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ACTIVE CONTRACTION OF THE THORACOLUMBAR FASCIA - INDICATIONS OF A NEW FACTOR IN LOW BACK PAIN RESEARCH WITH IMPLICATIONS FOR MANUAL THERAPY

Authors:
Robert Schleip at Technical University of Munich
Robert Schleip
Werner Klingler at Ulm University
Werner Klingler
Frank Lehmann-Horn at Ulm University
Frank Lehmann-Horn
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5th Interdisciplinary World Congress on Low Back & Pelvic Pain
Melbourne, November 2004 www.worldcongresslbp.com
ACTIVE CONTRACTION OF THE THORACOLUMBAR
FASCIA - INDICATIONS OF A NEW FACTOR IN LOW
BACK PAIN RESEARCH WITH IMPLICATIONS FOR
MANUAL THERAPY
Robert Schleip, Werner Klingler MD, Frank Lehmann-Horn PhD
Applied Physiology, Ulm University, Germany
Email: robert.schleip@medizin.uni-ulm.de
INTRODUCTION
The fascia and ligaments are usually considered to be a passive element in the neuro-myofascial
dynamics of joint stability. The presence of contractile connective tissue cells and the ability of
fascia to contract on its own suggests that fascia may play a more active role in joint dynamics and
regulation.
BACKGROUND AND PURPOSE
Tensile transmission across the thoracolumbar fascia (TLF) serves as an important element for
back stability(1). Previous viscoelastic examinations of the TLF exposed to in vitro isometric
stretch demonstrated an unexpected ability for autonomous fascial contraction within several
minutes (2). Since the musculature of visceral organs exhibits a similar capacity, a histological
examination of the TLF for intrafascial cells with smooth muscle like contractility had been
suggested (2,3). Contractile cells containing smooth muscle actin have been found not only in
wound healing and pathologically contracted fascia (Morbus Dupuytren, club foot, frozen
shoulder) but also in normal ligaments (4,5), tendons (6) and fascia (7,3). The current study
therefore examines the existence of cells containing contractile smooth muscle actin in the TLF.
Additionally some of the possible variables influencing TLF active contraction are investigated.
Figure1. Left side: tissue section of lumbar fascia from a man of 19 yrs with dense population of
cells staining positively for alpha smooth muscle actin (here in black) and with high degree of
collagen crimp. Right side: section from man of 76 yrs. with hardly any collagen crimping and no
positively stained cells in this area.
5th Interdisciplinary World Congress on Low Back & Pelvic Pain
Melbourne, November 2004 www.worldcongresslbp.com
MATERIAL AND METHODS
Immunohistochemistry: 39 tissue samples of the superficial lamina of the posterior layer of the
TLF at the level of L2 and L4 from 11 human cadavers of 3 different age groups were taken
(Group A: 19-26 yrs, 4 males. Group B: 54-56 yrs, 1 female, 2 male. Group C: 71-76 yrs, 1
female, 3 male). Samples were analyzed by immunohistochemistry for cells containing alpha
smooth muscle actin using a monoclonal antibody,
In vitro contraction tests: Test pieces of fresh porcine lumbar fascia (size 30 mm x 2 mm x 2 mm)
were dissected along the main longitudinal fiber direction. The samples were fixed at either end
and oriented vertically in an organ bath containing Krebs-Ringer solution (pH buffered, supplied
with 95% O2 and 5% CO2) at 35o C. Samples were prestretched with a constant 5% isometric
strain. Force registrations were performed after an adaptation period of at least 30 minutes to
ensure steady state conditions. The tension force of the tissue was recorded by a computer over a
testing period of 15 min., during which the tissue was either challenged with electrical stimulation
or with chemical stressors, thereby testing for a possible response to acetylcholine, caffeine, the
NO-donator glyceroltrinitrate, and a potassium enriched solution.
RESULTS
Immunohistochemistry: Cells containing alpha smooth muscle actin were found in all tissue
samples. Mean density of these cells in longitudinal sections was 128/mm2 (± 51/mm2) in group A
(<32 yrs), 13/mm2 (±8/mm2) in group B (54-56 yrs) and 12/mm2 (± 3/mm2) in group C (<70 yrs).
