Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Influence of age and duration of symptoms on fibre type distribution and size of the back muscles in chronic low back pain patients (2000)
    Springer
    European spine journal 9 (2000), S. 273-281 
    Details
    ISSN: 1432-0932
    Keywords: Key words Chronic low back pain ; Erector spinae muscle ; MRI ; Muscle biopsy ; Fibre type ; distribution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Many studies have documented an association between chronic low back pain (LBP) and deficits in back muscle strength and endurance. The sub-optimal performance is believed to be the result of alterations in the size and structure of the muscle, although the long-standing issue of whether the observed changes precede or are a consequence of the pain remains unresolved. If consequent to the problem, and predominantly related to disuse of the muscles, then it may be expected that a relationship between muscle structure and symptom duration would exist. Lumbar paraspinal muscle samples were obtained from 59 chronic LBP patients using the percutaneous biopsy technique. The samples were subject to routine histochemical analysis for the examination of muscle fibre type characteristics and cytochemical architectural changes. In 55 of the patients, the gross cross-sectional areas of magnetic resonance images of the trunk muscles were also measured. Multivariate analysis showed that symptom duration was the strongest predictor of the individual proportions of the fast-fatigable type IIX fibres; with age and gender included in the model, nearly 30% of the variance in fibre type distribution could be accounted for. Duration of pain had no influence on fibre size. Gross muscle cross-sectional area correlated directly with lean body mass and inversely with age, but showed no relationship with symptom duration. Pathological changes in the internal fibre structure were more frequently encountered in older patients, and were independent of symptom duration. The results suggest that, over the long term, fibre type transformations rather than alterations in fibre size are the predominant changes to be found in the muscles of chronic LBP patients. The direction of change supports the results of many previous studies that have demonstrated corresponding differences in the fatigability of the muscles. There is a strong case for the early implementation of active measures to attempt to offset the development of these changes in back pain patients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005860000189
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Paraspinal muscle fibre type alterations associated with scoliosis: an old problem revisited with new evidence (1998)
    Springer
    European spine journal 7 (1998), S. 289-293 
    Details
    ISSN: 1432-0932
    Keywords: Key words Scoliosis ; Muscle ; fibre types ; Paraspinal muscles ; Multifidus ; Erector spinae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To establish the extent to which the paraspinal muscles are affected in idiopathic scoliosis, samples from patients must be compared with controls of a similar gender and age. To date, insufficient control data has been available for these purposes. The aim of this study was to redress this tissue, in order to identify whether one side of the apex of the scoliotic curve showed greater muscular abnormalities than the other. Bilateral samples of the paraspinal muscles were obtained during surgery from 14 female scoliosis patients, at the apex of the scoliotic curve at T9–T11. Percutaneous muscle biopsy samples were obtained from nine female volunteers, on the left side of the spine at T10. Samples were prepared for routine histochemistry for the identification of muscle fibre types. Fibre size was measured using computerised image analysis. Compared with control muscle, there was a significantly lower proportion of type I (slow-twitch oxidative) fibres in the muscle on the concave side of the scoliotic curve, but no difference on the convex side. The proportion of type IIB (fast-twitch, glycolytic) fibres was higher on both sides of the curve compared with controls, with the effect being significantly more marked on the concave side. The percentage of type IIA (slow-twitch, oxidative-glycolytic) fibres did not differ between the groups, and neither did fibre size (although there was a tendency for the controls to have larger type IIA fibres than the patients). Collectively, the differences in fibre type size and distribution meant that on the concave side the relative area of the muscle occupied by type I fibres was smaller, and on both sides of the curve the relative area occupied by type IIB fibres was greater and by type IIA fibres smaller, in comparison with controls. In scoliosis, the spinal musculature is most affected on the concave side of the curve’s apex. The muscle adopts a ‘faster’, or more ‘glycolytic’ profile, which would be consistent with a reduced low-level tonic activity of the muscle, perhaps consequent to a local change in activity on this side of the spine following progression of the curve. Less marked changes, in the same direction, are also evident on the convex side; these may be the result of general disuse of the paraspinal muscles associated with the spinal deformity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005860050077
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Range of global motion of the cervical spine: intraindividual reliability and the influence of measurement device (2000)
    Springer
    European spine journal 9 (2000), S. 379-385 
    Details
    ISSN: 1432-0932
    Keywords: Key words Cervical spine ; Global mobilityMotion analysis devices ; Reliability ; CA6000
