| 1. |
- Drake, Anna Maria, et al.
(författare)
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Ankle dorsiflexor muscle performance in healthy young men and women: reliability of eccentric peak torque and work measurements
- 2001
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Ingår i: Journal of Rehabilitation Medicine. - : Medical Journals Sweden AB. - 1651-2081 .- 1650-1977. ; 33:2, s. 90-96
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Tidskriftsartikel (refereegranskat)abstract
- The aims of this study were: (i) to assess the test-retest intrarater reliability of eccentric ankle dorsiflexor muscle performance in young healthy men and women using the Biodex dynamometer; and (ii) to examine different statistical indices for the interpretation of reliability. Thirty men and women (age 22.5 +/- 2.5 years, mean +/- S.D.) performed three maximal eccentric contractions at 30 degrees/second and 90 degrees/second, with 7-10 days between test sessions. Reliability was evaluated with three intraclass correlation coefficients (ICC1,1, ICC2,1 and ICC3,1), and was excellent for peak torque (ICC 0.90-0.96) and good to excellent for work (ICC 0.69-0.83), with no discernible differences among the three ICCs. Method errors, assessed by the standard error of the measurement (S.E.M.) and S.E.M.%, were low. The Bland & Altman graphs and analyses indicated no significant systematic bias in the data. In conclusion, measurements of eccentric ankle dorsiflexor muscle performance in young healthy individuals using the Biodex are highly reliable.
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| 2. |
- Drake, Anna Maria, et al.
(författare)
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Assessment of contractile and noncontractile components in human skeletal muscle by magnetic resonance imaging.
- 2002
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 25:2, s. 251-258
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Tidskriftsartikel (refereegranskat)abstract
- A magnetic resonance imaging (MRI) technique for the assessment of contractile and noncontractile components of human skeletal muscle is described, and the inter-rater and intra-rater test-retest reliability for repeated measurements from the same MR image are examined. Twenty cross-sectional MR images from the right lower leg were obtained from 30 healthy young men and women (mean age 24.1 years, SD 3.3). The anatomical cross-sectional area (aCSA; cm2), the cross-sectional area of noncontractile components (Noncon; cm2), the contractile cross-sectional area (cCSA = aCSA minus Noncon; cm2), and the relative amount of Noncon (%), of the ankle dorsiflexor muscle compartment were determined for each slice using a computer-based image analysis system. Reliability for repeated measurements of the slice with the largest aCSA for the 30 subjects was analyzed by two raters on two different occasions. Inter-rater reliability on both occasions, assessed by the intraclass correlation coefficient (ICC), was excellent for cCSA (ICC3.1 = 0.99) and Noncon (ICC(3.1)
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| 3. |
- Drake, Anna Maria, et al.
(författare)
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Reliability of isokinetic ankle dorsiflexor strength measurements in healthy young men and women
- 1999
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Ingår i: Scandinavian Journal of Rehabilitation Medicine. - : Informa UK Limited. - 0036-5505 .- 1940-2228. ; 31:4, s. 229-239
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Tidskriftsartikel (refereegranskat)abstract
- The purposes of this study were: (i) to determine the test-retest reliability of isokinetic ankle dorsiflexor strength measurements in young healthy adults using the Biodex dynamometer, and (ii) to examine several statistical measures for the interpretation of reliability. Thirty men and women (mean age 23 +/- 3 years) performed three maximal concentric contractions at 30 degrees/s, 60 degrees/s, 90 degrees/s, 120 degrees/s and 150 degrees/s. Reliability of peak torque, work and torque at a specific time were assessed by calculating the intraclass correlation coefficient (ICC 2,1), Pearson product moment correlation coefficient (r), standard error of the measurement (SEM), method error (ME) and coefficient of variation (CV), and by plotting the differences between observations against their means. Isokinetic tests of ankle dorsiflexor strength in healthy young adults using the Biodex dynamometer were highly reliable (ICC 0.61-0.93). It is recommended that test-retest reliability analyses include the ICC and assessments of measurement errors (SEM, ME or CV), as well as graphs to indicate any systematic variations in the data.
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| 4. |
- Drake, Anna Maria, et al.
