| 1. |
- Jyväsjärvi, J., et al.
(författare)
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Climate-induced warming imposes a threat to north European spring ecosystems
- 2015
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Ingår i: Global Change Biology. - : Blackwell Publishing. - 1354-1013 .- 1365-2486. ; 21:12, s. 4561-4569
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Tidskriftsartikel (refereegranskat)abstract
- Interest in climate change effects on groundwater has increased dramatically during the last decade. The mechanisms of climate-related groundwater depletion have been thoroughly reviewed, but the influence of global warming on groundwater-dependent ecosystems (GDEs) remains poorly known. Here we report long-term water temperature trends in 66 northern European cold-water springs. A vast majority of the springs (82%) exhibited a significant increase in water temperature during 1968-2012. Mean spring water temperatures were closely related to regional air temperature and global radiative forcing of the corresponding year. Based on three alternative climate scenarios representing low (RCP2.6), intermediate (RCP6) and high-emission scenarios (RCP8.5), we estimate that increase in mean spring water temperature in the region is likely to range from 0.67 °C (RCP2.6) to 5.94 °C (RCP8.5) by 2086. According to the worst-case scenario, water temperature of these originally cold-water ecosystems (regional mean in the late 1970s: 4.7 °C) may exceed 12 °C by the end of this century. We used bryophyte and macroinvertebrate species data from Finnish springs and spring-fed streams to assess ecological impacts of the predicted warming. An increase in spring water temperature by several degrees will likely have substantial biodiversity impacts, causing regional extinction of native, cold-stenothermal spring specialists, whereas species diversity of headwater generalists is likely to increase. Even a slight (by 1 °C) increase in water temperature may eliminate endemic spring species, thus altering bryophyte and macroinvertebrate assemblages of spring-fed streams. Climate change-induced warming of northern regions may thus alter species composition of the spring biota and cause regional homogenization of biodiversity in headwater ecosystems.
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| 4. |
- Brodin, N., et al.
(författare)
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Coaching patients with early rheumatoid arthritis to healthy physical activity : A multicenter, randomized, controlled study
- 2008
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Ingår i: Arthritis and Rheumatism. - Hoboken, NJ : Wiley. - 0004-3591 .- 1529-0131. ; 59:3, s. 325-331
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To investigate the effect of a 1-year coaching program for healthy physical activity on perceived health status, body function, and activity limitation in patients with early rheumatoid arthritis. Methods. A total of 228 patients (169 women, 59 men, mean age 55 years, mean time since diagnosis 21 months) were randomized to 2 groups after assessments with the EuroQol visual analog scale (VAS), Grippit, Timed-Stands Test, Escola Paulista de Medicina Range of Motion scale, walking in a figure-of-8, a visual analog scale for pain, the Health Assessment Questionnaire disability index, a self-reported physical activity questionnaire, and the Disease Activity Score in 28 joints. All patients were regularly seen by rheumatologists and underwent rehabilitation as prescribed. Those in the intervention group were further individually coached by a physical therapist to reach or maintain healthy physical activity (=30 minutes, moderately intensive activity, most days of the week). Results. The retention rates after 1 year were 82% in the intervention group and 85% in the control group. The percentages of individuals in the intervention and control groups fulfilling the requirements for healthy physical activity were similar before (47% versus 51%, P > 0.05) and after (54% versus 44%, P > 0.05) the intervention. Analyses of outcome variables indicated improvements in the intervention group over the control group in the EuroQol VAS (P = 0.025) and muscle strength (Timed-Stands Test, P = 0.000) (Grippit, P = 0.003), but not in any other variables assessed. Conclusion. A 1-year coaching program for healthy physical activity resulted in improved perceived health status and muscle strength, but the mechanisms remain unclear, as self-reported physical activity at healthy level did not change. © 2008, American College of Rheumatology.
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| 5. |
- Ericson, Mats O, et al.
(författare)
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Efficiency of pedal forces during ergometer cycling.
- 1988
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Ingår i: International Journal of Sports Medicine. - : Georg Thieme Verlag KG. - 0172-4622 .- 1439-3964. ; 9:2, s. 118-22
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to record the forces applied to the pedal during ergometer cycling and to calculate the effectiveness of these force vectors. Six healthy subjects rode a weight-braked bicycle ergometer at different work loads, pedaling rates, saddle heights, and pedal foot positions. The left lower limb and crank motions were recorded by a cinefilm camera and pedal reaction forces by a Kistler force measuring transducer mounted on the left pedal. The force effectiveness was computed as a ratio between the force tangential to instantaneous direction of pedal movement and the resultant force. The mean force efficiency ratio significantly increased by an increase of the ergometer work load or use of the anterior foot position instead of the posterior. It was not significantly changed due to alterations of the pedaling rate or saddle height.
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| 6. |
- Ericson, Mats O, et al.
(författare)
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Load moments about the hip and knee joints during ergometer cycling.