Mean average density of contractile cells was 79/mm2, with an average cellular diameter of 4.2 µm
and a length of 18.1 µm. Density seemed to be related to the degree of collagen crimping, which
had a mean amplitude of 8 µm (± 1.5µm) in the youngest group, 4.4 µm (± 0.7µm) in the middle
group, and 3.9 µm (± 0.6µm) in the eldest group. The youngest group showed significantly more
contractile cells (p<0.002) and higher crimp amplitude (p>0.0005) compared with any of the two
other groups.
In vitro contraction tests: Caffeine in concentrations up to 50 mM did not result in reproducible
significant tension increase or decrease, neither did acetylcholine (10-8 to 10-6 M) or a potassium
enriched solution of up to 80 mM. Yet electrical stimulation of 5 Hz (7 V, 2 ms) tends to increase
the force (mean increase 2.1%, ± 1.7%, n=12), a 20 Hz stimulation (7V, 2 ms) tends to decrease it
(by 1.6%, ±1.4%, n=10), and the NO-donator glyceroltrinitrate tends to decrease the force as well
(by 1.2%, ± 1.5%, with 2 mg/ml, n=9). Because of the small number of repetitions for each tested
variable, these in vitro results still require further verification.
CONCLUSION
Contractile cells containing smooth muscle actin are commonly present in the posterior layer of the
thoracolumbar fascia. The density of these cells is higher in younger people and correlates
positively with the amplitude of crimp in collagen fiber arrangement. Assuming the known
potential force of smooth muscle cells or contractile myofibroblasts, the amount of cells could be
sufficient to result in significant fascial contractions such as in compartment syndrome.
Using in vitro testing of fresh porcine lumbar fascia, a transient temporary contraction or release
can be triggered by electrical as well as chemical stimulation. We suggest that these preliminary
results support the possibility that active contraction of intrafascial smooth muscle like cells could
play a contributing role in temporary or chronic changes in force transmission of the thoracolumbar
5th Interdisciplinary World Congress on Low Back & Pelvic Pain
Melbourne, November 2004 www.worldcongresslbp.com
fascia. Further studies including antibodies specific for smooth muscle cells and in vitro tests with
human samples are needed to get a more specific understanding of fascial contraction. If verified
by future research, active fascial contractility could offer new insights for the understanding of low
back stability, compartment syndromes, and myofascial release therapies.
128
13 12
80
44 39
<32 yrs 54-56 yrs >71 yrs
Contractile Cells / mm2 Collagen Crimp (amplitude in 0.1 µm)
Figure 2. Comparison of density of intrafascial contractile cells and amount of collagen crimp
between 3 age groups
REFERENCES
1. Barker P J, Briggs C A, Bogeski G 2004 Tensile transmission across the lumbar fascia in
unembalmed cadavers: effects of tension to various muscular attachements. Spine 29(2): 129-
138
2. Yahia H, Pigeon P, DesRoisiers E A 1993 Viscoelastic properties of the human lumbodorsal
fascia. J Biomech Eng 15: 425-29
3. Schleip R 2003 Fascial plasticity - A new neurobiological explanation – Part 2. Journal of
Bodywork and Movement Therapies 7(2): 104-16
5th Interdisciplinary World Congress on Low Back & Pelvic Pain
Melbourne, November 2004 www.worldcongresslbp.com
4. Murray M M, Spector M 1999 Fibroblast distribution in the anteromedial bundle of the
human anterior cruciate ligament: the presence of alpha-smooth muscle actin-positive cells. J
