| 1. |
- Fridén, Thomas, et al.
(författare)
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Function after anterior cruciate ligament injuries. Influence of visual control and proprioception
- 1998
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Ingår i: Acta Orthopaedica Scandinavica. - : Medical Journals Sweden AB. - 0001-6470. ; 69:6, s. 590-594
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Tidskriftsartikel (refereegranskat)abstract
- Information about limb positions and movements consists of input from visual, vestibular, cutaneous, muscular, tendinous and joint receptors, but the relative contribution from each type and location of receptors is not known. The aim of this study was: a) to measure the contribution from visual control on extremity function, as measured with a one-leg hop test in healthy persons, in patients with an asymptomatic ACL injury, after non-operative treatment and in patients with a stable knee after an ACL reconstruction, b) to investigate if there was any relation between proprioception from the extremity, as measured with the threshold for detecting passive motion of the knee, and the one-leg hop test with a gradual decrease in visual control. There was a decrease in hop-length when the subjects were deprived of visual control that was significant when the dominant eye or both eyes were blinded, both in the 2 patient groups and the reference population. The magnitude of the length reduction did not differ between the groups or between injured and healthy limbs. In all 4 threshold tests performed as a measure of peripheral proprioception, a stronger relation to hop-length was recorded for the blinded hop than with full visual control in the patients with nonoperated ACL injuries. The coefficients of correlation between hop-length and the proprioceptive recordings in the injured limb were of the same magnitude as on the healthy side.
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| 2. |
- Fridén, Thomas, et al.
(författare)
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Proprioception after an acute knee ligament injury: a longitudinal study on 16 consecutive patients
- 1997
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Ingår i: Journal of Orthopaedic Research. - : Wiley. - 1554-527X .- 0736-0266. ; 15:5, s. 637-644
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Tidskriftsartikel (refereegranskat)abstract
- A defect in proprioception has been found in selected patient groups that have an anterior cruciate ligament deficient knee at different times after the original injury. The time of development and the extent of such defects were studied longitudinally on 16 consecutive patients. During the first year after a primary knee injury, which included a complete rupture of the anterior cruciate ligament, we repeatedly performed three tests of proprioception: (a) one to determine the threshold for detecting a passive motion from starting positions of 20 and 40 degrees, (b) an active reproduction of a passive angular change, and (c) a visual estimation of a passive angular change. The injured limb was compared with the uninjured limb and with the limbs of an age-matched reference group of healthy subjects. The population did not have a normal distribution, and some patients had consistently extreme recordings in the threshold tests at the various times of testing. Significant differences were found between the groups at the starting position of 20 degrees, when the injured knee was compared with the uninjured knee, after 1 month (p = 0.05), and after 2 months (p = 0.03). There was a trend toward a higher threshold for detecting a passive motion when the injured side was compared with the knees of the reference group at 1 month (p = 0.06) but not later on. A similar pattern was found for the injured knee at the starting position of 40 degrees, but it was not significant. An impaired ability to detect a passive motion was registered for the nearly extended knee 1 and 2 months after a primary injury. In the active reproduction and visual estimation tests, no significant defects were found at any time during the first year in these consecutively studied patients.
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| 3. |
- Fridén, Thomas, et al.