(författare)
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Reproducibility of isokinetic ankle dorsiflexor strength and fatigue measurements in healthy older subjects.
- 2007
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Ingår i: Isokinetics and Exercise Science. - 1878-5913 .- 0959-3020. ; 15:4, s. 263-270
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to determine the test-retest (two occasions seven days part) reproducibility of isokinetic (Biodex) concentric (CON) and eccentric (ECC) ankle dorsiflexor strength and fatigue measurements in older subjects using several statistical methods. Thirty healthy men (n=15) and women (n=15) aged between 70 and 85 years participated in the study. To determine the reproducibility of strength measurements, the 30 individuals performed three maximal CON and ECC contractions at 30°/s and 90°/s. The intraclass correlation coefficient (ICC_{2.1}) for CON and ECC strength measurements was high and ranged from 0.94 to 0.98. Bland & Altman graphs and analyses indicted no systematic bias. The standard error of measurement (SEM), representing the smallest change that indicates a real improvement (or deterioration) for a group of individuals, was small (< 2.3 Nm). The smallest real difference (SRD), representing the smallest detectable change that indicates a real improvement (or deterioration) for a single subject, was also small ('error bands' from −7.2 Nm to 5.6 Nm). A high correlation (Pearson's r > 0.94) between CON peak torque at 30°/s and 90°/s, as well as ECC peak torque at 30°/s and 90°/s, suggested that any of these two velocities could be used as a reference. To determine the reproducibility of fatigue measurements, 28 of the 30 individuals performed 50 maximal CON contractions at 60°/s. Reproducibility of the loss in work (work fatigue) and the relative loss in peak torque, comparing the first three to the last three contractions (3-3), was determined and the ICC was 0.71 and 0.60, respectively. In addition, the SEM was small (< 8.4%) and the 'error bands' to define the SRD for a single subject were also small (from −23.5% to 24.5%). In conclusion, these values indicate small measurement errors and thus provide a clinically acceptable basis for testing ankle dorsiflexion strength and fatigue of the dominant side in healthy older people.
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| 5. |
- Drake, Anna Maria, et al.
(författare)
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The structure and function of the ankle dorsiflexor muscles in young and moderately active men and women.
- 2003
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Ingår i: Journal of Applied Physiology. - : American Physiological Society. - 1522-1601 .- 8750-7587. ; 95:6, s. 2416-2424
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to investigate determinants of ankle dorsiflexor muscle (DF) strength and size in moderately active young men and women ( n = 30; age 20–31 yr). Concentric (Con) and eccentric (Ecc) strength were measured isokinetically. Magnetic resonance imaging was used to determine the muscle cross-sectional area (CSA). Multiple biopsies were obtained from the tibialis anterior muscle to determine total numbers, areas (Area I and II) and proportions (Prop I and II) of type I and II fibers, respectively, and relative contents of myosin heavy chain (MHC) isoforms MHC1, MHC2a, and MHC2x. Women had lower Con and Ecc strength (24 and 27%; P < 0.01), smaller CSA (19%; P < 0.001), lower Ecc DF specific strength (strength/CSA) (10%; P < 0.01), and smaller Area I and Area II (21 and 31%; P < 0.01) than men. Prop I, MHC1, estimated total number of fibers, and Con DF specific strength were similar for both sexes. Con DF strength was up to 72% determined by CSA and Prop I, and Ecc DF strength was up to 81% determined by CSA, Prop I, and sex; variables other than CSA explained at most 9%. Body weight and fiber areas explained >50% of the variation in CSA. In conclusion, CSA was the predominant determinant of DF strength, CSA was to a great extent determined by the body weight and the sizes of muscle fibers, and sex differences in Ecc specific strength require further study.
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| 6. |
- Flansbjer, Ulla-Britt, et al.
(författare)
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Reliability of gait performance tests in men and women with hemiparesis after stroke.