Orthop Res 17(1): 18-27
5. Wilson C T, Dahners L E 1988 An examination of the mechanism of ligament contracture.
Clinic Orthop 227(2): 286-91
6. Ralphs J R, Waggett A D, Benjamin M 2002 Actin stress fibres and cell-cell adhesion
molecules in tendons. Matrix Biology 21: 67-74
7. Staubesand J, Li Y 1996 Zum Feinbau der Fascia cruris mit besonderer Berücksichtigung
epi- und intrafaszialer Nerven. Manuelle Medizin 34: 196-200
Citation:
Schleip R, Klingler W, Lehmann-Horn F: Active contraction of the thoracolumbar fascia - Indications of a new factor
in low back pain research with implications for manual therapy. In: The proceedings of the Fifth interdisciplinary
world congress on low back and pelvic pain. Melbourne. Editors: Vleeming A, Mooney V, Hodges P. 2004; ISBN 90-
802551-4-9
... Their smooth muscle-like contractile kinetics make myofibroblasts well suited for long lasting isometric contractions, and their contraction plays a major role in wound healing as well as in pathological fascial contractures such as Dupuytren disease, plantar fibromatosis, or frozen shoulder [11]. The presence of myofibroblasts in normal (nonpathological ) fascia has already been demon- strated121314. Unfortunately, no quantitative histological examination has yet been published examining possible differences in myofibroblast density between the epi-, peri-and endomysial fascial layers. ...
... The smooth muscle relaxing substances nifedipine and EDTA as well as the microtubule disrupting substance cytochalasin-D exhibited a relaxing effect . A relaxing response in porcine lumbar fascia to the substance glyceryltrinitrate (a NO donor and smooth muscle relaxant) has been reported by Schleip et al. [12]. Malata found that mepyramine-induced contractions in rat subcutaneous fascia were enhanced by previous incubation with heparin [25] . ...
... Malata found that mepyramine-induced contractions in rat subcutaneous fascia were enhanced by previous incubation with heparin [25] . Using an immunohistochemical analysis of 39 tissue samples from the thoracolumbar fascia of 11 human donors (ages 19–76 years), Schleip et al. [12] demonstrated the widespread presence of myofibroblasts in all samples, with an average density of 79 cells/mm 2 in his longitudinal sections. Taken together, these findings confirm that fascial tissues can actively contract, and that their contractility appears to be driven by myofibroblasts . ...
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... Their smooth muscle-like contractile kinetics make myofibroblasts well suited for long lasting isometric contractions, and their contraction plays a major role in wound healing as well as in pathological fascial contractures such as Dupuytren disease, plantar fibromatosis, or frozen shoulder [11]. The presence of myofibroblasts in normal (nonpathological ) fascia has already been demon- strated121314. Unfortunately, no quantitative histological examination has yet been published examining possible differences in myofibroblast density between the epi-, peri-and endomysial fascial layers. ...
... The smooth muscle relaxing substances nifedipine and EDTA as well as the microtubule disrupting substance cytochalasin-D exhibited a relaxing effect . A relaxing response in porcine lumbar fascia to the substance glyceryltrinitrate (a NO donor and smooth muscle relaxant) has been reported by Schleip et al. [12]. Malata found that mepyramine-induced contractions in rat subcutaneous fascia were enhanced by previous incubation with heparin [25] . ...
... Malata found that mepyramine-induced contractions in rat subcutaneous fascia were enhanced by previous incubation with heparin [25] . Using an immunohistochemical analysis of 39 tissue samples from the thoracolumbar fascia of 11 human donors (ages 19–76 years), Schleip et al. [12] demonstrated the widespread presence of myofibroblasts in all samples, with an average density of 79 cells/mm 2 in his longitudinal sections. Taken together, these findings confirm that fascial tissues can actively contract, and that their contractility appears to be driven by myofibroblasts . ...
Passive muscle stiffness may be influenced by active contractility of intramuscular connective tissue
Article
  • Feb 2006
  • MED HYPOTHESES
The article introduces the hypothesis that intramuscular connective tissue, in particular the fascial layer known as the perimysium, may be capable of active contraction and consequently influence passive muscle stiffness, especially in tonic muscles. Passive muscle stiffness is also referred to as passive elasticity, passive muscular compliance, passive extensibility, resting tension, or passive muscle tone. Evidence for the hypothesis is based on five indications: (1) tonic muscles contain more perimysium and are therefore stiffer than phasic muscles; (2) the specific collagen arrangement of the perimysium is designed to fit a load-bearing function; (3) morphological considerations as well as histological observations in our laboratory suggest that the perimysium is characterized by a high density of myofibroblasts, a class of fibroblasts with smooth muscle-like contractile kinetics; (4) in vitro contraction tests with fascia have demonstrated that fascia, due to the presence of myofibroblasts, is able to actively contract, and that the resulting contraction forces may be strong enough to influence musculoskeletal dynamics; (5) the pronounced increase of the perimysium in muscle immobilization and in the surgical treatment of distraction osteogenesis indicates that perimysial stiffness adapts to mechanical stimulation and hence influences passive muscle stiffness. In conclusion, the perimysium seems capable of response to mechanostimulation with a myofibroblast facilitated active tissue contraction, thereby adapting passive muscle stiffness to increased tensional demands, especially in tonic musculature. If verified, this new concept may lead to novel pharmaceutical or mechanical approaches to complement existing treatments of pathologies which are accompanied by an increase or decrease of passive muscle stiffness (e.g., muscle fibroses such as torticollis, peri-partum pelvic pain due to pelvic instability, and many others). Methods for testing this new concept are suggested, including histological examinations and specific in vitro contraction tests.