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Range of motion tests are often employed in the quantification of musculoskeletal impairment and in the assessment of the efficacy of therapeutic interventions. The aim of the present study was to compare the absolute values for, and the day-to-day reliability of, measures of cervical spinal mobility made with two computerised motion analysis devices. The ranges of cervical flexion, extension, lateral bending, axial rotation, and axial rotation in flexion and extension were determined for 19 volunteers using both the CA6000 Spine Motion Analyser and the Zebris CMS system; all measures were repeated on a second occasion 1–3 days later. The test-retest reliability was good for each instrument: there was no significant difference between the mean values derived on the two separate days (P〉0.05), and the corresponding intraclass correlation coefficients were 0.75–0.93 for all primary movements and 0.57–0.93 for axial rotation in flexion or in extension. For each primary movement, ¶a small but significant difference (1–10%; P〈0.05) between the values derived from the two instruments was observed, the systematic nature of which was revealed by the excellent correlation coefficients between them. For the measures of axial rotation in flexion or in extension, however, there was not only a poor correlation between the data obtained from the two devices, but the mean values also differed significantly. Each device is highly reliable in itself and can be used with confidence in longitudinal studies. The establishment of ‘normal’ values for the primary motions should take account of the slight differences observed between devices. Normal values for rotation in flexion or extension cannot be established until the source of the device-dependent difference is identified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s005860000187
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Effects of isokinetic training of the knee extensors on isometric strength and peak power output during cycling (1992)
    Springer
    European journal of applied physiology 65 (1992), S. 370-375 
    Details
    ISSN: 1439-6327
    Keywords: Isokinetic training ; Strength ; Maximum voluntary contraction ; Knee extensors ; Sprint cycle power output
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Isokinetic training of right and left quadriceps femoris was undertaken three times per week for 16 weeks. One group of subjects (n=13) trained at an angular velocity of 4.19 rad·s−1 and a second group (n=10) at 1.05 rad·s−1. A control group (n=10) performed no training. Maximal voluntary contraction (MVC) of the quadriceps, and peak pedal velocity (νp,peak) and peak power output (W peak) during all-out cycling (against loads equivalent to 9, 10, 11, 12, 13 and 14% MVC) were assessed before and after training. The two training groups did not differ significantly from each other in their training response to any of the performance variables (P〉0.05). No significant difference in MVC was observed for any group after the 16-week period (P=0.167). The post-training increases in averageW peak (7%) and νp,peak (6%) during the cycle tests were each significantly different from the control group response (P=0.018 andP=0.008, respectively). It is concluded that 16 weeks of isokinetic strength training of the knee extensors is able to significantly improve νp,peak andW peak during sprint cycling, an activity which demands considerable involvement of the trained muscle group but with its own distinct pattern of coordination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00868143
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Carnosine and anserine concentrations in the quadriceps femoris muscle of healthy humans (1992)
    Springer
    European journal of applied physiology 64 (1992), S. 47-50 
    Details
    ISSN: 1439-6327
    Keywords: Carnosine ; Anserine ; Skeletal muscle buffering
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The content of anserine and carnosine in the lateral portion of the quadriceps femoris muscle of 50 healthy, human subjects has been studied. Anserine was undetectable in all muscle samples examined. Muscle carnosine values for the group conformed to a normal distribution with a mean (SD) value of 20.0 (4.7) mmol · kg−1 of dry muscle mass. The concentration of carnosine was significantly higher in the muscle of male subjects (21.3, 4.2 mmol · kg−1 dry mass) than in females of a similar age and training status (17.5, 4.8 mmol · kg−1 dry mass) (P〈 0.005). The test-retest reliability of measures was determined on a subgroup of 17 subjects. No significant difference in mean carnosine concentration was found between the two trials [21.5 (4.0) and 22.0 (5.2) mmol · kg−1 dry muscle mass; P〉0.05]. The importance of carnosine as a physicochemical buffer within human muscle was examined by calculating its buffering ability over the physiological pH range. From the range of carnosine concentrations observed (7.2–30.7 mmol · kg−1 dry muscle mass), it was estimated that the dipeptide could buffer between 2.4 and 10.1 mmol H+ · kg−1 dry mass over the physiological pH range 7.1–6.5, contributing, on average, approximately 7% to the total muscle buffering. This suggests that in humans, in contrast to many other species, carnosine is of only limited importance in preventing the reduction in pH observed during high intensity exercise.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00376439
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Effects of isokinetic training of the knee extensors on high-intensity exercise performance and skeletal muscle buffering (1994)
    Springer
    European journal of applied physiology 68 (1994), S. 356-361 
    Details
    ISSN: 1439-6327
    Keywords: Isokinetic training ; Knee extensors ; High-intensity exercise ; Muscle carnosine ; Muscle buffering