- 2005
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Ingår i: Journal of Rehabilitation Medicine. - : Medical Journals Sweden AB. - 1650-1977 .- 1651-2081. ; 37:2, s. 75-82
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To assess the reliability of 6 gait performance tests in individuals with chronic mild to moderate post-stroke hemiparesis.DESIGN: An intra-rater (between occasions) test-retest reliability study. Subjects: Fifty men and women (mean age 58+/-6.4 years) 6-46 months post-stroke.METHODS: The Timed "Up & Go" test, the Comfortable and the Fast Gait Speed tests, the Stair Climbing ascend and descend tests and the 6-Minute Walk test were assessed 7 days apart. Reliability was evaluated with the intraclass correlation coefficient (ICC(2,1)), the Bland & Altman analysis, the standard error of measurement (SEM and SEM%) and the smallest real difference (SRD and SRD%).RESULTS: Test-retest agreements were high (ICC(2,1) 0.94-0.99) with no discernible systematic differences between the tests. The standard error of measurement (SEM%), representing the smallest change that indicates a real (clinical) improvement for a group of individuals, was small (< 9%). The smallest real difference (SRD%), representing the smallest change that indicates a real (clinical) improvement for a single individual, was also small (13-23%).CONCLUSION: These commonly used gait performance tests are highly reliable and can be recommended to evaluate improvements in various aspects of gait performance in individuals with chronic mild to moderate hemiparesis after stroke.
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| 7. |
- Flansbjer, Ulla-Britt, et al.
(författare)
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What change in isokinetic knee muscle strength can be detected in men and women with hemiparesis after stroke?
- 2005
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Ingår i: Clinical Rehabilitation. - : SAGE Publications. - 1477-0873 .- 0269-2155. ; 19:5, s. 514-522
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To assess the intra-rater (between occasions) test-retest reliability of isokinetic knee muscle strength measurements in subjects with chronic poststroke hemiparesis and to define limits for the smallest change that indicates real (clinical) improvements for stroke patients. Subjects: Fifty men and women (mean age 589±6.4 years) 6=±46 months post stroke, able to walk at least 300 m with or without a unilateral assistive device. Methods: Maximal concentric knee extension and flexion contractions at 608/s and 1208/s, and maximal eccentric knee extension contractions at 608/s, with the paretic and nonparetic limbs, were performed seven days apart using a Biodex dynamometer. Measures: Reliability of the maximum peak torque measurements was evaluated with the intraclass correlation coefficient (ICC2,1), the Bland and Altman analyses, the standard error of measurement (SEM and SEM%) and the smallest real difference (SRD and SRD%). Results: Test retest agreements were high (ICC2,1 0.89-0.96) with no discernible systematic differences between limbs, angular velocities and modes. The SEM%, representing the smallest change that indicates a real (clinical) improvement for a group of subjects, was relatively small (8-20%). The SRD%, representing the smallest change that indicates a real improvement for a single subject ranged from 26% to 33% for concentric knee extension, from 39% to 55% for concentric knee flexion, and from 22% to 25% for eccentric knee extension. Conclusion: Isokinetic knee muscle strength can be reliably measured and used to detect real improvements following an intervention for single subjects as well as for groups of subjects with chronic mild to moderate hemiparesis after stroke.
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| 8. |
- Jaworowski, Å, et al.
(författare)
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Enzyme activities in the tibialis anterior muscle of young moderately active men and women: relationship with body composition, muscle cross-sectional area and fibre type composition.