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... This connective tissue is considered to serve a passive role in biomechanical dynamics, transmitting mechanical tension. However, recent data from animal studies suggest that fascial tissue might have contractile properties [6, 7]. Several neuromuscular diseases are associated with increasing amounts of connective tissue, and an above average coincidence of clinical MH-suspicion and disorders of connective tissue as well as musculoskeletal disorders has been suggested [8, 9]. ...
... Contracture curves were displayed and recorded with a computer-based data evaluation program. For further details, see Ording et al. [6]. In the quantitative analysis of histological data, a Mann–Whitney test (U-test) was used to test significant differences between samples from different individuals . ...
Contractile elements in muscular fascial tissue - Implications for in-vitro contracture testing for malignant hyperthermia
Article
  • Jun 2014
Malignant hyperthermia is a dreaded complication of general anaesthesia. Predisposed individuals can be identified using the standardised caffeine/halothane in-vitro contracture test on a surgically dissected skeletal muscle specimen. Skeletal muscle is composed of muscle fibres and interwoven fascial components. Several malignant hyperthermia-associated neuromuscular diseases are associated with an altered connective tissue composition. We analysed adjacent fascial components of skeletal muscle histologically and physiologically. We investigated whether the fascial tissue is sensitive to electrical or pharmacological stimulation in a way similar to the in-vitro contracture test for diagnosing malignant hyperthermia. Using immunohistochemical staining, α-smooth muscle actin-positive cells (myofibroblasts) were detected in the epi-, endo- and perimysium of human fascial tissue. Force measurements on isolated fascial strips after pharmacological challenge with mepyramin revealed that myofascial tissue is actively regulated by myofibroblasts, thereby influencing the biomechanical properties of skeletal muscle. Absence of electrical reactivity and insensitivity to caffeine and halothane suggests that, reassuringly, the malignant hyperthermia diagnostic in-vitro contracture test is not influenced by the muscular fascial tissue.
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... As the TLF plays a key role in generation, dispersal of forces and stabilization, it is important to consider its role in back pain for evaluation and developing intervention strategies. Above stated reasons have lead research to investigate TLF as a potential pain generating structure in the back [Stevens et al., 2010;Langevin et al., 2011;Schleip, 2004]. One study showed increased thickness and echogenicity of the TLF in patients with chronic low back [Stevens et al., 2010]. ...
Association of thoraco-lumbar fascia length in individuals with non-specific low back pain - an observational study
Article
  • Oct 2020
Objective The purpose of the study was to assess the length of TLF and to evaluate the strength of muscles attached to it in subjects with and without nonspecific low back pain (NSLBP). Methods 31 patients with NSLBP and 31 healthy individuals were included in the study. In each subject the TLF length was assessed by quantifying lumbar rotation using Back range of motion (BROM-II) instrument. The endurance of transverses abdominis was assessed using the pressure biofeedback unit while the strength of Latissimus dorsi, internal and external oblique's were assessed using MMT. Outcome measure such as Range of Motion (ROM) was compared across the group using independent sample T-test. While the muscle strength of Latissimus dorsi and oblique's were compared across the group using Man-whitney U- test. Transverse abdominis endurance was tested using chi-square test. Results There was statistically significant difference in the length of TLF of subjects with NSLBP when compared with subjects without NSLBP. When the strength of Latissimus dorsi muscle, transverses abdominis muscle and internal and external oblique's muscle was assessed no significant (p value > 0.05) difference was found in either group. Conclusions There was statistically significant reduction in length of TLF but there was no difference in the strength of Latissimus dorsi, internal and external oblique's or endurance of transverses abdominus attached to the TLF in individuals with NSLBP and without low back pain. This study will help in determining the inclusion of TLF and the associated structures in evaluation and management of subjects with NSLBP.
