scholarly journals Effects of Acute Fatigue of the Hip Flexor Muscles on Hamstring Muscle Extensibility

2016 ◽  
Vol 53 (1) ◽  
pp. 23-31 ◽  
Author(s):  
José M. Muyor ◽  
Francisco M. Arrabal-Campos
Keyword(s):  
Correlation Coefficients ◽  
Knee Extension ◽  
Mean Difference ◽  
Hamstring Muscle ◽  
Flexor Muscles ◽  
Straight Leg Raise ◽  
Hip Flexor ◽  
Active Adults

AbstractThe purpose of the present study was to evaluate the influence of acute fatigue of the hip flexor muscles on scores attained in tests frequently used in literature to measure hamstring muscle extensibility, namely the passive straight leg raise (PSLR), active straight leg raise (ASLR), passive knee extension (PKE), active knee extension (AKE), sit-and-reach (SR) and toe-touch (TT) tests. A total of seventy-five healthy and recreationally active adults voluntarily participated in this study. To reach fatigue, the participants actively lifted their legs alternately as many times as possible. In the passive tests, the results were 7.10 ± 5.21° and 5.68 ± 4.54° higher (p < 0.01) for PSLR and PKE tests, respectively, after acute fatigue. However, in the ASLR test, the results were lower post-fatigue than pre-fatigue (mean difference = -5.30° ± 9.51°; p < 0.01). The AKE, SR and TT tests did not show significant differences between pre- and post-fatigue (p > 0.05). Moderate (r = 0.40) to high (r = 0.97) correlation coefficients were found, which were statistically significant among all the measured flexibility tests both pre- and post-fatigue. In conclusion, the active implication of the hip flexor muscles until reaching fatigue had acute influences on the results of the PSLR, PKE and ASLR tests, but not on the results of the AKE, SR and TT tests. It is recommended to use the AKE test to assess hamstring muscle extensibility in situations where athletes show fatigue in their hip flexor muscles.

Validity and Reliability of a New Device (WIMU®) for Measuring Hamstring Muscle Extensibility

2017 ◽  
Vol 38 (09) ◽  
pp. 691-695 ◽  
Author(s):  
José Muyor
Keyword(s):  
Standard Error ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Systematic Bias ◽  
Hamstring Muscle ◽  
Validity And Reliability ◽  
Retest Reliability ◽  
New Device ◽  
Test Retest Reliability ◽  
Straight Leg Raise

AbstractThe aims of the current study were 1) to evaluate the validity of the WIMU® system for measuring hamstring muscle extensibility in the passive straight leg raise (PSLR) test using an inclinometer for the criterion and 2) to determine the test-retest reliability of the WIMU® system to measure hamstring muscle extensibility during the PSLR test. 55 subjects were evaluated on 2 separate occasions. Data from a Unilever inclinometer and WIMU® system were collected simultaneously. Intraclass correlation coefficients (ICCs) for the validity were very high (0.983–1); a very low systematic bias (−0.21°–−0.42°), random error (0.05°–0.04°) and standard error of the estimate (0.43°–0.34°) were observed (left–right leg, respectively) between the 2 devices (inclinometer and the WIMU® system). The R2 between the devices was 0.999 (p<0.001) in both the left and right legs. The test-retest reliability of the WIMU® system was excellent, with ICCs ranging from 0.972–0.995, low coefficients of variation (0.01%), and a low standard error of the estimate (0.19–0.31°). The WIMU® system showed strong concurrent validity and excellent test-retest reliability for the evaluation of hamstring muscle extensibility in the PSLR test.

scholarly journals Repeatability and comparison of clinical tests in children with spastic diplegia and with typical development,

2015 ◽  
Vol 28 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Tainá Ribas Mélo ◽  
André Luiz Félix Rodacki ◽  
Ana Tereza Bittencourt Guimarães ◽  
Vera Lúcia Israel
Keyword(s):  
Cerebral Palsy ◽  
Range Of Motion ◽  
Spastic Diplegia ◽  
Typical Development ◽  
Flexor Muscle ◽  
Cross Sectional ◽  
Flexor Muscles ◽  
Td Methods ◽  
Straight Leg Raise ◽  
Hip Flexor