- 2002
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Ingår i: Acta Physiologica Scandinavica. - 0001-6772 .- 1365-201X. ; 176:3, s. 215-225
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Tidskriftsartikel (refereegranskat)abstract
- The aims of this study were (i) to assess the differences between men and women in maximal activities of selected enzymes of aerobic and anaerobic pathways involved in skeletal muscle energy production, and (ii) to assess the relationships between maximal enzyme activities, body composition, muscle cross-sectional area (CSA) and fibre type composition. Muscle biopsies were obtained from the tibialis anterior (TA) muscle of 15 men and 15 women (age 20-31 years) with comparable physical activity levels. The muscle CSA was determined by magnetic resonance imaging (MRI). Maximal activities of lactate dehydrogenase (LDH), phosphofructokinase (PFK), beta-hydroxyacyl-coenzyme A dehydrogenase (HAD), succinate dehydrogenase (SDH) and citrate synthase (CS), were assayed spectrophotometrically. The proportion, mean area and relative area (proportion x area) of type 1 and type 2 fibres were determined from muscle biopsies prepared for enzyme histochemistry [myofibrillar adenosine triphosphatase (mATPase)]. The men were significantly taller (+6.6%; P < 0.001) and heavier (+19.1%; P < 0.001), had significantly larger muscle CSA (+19.0%; P < 0.001) and significantly larger areas and relative areas of both type 1 and type 2 fibres (+20.5-31.4%; P = 0.007 to P < 0.001). The men had significantly higher maximal enzyme activities than women for LDH (+27.6%; P = 0.007) and PFK (+25.5%; P = 0.003). There were no significant differences between the men and the women in the activities of HAD (+3.6%; ns), CS (+21.1%; P = 0.084) and SDH (+7.6%; ns). There were significant relationships between height and LDH (r = 0.41; P = 0.023), height and PFK (r = 0.41; P = 0.025), weight and LDH (r = 0.45; P = 0.013), and weight and PFK (r = 0.39; P = 0.032). The relationships were significant between the muscle CSA and the activities of LDH (r = 0.61; P < 0.001) and PFK (r = 0.56; P = 0.001), and between the relative area of type 2 fibres and the activities of LDH (r = 0.49; P = 0.006) and PFK (r = 0.42; P = 0.023). There were no significant relationships between HAD, CS and SDH, and height, weight, muscle CSA and fibre type composition, respectively. These data indicate that the higher maximal activities of LDH and PFK in men are related to the height, weight, muscle CSA and the relative area of type 2 fibres, which are all significantly larger in men than women.
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| 9. |
- Miller, Michael, et al.
(författare)
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Voluntary activation and central activation failure in the knee extensors in young women and men
- 2006
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 16:4, s. 274-81
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Tidskriftsartikel (refereegranskat)abstract
- Quadriceps muscle weakness is common after knee injuries. This weakness is caused, in part, by reduced voluntary activation (VA) because of central activation failure (CAF). Superimposed electrical stimulation techniques are used to assess VA and to detect CAF. The aim of this study was to assess VA during knee extension in young healthy women and men, and to evaluate subjective discomfort from the electrical stimulation. The quadriceps muscle in six young healthy women (mean age 22 years) and six young healthy men (mean age 29 years) was stimulated during maximal voluntary contractions using a 100 Hz pulse train. Data were collected from two test sessions separated by 6-8 days and each session comprised of two trials. A visual analog scale for pain (VAS-pain) was used to evaluate subjective discomfort. Overall, young healthy, moderately active men and women did have the ability to fully activate their knee extensors isometrically, but they did not achieve full activation on every trial. In those trials where a CAF was detected, the degree was small (mean less than 2%), and did not vary between the two test sessions. Subjective discomfort was generally moderate and tolerable (mean VAS-pain score 35 mm). These results will assist the clinical assessment of muscle weakness following a knee injury and facilitate the design and evaluation of appropriate rehabilitation interventions.
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| 10. |
- Porter, MM, et al.
(författare)
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Reliability of concentric ankle dorsiflexion fatigue testing
- 2002
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Ingår i: Canadian Journal of Applied Physiology. - : Canadian Science Publishing. - 1066-7814 .- 1543-2718. ; 27:2, s. 116-127
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to determine the reliability of an isokinetic test for ankle dorsiflexion fatigue on a Biodex dynamometer Young (21 to 32 years), recreationally active men (n = 10) and women (n = 10) performed 50 concentric (60degrees . s(-1)) dorsiflexion contractions, on two different occasions. Total work (TW), losses in work (work fatigue; WF), as well as relative losses in peak torque, an example being "3-3" which compared the first three to last three repetitions, were measured. The intra-class correlation coefficients (ICC2,1) and coefficients of variation (CV), as well as the Bland-Altman plots and analyses showed that the variables using peak torque and TW were more reliable than WF with WF having a CV of 11.3% and the best peak torque variable, 3-3, having a CV of 5.6%. In conclusion, ankle dorsiflexion fatigue can be reliably assessed on a Biodex dynamometer.
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