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... They showed that lumbar fascia, plantar fascia, and the fascia lata contain myofibroblast cells that stain for a-smoothmuscle actin. 50 Further in vitro research showed that smooth muscle-like contractions can be both induced and inhibited pharmacologically. 51 Schleip and colleagues recognized that *The terms, myotomes, dermatomes and sclerotomes refer to tissues that develop from particular masses of embryonic mesoderm. ...
Visceral and Somatic Disorders: Tissue Softening with Frequency-Specific Microcurrent
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Full-text available
  • Jul 2012
  • J ALTERN COMPLEM MED
Abstract Frequency-specific microcurrent (FSM) is an emerging technique for treating many health conditions. Pairs of frequencies of microampere-level electrical stimulation are applied to particular places on the skin of a patient via combinations of conductive graphite gloves, moistened towels, or gel electrode patches. A consistent finding is a profound and palpable tissue softening and warming within seconds of applying frequencies appropriate for treating particular conditions. Similar phenomena are often observed with successful acupuncture, cranial-sacral, and other energy-based techniques. This article explores possible mechanisms involved in tissue softening. In the 1970s, neuroscientist and osteopathic researcher Irvin Korr developed a "γ-loop hypothesis" to explain the persistence of increased systemic muscle tone associated with various somatic dysfunctions. This article summarizes how physiologists, neuroscientists, osteopaths, chiropractors, and fascial researchers have expanded on Korr's ideas by exploring various mechanisms by which injury or disease increase local muscle tension or systemic muscle tone. Following on Korr's hypothesis, it is suggested that most patients actually present with elevated muscle tone or tense areas due to prior traumas or other disorders, and that tissue softening indicates that FSM or other methods are affecting the cause of their pathophysiology. The authors believe this concept and the research it has led to will be of interest to a wide range of energetic, bodywork, and movement therapists.
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Gait Characteristics, Range of Motion, and Spasticity Changes in Response to Massage in a Person with Incomplete Spinal Cord Injury: Case Report
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  • Mar 2011
Our study set out to measure the effect of a specific routine of massage on gait characteristics, range of motion, and spasticity in a person with incomplete spinal cord injury. This descriptive, pre-post case study, conducted at the outpatient program of a rehabilitation facility, used neuromuscular techniques in massage for a 42-year-old man with incomplete chronic C5 spinal cord injury. The massage was applied to the iliopsoas, triceps surae, and hamstring muscle groups for 3 consecutive days. Pre- and post-intervention testing included standard goniometric measurement of joint range of motion in the lower extremities, spasticity evaluation using the modified Ashworth scale, and evaluation of gait characteristics using GAITRite Walkway (CIR Systems, Havertown, PA, USA) pressure mapping for ambulation time, cadence, velocity, stride length, base of support, and single- and double-limb support. AFTER THE THERAPEUTIC INTERVENTION, THE FOLLOWING GAIT CHANGES WERE DEMONSTRATED: increase in velocity and cadence of gait, decrease in ambulation time, increase in stride length, and improvements in the percentages of the swing and stance phases of the gait cycle. Specific application of massage therapy influenced gait speed, stride length, and swing and stance phase percentages in one person with incomplete spinal cord injury. Further study is warranted to determine the extent to which massage may affect musculoskeletal and neural impairments that limit gait in people with incomplete spinal cord injury, and the method or routine whose application will yield the most benefit.
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Letter to the Editor concerning "A hypothesis of chronic back pain: Ligament subfailure injuries lead to muscle control dysfunction" (M. Panjabi) [1]
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Full-text available
  • Nov 2007
pain. While we agree with the basic hypothesis and its emphasis on the transducer (mechanosensory) function of ligamentous tissues, we suggest to refine the model in terms of an inclusion of the thoracolumbar fascia (TLF). We present evidence that the TLF is significantly involved in all three levels of the hypothesis concerning spinal ligamentous structures: the transducer function of these tissues, their structural spinal function, and their proneness for subfailure injuries.
