Scandinavian journal of medicine & science in sports
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Scand J Med Sci Sports · Aug 2018
Interseason variability in isokinetic strength and poor correlation with Nordic hamstring eccentric strength in football players.
In elite sport, the use of strength testing to establish muscle function and performance is common. Traditionally, isokinetic strength tests have been used, measuring torque during concentric and eccentric muscle action. A device that measures eccentric hamstring muscle strength while performing the Nordic hamstring exercise is now also frequently used. ⋯ The strength imbalance between limbs calculated for both test modes was not correlated (r = .037). There is substantial intraindividual variability in all isokinetic test measures, whether separated by 1 or 2 seasons, irrespective of injury. Also, eccentric hamstring strength and limb-to-limb imbalance were poorly correlated between the isokinetic and Nordic hamstring exercise tests.
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Scand J Med Sci Sports · Jun 2018
Technical determinants of biathlon standing shooting performance before and after race simulation.
The aim of this study was to identify performance-determining factors in biathlon standing shooting in rest and after intense exercise. Eight Finnish national- and nine junior-team biathletes participated in the study. Participants fired 40 resting shots (REST) and 2 × 5 competition simulation shots (LOAD) after 5 minutes of roller skiing at 95% of peak heart rate. ⋯ National- and junior-team biathletes differed only in hit percentage in REST (92 ± 8% vs 81 ± 8%, P < .05) and left leg postural balance in shooting direction in LOAD (0.31 ± 0.18 mm vs 0.52 ± 0.20 mm, P < .05), and the intense exercise affected the shooting technical components similarly in both national and junior groups. Biathletes should focus on cleanness of triggering and vertical stability of hold in order to improve biathlon standing shooting performance. More stable postural balance in shooting direction could help to improve these shooting technical components.
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Scand J Med Sci Sports · Mar 2018
Controlled Clinical TrialThe effect of a two-year school-based daily physical activity intervention on a clustered CVD risk factor score-The Sogndal school-intervention study.
To evaluate changes in clustered cardiovascular disease (CVD) risk factors in 9-year-old children following a 2-year school-based physical activity intervention. In total, 259 children (age 9.3 ± 0.3 years) were invited, of whom 256 participated. The intervention group (63 boys, 62 girls) carried out 60-minute teacher-controlled daily physical activity over two school years. ⋯ The cluster score improved after the intervention (ES = .29). Furthermore, the analyses showed significant effects in favor of the intervention group for systolic blood pressure (ES = .35), total cholesterol-to-HDL-c ratio (ES = .23), triglyceride (ES = .40), and VO2peak (ES = .57). A teacher-led school-based physical activity intervention that is sufficiently long and includes a substantial amount of daily physical activity can beneficially modify children's clustered CVD risk profile.
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Scand J Med Sci Sports · Mar 2018
Achilles and patellar tendinopathy display opposite changes in elastic properties: A shear wave elastography study.
To compare tendon elastic and structural properties of healthy individuals with those with Achilles or patellar tendinopathy. Sixty-seven participants (22 Achilles tendinopathy, 17 patellar tendinopathy, and 28 healthy controls) were recruited between March 2015 and March 2016. Shear wave velocity (SWV), an index of tissue elastic modulus, and tendon thickness were measured bilaterally at mid-tendon and insertional regions of Achilles and patellar tendons by an examiner blinded to group. ⋯ Compared to controls, participants with patellar tendinopathy had higher SWV at both regions (MD 1.25; 0.40-2.10 m/s; P = .005) and greater thickness proximally (MD 0.17; 0.06-0.29 cm; P = .003). Compared to controls, participants with Achilles and patellar tendinopathy displayed lower Achilles tendon elastic modulus and higher patellar tendon elastic modulus, respectively. More research is needed to explore whether maturation, aging, or chronic load underlie these findings and whether current management programs for Achilles and patellar tendinopathy need to be tailored to the tendon.
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Scand J Med Sci Sports · Mar 2018
Sensory processing and central pain modulation in patients with chronic shoulder pain: A case-control study.
Chronicity and recurrence in musculoskeletal shoulder pain are highly prevalent and can possibly be attributed to the concept of central sensitization. Available studies suggest a role for central sensitization in explaining chronic shoulder pain, but so far a comprehensive quantitative sensory testing (QST) protocol has not been used. The aim of this study was to gain knowledge on sensory processing and central pain modulatory mechanisms in patients suffering from chronic shoulder pain using such a QST protocol. ⋯ Moderate positive correlations (r = .5) were found between pressure pain thresholds (PPTs) and the amount of sports participation. Weak-to-moderate negative correlations (r = -.3 à -.5) were found between PPTs and psychosocial factors such as pain catastrophizing. Based on these findings, we can conclude that central sensitization is no characteristic feature in chronic musculo-skeletal shoulder pain but can be present in individual cases.