scholarly journals Lengthening But Not Shortening History of Paraspinal Muscle Spindles in the Low Back Alters Their Dynamic Sensitivity

2011 ◽  
Vol 105 (1) ◽  
pp. 434-441 ◽  
Author(s):  
Dong-Yuan Cao ◽  
Joel G. Pickar
Keyword(s):  
Spinous Process ◽  
Dynamic Test ◽  
Muscle Spindles ◽  
Intermediate Position ◽  
Paraspinal Muscle ◽  
Low Back ◽  
Mean Velocity ◽  
Static Test ◽  
Velocity Sensitivity ◽  
Movement History

Proprioception is considered important for maintaining spinal stability and for controlling posture and movement in the low back. Previous studies demonstrate the presence of thixotropic properties in lumbar muscle spindles, wherein a vertebra's positional history alters spindle responsiveness to position and movement. This study investigated whether a vertebra's movement history affects the velocity sensitivity of paraspinal muscle spindles in the low back. Afferent activity from multifidus and longissimus muscle spindles was recorded in the L6 dorsal root in 30 anesthetized cats. To alter movement history, a feedback-controlled motor attached to the L6 spinous process held (conditioned for 4 s) the L6 vertebra at an intermediate position or at positions that either lengthened or shortened the muscles. With the vertebra returned to the intermediate position, resting spindle discharge was measured over the next 0.5 s (static test) and then during a dynamic test consisting of ramp vertebral movement at four velocities (0.2, 0.5, 1.0, 2.0 mm/s). Spindle activity during the tests was measured relative to hold-intermediate. For both tests, hold-long decreased and hold-short increased muscle spindle responsiveness. For the static test position responsiveness was not different among the velocity protocols for either hold-long or hold-short ( P = 0.42 and 0.24, respectively). During the dynamic test, hold-long conditioning significantly decreased [ F(3,119) = 7.99, P < 0.001] spindle responsiveness to increasing velocity. Mean velocity sensitivity was 4.44, 3.39, and 1.41 (impulses/s)/(mm/s) for the hold-short, hold-intermediate, and hold-long protocols, respectively. The nearly 2.5-fold decrease in velocity sensitivity following hold-long was significantly less than that for either hold-intermediate ( P = 0.005) or hold-short conditioning ( P < 0.001). Hold-short conditioning had little effect on velocity responses during the dynamic test [ F(3,119) = 0.23, P = 0.87]. In conclusion, only movement histories that stretch but not shorten muscle spindles alter their velocity sensitivity. In the low back, forward flexion and lateral bending postures would likely be the most provocative.

The Role of Paraspinal Muscle Spindles in Lumbosacral Position Sense in Individuals With and Without Low Back Pain

Spine ◽  
2000 ◽  
Vol 25 (8) ◽  
pp. 989-994 ◽  
Author(s):  
Simon Brumagne ◽  
Paul Cordo ◽  
Roeland Lysens ◽  
Sabine Verschueren ◽  
Stephan Swinnen
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Muscle Spindles ◽  
Position Sense ◽  
Paraspinal Muscle ◽  
Low Back

scholarly journals Position Sensitivity of Feline Paraspinal Muscle Spindles to Vertebral Movement in the Lumbar Spine

2009 ◽  
Vol 101 (4) ◽  
pp. 1722-1729 ◽  
Author(s):  
Dong-Yuan Cao ◽  
Joel G. Pickar ◽  
Weiginq Ge ◽  
Allyson Ianuzzi ◽  
Partap S. Khalsa
Keyword(s):  
Lumbar Spine ◽  
Muscle Spindle ◽  
Facet Joint ◽  
Spinous Process ◽  
Muscle Length ◽  
Muscle Spindles ◽  
Paraspinal Muscle ◽  
High Position ◽  
Position Sensitivity ◽  
The Relationship

Muscle spindles contribute to sensorimotor control by supplying feedback regarding muscle length and consequently information about joint position. While substantial study has been devoted to determining the position sensitivity of spindles in limb muscles, there appears to be no data on their sensitivity in the low back. We determined the relationship between lumbar paraspinal muscle spindle discharge and paraspinal muscle lengthening estimated from controlled cranialward movement of the L6 vertebra in anesthetized cats. Ramp (0.4 mm/s) and hold displacements (0.2, 0.4, 0.6, 0.8, and 1.2 mm for 2.5 s) were applied at the L6 spinous process. Position sensitivity was defined as the slope of the relationship between the estimated increase in muscle length and mean instantaneous frequency at each length. To enable comparisons with appendicular muscle spindles where joint angle was measured, we also calculated sensitivity in terms of the L6 and L7 intervertebral flexion angle (IVA). This angle was estimated from measurements of facet joint capsule strain (FJC) based on a previously established relationship between IVA and FJC strain in the cat lumbar vertebral column during lumbar flexion. Single-unit recordings were obtained from 12 muscle spindle afferents. Longissimus and multifidus muscles contained the receptive field of 10 and 2 afferents, respectively. Mean position sensitivity was 16.3 imp·s−1·mm−1 [10.6–22.1, 95% confidence interval (CI), P < 0.001]. Mean angular sensitivity was 5.2 imp·s−1·°−1 (2.6–8.0, P < 0.003). These slope estimates were more than 3.5 times greater compared with appendicular muscle spindles, and their CIs did not contain previous slope estimates for the sensitivity of appendicular spindles from the literature. Potential reasons for and the significance of the apparently high position sensitivity in the lumbar spine are discussed.

