Ulla Svantesson

Quadriceps muscle performance in sitting and standing in young women with patellofemoral pain syndrome and young healthy women

The aim of this study was to evaluate and compare muscular activation in sitting and standing in patients with patellofemoral pain syndrome and healthy controls. Eleven women with patellofemoral pain syndrome and nine healthy controls were evaluated regarding: (a) muscle performance in sitting compared to standing ‐ knee extensor torque was registered in sitting with a Kin Com dynamometer and in standing with a force plate, and quadriceps muscle activity was registered with EMG in both sitting and standing; and (b) ability to maximally voluntarily activate during sitting isometric knee extension.

Tests of functional limitations in fibromyalgia syndrome: a reliability study.

OBJECTIVE To evaluate the reliability and discriminative ability of a test battery consisting of 7 tests designed for the assessment of functional limitations in patients with fibromyalgia syndrome (FMS). METHODS The intrarater reliability of the test battery was evaluated for 15 women with FMS. Interrater reliability was calculated on 4 tests separately. Fifteen healthy women constituted a reference group. RESULTS The intrarater coefficient of variation was < 8% for the shoulder range of motion tests, chair test, and 6-minute walk test, and < 21% for the shoulder endurance test, with correlation coefficients above 0.80 for all tests. Kappa was 0.70-0.80 for the hand-to-scapula tests. The interrater coefficient of variation was < 5% for shoulder range of motion. The performances of the FMS patients were significantly decreased in comparison with healthy subjects in all the tests except for the hand-to-scapula movement. CONCLUSIONS All but 1 of the selected 7 tests were considered to possess acceptable intrarater reliability for use in FMS in clinical physical therapy practice.

Test-retest reliability of three different countermovement jumping tests.

In studies of physical performance comprising muscle strength and power, a vertical jump is a test method that frequently is used. It is important to have access to accurate measuring tools providing data with high reproducibility. Studies have shown that body composition also may play an important part in physical performance. The purpose of this study was to determine test-retest reliability for 3 different kinds of vertical jumps and to correlate jump height with body composition. Thirty-four normally trained subjects (women n = 17) between 18 and 25 years participated. Test-retest, on 3 kinds of vertical jumps, was performed with a median of 7 days between jumps. Methods used were a countermovement jump (CMJ) on a contact mat, with and without arm swing, and an Abalakow jump (AJ) using measuring tape, with arm swing. Body composition was assessed with the use of bioelectric impedance analysis. The results showed that high intraclass correlation coefficients (ICCs) were observed between testing occasions for all 3 vertical jumps (ICC between 0.48 and 0.88). The AJ in women presented the lowest ICC. Also the correlation between CMJ and AJ was high (rs = 0.88). Moderate-to-high correlations could be shown between body composition and CMJ in women (rs = −0.57-0.76). In conclusion, very high test-retest reliability for CMJ on a contact mat was found. For the AJ using a measuring tape, ICC were overall high, but a moderate nonsignificant ICC were found in women, indicating poor reproducibility. The data from the CMJ and AJ may be compared if approximately 25% of the AJ value is subtracted. In practice, this means that vertical jump tests have high reproducibility and can be used as measures of power development.

Injuries and preventive actions in elite Swedish volleyball.

The purpose of this study was to examine the prevalence of injury and the extent of preventive actions in elite Swedish volleyball players. Injuries to players in the elite male and female Swedish division, during the 2002–2003 season, were registered by using a questionnaire. Of the 158 volleyball players (70% response rate), a total of 82 players (52%) reported 121 injuries, during a total exposure time of 24 632 h, representing an overall incidence of 0.77 injuries per player. The majority of the injuries were located in the ankle (23%), followed by the knee (18%) and the back (15%). Most injuries (62%) were classified as being of minor severity. Most injuries occurred during training (47%), and 41% of the injuries had a gradual onset. Fifty‐four percent of the injuries that could be related to a specific court situation occurred during blocking, and 30% during spiking. Most players (96%) participated in injury prevention training of some kind, generally performed without supervision (58%).