- 1986
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Ingår i: Scandinavian Journal of Rehabilitation Medicine. - 0036-5505 .- 1940-2228. ; 18:4, s. 165-72
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to calculate the magnitudes of moments of force acting about the bilateral hip and knee joint axes during ergometer cycling. Six healthy subjects pedalled a weight-braked bicycle ergometer at different workloads, pedalling rates, saddle heights and pedal foot position. During cycling at 120 Watts, 60 revolutions per minute with mid-saddle height and anterior pedal foot position, the mean peak flexing and extending hip load moments were 34.3 and 8.9 Nm, respectively. Mean peak flexing knee load moments was 28.8 Nm and extending moment was 11.9 Nm. Hip load moments were significantly increased by increasing the ergometer workload or pedalling rate. For knee load moments, workload was the most important factor. The flexing knee load moment did not change with changes in pedalling rate. Different saddle heights or pedal food positions had a slight but not always statistically significant influence on the hip and knee joint loads. The maximum hip and knee joint load moments induced during cycling were small compared with those obtained during other exercises or normal activities such as level walking, stair climbing, and lifting.
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| 7. |
- Ericson, Mats O, et al.
(författare)
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Muscular activity during ergometer cycling.
- 1985
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Ingår i: Scandinavian Journal of Rehabilitation Medicine. - 0036-5505 .- 1940-2228. ; 17:2, s. 53-61
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to quantify the activity as recorded by electromyography during ergometer cycling in eleven different muscles of the lower extremity. Eleven healthy subjects rode in twelve different ways at different work-load, pedalling rate, saddle height and pedal foot position. Vastus medialis and lateralis, gastrocnemius medialis and lateralis and the soleus muscle were the most activated muscles. Changes in muscle activity during different calibrations were studied in eight of the eleven muscles. An increase in work-load significantly increased the mean maximum activity in all the eight muscles investigated. An increase of the pedalling rate increased the activity in the gluteus maximus, gluteus medius, vastus medialis, medial hamstring, gastrocnemius medialis and soleus muscles. An increase of the saddle height increased the muscle activity in the gluteus medius, medial hamstring and gastrocnemius medialis muscles. Use of a posterior pedal foot position increased the activity in the gluteus medius and rectus femoris muscles, and decreased the activity in the soleus muscle.
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| 8. |
- Ericson, Mats O, et al.
(författare)
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Patellofemoral joint forces during ergometric cycling.
- 1987
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Ingår i: Physical Therapy. - : Oxford University Press (OUP). - 0031-9023 .- 1538-6724. ; 67:9, s. 1365-9
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Tidskriftsartikel (refereegranskat)abstract
- We estimated the patellofemoral joint forces generated during pedaling on a bicycle ergometer. Our calculations were based on measurements from a force transducer mounted on the pedal, 16-mm cine-film sequences, and biomechanical models of the cycling motion and of the patellofemoral joint. Six healthy male subjects cycled at different work loads, pedaling rates, saddle heights, and pedal foot positions. The maximum patellofemoral compressive force was 905 N (1.3 times body weight [BW]) when cycling with an anterior foot position at 120 W, 60 rpm, and middle saddle height. The mean peak compressive force between the quadriceps tendon and the intercondylar groove was 295 N (0.4 BW), and the patellar-tendon and quadriceps-tendon strain forces were 661 N (0.9 BW) and 938 N (1.3 BW), respectively. The patellofemoral joint forces were increased with increased work load or decreased saddle height. Different pedaling rates or foot positions did not significantly change these forces.
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| 9. |
- Ericson, Mats O, et al.
(författare)
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Power output and work in different muscle groups during ergometer cycling.
- 1986
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Ingår i: European Journal of Applied Physiology and Occupational Physiology. - 0301-5548 .- 1432-1025. ; 55:3, s. 229-35
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to calculate the magnitude of the instantaneous muscular power output at the hip, knee and ankle joints during ergometer cycling. Six healthy subjects pedalled a weight-braked bicycle ergometer at 120 watts (W) and 60 revolutions per minute (rpm). The subjects were filmed with a cine camera, and pedal reaction forces were recorded from a force transducer mounted in the pedal. The muscular work at the hip, knee and ankle joint was calculated using a model based upon dynamic mechanics described elsewhere. The mean peak concentric power output was, for the hip extensors, 74.4 W, hip flexors, 18.0 W, knee extensors, 110.1 W, knee flexors, 30.0 W and ankle plantar flexors, 59.4 W. At the ankle joint, energy absorption through eccentric plantar flexor action was observed, with a mean peak power of 11.4 W and negative work of 3.4 J for each limb and complete pedal revolution. The energy production relationships between the different major muscle groups were computed and the contributions to the total positive work were: hip extensors, 27%; hip flexors, 4%; knee extensors, 39%; knee flexors, 10%; and ankle plantar flexors 20%.
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| 10. |
- Ericson, Mats O, et al.
(författare)
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Quantified electromyography of lower-limb muscles during level walking.
- 1986
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Ingår i: Scandinavian Journal of Rehabilitation Medicine. - 0036-5505 .- 1940-2228. ; 18:4, s. 159-63
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Tidskriftsartikel (refereegranskat)abstract
- The electromyography (EMG) of eleven different lower limb muscles of ten healthy subjects was quantified during normal level walking. The surface EMGs obtained were normalized, in percentage, to the activity obtained during an isometric maximum voluntary test contraction of each subject. The mean peak activities of the gluteus maximus, gluteus medius, rectus femoris, vastus medialis, vastus lateralis, biceps femoris and medial hamstring muscles occurred at heel-strike and were between 5 and 15% of max isometric EMG. The magnitudes of tibialis anterior and triceps surae muscular activity were higher than those of the other muscles investigated. Mean peak activity in tibialis anterior was 27%, in gastrocnemius medialis 42%, in gastrocnemius lateralis 19% and in soleus 40%. The important role of the triceps surae during walking was reflected in comparatively high muscular activity at push-off.
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