Ulla-Britt Flansbjer

What change in isokinetic knee muscle strength can be detected in men and women with hemiparesis after stroke

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.

The Reproducibility of Berg Balance Scale and the Single-Leg Stance in Chronic Stroke and the Relationship Between the Two Tests

To assess the reproducibility of the Berg Balance Scale (BBS) and the Single‐leg Stance (SLS), and the validity of the SLS as an independent test of upright postural control in patients with chronic stroke.

Long-term benefits of progressive resistance training in chronic stroke: A 4-year follow-up.

OBJECTIVES To evaluate the long-term benefits of progressive resistance training in chronic stroke. DESIGN A 4-year follow-up of a randomized controlled trial of progressive resistance training. SUBJECTS Eighteen women and men (mean age 66 (standard deviation 4) from the original group of 24 post-stroke participants. METHODS The training group (n = 11) had participated in supervised progressive resistance training of the knee extensors and flexors (80% of maximum) twice weekly for 10 weeks, whereas the control group (n = 7) had continued their usual daily activities. Muscle strength was evaluated isotonically and isokinetically (60º/s; Biodex), muscle tone with the Modified Ashworth Scale, gait performance by the Timed Up and Go test, the Fast Gait Speed test and 6-Minute Walk test, and perceived participation with the Stroke Impact Scale (Participation domain). RESULTS Four years after the intervention, the improvements in muscle strength in the training group were maintained, and there was no reduction in strength in the control group. Compared with baseline there were still significant between-group differences for both isotonic and isokinetic strength. No significant between-group differences were found in muscle tone, gait performance or perceived participation. CONCLUSION The results indicate that there is a long-term benefit of progressive resistance training in chronic stroke. This implies that progressive resistance training could be an effective training method to improve and maintain muscle strength in a long-term perspective.

Reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio.

OBJECTIVE To assess the reliability of knee extensor and flexor muscle strength measurements in persons with late effects of polio. DESIGN A test-retest reliability study. SUBJECTS Thirty men and women (mean age 63 (standard deviation 6.4) years) with verified late effects of polio. METHODS Knee extensor and flexor muscle strength in both lower limbs were measured twice 7 days apart using a Biodex dynamometer (isokinetic concentric contractions at 60 degrees /sec and isometric contractions with knee flexion angle 90 degrees) and a Leg Extension/Curl Rehab exercise machine with pneumatic resistance (HUR) (isotonic contractions). Reliability was assessed with the intraclass correlation coefficient (ICC1,1), the mean difference between the test sessions (d) together with the 95% confidence intervals for d, the standard error of measurement (SEM and SEM%), the smallest real difference (SRD and SRD%) and Bland-Altman graphs. RESULTS Test-retest agreements were high, (ICC1,1 0.93-0.99) and measurement errors generally small. The SEM% was 4-14% and the SRD% 11-39%, with the highest values for the isokinetic measurements. CONCLUSION Knee muscle strength can be measured reliably and can be used to detect real changes after an intervention for a group of persons with late effects of polio, whereas the values may be too high for single individuals or to detect smaller short-term changes over time for a group of individuals.

Reliability of Gait Performance Tests in Individuals With Late Effects of Polio.

To assess the reliability of 4 gait performance tests in individuals with late effects of polio.

No Effects of Whole-Body Vibration Training on Muscle Strength and Gait Performance in Persons With Late Effects of Polio: A Pilot Study.

OBJECTIVE To evaluate the feasibility and possible effects of whole-body vibration (WBV) training on muscle strength and gait performance in people with late effects of polio. DESIGN A case-controlled pilot study with assessments before and after training. SETTING A university hospital rehabilitation department. PARTICIPANTS People (N=5; 3 men, 2 women; mean age, 64+/-6.7y; range, 55-71y) with clinically and electrophysiologically verified late effects of polio. INTERVENTIONS All participants underwent 10 sessions of supervised WBV training (standing with knees flexed 40 degrees -55 degrees up to 60 seconds per repetition and 10 repetitions per session twice weekly for 5 weeks). MAIN OUTCOME MEASURES Isokinetic and isometric knee muscle strength (dynamometer), and gait performance (Timed Up & Go, Comfortable Gait Speed, Fast Gait Speed, and six-minute walk tests). RESULTS All participants completed the 5 weeks of WBV training, with no discernible discomfort. No significant changes in knee muscle strength or gait performance were found after the WBV training period. CONCLUSIONS This pilot study did not show any significant improvements in knee muscle strength and gait performance following a standard protocol of WBV training. Thus, the results do not lend support to WBV training for people with late effects of polio.

