The EMG/Mmax, although not VA%, results suggest that neural adaptations underpinned training-related changes at short quadriceps lengths, but hypertrophic changes predominated after training at long lengths. The findings of this study should contribute to the development of more effective and evidence-based rehabilitation and strength training protocols.

This study aimed to test the validity and reliability of an extended-field-of-view ultrasonography (EFOV) method for quadriceps muscle cross-sectional area (CSA) assessment. The CSA was measured at 10, 20, 30, 40 and 50% of the distance from the superior border of the patella to the medial aspect of anterior superior iliac spine by EFOV imaging and compared to the CSA measured by computed tomography (CT). Validity was tested by intra-class correlation (ICC) between the two methods and intra- and inter-experimenter and inter-day reliability were also examined. The ICC computed between the two techniques ranged between 0.951 and 0.998 (P < 0.000), but the 95% confidence intervals of the ICCs were in the acceptable range only for 30, 40 and 50% sections (0.842-0.999, 0.943-0.997 and 0.992-0.999, respectively). The standard error of the EFOV technique when compared to CT was 2.4, 4.3, 1.2, 1.2 and 0.6%, for 10, 20, 30, 40 and 50% sections, respectively. The coefficient of variation, showing intra- and inter-experimenter reliability, ranged from 0.6 to 2.7%. ICCs computed to assess the inter-day reliability were between 0.982 and 0.998 (95% confidence interval 0.892-1). When CSA was compared between sections statistically significant differences were found between them, regardless of the imaging technique used. Small standard errors of the measurement and high ICCs with the small confidence intervals suggest that, at proximal and mid-thigh sections, EFOV is a valid and reliable method to measure quadriceps muscle size.

1 other HighWire hosted articles This article has been cited by [PDF] [Full Text] [Abstract] , March 15, 2013; 114 (6): 761-769. pennation in humans: a systematic review Reliability and validity of ultrasound measurements of muscle fascicle length and including high resolution figures, can be found at: Updated information and services /content/109/6/1974.full.html can be found at: Journal of Applied Physiology about Additional material and information http://www.the-aps.org/publications/jappl This information is current as of February 5, 2015.

The aim of this review was to identify and summarise publications, which have reported clinical applications of upper limb accelerometry for stroke within free-living environments and make recommendations for future studies. Data was searched from MEDLINE®, Scopus, IEEExplore and Compendex databases. The final search was 31st October 2013. Any study was included which reported clinical assessments in parallel with accelerometry in a free-living hospital or home setting. Study quality is reflected by participant numbers, methodological approach, technical details of the equipment used, blinding of clinical measures, whether safety and compliance data was collected. First author screened articles for inclusion and inclusion of full text articles and data extraction was confirmed by the third author. Out of 1375 initial abstracts, 8 articles were included. All participants were stroke patients. Accelerometers were worn for either 24 hours or 3 days. Data were collected as summed acceleration counts over a specified time or as the duration of active/inactive periods. Activity in both arms was reported by all studies and the ratio of impaired to unimpaired arm activity was calculated in six studies. The correlation between clinical assessments and accelerometry was tested in five studies and significant correlations were found. The efficacy of a rehabilitation intervention was assessed using accelerometry by three studies: in two studies both accelerometry and clinical test scores detected a post-treatment difference but in one study accelerometry data did not change despite clinical test scores showing motor and functional improvements. Further research is needed to understand the additional value of accelerometry as a measure of upper limb use and function in a clinical context. A simple and easily interpretable accelerometry approach is required.Electronic supplementary materialThe online version of this article (doi:10.1186/1743-0003-11-144) contains supplementary material, which is available to authorized users.

This study aims to (1) determine whether isometric training at a short vs. long quadriceps muscle length affects concentric torque production; (2) examine the relationship between muscle hypertrophy and concentric torque; and (3) determine whether changes in fascicle length are associated with changes in concentric torque. Sixteen men performed isometric training at a short (SL, n = 8) or a long muscle length (LL, n = 8). Changes in maximal concentric torque were measured at 30, 60, 90, 120, 180, 240 and 300 rad · s(-1). The relationships between the changes in concentric torque, cross-sectional area, volume and fascicle length were tested. Concentric torque increased significantly after training only in LL and at angular velocities of 30 and 120 rad · s(-1) by 12-13% (P < 0.05). Muscle size increased in LL only, the changes were correlated (r = 0.73-0.93, P < 0.05) with the changes in concentric torque. Vastus lateralis (VL) fascicle length increased in both groups (5.4 ± 4.9%, P = 0.001) but the change was not correlated with changes in concentric torque in either group. Isometric training-induced increases in muscle size and concentric torque were best elicited by training at long muscle lengths. These results highlight a clear muscle length dependence of isometric training on dynamic torque production.