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Fascial plasticity - A new neurobiological explanation. Part 2
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  • Apr 2003
Part 1 of this two part article showed that immediate fascial responsiveness to manipulation cannot be explained by its mechanical properties alone. Fascia is densely innervated by mechanoreceptors which are responsive to myofascial manipulation. They are intimately connected with the central nervous system and specially with the autonomic nervous system. Part 2 of the article shows how stimulation of these receptors can trigger viscosity changes in the ground substance. The discovery and implications of the existence of fascial smooth muscle cells are of special interest in relation to fibromyalgia, amongst other conditions. An attitudinal shift is suggested, from a mechanical body concept towards a cybernetic model, in which the practitioner's intervention are seen as stimulation for self-regulatory processes within the client's organism. Practical implications of this approach in myofascial manipulation will be explored.
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An Examination of the Mechanism of Ligament Contracture
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  • Mar 1988
It has been proposed that the mechanism of ligament contraction involves conversion of fibroblasts to a contractile form similar to the phenomenon recently documented in wound contraction. In this study rat knees were surgically immobilized in flexion and a sham operation was performed on the contralateral knees. Mechanical studies revealed that the flexion contracture increased rapidly for two weeks. The anterior cruciate ligaments (ACL) were contracted and contributed to the flexion contractures. Histologic studies of the ACL showed no increase in the cellularity of the contracted ligaments. In the contracted ligaments, staining for the contractile protein actin was heavy. Previous transmission electron microscopy studies have demonstrated fibroblast cytoplasm in processes far from the visible cell body and it is hypothesized that this cytoplasm was responsible for increased actin staining away from the visible cell body. This study supports the concept that ligament fibroblasts, modulated to a form containing increased quantities of the contractile protein actin, play an active role in the contraction of ligamentous tissue.
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Viscoelastic properties of the human lumbodorsal fascia
Article
  • Oct 1993
  • J Biomed Eng
The purpose of this study is to provide better understanding of the mechanical response of the lumbodorsal fascia to dynamic and static traction loadings. Since the fascia shows a viscoelastic behaviour, tests in which time is a variable were used, namely hysteresis and stress relaxation. Load-strain and load-time curves obtained from the hysteresis and stress-relaxation tests point out three different phenomena. First, an increase in stiffness is noticed when ligaments are successively stretched, i.e. strains produced by successive and identical loads decrease. Second, if a sufficient resting period is allowed between loadings, stiffening is reversed and strains tend to recover initial values. The third phenomenon, observed in stress-relaxation tests as time progresses, is ligament contraction in stretched and isometrically held samples. This third phenomenon may be explained by the possibility that muscle fibres capable of contracting spontaneously could be present in lumbodorsal fascia ligaments.
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Fibroblast distribution in the anteromedial bundle of the human anterior cruciate ligament: The presence of alpha-smooth muscle actin-positive cells
Article
  • Jan 1999
The anterior cruciate ligament is a complex tissue composed of structural proteins, proteoglycans, and cells. The histology of the human anterior cruciate ligament is characterized by the specific distribution and density of the fibroblast phenotype as well as by the unique organization of the structural proteins. A notable finding of this study was the identification of three histologically different zones along the anteromedial bundle as it coursed from the femoral to the tibial attachment. Two of the zones, the fusiform and ovoid, were located in the proximal one-quarter of the bundle; the third zone, the spheroid, occupied the distal three quarters of the bundle fascicles. The fusiform cell zone was characterized by a high number density of longitudinally oriented cells with a fusiform-shaped nucleus, longitudinal blood vessels, and high crimp length. The cytoplasm of the cells in this zone appeared to be intimately attached to the extracellular collagen and followed the crimp waveform of the fibers. Fusiform cells were noted to stain positively for the alpha-smooth muscle actin isoform in this region, particularly at areas of crimp disruption. The ovoid cell zone was characterized by a high number density of cells with an ovoid-shaped nucleus, longitudinal vessels, and a high crimp length. In this zone as well, the cytoplasm of the cells appeared to follow the waveform of the adjacent collagen. Ovoid cells were noted to stain positively for the alpha-smooth muscle actin isoform in this region. The spheroid cell zone was characterized by a low density of spheroid cells, few blood vessels, and short crimp length. Cells were noted within and among fascicles, as well as within lacunae. In selected areas, as many as 50% of the cells in this region stained positively for the alpha-smooth muscle actin isoform. This is also the first report of cells expressing the alpha-smooth muscle actin isoform in the intact human anterior cruciate ligament. This specific type of contractile actin, initially identified only in smooth-muscle cells, pericytes, and myofibroblasts, was seen in cells with various morphologies and predominantly in cells located at areas of crimp disruption. Further work is necessary to elucidate the role of the various fibroblast phenotypes in the maintenance of the human anterior cruciate ligament.