What is the long-term benefit of constraint-induced movement therapy? A four-year follow-up:

Objective: To evaluate the long-term benefits of constraint-induced movement therapy in chronic stroke. Design: A four-year follow-up after constraint-induced group therapy assessing arm and hand function and self-reported daily hand use. Subjects: Fourteen post-stroke individuals (six women and eight men; mean age 59.6 ± 12.7 years, range 23—75 years) with mild to moderate impairments of hand function. Outcome measures: The Sollerman hand function test and the Motor Activity Log test. Results: Four years after constraint-induced group therapy the participants had maintained their hand function, as measured by the Sollerman hand function test. The self-reported use and quality of movements of the more affected hand, as measured by the Motor Activity Log test, had decreased compared to post-treatment and three months follow-up (P<0.01), but was still significantly higher than pre-treatment (P<0.05). Conclusion: There seems to be a long-term benefit of constraint-induced group therapy. Hand function was maintained over time and daily hand use had increased compared to pre-treatment. To provide guidelines about the clinical use of constraint-induced movement therapy further, larger and controlled studies are needed.

Voluntary activation of the knee extensors in chronic poststroke subjects.

Miller M, Flansbjer U-B, Lexell J: Voluntary activation of the knee extensors in chronic poststroke subjects. Objective:To assess the extent to which knee extensor muscle weakness in subjects with chronic mild to moderate poststroke hemiparesis is caused by a decreased voluntary activation. Design:Forty community dwelling and ambulant men and women (mean age, 59.8 ± 5.5 yrs) with residual hemiparesis (19.2 ± 8.5 mos poststroke) were tested. Torque measurements were performed on a computerized dynamometer and the superimposed electrical stimulation technique was used to assess voluntary activation of the knee extensors in both the paretic and the nonparetic lower limbs. Results:The mean voluntary activation ratio of the knee extensors in the nonparetic and paretic leg was 0.97 ± 0.04 and 0.86 ± 0.13, respectively. Subjects who had a greater relative weakness, implying a more pronounced poststroke impairment, also had lower voluntary activation ratios. The mean percentage difference in total torque between the nonparetic and the paretic knee extensors after the electrical stimulation was 36.4% ± 17.0%. Conclusions:Paretic knee extensor muscle weakness in chronic poststroke subjects is only partially explained by a reduced voluntary activation ability, indicating that other neuromuscular structural or functional factors contribute to poststroke hemiparetic muscle weakness.

Self-reported Walking Ability in Persons With Chronic Stroke and the Relationship With Gait Performance Tests

To assess self‐reported walking ability in individuals with chronic stroke and to determine the relationship with gait performance tests.

Superimposed electrical stimulation - Assessment of voluntary activation and perceived discomfort in healthy, moderately active older and younger women and men

Miller M, Flansbjer U-B, Downham D, Lexell J: Superimposed electrical stimulation: assessment of voluntary activation and perceived discomfort in healthy, moderately active older and younger women and men. Am J Phys Med Rehabil 2006;85:945–950. Objective:An inability of the nervous system to fully activate the muscle is one factor that can contribute to age-related muscle weakness. Superimposed electrical stimulation can be used to determine voluntary muscle activation (VA). The aim of this study was to assess VA of the quadriceps muscle in healthy older and younger subjects. Design:Electrical stimulation causes moderate discomfort in younger subjects, but no study has assessed discomfort in older subjects. The quadriceps muscle in 20 moderately active older subjects (mean age, 75 yrs) and 12 younger subjects (mean age, 25 yrs) was stimulated during two maximal voluntary contractions using a 100-Hz pulse train. A visual analog scale for pain (VAS–pain) was used to evaluate discomfort. Results:Ability to activate the quadriceps muscle was generally very high, and there was no significant difference between the older (mean, 0.96) and younger (mean, 0.98) subjects. Discomfort did not differ between the older (mean VAS–pain score, 41 mm) and younger (mean VAS–pain score, 37 mm) subjects. Conclusions:Our results indicate that healthy, moderately active older subjects have the ability to almost complete VA of the quadriceps muscle and that discomfort during electrical stimulation is generally moderate.