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1
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Sex Variation in Patellar Tendon Kinetics During Running

100%
Sinclair J., Taylor P. J.
Human Movement
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2015
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vol. 16
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issue 2
60-63
EN
Purpose. The aim of the current investigation was to determine whether female recreational runners exhibit distinct patellar tendon loading patterns in relation to their male counterparts. Methods. Twelve male (age 26.55 ± 4.11 years, height 1.78 ± 0.11 m, mass 77.11 ± 5.06 kg) and twelve female (age 26.67 ± 5.34 years, height 1.67 ± 0.12 m, mass 63.28 ± 9.75 kg) runners ran over a force platform at 4.0 m · s-1. Lower limb kinematics were collected using an eight-camera optoelectric motion capture system which operated at 250 Hz. Patellar tendon loads were examined using a predictive algorithm. Sex differences in limb, knee and ankle joint stiffness were examined statistically using independent samples t tests. Results. The results indicate that patellar tendon force (male = 6.49 ± 2.28, female = 7.03 ± 1.35) and patelllar tendon loading rate (male = 92.41 ± 32.51, female = 111.05 ± 48.58) were significantly higher in female runners. Conclusions. Excessive tendon loading in female runners indicates that female runners may be at increased risk of patellar tendon pathologies.
2
Content available remote

Digital Filtering of Three-Dimensional Lower Extremity Kinematics: an Assessment

81%
Sinclair J., Taylor P. J., Hobbs S. J.
Journal of Human Kinetics
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2013
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vol. 39
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issue 1
25-36
EN
Errors in kinematic data are referred to as noise and are an undesirable portion of any waveform. Noise is typically removed using a low-pass filter which removes the high frequency components of the signal. The selection of an optimal frequency cut-off is very important when processing kinematic information and a number of techniques exists for the determination of an optimal frequency cut-off. Despite the importance of cut-off frequency to the efficacy of kinematic analyses there is currently a paucity of research examining the influence of different cut-off frequencies on the resultant 3-D kinematic waveforms and discrete parameters. Twenty participants ran at 4.0 m•s-1 as lower extremity kinematics in the sagittal, coronal and transverse planes were measured using an eight camera motion analysis system. The data were filtered at a range of cut-off frequencies and the discrete kinematic parameters were examined using repeated measures ANOVA’s. The similarity between the raw and filtered waveforms were examined using intra-class correlations. The results show that the cut-off frequency has a significant influence on the discrete kinematic measure across displacement and derivative information in all three planes of rotation. Furthermore, it was also revealed that as the cut-off frequency decreased the attenuation of the kinematic waveforms became more pronounced, particularly in the coronal and transverse planes at the second derivative. In conclusion, this investigation provides new information regarding the influence of digital filtering on lower extremity kinematics and re-emphasizes the importance of selecting the correct cut-off frequency.
3
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The influence of lower extremity coronal plane movements on the passive regulation of instantaneous loading mechanics during running

81%
Sinclair J. K., Taylor P. J., Hobbs S. J.
|
EN
Background: The repetitive transmission of impact forces may contribute to the aetiology of overuse injuries. Therefore determining the mechanisms that regulate impact loading has potential clinical significance.This study aimed to determine the influence of lower extremity coronal plane kinematics on the regulation of impact loading during running. Material/Methods: Thirty-six participants ran at 4.0 m.s-1striking the centre of a piezoelectric force platform with their dominant limb. Coronal plane angular kinematics about the hip, knee and ankle joints were measured using an eight-camera motion analysis system operating at 250 Hz. Regression analyses with instantaneous loading rate magnitude as a criterion were used to identify the coronal plane parameters associated with impact loading. Results: The overall regression model yielded Adj R2 = 0.37, p ≤ 0.01. Two biomechanical parameters were obtained as significant predictors of the instantaneous loading rate. Peak ankle eversion Adj R2 = 0.22, p ≤ 0.01 and peak eversion angular velocity of the ankle Adj R2 = 0.15, p ≤ 0.01 were found to be significant predictors of instantaneous loading rate. Conclusions: The findings of the current investigation therefore suggest that passive joint motions in the coronal plane can regulate the magnitude of impact loading, linked to the development of chronic injuries.
4
Content available remote

The Test-Retest Reliability of Anatomical Co-Ordinate Axes Definition for the Quantification of Lower Extremity Kinematics During Running

