We focus on the effect of cadence and work rate on energy expenditure and efficiency in cycling, and present arguments to support the contention that gross efficiency can be considered to be the most relevant expression of efficiency. A linear relationship between work rate and energy expenditure appears to be a rather consistent outcome among the various studies considered in this review, irrespective of subject performance level. This relationship is an example of the Fenn effect, described more than 80 years ago for muscle contraction. About 91% of all variance in energy expenditure can be explained by work rate, with only about 10% being explained by cadence. Gross efficiency is strongly dependent on work rate, mainly because of the diminishing effect of the (zero work-rate) base-line energy expenditure with increasing work rate. The finding that elite athletes have a higher gross efficiency than lower-level performers may largely be explained by this phenomenon. However, no firm conclusions can be drawn about the energetically optimal cadence for cycling because of the multiple factors associated with cadence that affect energy expenditure.

This study examined the effects and specificity of structured and unstructured activities played at the playground Primo Sport 0246 in Northern Italy on motor skill competence in five years old children. The playground was specifically designed to promote gross motor skills in preschool children; in this study 71 children from local kindergartens came to the park once a week for ten consecutive weeks and were exposed to 30 minutes of free play and 30 minutes of structured activities. Before and after the ten visits, each child completed nine tests to assess levels of motor skills, three for fine-motor skills and six for gross-motor skills. As control, motor skills were also assessed on 39 children from different kindergartens who did not come to the park. The results show that the experimental group who practiced gross-motor activities in the playground for 1 hour a week for 10 weeks improved significantly in 4 out of the 6 gross motor tasks and in none of the fine motor tasks. The data indicate that limited transfer occurred between tasks referring to different domains of motor competences while suggesting cross feeding for improvement of gross-motor skills between different exercises when domains related to physical fitness and strength of specific muscle groups are involved. These results are relevant to the issue of condition(s) appropriate for maintaining and developing motor skills in this age group as well as for the planning, organization and implementation of play and physical activities in kindergartens.

BackgroundNeck pain is associated with several alterations in neck motion and motor control. Previous studies have investigated single constructs of neck motor control, while few have applied a comprehensive set of tests to investigate cervical motor control. This comparative cross- sectional study aimed to investigate different motor control constructs in neck pain patients and healthy controls.MethodsA total of 166 subjects participated in the study, 91 healthy controls (HC) and 75 neck pain patients (NP) with long-lasting moderate to severe neck pain. Neck flexibility, proprioception, head steadiness, trajectory movement control, and postural sway were assessed using a 3D motion tracking system (Liberty). The different constructs of neck motion and motor control were based on tests used in previous studies.ResultsNeck flexibility was lower in NP compared to HC, indicated by reduced cervical ROM and conjunct motion. Movement velocity was slower in NP compared to HC. Tests of head steadiness showed a stiffer movement pattern in NP compared to HC, indicated by lower head angular velocity. NP patients departed less from a predictable trajectory movement pattern (figure of eight) compared to healthy controls, but there was no difference for unpredictable movement patterns (the Fly test). No differences were found for postural sway in standing with eyes open and eyes closed. However, NP patients had significantly larger postural sway when standing on a balance pad. Proprioception did not differ between the groups. Largest effect sizes (ES) were found for neck flexibility (ES range: 0.2- 0.8) and head steadiness (ES range: 1.3- 2.0). Neck flexibility was the only construct that showed a significant association with current neck pain, while peak velocity was the only variable that showed a significant association with kinesiophobia.ConclusionsNP patients showed an overall stiffer and more rigid neck motor control pattern compared to HC, indicated by lower neck flexibility, slower movement velocity, increased head steadiness and more rigid trajectory head motion patterns. Only neck flexibility showed a significant association with clinical features in NP patients.Electronic supplementary materialThe online version of this article (doi:10.1186/s12891-015-0517-2) contains supplementary material, which is available to authorized users.

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In this article, the psychometric properties of a new test battery aimed at quantifying motor competence across the life span are explored. The battery was designed to be quantitative, simple to administer, applicable for large-group testing, and reliably to monitor life span motor development. A total of 638 participants between 5 and 83 years of age completed assessment of four different motor tasks (two fine and two gross motor tasks), enabling us to investigate its feasibility, internal consistency, construct validity, and test-retest reliability. Feasibility: Overall pattern of results suggest that the test battery for motor competence presented here is applicable for the age-span studied (5-83). Important consideration in this regard is that the same tasks are applied for all ages. A u-shaped curve between age and total test score indicate the adequate sensitivity of the test battery for the age range examined. Internal consistency: All individual test item scores correlated positively with the total test score with correlations ranging from .48 to .64. Correlations between scores on individual test items were moderate to high (.31-.69). The Cronbach's alpha value for the standardized items was .79. Construct validity: Pearson correlation coefficient between total score Test of Motor Competence (TMC) and Movement Assessment Battery for Children (MABC) were .47 for 7-to 8-years-old children (n = 70) and .45 for 15-to 16-years-old (n = 101). Test-retest reliability: Intraclass correlation coefficients (ICCs) between test and retest scores ranged from .75 to .94, and test-retest coefficient for the total score was .87.