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Twenty-three subjects isokinetically trained the right and left quadriceps femoris, three times per week for 16 weeks; one group (n=13) trained at an angular velocity of 4.19 rad · s−1 and a second group (n=10), at 1.05 rad · s−1. A control group (n=10) performed no training. Isometric endurance time at 60% quadriceps maximum voluntary contraction (MVC), mean power output and work done (W) during all-out cycling, and the muscle buffer value (B) and carnosine concentration of biopsy samples from the vastus lateralis, were all assessed before and after training. The two training groups did not differ significantly from each other in their training response to any of these variables (P 〈 0.05). No significant difference in either 60% MVC endurance time or impulse [(endurance time × force) at 60% MVC] was observed for any group after the 16 week period (P 〉 0.05). However, the post-training increase (9%) in W during high-intensity cycling was greater in the training group than in the control group (P=0.04). NeitherB nor carnosine concentration showed any significant change following training (P=0.56 andP=0.37, respectively). It is concluded that 16 weeks of isokinetic training of the knee extensors enables subjects to do more work during high-intensity cycling. Although the precise adaptations responsible for the improved performance have yet to be identified, they are unlikely to include an increase inB.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00571457
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Relationship between myoelectric and mechanical manifestations of fatigue in the quadriceps femoris muscle group (1996)
    Springer
    European journal of applied physiology 74 (1996), S. 411-419 
    Details
    ISSN: 1439-6327
    Keywords: Key words Electromyography ; Power spectrum ; Median frequency ; Muscle force ; Muscle fatigue
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Fatigue is commonly defined as “the failure to maintain the required force”. As such, it may be argued that the use of electromyographic (EMG) power spectral statistics to monitor muscle fatigue is inappropriate, because, during the maintenance of a submaximal force of contraction, EMG changes are readily observable in the absence of any decline in the muscle’s mechanical output. However, it is possible that the EMG changes reflect the changing metabolic status of the muscle and hence its inability to generate its normal maximal force. The present study sought to examine whether the decline in EMG median frequency, which occurs during the maintenance of a submaximal force, is correlated with a reduction in the muscle’s maximum force-generating capacity. The maximum voluntary contraction (MVC) of the knee extensors in ten young, healthy subjects was determined. On five separate occasions, randomly assigned forces of 20, 30, 40,  50 and 60% MVC were held to the limit of endurance. At intervals throughout the sustained contractions, subjects were required to rapidly generate an MVC for 1–2 s, then return to the fixed submaxial target force. Surface EMG signals were recorded throughout the contractions from the rectus femoris and vastus lateralis muscles, from which the power spectrum median frequency was calculated. Regression analysis revealed highly significant relationships between the rate of decline in MF and the rate of decline in MVC, and between each of these parameters and endurance time to fatigue (P=0.0001, in each case). It is concluded that the decline in MF can be used to monitor fatigue, where fatigue is defined as the inability to generate the maximum force that can be produced by the muscle in its fresh state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004210050094
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Relationship between myoelectric and mechanical manifestations of fatigue in the quadriceps femoris muscle group (1996)
    Springer
    European journal of applied physiology 74 (1996), S. 411-419 
    Details
    ISSN: 1439-6327
    Keywords: Electromyography ; Power spectrum ; Median frequency ; Muscle force ; Muscle fatigue
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Fatigue is commonly defined as “the failure to maintain the required force”. As such, it may be argued that the use of electromyographic (EMG) power spectral statistics to monitor muscle fatigue is inappropriate, because, during the maintenance of a submaximal force of contraction, EMG changes are readily observable in the absence of any decline in the muscle's mechanical output. However, it is possible that the EMG changes reflect the changing metabolic status of the muscle and hence its inability to generate its normal maximal force. The present study sought to examine whether the decline in EMG median frequency, which occurs during the maintenance of a submaximal force, is correlated with a reduction in the muscle's maximum force-generating capacity. The maximum voluntary contraction (MVC) of the knee extensors in ten young, healthy subjects was determined. On five separate occasions, randomly assigned forces of 20, 30, 40, 50 and 60% MVC were held to the limit of endurance. At intervals throughout the sustained contractions, subjects were required to rapidly generate an MVC for 1–2 s, then return to the fixed submaxial target force. Surface EMG signals were recorded throughout the contractions from the rectus lemons and vastus lateralis muscles, from which the power spectrum median frequency was calculated. Regression analysis revealed highly significant relationships between the rate of decline in MF and the rate of decline in MVC, and between each of these parameters and endurance time to fatigue (P = 0.0001, in each case). It is concluded that the decline in MF can be used to monitor fatigue, where fatigue is defined as the inability to generate the maximum force that can be produced by the muscle in its fresh state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02337721
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...