Objective The aims of this study were to evaluate the reliability of three range of motion tests (Straight Leg Raise, Modified Thomas, and Duncan-Ely) using photographic measurements in children with spastic diplegic cerebral palsy (SD) and with typical development (TD). Methods A cross-sectional test-retest design was applied to compare muscle-tendon unit shortening tests between groups. Results The tests showed reliability that ranged from good to excellent (ICC > 0.8), except for the Thomas Test for the bi-articular hip flexor muscle-tendon unit of the TD group (ICC = 0.7). Differences between groups were found in all tests (p < 0.05), except when the range of motion of the bi-articular hip flexor muscles was assessed using the Thomas test (p > 0.05). Conclusion Children with SD presents a smaller range of motion than the TD group. However, the Thomas Test for the bi-articular hip flexor muscles was unable to determine differences between children with spastic diplegic cerebral palsy from that with typical development.

Reliability of an Active-Knee-Extension Test for Determining Hamstring Muscle Flexibility

1992 ◽  
Vol 1 (3) ◽  
pp. 181-187 ◽  
Author(s):  
Teddy W. Worrell ◽  
Michael K. Sullivan ◽  
Joseph J. DeJulia
Keyword(s):  
Confidence Interval ◽  
Confidence Intervals ◽  
Intraclass Correlation ◽  
Muscle Length ◽  
Correlation Coefficients ◽  
Accurate Method ◽  
Knee Extension ◽  
Hamstring Muscle ◽  
Intraclass Correlation Coefficients ◽  
Hamstring Flexibility

This study examined the intratester and intertester reliability of an active-knee-extension test (AKET) for determining hamstring muscle length (flexibility). Three testers performed repeated AKET measurements on 22 subjects. Intraclass correlation coefficients (ICC were used to calculate intratester and intertester reliability. Also, standard error of measurements (SEM) were calculated. The ICC and SEM were .96 and 1.82°, respectively, for Tester 1, .99 and 1.75° for Tester 2, and .99 and 1.80° for Tester 3. Intratester 95% confidence intervals ranged from 60.54 to 69.82°. Intertester ICC and SEM for two testers were .93 and 4.81°, respectively. A 95% intertester confidence interval ranged from 56.35 to 75.21 °; this reveals that intertester AKET values contained more error and suggests that only intratester AKET values should be used when comparing hamstring flexibility values. The AKET may provide a more accurate method for determining hamstring flexibility and quantifying changes that occur as a result of injury and stretching procedures.

scholarly journals The Influence of Stretching the Hip Flexor Muscles on Performance Parameters. A Systematic Review with Meta-Analysis

2021 ◽  
Vol 18 (4) ◽  
pp. 1936
Author(s):  
Andreas Konrad ◽  
Richard Močnik ◽  
Sylvia Titze ◽  
Masatoshi Nakamura ◽  
Markus Tilp
Keyword(s):  
Systematic Review ◽  
Lumbar Spine ◽  
Positive Impact ◽  
Meta Analysis ◽  
Force Production ◽  
Performance Parameters ◽  
Plantar Flexors ◽  
Performance Change ◽  
Flexor Muscles ◽  
Hip Flexor