61%
Sinclair J., Taylor P. J., Greenhalgh A., Edmundson C. J., Brooks D., Hobbs S. J.
Journal of Human Kinetics
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2012
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vol. 35
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issue 1
15-25
EN
Three-dimensional (3-D) kinematic analyses are used widely in both sport and clinical examinations. However, this procedure depends on reliable palpation of anatomical landmarks and mal-positioning of markers between sessions may result in improperly defined segment co-ordinate system axes which will produce in-consistent joint rotations. This had led some to question the efficacy of this technique. The aim of the current investigation was to assess the reliability of the anatomical frame definition when quantifying 3-D kinematics of the lower extremities during running. Ten participants completed five successful running trials at 4.0 m·s-1 ± 5%. 3-D angular joint kinematics parameters from the hip, knee and ankle were collected using an eight camera motion analysis system. Two static calibration trials were captured. The first (test) was conducted prior to the running trials following which anatomical landmarks were removed. The second was obtained following completion of the running trials where anatomical landmarks were re-positioned (retest). Paired samples t-tests were used to compare 3-D kinematic parameters quantified using the two static trials, and intraclass correlations were employed to examine the similarities between the sagittal, coronal and transverse plane waveforms. The results indicate that no significant (p>0.05) differences were found between test and retest 3-D kinematic parameters and strong (R2≥0.87) correlations were observed between test and retest waveforms. Based on the results obtained from this investigation, it appears that the anatomical co-ordinate axes of the lower extremities can be defined reliably thus confirming the efficacy of studies using this technique.
5
Content available remote

The Reliability of Electromyographic Normalization Methods for Cycling Analyses

61%
Sinclair J., Taylor P. J., Hebron J., Brooks D., Hurst H. T., Atkins S.
Journal of Human Kinetics
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2015
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vol. 46
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issue 1
19-27
EN
Electromyography (EMG) is normalized in relation to a reference maximum voluntary contraction (MVC) value. Different normalization techniques are available but the most reliable method for cycling movements is unknown. This study investigated the reliability of different normalization techniques for cycling analyses. Twenty-five male cyclists (age 24.13 ± 2.79 years, body height 176.22 ± 4.87 cm and body mass 67.23 ± 4.19 kg, BMI = 21.70 ± 2.60 kg·m−1) performed different normalization procedures on two occasions, within the same testing session. The rectus femoris, biceps femoris, gastrocnemius and tibialis anterior muscles were examined. Participants performed isometric normalizations (IMVC) using an isokinetic dynamometer. Five minutes of submaximal cycling (180 W) were also undertaken, allowing the mean (DMA) and peak (PDA) activation from each muscle to serve as reference values. Finally, a 10 s cycling sprint (MxDA) trial was undertaken and the highest activation from each muscle was used as the reference value. Differences between reference EMG amplitude, as a function of normalization technique and time, were examined using repeated measures ANOVAs. The testretest reliability of each technique was also examined using linear regression, intraclass correlations and Cronbach’s alpha. The results showed that EMG amplitude differed significantly between normalization techniques for all muscles, with the IMVC and MxDA methods demonstrating the highest amplitudes. The highest levels of reliability were observed for the PDA technique for all muscles; therefore, our results support the utilization of this method for cycling analyses.
6
Content available remote

Effects of Varus Orthotics on Lower Extremity Kinematics During the Pedal Cycle

61%
Sinclair J., Vincent H., Taylor P. J., Hebron J., Hurst H. T., Atkins S.
Human Movement
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2014
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vol. 15
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issue 4
221-226
EN
Purpose. Cycling has been shown to be associated with a high incidence of chronic pathologies. Foot orthoses are frequently used by cyclists in order to reduce the incidence of chronic injuries. The aim of the current investigation was to examine the influence of different varus orthotic inclines on the three-dimensional kinematics of the lower extremities during the pedal cycle. Methods. Kinematic information was obtained from ten male cyclists using an eight-camera optoelectronic 3-D motion capture system operating at 250 Hz. Participants cycled with and without orthotic intervention at three different cadences (70, 90 and 110 RPM). The orthotic device was adjustable and four different wedge conditions (0 mm - no orthotic, 1.5 mm, 3.0 mm and 4.5 mm) were examined. Two-way repeated measures ANOVAs were used to compare the kinematic parameters obtained as a function of orthotic inclination and cadence. Participants were also asked to subjectively rate their comfort in cycling using each of the four orthotic devices on a 10-point Likert scale. Results. The kinematic analysis indicated that the orthotic device had no significant influence at any of the three cadences. Analysis of subjective preferences showed a clear preference for the 0 mm, no orthotic, condition. Conclusions. This study suggests that foot orthoses do not provide any protection from skeletal malalignment issues associated with the aetiology of chronic cycling injuries.
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