(författare)
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Proprioception in the nearly extended knee. Measurements of position and movement in healthy individuals and in symptomatic anterior cruciate ligament injured patients
- 1996
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Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy. - 1433-7347. ; 4:4, s. 217-224
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Tidskriftsartikel (refereegranskat)abstract
- Proprioception of the knee was measured in 19 healthy individuals to evaluate whether there were any differences between extension and flexion movements from two different starting positions. The threshold before detecting a passive movement, visual estimation on a protractor of a passive change in position (30 degrees angular change) and active reproduction of the same angular change were registered. The reference population was tested twice to study normal variation and reproducibility, followed by the evaluation of 20 patients with chronic, symptomatic and unilateral anterior cruciate ligament (ACL)-deficient knees. In the normal population no differences were found between the right and the left leg, men and women, or measurements made at the first and at the second test occasion. The thresholds from a starting position of 20 degrees were lower for extension than for flexion. When comparing the thresholds for extension between the 20 degrees and the 40 degrees starting position, lower values were found in the more extended position. The thresholds for flexion were lower from the 40 degrees starting position than from the 20 degrees starting position. The active reproduction of an angular change of 30 degrees was more accurate during flexion (30 degrees-60 degrees) than during extension (60 degrees-30 degrees). There were no differences in the reproduction tests or in thresholds from the 40 degrees starting position between the patients and the normal group, but the patients had higher thresholds from the 20 degrees starting position, in movements towards both extension 1.0 degree (range 0.5 degree-12.0 degrees) and flexion 1.5 degrees (range 0.5 degree-10.0 degrees) than the normal group 0.75 degree (range 0.5 degree-2.25 degrees) (P = 0.01) and 1.0 degree (range 0.5 degree-3.0 degrees) (P = 0.06), respectively. Thus, information of passive movements in the nearly extended knee position was more sensitive towards extension than towards flexion in threshold tests and the sensitivity improved closer to full extension, which implies a logical joint protective purpose. In this nearly extended knee position, which is the basis for most weight-bearing activities, patients with symptomatic ACL-deficient knees had an impaired awareness in detecting a passive movement. There were no differences in the more flexed position or in the reproduction tests between the patients and the normal group, and reproduction tests in the present form seem less appropriate to use in the evaluation of ACL injuries.
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| 4. |
- Fridén, Thomas, et al.
(författare)
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Proprioceptive defects after an anterior cruciate ligament rupture -- the relation to associated anatomical lesions and subjective knee function
- 1999
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Ingår i: Knee Surgery, Sports Traumatology, Arthroscopy. - : Springer Science and Business Media LLC. - 1433-7347 .- 0942-2056. ; 7:4, s. 226-231
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Tidskriftsartikel (refereegranskat)abstract
- A disturbed proprioception has been described in patients with an anterior cruciate ligament (ACL) deficient knee. The relation to demographic data and to different commonly associated anatomical lesions, as well as to subjective knee function, was prospectively studied in 16 consecutive patients after an acute knee ligament injury. All patients had a complete rupture of the ACL, but variable associated anatomical lesions. The threshold to detect a passive motion, as a measure of their proprioceptive ability, was registered repeatedly during the first year after injury. Four of the patients had consistently severe and persistent deficits at 1, 2 and 8 months. These four individuals had more chondral lesions and a lower subjective rating of their knee function than the remaining patients. In the whole group there were significant correlations between the recorded thresholds and associated chondral lesions, meniscal lesions and the subjective rating of knee function. We found no significant relation between age, gender, activity level, grade of mechanical laxity increase or a medial collateral ligament rupture, and the proprioceptive recordings. Thus, morphological lesions other than a rupture of the ACL seem to contribute to the proprioceptive deficits after a knee ligament injury, and the patients' ability to detect a passive motion showed a relation to subjective knee function from the time of injury onwards.
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| 5. |
- Møller, Ian M., et al.
(författare)
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Ubiquinone-1 induces external deamino-NADH oxidation in potato tuber mitochondria
- 1996
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Ingår i: Plant Physiology. - 0032-0889. ; 112:1, s. 75-78
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Tidskriftsartikel (refereegranskat)abstract
- The addition of ubiquinone-1 (UQ-1) induced Ca2+-independent oxidation of deamino-NADH and NADH by intact potato (Solanum tuberosum L. cv Bintje) tuber mitochondria. The induced oxidation was coupled to the generation of a membrane potential. Measurements of NAD+-malate dehydrogenase activity indicated that the permeability of the inner mitochondrial membrane to NADH and deamino-NADH was not altered by the addition of UQ-1. We conclude that UQ-1-induced external deamino-NADH oxidation is due to a change in specificity of the external rotenone-insensitive NADH dehydrogenase. The addition of UQ-1 also induced rotenone-insensitive oxidation of deamino-NADH by inside-out submitochondrial particles, but whether this was due to a change in the specificity of the internal rotenone-insensitive NAD(P)H dehydrogenase or to a bypass in complex I could not be determined.
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