The hip flexor muscles are major contributors to lumbar spine stability. Tight hip flexors can lead to pain in the lumbar spine, and hence to an impairment in performance. Moreover, sedentary behavior is a common problem and a major contributor to restricted hip extension flexibility. Stretching can be a tool to reduce muscle tightness and to overcome the aforementioned problems. Therefore, the purpose of this systematic review with meta-analysis was to determine the effects of a single hip flexor stretching exercise on performance parameters. The online search was performed in the following three databases: PubMed, Scopus, and Web of Science. Eight studies were included in this review with a total of 165 subjects (male: 111; female 54). In contrast to other muscle groups (e.g., plantar flexors), where 120 s of stretching likely decreases force production, it seems that isolated hip flexor stretching of up to 120 s has no effect or even a positive impact on performance-related parameters. A comparison of the effects on performance between the three defined stretch durations (30–90 s; 120 s; 270–480 s) revealed a significantly different change in performance (p = 0.02) between the studies with the lowest hip flexor stretch duration (30–90 s; weighted mean performance change: −0.12%; CI (95%): −0.49 to 0.41) and the studies with the highest hip flexor stretch duration (270–480 s; performance change: −3.59%; CI (95%): −5.92 to −2.04). Meta-analysis revealed a significant (but trivial) impairment in the highest hip flexor stretch duration of 270–480 s (SMD effect size = −0.19; CI (95%) −0.379 to 0.000; Z = −1.959; p = 0.05; I2 = 0.62%), but not in the lowest stretch duration (30–90 s). This indicates a dose-response relationship in the hip flexor muscles. Although the evidence is based on a small number of studies, this information will be of great importance for both athletes and coaches.

scholarly journals An Electromyographic Analysis of the Deep Cervical Flexor Muscles in Performance of Craniocervical Flexion

2003 ◽  
Vol 83 (10) ◽  
pp. 899-906 ◽  
Author(s):  
Deborah Falla ◽  
Gwendolen Jull ◽  
Paul Dall'Alba ◽  
Alberto Rainoldi ◽  
Roberto Merletti
Keyword(s):  
Muscle Activity ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Bipolar Electrodes ◽  
Intraclass Correlation Coefficients ◽  
Reliability Estimates ◽  
Flexor Muscles ◽  
The Mean ◽  
Electromyographic Analysis ◽  
Electromyographic Signals

Abstract Background and Purpose. This study evaluated an electromyographic technique for the measurement of muscle activity of the deep cervical flexor (DCF) muscles. Electromyographic signals were detected from the DCF, sternocleidomastoid (SCM), and anterior scalene (AS) muscles during performance of the craniocervical flexion (CCF) test, which involves performing 5 stages of increasing craniocervical flexion range of motion—the anatomical action of the DCF muscles. Subjects. Ten volunteers without known pathology or impairment participated in this study. Methods. Root-mean-square (RMS) values were calculated for the DCF, SCM, and AS muscles during performance of the CCF test. Myoelectric signals were recorded from the DCF muscles using bipolar electrodes placed over the posterior oropharyngeal wall. Reliability estimates of normalized RMS values were obtained by evaluating intraclass correlation coefficients and the normalized standard error of the mean (SEM). Results. A linear relationship was evident between the amplitude of DCF muscle activity and the incremental stages of the CCF test (F=239.04, df=36, P&lt;.0001). Normalized SEMs in the range 6.7% to 10.3% were obtained for the normalized RMS values for the DCF muscles, providing evidence of reliability for these variables. Discussion and Conclusion. This approach for obtaining a direct measure of the DCF muscles, which differs from those previously used, may be useful for the examination of these muscles in future electromyographic applications.

Strength, Power, and Aerobic Exercise Correlates of 5-km Cross-Country Running Performance in Adolescent Runners

2006 ◽  
Vol 18 (3) ◽  
pp. 374-384 ◽  
Author(s):  
Andrew S. Cole ◽  
Megan E. Woodruff ◽  
Mary P. Horn ◽  
Anthony D. Mahon
Keyword(s):  
Muscle Power ◽  
Pearson Correlation ◽  
Vertical Jump ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Correlation Coefficients ◽  
Knee Extension ◽  
Running Economy ◽  
Running Performance ◽  
Cross Country

Relationships between physiological parameters and 5-km running performance were examined in 15 male runners (17.3 ± 0.9 years). Running economy (RE) and blood lactate concentration ([BLa]) at 241.2 m/min, VO2max, velocity at VO2max (vVO2max), vertical jump height and muscle power, and isokinetic knee extension strength at 60°/sec and 240°/sec were measured. The participants’ best 5-km race time over the last month of the cross-country season (16.98 ± 0.76 min) was used in the analysis. The data were analyzed using Pearson correlation coefficients. Significant relationships to run time were observed for VO2max (r = -.53), RE (r = .55), and vVO2max (r = -.66), but not [BLa], isokinetic muscle torque, or vertical jump. Identifying the unique strength and power characteristics related to running performance in this age group is warranted.