scholarly journals Effect of preservation of the C-6 spinous process and its paraspinal muscular attachment on the prevention of postoperative axial neck pain in C3–6 laminoplasty

2015 ◽  
Vol 22 (3) ◽  
pp. 221-229 ◽  
Author(s):  
Eiji Mori ◽  
Takayoshi Ueta ◽  
Takeshi Maeda ◽  
Itaru Yugué ◽  
Osamu Kawano ◽  
...  
Keyword(s):  
Neck Pain ◽  
Spinous Process ◽  
Posterior Longitudinal Ligament ◽  
Paraspinal Muscle ◽  
Vas Scores ◽  
The Mean ◽  
Axial Neck Pain ◽  
Process Length ◽  
Preservation Technique

OBJECT Axial neck pain after C3–6 laminoplasty has been reported to be significantly lesser than that after C3–7 laminoplasty because of the preservation of the C-7 spinous process and the attachment of nuchal muscles such as the trapezius and rhomboideus minor, which are connected to the scapula. The C-6 spinous process is the second longest spinous process after that of C-7, and it serves as an attachment point for these muscles. The effect of preserving the C-6 spinous process and its muscular attachment, in addition to preservation of the C-7 spinous process, on the prevention of axial neck pain is not well understood. The purpose of the current study was to clarify whether preservation of the paraspinal muscles of the C-6 spinous process reduces postoperative axial neck pain compared to that after using nonpreservation techniques. METHODS The authors studied 60 patients who underwent C3–6 double-door laminoplasty for the treatment of cervical spondylotic myelopathy or cervical ossification of the posterior longitudinal ligament; the minimum follow-up period was 1 year. Twenty-five patients underwent a C-6 paraspinal muscle preservation technique, and 35 underwent a C-6 nonpreservation technique. A visual analog scale (VAS) and VAS grading (Grades I–IV) were used to assess axial neck pain 1–3 months after surgery and at the final follow-up examination. Axial neck pain was classified as being 1 of 5 types, and its location was divided into 5 areas. The potential correlation between the C-6/C-7 spinous process length ratio and axial neck pain was examined. RESULTS The mean VAS scores (± SD) for axial neck pain were comparable between the C6-preservation group and the C6-nonpreservation group in both the early and late postoperative stages (4.1 ± 3.1 vs 4.0 ± 3.2 and 3.8 ± 2.9 vs 3.6 ± 3.0, respectively). The distribution of VAS grades was comparable in the 2 groups in both postoperative stages. Stiffness was the most prevalent complaint in both groups (64.0% and 54.5%, respectively), and the suprascapular region was the most common site in both groups (60.0% and 57.1%, respectively). The types and locations of axial neck pain were also similar between the groups. The C-6/C-7 spinous process length ratios were similar in the groups, and they did not correlate with axial neck pain. The reductions of range of motion and changes in sagittal alignment after surgery were also similar. CONCLUSIONS The C-6 paraspinal muscle preservation technique was not superior to the C6-nonpreservation technique for preventing postoperative axial neck pain.

Dynamic Fracture Toughness Testing for Welding Part of Nuclear Piping Using Normalization Data Reduction Technique

2006 ◽  
Vol 306-308 ◽  
pp. 73-78
Author(s):  
Yong Huh ◽  
Hyung Ick Kim ◽  
Chang Sung Seok
Keyword(s):  
Fracture Toughness ◽  
Dynamic Fracture ◽  
Data Reduction ◽  
Dynamic Test ◽  
Dynamic Fracture Toughness ◽  
Reduction Technique ◽  
Fracture Toughness Test ◽  
Static Test ◽  
Welding Part ◽  
Data Reduction Technique

In this study, we performed the static test of nuclear piping materials by the unloading compliance method and the normalization data reduction technique and obtained two fracture resistance curves (J-R curves). The two curves were similar, which proves that the normalization data reduction technique can be adopted in the static test. Then we performed the dynamic fracture toughness test for welding part of nuclear piping. The J-R curves were obtained from the dynamic test by the normalization data reduction technique and were compared to those of the static test results.