Early loading in physiotherapy treatment after full-thickness rotator cuff repair: a prospective randomized pilot-study with a two-year follow-up

Objective: To describe the clinical changes following two different physiotherapy treatment protocols after rotator cuff repair. Design: A prospective, randomized pilot study with a two-year follow-up. Subjects: Five women and nine men, 55 (40—64) years old, were included. Intervention: The progressive group (n = 7) started with dynamic, specific muscle activation of the rotator cuff the day after surgery as well as passive range of motion. After four weeks of immobilization the loading to the rotator cuff increased and in a progressive manner throughout the rehabilitation. In the traditional group (n = 7) the rotator cuff was protected from loading. Patients were immobilized for six weeks and started with passive range of motion the day after surgery. No specific exercises to the rotator cuff were introduced during this period. Main measures: A clinical evaluation was made preoperatively, 3, 6, 12 and 24 months after surgery. Pain rating during activity and at rest, patient satisfaction, active range of motion and muscle strength, Constant score, hand in neck, hand in back and pour out of a pot, as well as Functional Index of the Shoulder were used. Results: At two years follow-up, the progressive group and traditional group scored pain during activity visual analogue scale (VAS) 2/0 mm and pain at rest 0/0 mm, respectively. The groups attained 170/175° in active abduction in standing and 70/90° in passive external rotation while lying in supine. Using Constant score, the groups attained 82/77 points respectively. Conclusion: The present study showed that the progressive protocol produced no adverse effects compared with the traditional protocol.

Upper motor neuron lesions: Their effect on muscle performance and appearance in stroke patients with minor motor impairment

OBJECTIVE To evaluate muscular performance and appearance in patients with prior stroke who were ambulatory. DESIGN Nonrandomized study. SETTING University hospital laboratory. SUBJECTS Sixteen persons (11 men, 5 women) with minor motor impairments, 6 to 24 months after stroke, were included. As reference, data were used from a population-based sample of 144 men and women. MAIN OUTCOME MEASUREMENTS Muscle performance was evaluated using a Kin-Com dynamometer in both the affected and the nonaffected leg. Peak isometric strength was measured at a 60 degree angle in both extension and flexion. Maximal isokinetic strength was measured at 60 degrees/sec and at 180 degrees/sec. Endurance was evaluated during isometric and dynamic knee extensions. Muscle biopsies were taken on nine patients and muscle tissue areas were determined with computed tomography. RESULTS The affected leg was weaker but not different in relative endurance compared with the nonaffected side. The performance of the nonaffected side was somewhat lower than that of a matched reference population. No major difference in fiber composition between the affected and nonaffected legs was noted, except for a lower degree of capillarization in the affected leg. CONCLUSION In well-functioning stroke patients with good motor performance, further muscle training that includes resistance exercise might be indicated.

Use of a Kin-Com dynamometer to study the stretch-shortening cycle during plantar flexion

SummaryThe aim of this study was to evaluate the Kin-Com II dynamometer in the study of the stretch-shortening cycle (a concentric muscle action preceded by an eccentric muscle action). Measurements were made of plantar flexion at different angular velocities (120° · s−1 and 240° · s−1) with the knee at two different angles (0° and 90°). Ten healthy women ranging in age from 22 to 41 years were studied. Torque values were recorded simultaneously with surface electromyograms (EMG); maximal voluntary concentric torque values were recorded and, after a short rest, the torque values of the concentric action which followed immediately after an eccentric action of the same velocity, both with maximal effort. Mean values were taken at different ankle positions and also averaged over different ranges. A concentric action preceded by an eccentric action generated a torque value on an average about 100% larger than a concentric action alone. The EMG activity was lower or unchanged. It was concluded that the present method could be useful in the study of the stretch-shortening cycle in plantar flexion and in the testing of the behaviour of the elastic components in people with disabilities in the lower limbs.