Despite the many benefits of involvement in youth sports, participation in them declines throughout childhood and adolescence. The present study performed a systematic review and meta-analysis of 12 studies reporting dropout rates in youth soccer, involving a total of 724,036 youths ages 10-18 years from five countries. The mixed effects meta-regression analyses took into account age and sex as statistical moderators of dropout rate. Potential articles were identified through computerized searches of the databases PubMed, MedLine, Embase, and SportDiscus up until August 2014, without any further time limit. Based on results reported in the 10 included articles, the annual weighted mean dropout rate is 23.9% across the included cohorts. Meta-regression indicated that annual dropout rates are stable from the ages of 10-19 years, with higher rates for girls (26.8%) compared to boys (21.4%). The present study suggests that youth soccer players are prone to dropout rates in which close to one-fourth of players leave the sport annually, which appears to be a consistent finding across ages 10-18 years.

BackgroundTo improve the goal-directedness of strength exercises for patients with knee osteoarthritis (KOA), physical rehabilitation specialists need to know which muscle-groups are most substantially weakened across the kinetic chain of both lower extremities. The purpose was to improve the knowledge base for strength exercise therapy. The objective was to explore the relative differences in muscle strength in the main directions bilaterally across the hip, knee, and ankle joints between patients with light-to-moderate symptomatic and radiographic KOA and people without knee complaints.MethodsThe design was an exploratory, patient vs. healthy control, and cross-sectional study in primary/secondary care. Twenty-eight patients with mild to moderate KOA (18 females, mean age 61) and 31 matched healthy participants (16 females, mean age 55), participated. Peak strength was tested concentrically or isometrically in all main directions for the hip, knee, and ankle joints bilaterally, and compared between groups. Strength was measured by a Biodex Dynamometer or a Commander II Muscle Tester (Hand-Held Dynamometer). Effect sizes (ES) as Cohen’s d were applied to scale and rank the difference in strength measures between the groups. Adjustment for age was performed by analysis of covariance.ResultsThe most substantial muscle weaknesses were found for ankle eversion and hip external and internal rotation in the involved leg in the KOA-group compared to the control-group (ES [95% CI] −0.73 [−1.26,-0.20], − 0.74 [−1.26,-0.21], −0.71 [−1.24,-0.19], respectively; p < 0.01). Additionally, smaller but still significant moderate muscle weaknesses were indicated in four joint–strength directions: the involved leg’s ankle inversion, ankle plantar flexion, and knee extension, as well as the uninvolved leg’s ankle dorsal flexion (p < 0.05). There was no significant difference for 17 of 24 tests.ConclusionsFor patients with KOA between 45 and 70 years old, these explorative findings indicate the most substantial weaknesses of the involved leg to be in ankle and hip muscles with main actions in the frontal and transverse plane in the kinetic chain of importance during gait. Slightly less substantial, they also indicate important weakness of the knee extensor muscles. Confirmatory studies are needed to further validate these exploratory findings.

The coach-created motivational climate within youth sports teams has been shown to be of great importance for the quality of youths’ sports experiences as well as their motivation for continuing or discontinuing sport participation. While the player’s perspective on motivational climates has been studied extensively, the coach’s perspective has received considerably less attention. Thus, little is known about the concordance of perceptions of the motivational climate between coaches and their players, or the lack thereof. The purpose of the present study was to directly compare players’ and coaches’ perceptions of the motivational climate within their respective teams. To this end, 256 male and female soccer players (15–17 years of age) from 17 different teams and their coaches (n = 29) responded to the Perceived Motivational Climate in Sports Questionnaire-2 (PMCSQ-2). The study design included responses from both coaches and players to the same questionnaire, and both groups were aware of the other part’s participation. Statistical analyses revealed significant differences between players’ and coaches’ perceptions of the motivational climate. Specifically, players of both sexes perceived the motivational climate to be significantly more performance-oriented and significantly less mastery-oriented compared with the coaches. These findings may advance our understanding of the coach-athlete relationship, and may be of importance for understanding players’ motivation for persistence or discontinuation of the sport.