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Actin stress fibres and cell-cell adhesion molecules in tendons: Organisation in vivo and response to mechanical loading of tendon cells in vitro
Article
  • Feb 2002
  • MATRIX BIOL
Tendons consist of parallel longitudinal rows of cells separated by collagen fibres. The cells are in intimate contact longitudinally within rows, and laterally via sheet-like lateral cell processes between rows. At points of contact, they are linked by gap junctions. Since tendons stretch under load, such cell contacts require protection. Here we describe the organisation of the actin cytoskeleton and actin-based cell-cell interactions in vivo and examine the effect of cyclic tensile loading on tendon cells in vitro. Cells within longitudinal rows contained short longitudinally running actin stress fibres. Each fibre was aligned with similar fibres in the cells longitudinally on either side, and fibres appeared to be linked via adherens junctions. Overall, these formed long oriented rows of stress fibres running along the rows of tendon cells. In culture, junctional components n-cadherin and vinculin and the stress fibre component tropomyosin increased in strained cultures, whereas actin levels remained constant. These results suggest that: (1) cells are linked via actin-associated adherens junctions along the line of principal strain; and (2) under load, cells appear to attach themselves more strongly together, and assemble more of their cytoplasmic actin into stress fibres with tropomyosin. Taken together, this suggests that cell-cell contacts are protected during stretch, and also that the stress fibres, which are contractile, may provide an active mechanism for recovery from stretch. In addition, stress fibres are ideally oriented to monitor tensile load and thus may be important in mechanotransduction and the generation of signals passed via the gap junction network.
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Tensile Transmission Across the Lumbar Fasciae in Unembalmed Cadavers
Article
  • Feb 2004
  • SPINE
Traction was applied to muscles attaching to the posterior and middle layers of lumbar fascia (PLF, MLF). Effects on fasciae were determined via tensile force measures and movement of markers. To document tensile transmission to the PLF and MLF when traction was applied to latissimus dorsi (LD), gluteus maximus (GM), external and internal oblique (EO, IO), and transversus abdominis (TrA) in unembalmed cadavers. A previous study on embalmed cadavers applied traction to muscle attachments while monitoring fascial movement but did not test TrA or the MLF. The PLF and MLF were dissected then marked on eight unembalmed cadavers. A strain gauge was inserted through fascia at L3; 10N traction was applied to each muscle attachment while photographs and tension measures were taken. Movement of fascial markers was detected photographically. Fascial widths were also measured. Tension was clearly transmitted to fascial vertebral attachments. Tensile forces and fascial areas affected were highest for traction on LD and TrA in the PLF and for TrA in the MLF. Movement of PLF markers from tension on LD and TrA occurred bilaterally between T12 and S1. Effects from other muscles were variably bilateral, with those from GM and IO occurring below L3 and those from EO occurring above L3. Tensile forces were relatively high in the MLF and its width was less than half that of the PLF. Low levels of tension are effectively transmitted between TrA and the MLF or PLF. Via them, TrA may influence intersegmental movement.
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Zum Feinbau der Fascia cruris mit besonderer Berücksichtigung epi-und intrafaszialer Nerven
  • Jan 1996
  • 196-200
  • J Staubesand
  • Y Li
Staubesand J, Li Y 1996 Zum Feinbau der Fascia cruris mit besonderer Berücksichtigung epi-und intrafaszialer Nerven. Manuelle Medizin 34: 196-200