Muscle and tendon stiffness in patients with upper motor neuron lesion following a stroke.

Abstract The objective of this study was to investigate muscle and tendon stiffness in the triceps surae muscles in patients who had previously had a stroke. The participants were 12 men showing slight to moderate degrees of muscle tonus in the affected leg. All patients showed minimal or no overt clinical motor symptoms, and all walked without mechanical aid. Muscle strengths in isometric and isokinetic activities were measured, as was passive resistance during plantarflexion in each leg. Walking speed was also measured. Evaluations of physical performance and muscle tone were made. Muscle and tendon stiffness was calculated from measurements whilst passively stretching during electrical stimulation, separately for each leg. Muscle strength was significantly higher in the non-affected than in the affected leg. Muscle stiffness was significantly higher in the affected leg than in the non-affected leg. Tendon stiffness was significantly higher in the non-affected than in the affected leg. The higher muscle stiffness in the affected leg might enhance the possibility for storing elastic energy during preactivation. Lower tendon stiffness in the affected leg might reduce the development of fatigue in movements at low velocities.

Development of fatigue during repeated eccentric-concentric muscle contractions of plantar flexors in patients with stroke

OBJECTIVE To better understand the mechanisms behind fatigue in muscles affected by a neuromuscular disease. DESIGN Patients recruited by convenience compared to age-matched healthy subjects from a population study. SETTING University hospital laboratory. METHODS Repetitive eccentric-concentric plantar flexions at 60 degrees/sec were performed on a dynamometer until exhaustion. The mean power frequency and root mean square of the electromyogram were recorded, and work was calculated. SUBJECTS Both legs of seven patients with upper motor neuron lesion from stroke and one leg of healthy men were tested. RESULTS There were no significant (p > .05) differences in number of cycles performed or decrease of work between any of the tested legs. There was a significant (p > .05) difference in work performed by the affected leg and the reference group. Mean power frequency decreased significantly (p > .05) for the gastrocnemius muscle in the nonaffected leg and for the reference group, while no such decreases were found in the affected leg. The statistical methods used were the nonparametric tests: the Wilcoxon one-sample for differences between paired observations, and the Mann-Whitney U for differences between groups. CONCLUSION A reduction in work in high-intensity dynamic muscle activity may not be associated with a reduction in mean power frequency, especially in patients with altered supraspinal control. There may be peripheral fatigue factors not reflected in the electromyographic activity.

Torque, work and EMG development in a heel-rise test

OBJECTIVE: To study the fatigue process in the calf muscle during a standing heel-rise test. DESIGN: Heel-rises were performed on a force plate measuring development of torque in the ankle joint. BACKGROUND: The heel-rise test is a commonly employed clinical test to evaluate the function of the calf muscle by counting the number of heel-rises before exhaustion. Development of fatigue during other eccentric-concentric actions has earlier been studied as decreases in force, work and EMG. METHODS: Ten healthy males (mean age 25 yr) participated in the study. Torque and work were calculated using measurements from a force plate. Mean power frequency and root-mean-square of the EMG in the triceps surae were evaluated separately in the eccentric and concentric phases. RESULTS: Increases of mean torque during both the eccentric and concentric phases were found. Work performed decreased during the concentric phases due to decreased range of motion. No changes in root-mean-square and decreases in mean power frequency during the concentric phases indicated development of muscular fatigue, whereas decreases in both root-mean-square and mean power frequency during the eccentric phases indicated decreasing muscular activity. CONCLUSIONS: Accordingly, the limiting factor for the heel-rise test was not loss of muscle force at the range of motion used, but rather a failure to maintain the initial range of motion owing to muscle fatigue. RELEVANCE: This method of calculating torque development in the ankle joint provides an opportunity to study the fatigue process in terms of performance. The results show that the heel-rise test reflects muscle endurance rather than strength of the calf muscle.