilization of the sacroiliac joints.
Methods:
Thirty male subjects experienced four levels of trunk loading (0%, 5%, 10% and 15% of body weight) by holding a bucket at one side, at three conditions: 1) two-legged standing with the bucket in the dominant hand, 2) ipsilateral loading: one-legged standing with the bucket in the dominant hand while using the same-side leg, and 3) contralateral loading: one-legged standing using the same leg used in condition 2, but with the bucket in the non-dominant hand. During these tasks, EMG signals from eight lumbopelvic muscles were collected. ANOVA with repeated design was performed on normalized EMG's to test the main effect of load and condition, and interaction effects of load by condition.
Results:
Latissimus dorsi and erector spinae muscles showed an antagonistic pattern of activity toward the direction of load which may suggest these muscles as lateral trunk stabilizers. Internal oblique muscles showed a co-activation pattern with increasing task demand, which may function to increase lumbopelvic stability (P < 0.05). No unilateral pattern of the internal obliques was observed during all trials.
Conclusions:
Our results suggest that the lumbopelvic region uses a similar strategy for load transfer in both double and single leg support positions which is not compatible with the arch analogy. Our findings are more consistent with a suspensory system (wire-spoke wheel model). If our proposed model holds true, the pelvic ring can only be integrated by adjusting tension in the spokes and by preserving rim integrity or continuity. Thus, we propose that in order to restore tension integrity throughout the pelvic ring, efforts to unlock restrictions, muscular correction of positional faults and lumbopelvic or even respiratory exercises following sacroiliac joint dysfunctions must be taken into consideration. Our hypothetical model may initiate thinking and act as a guide to future work based on a biomechanical approach to the problem of sacroiliac joint dysfunction.
... 2 Levin 11 visually examined normal bones during surgery and found that they never compressed each other in living subjects. This would imply that bones are held apart by soft tissues and the mechanics of the shoulder, 12 spine, 13 pelvis, 14 cranial vault 15 and distal radio-ulnar joint 16 have been described in this way, but these observations have not been widely recognized. ...
The elbow is conventionally described as a uniaxial hinge joint and the pivot of proximal forearm rotation; the joint surfaces guide motion, the ligaments maintain joint integrity and the muscles cause motion. However, this simplicity is less clear on detailed examination and masks uncertainties over its component structures and their functions. Elbow anatomy is examined from a tensegrity perspective with a re-assessment of these functions. Tensegrity structures, like the elbow, are inherently stable and maintain a balanced equilibrium during changes in shape because of ‘continuous tension’. Connective tissues mechanically integrate local and distantly related components into a single functional unit while proprioceptive sensors neurally influence motor activity; both control joint dynamics. It is suggested that this has relevance to understanding the commonly encountered but vague pathologies such as ‘tennis elbow’ and ‘repetitive strain injury’; the aetiologies of these conditions continue to be the subject of debate.
... G. Scarr + MODEL Ingber, 2003a;Levin, 2007). Curved compression elements ( Figure 32) differ from straight struts ( Figure 22) because their outer convex surfaces are actually under tension and inner concave surfaces under compression, but like the struts in a geodesic dome, biological materials deal with both types of loading as a result of their nano and micro structures (Gordon, 1978;Lakes, 1993;Puxkandl et al., 2002;Gao et al., 2003;Gupta et al., 2006;Brangwynne et al., 2006). ...
... Curved compression elements ( Figure 32) differ from straight struts ( Figure 22) because their outer convex surfaces are actually under tension and inner concave surfaces under compression, but like the struts in a geodesic dome, biological materials deal with both types of loading as a result of their nano and micro structures (Gordon, 1978;Lakes, 1993;Puxkandl et al., 2002;Gao et al., 2003;Gupta et al., 2006;Brangwynne et al., 2006). Inferences that this is ultimately due to their tensegrity construction have been made (Skelton et al., 2001;Levin, 2007;Ingber, 2008). In addition, when spheres are added to the outside of an icosahedron they do not close-pack completely, and an instability develops ( Figures 18def and 21a). ...
... The pelvis is also like a wheel with the iliac crests, anterior spines, pubis and ischia representing the outer rim; and the sacrum representing the hub, tied in with strong sacro-iliac, sacro-tuberous and sacro-spinous ligaments. Similarly, the femoral heads may function as hubs within the 'spokes' of the ilio-femoral, pubo-femoral and ischiofemoral ligaments (Levin, 2007). ...
SUMMARY: Many cultures throughout history have used the regularities of numbers and patterns as a means of describing their environment. The ancient Greeks believed that just five archetypal forms--the 'platonic solids'--were part of natural law, and could describe everything in the universe because they were pure and perfect. The formation of simple geometric shapes through the interactions of physical forces, and their development into more complex biological structures, supports a re-appreciation of these pre-Darwinian laws. The self-assembly of molecular components at the nano-scale, and their organization into the tensegrities of complex organisms is explored here. Hierarchies of structure link the nano and micro realms with the whole organism, and have implications for manual therapies.