Influence of Handgrip Stabilization During Isokinetic Knee Strength Assessment in Older Women

2020 ◽  
Vol 127 (4) ◽  
pp. 671-683
Author(s):  
João P. Nunes ◽  
Paolo M. Cunha ◽  
Jerry L. Mayhew ◽  
Alex S. Ribeiro ◽  
Paulo S. Junior ◽  
...  
Keyword(s):  
Older Women ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Knee Extension ◽  
Convenience Sample ◽  
Strength Assessment ◽  
Intraclass Correlation Coefficients ◽  
Knee Strength ◽  
Hands On ◽  
Angular Velocities

The present study aimed to evaluate the influence of holding the chair handles during the assessment of older women’s knee flexion and extension isokinetic and isometric strength. Of 57 older women (≥60 years) selected from a convenience sample for this research, 23 were randomly chosen to perform the tests twice for reliability analyses. Each participant performed maximal isokinetic knee extension and flexion at 60°/s and 180°/s angular velocities and isometric tests under two conditions: (a) holding the lateral handle of the chair (HOLD) and (b) supporting the hands on the shoulders with the arms crossed (i.e., not holding the handle [NHOLD]). Participants performed significantly better in the HOLD compared with the NHOLD condition. Slightly lower intraclass correlation coefficients (ICC = 0.870–0.956) were noted for the HOLD than for the NHOLD condition (ICC = 0.900–0.981) so that the HOLD performance on Days 1 and 2 was different on some measures. Owing to the higher reliability coefficients in the NHOLD condition, results suggest that, when assessing knee strength in older women, the evaluee should place their hands over their shoulders with arms crossed in front of the chest (NHOLD) to maximize assessment reliability (reproducibility of performance).

Accuracy of a mixed effects model interpolation technique for the estimation of pregnancy weight values

2019 ◽  
Vol 73 (8) ◽  
pp. 786-792 ◽  
Author(s):  
Anne Marie Darling ◽  
Martha M Werler ◽  
David E Cantonwine ◽  
Wafaie W Fawzi ◽  
Thomas F McElrath
Keyword(s):  
Linear Model ◽  
Repeated Measures ◽  
Correlation Coefficients ◽  
Absolute Error ◽  
Mixed Effects ◽  
Mean Difference ◽  
Mixed Effects Models ◽  
Measured Weight ◽  
Mean Differences ◽  
Pregnancy Weight

BackgroundInterpolation of missing weight values is sometimes used in studies of gestational weight gain, but the accuracy of these methods has not been established. Our objective was to assess the accuracy of estimated weight values obtained by interpolating from the nearest observed weight values and by linear and spline regression models when compared with measured weight values.MethodsThe study population included participants enrolled in the LIFECODES cohort at Brigham and Women’s Hospital. We estimated weights at 28 (n=764) and 40 (n=382) weeks of gestation using participants’ two nearest observed weights and subject-specific slopes and intercepts derived from repeated measures mixed effects models. In separate models, gestational age was parameterised as a linear and restricted cubic spline variable. Mean differences, absolute error measures and correlation coefficients comparing observed and estimated weights were calculated.ResultsMean differences and mean absolute error for weights derived from the 28-week linear model (0.18 lbs (SD 6.92), 2.73 lbs (SD 6.35)) and 40-week linear model (−0.40 lbs (SD 5.43) and 2.84 lbs (SD 4.65)) were low. Mean differences were somewhat greater at 28 weeks for weight values derived from the nearest two observed values (mean difference −1.97 lbs (SD 8.74)) and from spline models (mean difference −2.25 lbs (SD 7.13)). Results were similar at 40 weeks.ConclusionsOverall, weight values estimated using this interpolation approach showed good agreement with observed values. When repeated measures of weight are available, mixed effects models may be used to interpolate of missing weight values with minimal error.

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