Reliability Evaluation and Study of Static and Dynamic Load Tests of Long Span Continuous Bridge with Variable Section

2011 ◽  
Vol 374-377 ◽  
pp. 2411-2420
Author(s):  
Sui Tan ◽  
Zhi Wu Yu ◽  
Hua Shuai Zhang
Keyword(s):  
Evaluation Method ◽  
Concrete Strength ◽  
Dynamic Test ◽  
Reliability Evaluation ◽  
Scientific Basis ◽  
Static Test ◽  
Long Span ◽  
Variable Section ◽  
Load Tests ◽  
Relationship Of

The reliability evaluation for the bridge in service can provide a scientific basis for decision-making in bridge repair and reinforcement. A comprehensive method for reliability evaluation was introduced in this paper based on a long span continuous bridge with variable section evaluation. Appearance survey of the bridge, concrete strength and carbonization test, static test and dynamic test would be done as well as the finite element simulation model to determine the properties of the bridge for reliability evaluation. The relationship of the natural frequency stiffness evaluation method and the effective coefficient method would be established in this paper based on the test results. Based on the static and dynamic test, we classify the bridge as class 3 while the bending stiffness is good, the dynamic rigidity is a little weak, and the damping coefficient a little larger.

scholarly journals Viscoelastic Parameters of Asphalt Mixtures Identified in Static and Dynamic Tests

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2084 ◽  
Author(s):  
Piotr Mackiewicz ◽  
Antoni Szydło
Keyword(s):  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Dynamic Test ◽  
Asphalt Mixtures ◽  
Rheological Parameters ◽  
Dynamic Tests ◽  
Static Test ◽  
Viscoelastic Parameters ◽  
Static Creep ◽  
Asphalt Content

We present two methods used in the identification of viscoelastic parameters of asphalt mixtures used in pavements. The static creep test and the dynamic test, with a frequency of 10 Hz, were carried out based on the four-point bending beam (4BP). In the method identifying viscoelastic parameters for the Brugers’ model, we included the course of a creeping curve (for static creep) and fatigue hysteresis (for dynamic test). It was shown that these parameters depend significantly on the load time, method used, and temperature and asphalt content. A similar variation of parameters depending on temperature was found for the two tests, but different absolute values were obtained. Additionally, the share of viscous deformations in relation to total deformations is presented, on the basis of back calculations and finite element methods. We obtained a significant contribution of viscous deformations (about 93% for the static test and 25% for the dynamic test) for the temperature 25 °C. The received rheological parameters from both methods appeared to be sensitive to a change in asphalt content, which means that these methods can be used to design an optimal asphalt mixture composition—e.g., due to the permanent deformation of pavement. We also found that the parameters should be determined using the creep curve for the static analyses with persistent load, whereas in the case of the dynamic studies, the hysteresis is more appropriate. The 4BP static creep and dynamic tests are sufficient methods for determining the rheological parameters for materials designed for flexible pavements. In the 4BP dynamic test, we determined relationships between damping and viscosity coefficients, showing material variability depending on the test temperature.

scholarly journals Comparison of post-spinal back pain after midline versus paramedian approaches for urologic surgeries

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Payman Dadkhah ◽  
Masoud Hashemi ◽  
Babak Gharaei ◽  
Mohammad Hassan Bigdeli ◽  
Ali Solhpour
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Spinal Anesthesia ◽  
Rating Scale ◽  
Numerical Rating Scale ◽  
Spinous Process ◽  
Lithotomy Position ◽  
Significant Variable ◽  
Low Back ◽  
Increased Risk

Abstract Introduction Low back pain after spinal anesthesia is of concern in lithotomy position. During our study, low back pain in both midline and paramedian approaches after spinal anesthesia in lithotomy position was compared. Material and methods Spinal anesthesia was performed by two approaches of midline and paramedian by an expert. The midline at middle line and paramedian at 1 cm inferior and 1 cm lateral to the spinous process performed with the needle type of Quincke 25G. The severity of back pain in patients was measured with numerical rating scale method by an anesthesiology assistant 24 and 72 h and a week after surgery. Results A total of 139 patients were studied. After 24 h, back pain in the midline group was 21% and in the paramedian group was 25.4%, respectively. There were no significant differences between them. In the first 24 h, the only significant variable was the number of tries. In patients with ≥ 2 times of tries for performing spinal anesthesia, multivariate analysis of patients showed back pain to be 4.7 times more common compared to single try (OR 4.70, CI 1.79–10.18; p = 0.001). Conclusion There were no significant differences between the two methods of midline and paramedian approaches after spinal anesthesia in the incidence of back pain. However, two or more times of tries compared with one time try had increased risk of low back pain.

Dynamic responsiveness of lumbar paraspinal muscle spindles during vertebral movement in the cat

2009 ◽  
Vol 197 (4) ◽  
pp. 369-377 ◽  
Author(s):  
Dong-Yuan Cao ◽  
Partap S. Khalsa ◽  
Joel G. Pickar
Keyword(s):  
Muscle Spindles ◽  
Paraspinal Muscle
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